Merge branch 'siyaoH/1.17/material' of https://github.com/Unity-Technologies/com.unity.uiwidgets into siyaoH/1.17/material

com.unity.uiwidgets/Runtime/animation/tween.cs

         }
     }
 
-    public abstract class Tween<T> : Animatable<T>, IEquatable<Tween<T>> {
+    public class Tween<T> : Animatable<T>, IEquatable<Tween<T>> {
         public Tween(T begin, T end) {
             this.begin = begin;
             this.end = end;
 
         public virtual T end { get; set; }
 
-        public abstract T lerp(float t);
-        
+        public virtual T lerp(float t) {
+            D.assert(begin != null);
+            D.assert(end != null);
+            return default; //begin + (end - begin) * t as T;
+        }
+
         public override T transform(float t) {
             if (t == 0.0)
                 return begin;

com.unity.uiwidgets/Runtime/cupertino/context_menu.cs

                     )
             );
         }
-        public override Widget build(BuildContext context) {
-          List<Widget> widgets = new List<Widget>();
-          widgets.Add(new  AnimatedBuilder(
-            builder: _buildAnimation,
-            animation: widget.controller
-          ));
-          return new Stack(
-            children: widgets
-          );
+        public override Widget build(BuildContext context) { 
+            List<Widget> widgets = new List<Widget>();
+            widgets.Add(new  AnimatedBuilder(
+                builder: _buildAnimation,
+                animation: widget.controller)
+            ); 
+            return new Stack(
+                children: widgets
+                );
-    public class _ContextMenuRoute : PopupRoute {
-      public _ContextMenuRoute(
-        List<Widget> actions = null,
-        _ContextMenuLocation contextMenuLocation = default,
-        string barrierLabel = null,
-        _ContextMenuPreviewBuilderChildless builder = null,
-        ImageFilter filter = null,
-        Rect previousChildRect = null,
-        RouteSettings settings = null
-      ) : base(
-        filter: filter,
-        settings: settings
-      ){
-        D.assert(actions != null && actions.isNotEmpty());
-        D.assert(contextMenuLocation != null);
-        this.barrierLabel = barrierLabel;
-         _actions = actions;
-        _builder = builder;
-        _contextMenuLocation = contextMenuLocation;
-        _previousChildRect = previousChildRect;
-      } 
-      public readonly static Color _kModalBarrierColor = new Color(0x6604040F);
-      public readonly TimeSpan _kModalPopupTransitionDuration =new TimeSpan(0, 0, 0, 0, 335);
-      public readonly List<Widget> _actions;
-      public readonly _ContextMenuPreviewBuilderChildless _builder;
-      public readonly GlobalKey _childGlobalKey = new LabeledGlobalKey<State<StatefulWidget>>();
-      public readonly _ContextMenuLocation _contextMenuLocation;
-      public bool _externalOffstage = false;
-      public bool _internalOffstage = false;
-      public Orientation _lastOrientation;
-      public readonly Rect _previousChildRect;
-      public float _scale = 1.0f;
-      public readonly GlobalKey _sheetGlobalKey = new LabeledGlobalKey<State<StatefulWidget>>();//GlobalKey();
-      public readonly static CurveTween _curve = new CurveTween(
-        curve: Curves.easeOutBack
-      ); 
-      public readonly static  CurveTween _curveReverse = new CurveTween(
-        curve: Curves.easeInBack
-      );
-      public readonly static RectTween _rectTween = new RectTween();
-      public readonly static Animatable<Rect> _rectAnimatable = _rectTween.chain(_curve);
-      public readonly static RectTween _rectTweenReverse = new RectTween();
-      public readonly static Animatable<Rect> _rectAnimatableReverse = _rectTweenReverse.chain(_curveReverse);
+    public class _ContextMenuRoute : PopupRoute { 
+        public _ContextMenuRoute(
+            List<Widget> actions = null, 
+            _ContextMenuLocation contextMenuLocation = default, 
+            string barrierLabel = null, 
+            _ContextMenuPreviewBuilderChildless builder = null, 
+            ImageFilter filter = null, 
+            Rect previousChildRect = null, 
+            RouteSettings settings = null
+            ) : base(filter: filter, settings: settings){ 
+            
+            D.assert(actions != null && actions.isNotEmpty());
+            D.assert(contextMenuLocation != null);
+            this.barrierLabel = barrierLabel;
+            _actions = actions;
+            _builder = builder;
+            _contextMenuLocation = contextMenuLocation;
+            _previousChildRect = previousChildRect;
+        } 
+        public readonly static Color _kModalBarrierColor = new Color(0x6604040F);
+        public readonly TimeSpan _kModalPopupTransitionDuration =new TimeSpan(0, 0, 0, 0, 335);
+        public readonly List<Widget> _actions;
+        public readonly _ContextMenuPreviewBuilderChildless _builder;
+        public readonly GlobalKey _childGlobalKey = new LabeledGlobalKey<State<StatefulWidget>>();
+        public readonly _ContextMenuLocation _contextMenuLocation;
+        public bool _externalOffstage = false;
+        public bool _internalOffstage = false;
+        public Orientation _lastOrientation;
+        public readonly Rect _previousChildRect;
+        public float _scale = 1.0f;
+        public readonly GlobalKey _sheetGlobalKey = new LabeledGlobalKey<State<StatefulWidget>>();//GlobalKey();
+        public readonly static CurveTween _curve = new CurveTween(
+            curve: Curves.easeOutBack
+        ); 
+        public readonly static  CurveTween _curveReverse = new CurveTween(
+            curve: Curves.easeInBack
+        );
+        public readonly static RectTween _rectTween = new RectTween();
+        public readonly static Animatable<Rect> _rectAnimatable = _rectTween.chain(_curve);
+        public readonly static RectTween _rectTweenReverse = new RectTween();
+        public readonly static Animatable<Rect> _rectAnimatableReverse = _rectTweenReverse.chain(_curveReverse);
-      public readonly static RectTween _sheetRectTween = new RectTween();
-      public readonly Animatable<Rect> _sheetRectAnimatable = _sheetRectTween.chain(_curve);
-      public readonly Animatable<Rect> _sheetRectAnimatableReverse = _sheetRectTween.chain(_curveReverse);
-      public readonly static  Tween< float> _sheetScaleTween = new FloatTween(0.0f,0.0f);
-      public readonly static  Animatable< float> _sheetScaleAnimatable = _sheetScaleTween.chain(_curve);
-      public readonly static  Animatable< float> _sheetScaleAnimatableReverse = _sheetScaleTween.chain(_curveReverse);
-      public readonly Tween< float> _opacityTween = new FloatTween(begin: 0.0f, end: 1.0f);
-      public Animation< float> _sheetOpacity;
+        public readonly static RectTween _sheetRectTween = new RectTween();
+        public readonly Animatable<Rect> _sheetRectAnimatable = _sheetRectTween.chain(_curve);
+        public readonly Animatable<Rect> _sheetRectAnimatableReverse = _sheetRectTween.chain(_curveReverse);
+        public readonly static  Tween< float> _sheetScaleTween = new FloatTween(0.0f,0.0f);
+        public readonly static  Animatable< float> _sheetScaleAnimatable = _sheetScaleTween.chain(_curve);
+        public readonly static  Animatable< float> _sheetScaleAnimatableReverse = _sheetScaleTween.chain(_curveReverse);
+        public readonly Tween< float> _opacityTween = new FloatTween(begin: 0.0f, end: 1.0f);
+        public Animation< float> _sheetOpacity;
-      public readonly string barrierLabel;
+        public readonly string barrierLabel;
-      public Color barrierColor {
-        get { return _kModalBarrierColor; }
-      }
-      
-      public bool barrierDismissible{ 
-        get { return false; }
-      }
+        public Color barrierColor {
+            get { return _kModalBarrierColor; }
+        }
+        public bool barrierDismissible{ 
+            get { return false; }
+        }
-      public bool semanticsDismissible { 
-        get { return true; }
-      }
+        public bool semanticsDismissible { 
+            get { return true; }
+        }
-      public TimeSpan transitionDuration {
-        get {
-          return _kModalPopupTransitionDuration;
+        public TimeSpan transitionDuration {
+            get {
+                return _kModalPopupTransitionDuration;
+            }
+        }
+        /*public static AlignmentDirectional getSheetAlignment(_ContextMenuLocation contextMenuLocation) {
+            switch (contextMenuLocation) {
+                case _ContextMenuLocation.center:
+                    return AlignmentDirectional.topCenter;
+                case _ContextMenuLocation.right:
+                    return AlignmentDirectional.topEnd;
+                default:
+                    return AlignmentDirectional.topStart;
+            }
+        }*/
+        public static Rect _getScaledRect(GlobalKey globalKey,  float scale) {
+            Rect childRect = CupertinoContextMenuUtils._getRect(globalKey);
+            Size sizeScaled = childRect.size * scale;
+            Offset offsetScaled = new Offset(
+            childRect.left + (childRect.size.width - sizeScaled.width) / 2,
+            childRect.top + (childRect.size.height - sizeScaled.height) / 2
+            );
+            return offsetScaled & sizeScaled;
+        }
+        public static Rect _getSheetRectBegin(Orientation orientation, _ContextMenuLocation contextMenuLocation, Rect childRect, Rect sheetRect) { 
+            switch (contextMenuLocation) { 
+                case _ContextMenuLocation.center: 
+                    Offset target1 = (orientation == Orientation.portrait) 
+                        ? childRect.bottomCenter
+                        : childRect.topCenter;
+                    Offset centered = target1 - new Offset(sheetRect.width / 2, 0.0f);
+                    return centered & sheetRect.size;
+                case _ContextMenuLocation.right: 
+                    Offset target2 = ((orientation == Orientation.portrait) 
+                        ? childRect.bottomRight 
+                        : childRect.topRight); 
+                    return (target2 - new Offset(sheetRect.width, 0.0f)) & sheetRect.size; 
+                default: 
+                    Offset target3 = orientation == Orientation.portrait 
+                        ? childRect.bottomLeft 
+                        : childRect.topLeft; 
+                    return target3 & sheetRect.size;
+            }
+        } 
+        public void _onDismiss(BuildContext context, float scale, float opacity) { 
+            _scale = scale;
+            _opacityTween.end = opacity;
+            _sheetOpacity = _opacityTween.animate(
+                new CurvedAnimation(
+                    parent: animation, 
+                    curve: new Interval(0.9f, 1.0f)
+                  ));
+            Navigator.of(context).pop<object>();
+        }
+        public void _updateTweenRects() { 
+            Rect childRect = _scale == null 
+                ? CupertinoContextMenuUtils._getRect(_childGlobalKey) 
+                : _getScaledRect(_childGlobalKey, _scale); 
+            _rectTween.begin = _previousChildRect; 
+            _rectTween.end = childRect; 
+            Rect childRectOriginal = CupertinoContextMenuUtils.fromCenter(
+                center: _previousChildRect.center,
+                width: _previousChildRect.width / CupertinoContextMenuUtils._kOpenScale,
+                height: _previousChildRect.height / CupertinoContextMenuUtils._kOpenScale
+            ); 
+            Rect sheetRect = CupertinoContextMenuUtils._getRect(_sheetGlobalKey);
+            Rect sheetRectBegin = _getSheetRectBegin(
+                _lastOrientation,
+                _contextMenuLocation,
+                childRectOriginal,
+                sheetRect
+            ); 
+            _sheetRectTween.begin = sheetRectBegin;
+            _sheetRectTween.end = sheetRect;
+            _sheetScaleTween.begin = 0.0f;
+            _sheetScaleTween.end = _scale;
+            _rectTweenReverse.begin = childRectOriginal; 
+            _rectTweenReverse.end = childRect;
-      }
-      public static Rect _getScaledRect(GlobalKey globalKey,  float scale) {
-        Rect childRect = CupertinoContextMenuUtils._getRect(globalKey);
-        Size sizeScaled = childRect.size * scale;
-        Offset offsetScaled = new Offset(
-          childRect.left + (childRect.size.width - sizeScaled.width) / 2,
-          childRect.top + (childRect.size.height - sizeScaled.height) / 2
-        );
-        return offsetScaled & sizeScaled;
-      }
-      /*public static AlignmentDirectional getSheetAlignment(_ContextMenuLocation contextMenuLocation) {
-        switch (contextMenuLocation) {
-          case _ContextMenuLocation.center:
-            return AlignmentDirectional.topCenter;
-          case _ContextMenuLocation.right:
-            return AlignmentDirectional.topEnd;
-          default:
-            return AlignmentDirectional.topStart;
+        public void _setOffstageInternally() {
+            base.offstage = _externalOffstage || _internalOffstage;
+            changedInternalState();
-      }*/
-      public static Rect _getSheetRectBegin(Orientation orientation, _ContextMenuLocation contextMenuLocation, Rect childRect, Rect sheetRect) {
-        switch (contextMenuLocation) {
-          case _ContextMenuLocation.center:
-            Offset target1 = (orientation == Orientation.portrait) 
-              ? childRect.bottomCenter 
-              : childRect.topCenter;
-            Offset centered = target1 - new Offset(sheetRect.width / 2, 0.0f);
-            return centered & sheetRect.size;
-          case _ContextMenuLocation.right:
-            Offset target2 = ((orientation == Orientation.portrait) 
-            ? childRect.bottomRight 
-            : childRect.topRight);
-            return (target2 - new Offset(sheetRect.width, 0.0f)) & sheetRect.size;
-          default:
-            Offset target3 = orientation == Orientation.portrait
-              ? childRect.bottomLeft
-              : childRect.topLeft;
-            return target3 & sheetRect.size;
+        public bool didPop(object result) {
+            _updateTweenRects();
+            return base.didPop(result);
-      }
-      public void _onDismiss(BuildContext context, float scale, float opacity) {
-        _scale = scale;
-        _opacityTween.end = opacity;
-        _sheetOpacity = _opacityTween.animate(
-          new CurvedAnimation(
-            parent: animation,
-            curve: new Interval(0.9f, 1.0f)
-        ));
-        Navigator.of(context).pop<object>();
-      }
-
-      public void _updateTweenRects() {
-        Rect childRect = _scale == null 
-          ? CupertinoContextMenuUtils._getRect(_childGlobalKey) 
-          : _getScaledRect(_childGlobalKey, _scale);
-        _rectTween.begin = _previousChildRect;
-        _rectTween.end = childRect;
-        Rect childRectOriginal = CupertinoContextMenuUtils.fromCenter(
-          center: _previousChildRect.center,
-          width: _previousChildRect.width / CupertinoContextMenuUtils._kOpenScale,
-          height: _previousChildRect.height / CupertinoContextMenuUtils._kOpenScale
-        );
-        Rect sheetRect = CupertinoContextMenuUtils._getRect(_sheetGlobalKey);
-        Rect sheetRectBegin = _getSheetRectBegin(
-          _lastOrientation,
-          _contextMenuLocation,
-          childRectOriginal,
-          sheetRect
-        );
-        _sheetRectTween.begin = sheetRectBegin;
-        _sheetRectTween.end = sheetRect;
-        _sheetScaleTween.begin = 0.0f;
-        _sheetScaleTween.end = _scale;
-        _rectTweenReverse.begin = childRectOriginal; 
-        _rectTweenReverse.end = childRect;
-      }
-      public void _setOffstageInternally() {
-        base.offstage = _externalOffstage || _internalOffstage;
-        changedInternalState();
-      }
-      public bool didPop(object result) {
-        _updateTweenRects();
-        return base.didPop(result);
-      }
 
         public bool offstage{
            set{
         }
-        
-      
-      public TickerFuture didPush() {
-        _internalOffstage = true;
-        _setOffstageInternally();
-        SchedulerBinding.instance.addPostFrameCallback((TimeSpan timeSpan)=>{
-          _updateTweenRects();
-          _internalOffstage = false;
-          _setOffstageInternally();
-        });
-        return base.didPush();
-      }
-      public Animation<float> createAnimation() { 
-        Animation< float> animation = base.createAnimation();
-        _sheetOpacity = _opacityTween.animate(new CurvedAnimation(
-          parent: animation,
-          curve: Curves.linear
-        ));
-        return animation;
-      }
-      public override Widget buildPage(BuildContext context, Animation< float> animation, Animation< float> secondaryAnimation) {
-        return null;
-      }
-      public override Widget buildTransitions(BuildContext context1, Animation< float> animation, Animation< float> secondaryAnimation, Widget child) {
-        return new OrientationBuilder(
-          builder: (BuildContext context2, Orientation orientation)=>{
-            _lastOrientation = orientation;
-            if (!animation.isCompleted) {
-              bool reverse = animation.status == AnimationStatus.reverse;
-              Rect rect = reverse
-                ? _rectAnimatableReverse.evaluate(animation)
-                : _rectAnimatable.evaluate(animation);
-              Rect sheetRect = reverse
-                ? _sheetRectAnimatableReverse.evaluate(animation)
-                : _sheetRectAnimatable.evaluate(animation);
-              float sheetScale = reverse
-                ? _sheetScaleAnimatableReverse.evaluate(animation)
-                : _sheetScaleAnimatable.evaluate(animation); 
-              List<Widget> widgets = new List<Widget>();
-              widgets.Add(
-                Positioned.fromRect(
-                  rect: sheetRect,
-                  child: new Opacity(
-                    opacity: _sheetOpacity.value,
-                    child: Transform.scale(
-                      //alignment: getSheetAlignment(_contextMenuLocation),
-                      scale: sheetScale,
-                      child: new _ContextMenuSheet(
-                        key: _sheetGlobalKey,
+        public TickerFuture didPush() {
+            _internalOffstage = true;
+            _setOffstageInternally();
+            SchedulerBinding.instance.addPostFrameCallback((TimeSpan timeSpan)=>{
+                _updateTweenRects();
+                _internalOffstage = false;
+                _setOffstageInternally();
+            });
+            return base.didPush();
+        }
+        public Animation<float> createAnimation() { 
+            Animation< float> animation = base.createAnimation();
+            _sheetOpacity = _opacityTween.animate(new CurvedAnimation(
+                parent: animation,
+                curve: Curves.linear
+            ));
+            return animation;
+        }
+        public override Widget buildPage(BuildContext context, Animation< float> animation, Animation< float> secondaryAnimation) {
+            return null;
+        }
+        public override Widget buildTransitions(BuildContext context1, Animation< float> animation, Animation< float> secondaryAnimation, Widget child) {
+            return new OrientationBuilder(
+                builder: (BuildContext context2, Orientation orientation)=>{ 
+                    _lastOrientation = orientation; 
+                    if (!animation.isCompleted) { 
+                        bool reverse = animation.status == AnimationStatus.reverse;
+                        Rect rect = reverse 
+                            ? _rectAnimatableReverse.evaluate(animation) 
+                            : _rectAnimatable.evaluate(animation);
+                        Rect sheetRect = reverse
+                            ? _sheetRectAnimatableReverse.evaluate(animation)
+                            : _sheetRectAnimatable.evaluate(animation);
+                        float sheetScale = reverse
+                            ? _sheetScaleAnimatableReverse.evaluate(animation)
+                            : _sheetScaleAnimatable.evaluate(animation); 
+                        List<Widget> widgets = new List<Widget>(); 
+                        widgets.Add(
+                            Positioned.fromRect(
+                                rect: sheetRect, 
+                                child: new Opacity(
+                                    opacity: _sheetOpacity.value, 
+                                    child: Transform.scale( 
+                                        //alignment: getSheetAlignment(_contextMenuLocation),
+                                        scale: sheetScale, 
+                                        child: new _ContextMenuSheet(
+                                            key: _sheetGlobalKey, 
+                                            actions: _actions, 
+                                            contextMenuLocation: _contextMenuLocation, 
+                                            orientation: orientation
+                                            )
+                                        )
+                                    )
+                                )
+                            ); 
+                        widgets.Add(
+                            Positioned.fromRect(
+                                key: _childGlobalKey, 
+                                rect: rect, 
+                                child: _builder(context2, animation)
+                                )); 
+                        return new Stack(
+                            children: widgets
+                            ); 
+                    } 
+                    return new _ContextMenuRouteStatic(
+                        child: _builder(context1, animation),
+                        childGlobalKey: _childGlobalKey,
-                        orientation: orientation
-                      )
-                    )
-                  )
-                )
-              );
-              widgets.Add(
-                Positioned.fromRect(
-                  key: _childGlobalKey,
-                  rect: rect,
-                  child: _builder(context2, animation)
-                )
-              );
-              return new Stack(
-                children: widgets
-              );
-            }
-          return new _ContextMenuRouteStatic(
-            actions: _actions,
-            child: _builder(context1, animation),
-            childGlobalKey: _childGlobalKey,
-            contextMenuLocation: _contextMenuLocation,
-            onDismiss: _onDismiss,
-            orientation: orientation,
-            sheetGlobalKey: _sheetGlobalKey
-          );
+                        onDismiss: _onDismiss,
+                        orientation: orientation,
+                        sheetGlobalKey: _sheetGlobalKey
+                        );
+                }
+            );
-      );
-  }
-  public class _ContextMenuRouteStatic : StatefulWidget {
-    public _ContextMenuRouteStatic(
-      Key key = null,
-      List<Widget> actions = null,
-      Widget child = null,
-      GlobalKey childGlobalKey = null,
-      _ContextMenuLocation contextMenuLocation = default,
-      _DismissCallback onDismiss =default,
-      Orientation orientation = default,
-      GlobalKey sheetGlobalKey = null
-    ) : base(key: key) {
-      D.assert(contextMenuLocation != null);
-      D.assert(orientation != null);
-      this.actions = actions;
-      this.child = child;
-      this.childGlobalKey = childGlobalKey;
-      this.contextMenuLocation = contextMenuLocation;
-      this.onDismiss = onDismiss;
-      this.orientation = orientation;
-      this.sheetGlobalKey = sheetGlobalKey;
-    }
-    public readonly List<Widget> actions;
-    public readonly Widget child;
-    public readonly GlobalKey childGlobalKey;
-    public readonly _ContextMenuLocation contextMenuLocation;
-    public readonly _DismissCallback onDismiss;
-    public readonly Orientation orientation;
-    public readonly GlobalKey sheetGlobalKey;
+    public class _ContextMenuRouteStatic : StatefulWidget { 
+        public _ContextMenuRouteStatic(
+            Key key = null,
+            List<Widget> actions = null,
+            Widget child = null,
+            GlobalKey childGlobalKey = null,
+            _ContextMenuLocation contextMenuLocation = default,
+            _DismissCallback onDismiss =default,
+            Orientation orientation = default,
+            GlobalKey sheetGlobalKey = null
+            ) : base(key: key) {
+            
+            D.assert(contextMenuLocation != default);
+            D.assert(orientation != default);
+            this.actions = actions;
+            this.child = child;
+            this.childGlobalKey = childGlobalKey; 
+            this.contextMenuLocation = contextMenuLocation;
+            this.onDismiss = onDismiss;
+            this.orientation = orientation;
+            this.sheetGlobalKey = sheetGlobalKey;
+        }
+        public readonly List<Widget> actions;
+        public readonly Widget child;
+        public readonly GlobalKey childGlobalKey;
+        public readonly _ContextMenuLocation contextMenuLocation;
+        public readonly _DismissCallback onDismiss;
+        public readonly Orientation orientation;
+        public readonly GlobalKey sheetGlobalKey;
-    public override State createState() {
-      return new _ContextMenuRouteStaticState();
+        public override State createState() { 
+            return new _ContextMenuRouteStaticState();
+        }
-  }
-  public class _ContextMenuRouteStaticState : TickerProviderStateMixin<_ContextMenuRouteStatic> {
-    public readonly static  float _kMinScale = 0.8f;
-    public readonly static  float _kSheetScaleThreshold = 0.9f;
-    public readonly static  float _kPadding = 20.0f;
-    public readonly static  float _kDamping = 400.0f;
-    public readonly static TimeSpan _kMoveControllerDuration = new TimeSpan(0,0,0,600);
-    public Offset _dragOffset;
-    public float _lastScale = 1.0f;
-    public AnimationController _moveController;
-    public AnimationController _sheetController;
-    public Animation<Offset> _moveAnimation;
-    public Animation< float> _sheetScaleAnimation;
-    public Animation< float> _sheetOpacityAnimation;
-    public static float _getScale(Orientation orientation,  float maxDragDistance,  float dy) {
-      float dyDirectional = dy <= 0.0 ? dy : -dy;
-      return Mathf.Max(
-        _kMinScale,
-        (maxDragDistance + dyDirectional) / maxDragDistance
-      );
-    }
-    void _onPanStart(DragStartDetails details) {
-      _moveController.setValue(1.0f) ;
-      _setDragOffset(Offset.zero);
-    }
-    void _onPanUpdate(DragUpdateDetails details) {
-      _setDragOffset(_dragOffset + details.delta);
-    }
-    void _onPanEnd(DragEndDetails details) {
-      if (details.velocity.pixelsPerSecond.dy.abs() >= CupertinoContextMenuUtils.kMinFlingVelocity) {
-        bool flingIsAway = details.velocity.pixelsPerSecond.dy > 0;
-        float finalPosition = flingIsAway
-          ? _moveAnimation.value.dy + 100.0f
-          : 0.0f;
-        if (flingIsAway && _sheetController.status != AnimationStatus.forward) {
-          _sheetController.forward();
-        } else if (!flingIsAway && _sheetController.status != AnimationStatus.reverse) {
-          _sheetController.reverse();
-        }
+    public class _ContextMenuRouteStaticState : TickerProviderStateMixin<_ContextMenuRouteStatic> {
+        public readonly static  float _kMinScale = 0.8f;
+        public readonly static  float _kSheetScaleThreshold = 0.9f;
+        public readonly static  float _kPadding = 20.0f;
+        public readonly static  float _kDamping = 400.0f;
+        public readonly static TimeSpan _kMoveControllerDuration = TimeSpan.FromMilliseconds(600);
+        Offset _dragOffset;
+        public float _lastScale = 1.0f;
+        public AnimationController _moveController;
+        public AnimationController _sheetController;
+        public Animation<Offset> _moveAnimation;
+        public Animation< float> _sheetScaleAnimation;
+        public Animation< float> _sheetOpacityAnimation; 
+        public static float _getScale(Orientation orientation,  float maxDragDistance,  float dy) { 
+            float dyDirectional = dy <= 0.0f ? dy : -dy;
+            return Mathf.Max(
+                _kMinScale, 
+                (maxDragDistance + dyDirectional) / maxDragDistance
+            );
+        } 
+        void _onPanStart(DragStartDetails details) {
+            _moveController.setValue(1.0f) ;
+            _setDragOffset(Offset.zero);
+        } 
+        void _onPanUpdate(DragUpdateDetails details) {
+            _setDragOffset(_dragOffset + details.delta);
+        } 
+        void _onPanEnd(DragEndDetails details) { 
+            if (details.velocity.pixelsPerSecond.dy.abs() >= CupertinoContextMenuUtils.kMinFlingVelocity) { 
+                bool flingIsAway = details.velocity.pixelsPerSecond.dy > 0; 
+                float finalPosition = flingIsAway 
+                    ? _moveAnimation.value.dy + 100.0f
+                    : 0.0f; 
+                if (flingIsAway && _sheetController.status != AnimationStatus.forward) { 
+                    _sheetController.forward();
+                } else if (!flingIsAway && _sheetController.status != AnimationStatus.reverse) {
+                    _sheetController.reverse();
+                }
-        _moveAnimation = new OffsetTween(
-          begin: new Offset(0.0f, _moveAnimation.value.dy),
-          end:new  Offset(0.0f, finalPosition)
-        ).animate(_moveController);
-        _moveController.reset();
-        _moveController.duration = new  TimeSpan(0,0,0,64);
-        _moveController.forward();
-        _moveController.addStatusListener(_flingStatusListener);
-        return;
-      }
-      if (_lastScale == _kMinScale) {
-        widget.onDismiss(context, _lastScale, _sheetOpacityAnimation.value);
-        return;
-      }
-
-      // Otherwise animate back home.
-      _moveController.addListener(_moveListener);
-      _moveController.reverse();
+                _moveAnimation = new OffsetTween(
+                    begin: new Offset(0.0f, _moveAnimation.value.dy),
+                    end:new  Offset(0.0f, finalPosition)
+                ).animate(_moveController);
+                _moveController.reset();
+                _moveController.duration = TimeSpan.FromMilliseconds(64);
+                _moveController.forward();
+                _moveController.addStatusListener(_flingStatusListener);
+                return; 
+            } 
+            if (_lastScale == _kMinScale) {
+                widget.onDismiss(context, _lastScale, _sheetOpacityAnimation.value);
+                return;
+            }
+            _moveController.addListener(_moveListener);
+            _moveController.reverse();
-    void _moveListener() {
-      if (_lastScale > _kSheetScaleThreshold) {
-        _moveController.removeListener(_moveListener);
-        if (_sheetController.status != AnimationStatus.dismissed) {
-          _sheetController.reverse();
+    void _moveListener() { 
+        if (_lastScale > _kSheetScaleThreshold) {
+            _moveController.removeListener(_moveListener); 
+            if (_sheetController.status != AnimationStatus.dismissed) { 
+                _sheetController.reverse();
+            }
-      }
-    void _flingStatusListener(AnimationStatus status) {
-      if (status != AnimationStatus.completed) {
-        return;
-      }
-      _moveController.duration = _kMoveControllerDuration;
-      _moveController.removeStatusListener(_flingStatusListener);
-      if (_moveAnimation.value.dy == 0.0) {
-        return;
-      }
-      widget.onDismiss(context, _lastScale, _sheetOpacityAnimation.value);
+    void _flingStatusListener(AnimationStatus status) { 
+        if (status != AnimationStatus.completed) { 
+            return;
+        }
+        _moveController.duration = _kMoveControllerDuration;
+        _moveController.removeStatusListener(_flingStatusListener);
+        if (_moveAnimation.value.dy == 0.0) {
+            return;
+        }
+        widget.onDismiss(context, _lastScale, _sheetOpacityAnimation.value);
-
-    Alignment _getChildAlignment(Orientation orientation, _ContextMenuLocation contextMenuLocation) {
-      switch (contextMenuLocation) {
-        case _ContextMenuLocation.center:
-          return orientation == Orientation.portrait
-            ? Alignment.bottomCenter
-            : Alignment.topRight;
-        case _ContextMenuLocation.right:
-          return orientation == Orientation.portrait
-            ? Alignment.bottomCenter
-            : Alignment.topLeft;
-        default:
-          return orientation == Orientation.portrait
-            ? Alignment.bottomCenter
-            : Alignment.topRight;
-      }
+    Alignment _getChildAlignment(Orientation orientation, _ContextMenuLocation contextMenuLocation) { 
+        switch (contextMenuLocation) { 
+            case _ContextMenuLocation.center: 
+                return orientation == Orientation.portrait 
+                    ? Alignment.bottomCenter 
+                    : Alignment.topRight;
+            case _ContextMenuLocation.right: 
+                return orientation == Orientation.portrait 
+                    ? Alignment.bottomCenter
+                    : Alignment.topLeft;
+            default:
+                return orientation == Orientation.portrait
+                    ? Alignment.bottomCenter
+                    : Alignment.topRight;
+        }
-      // Allow horizontal and negative vertical movement, but damp it.
-      float endX = _kPadding * dragOffset.dx / _kDamping;
-      float endY = dragOffset.dy >= 0.0
-        ? dragOffset.dy
-        : _kPadding * dragOffset.dy / _kDamping;
-      setState(() =>{
-        _dragOffset = dragOffset;
-        _moveAnimation = new OffsetTween(
-          begin: Offset.zero,
-          end: new Offset(
-            endX.clamp(-_kPadding, _kPadding) ,
-            endY
-          )
-        ).animate(
-          new CurvedAnimation(
-            parent: _moveController,
-            curve: Curves.elasticIn
-          )
+        float endX = _kPadding * dragOffset.dx / _kDamping;
+        float endY = dragOffset.dy >= 0.0 
+            ? dragOffset.dy 
+            : _kPadding * dragOffset.dy / _kDamping; 
+        setState(() =>{ 
+            _dragOffset = dragOffset;
+            _moveAnimation = new OffsetTween(
+                begin: Offset.zero,
+                end: new Offset(
+                    endX.clamp(-_kPadding, _kPadding) , 
+                    endY
+                    )).animate(
+                new CurvedAnimation(
+                    parent: _moveController, 
+                    curve: Curves.elasticIn
+                    )
-        if (_lastScale <= _kSheetScaleThreshold
-            && _sheetController.status != AnimationStatus.forward
-            && _sheetScaleAnimation.value != 0.0f) {
-          _sheetController.forward();
-        } else if (_lastScale > _kSheetScaleThreshold
-            && _sheetController.status != AnimationStatus.reverse
-            && _sheetScaleAnimation.value != 1.0f) {
-          _sheetController.reverse();
-        }
-      });
+        if (_lastScale <= _kSheetScaleThreshold && _sheetController.status != AnimationStatus.forward
+                                                && _sheetScaleAnimation.value != 0.0f) { 
+            _sheetController.forward();
+        } else if (_lastScale > _kSheetScaleThreshold && _sheetController.status != AnimationStatus.reverse
+                                                      && _sheetScaleAnimation.value != 1.0f) { 
+            _sheetController.reverse();
+        } 
+        });
-
-    List<Widget> _getChildren(Orientation orientation, _ContextMenuLocation contextMenuLocation) {
-      Expanded child = new Expanded(
-        child: new Align(
-          alignment: _getChildAlignment(
-            widget.orientation,
-            widget.contextMenuLocation
-          ),
-          child: new AnimatedBuilder(
-            animation: _moveController,
-            builder: _buildChildAnimation,
-            child: widget.child
-          )
-        )
-      );
-      Container spacer = new Container(
-        width: _kPadding,
-        height: _kPadding
-      );
-      Expanded sheet = new Expanded(
-        child: new AnimatedBuilder(
-          animation: _sheetController,
-          builder: _buildSheetAnimation,
-          child: new _ContextMenuSheet(
-            key: widget.sheetGlobalKey,
-            actions: widget.actions,
-            contextMenuLocation: widget.contextMenuLocation,
-            orientation: widget.orientation
-          )
-        )
-      );
-      List<Widget> centerWidgets = new List<Widget>();
-      centerWidgets.Add(child);
-      centerWidgets.Add(spacer);
-      centerWidgets.Add(sheet);
-      List<Widget> rightWidgets = new List<Widget>();
-      rightWidgets.Add(sheet);
-      rightWidgets.Add(spacer);
-      rightWidgets.Add(child);
+    List<Widget> _getChildren(Orientation orientation, _ContextMenuLocation contextMenuLocation) { 
+        Expanded child = new Expanded(
+            child: new Align(
+                alignment: _getChildAlignment(
+                    widget.orientation, 
+                    widget.contextMenuLocation
+                ), 
+                child: new AnimatedBuilder(
+                    animation: _moveController,
+                    builder: _buildChildAnimation,
+                    child: widget.child
+                )
+            )
+        );
+        Container spacer = new Container(
+            width: _kPadding,
+            height: _kPadding
+            );
+        Expanded sheet = new Expanded(
+            child: new AnimatedBuilder(
+                animation: _sheetController,
+                builder: _buildSheetAnimation,
+                child: new _ContextMenuSheet(
+                    key: widget.sheetGlobalKey,
+                    actions: widget.actions,
+                    contextMenuLocation: widget.contextMenuLocation,
+                    orientation: widget.orientation
+                )
+            )
+        ); 
+        List<Widget> centerWidgets = new List<Widget>();
+        centerWidgets.Add(child);
+        centerWidgets.Add(spacer);
+        centerWidgets.Add(sheet);
+        List<Widget> rightWidgets = new List<Widget>();
+        rightWidgets.Add(sheet);
+        rightWidgets.Add(spacer);
+        rightWidgets.Add(child);
       switch (contextMenuLocation) {
         case _ContextMenuLocation.center:
             return new List<Widget>{child, spacer, sheet};
         vsync: this
       );
       _sheetController = new AnimationController(
-        duration: new TimeSpan(0,0,0,100),
-        //reverseDuration: new TimeSpan(0,0,0,300),/// TBC ???
+        duration: TimeSpan.FromMilliseconds(100),
+        reverseDuration: TimeSpan.FromMilliseconds(300),/// TBC ???
         vsync: this
       );
       _sheetScaleAnimation = new FloatTween(
       T offValue = default,
       float? intervalOn = null,
       float? intervalOff = null
-    ) /*: super(
-                      first: new Tween<T>(begin: offValue, end: onValue).animate(
-                          new CurvedAnimation(
-                              parent: controller,
-                              curve: new Interval(intervalOn, intervalOn)
-                          )
-                      ),
-                      next: new Tween<T>(begin: onValue, end: offValue).animate(
-                          new CurvedAnimation(
-                              parent: controller,
-                              curve: new Interval(intervalOff, intervalOff)
-                          )
-                          )
-                      )*////?????
+    ) : base(
+        first: new Tween<T>(begin: offValue, end: onValue).animate(
+            new CurvedAnimation(
+                parent: controller,
+                curve: new Interval(intervalOn == null ? 0.0f : (float)intervalOn, intervalOn == null ? 0.0f : (float)intervalOn)
+                )
+            ),
+        next: new Tween<T>(begin: onValue, end: offValue).animate(
+            new CurvedAnimation(
+                parent: controller,
+                curve: new Interval(intervalOff == null ? 0.0f : (float)intervalOff, intervalOff == null ? 0.0f : (float)intervalOff)
+                )
+            )
+        )
     {
       D.assert(intervalOn != null && intervalOn >= 0.0 && intervalOn <= 1.0);
       D.assert(intervalOff !=null && intervalOff >= 0.0 && intervalOff <= 1.0);
     public override T value {
       get {
-        return next.value; // == _offValue ? next.value : first.value; ????/
+        return next.value.Equals( _offValue) ? next.value : first.value; 
       }
     }
 

com.unity.uiwidgets/Runtime/cupertino/dialog.cs

+using System;
+using Unity.UIWidgets.animation;
 using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.gestures;
 using Unity.UIWidgets.painting;
             inherit:false,
             fontSize: 13.4f,
             fontWeight: FontWeight.w400,
-            //color: CupertinoColors.black,
             height: 1.036f,
             letterSpacing: -0.25f,
             textBaseline: TextBaseline.alphabetic
         public const float _kMinButtonFontSize = 10.0f;
         public const float _kDialogCornerRadius = 12.0f;
         public const float _kDividerThickness = 1.0f;
-        public const float _kMaxRegularTextScaleFactor = 1.4f;
+        
-        //public static readonly Color _kDialogColor = new Color(0xC0FFFFFF);
-        //public static readonly Color _kDialogPressedColor = new Color(0x90FFFFFF);
         public static readonly Color _kButtonDividerColor = new Color(0x40FFFFFF);
 
         public static readonly Color _kDialogColor = CupertinoDynamicColor.withBrightness(
             color: new Color(0xFFE1E1E1),
             darkColor: new Color(0xFF2E2E2E)
         );
+        public const float _kMaxRegularTextScaleFactor = 1.4f;
 
         public static bool _isInAccessibilityMode(BuildContext context) {
             MediaQueryData data = MediaQuery.of(context, nullOk: true);
             Widget content = null,
             List<Widget> actions = null,
             ScrollController scrollController = null,
-            ScrollController actionScrollController = null
+            ScrollController actionScrollController = null,
+            TimeSpan? insetAnimationDuration = null,
+            Curve insetAnimationCurve = null
-
+            this.insetAnimationDuration = insetAnimationDuration ?? TimeSpan.FromMilliseconds(100);
+            this.insetAnimationCurve = insetAnimationCurve ?? Curves.decelerate;
         }
 
         public readonly Widget title;
         public readonly ScrollController actionScrollController;
+        readonly TimeSpan? m_InsetAnimationDuration;
+        public readonly TimeSpan insetAnimationDuration;
+        public readonly Curve insetAnimationCurve;
-        Widget _buildContent() {
+        Widget _buildContent(BuildContext context) {
             List<Widget> children = new List<Widget>();
             if (title != null || content != null) {
                 Widget titleSection = new _CupertinoDialogAlertContentSection(
             }
 
             return new Container(
-                color: CupertinoDialogUtils._kDialogColor,
+                color: CupertinoDynamicColor.resolve(CupertinoDialogUtils._kDialogColor, context),
                 child: new Column(
                     mainAxisSize: MainAxisSize.min,
                     crossAxisAlignment: CrossAxisAlignment.stretch,
             bool isInAccessibilityMode = CupertinoDialogUtils._isInAccessibilityMode(context);
 
             float textScaleFactor = MediaQuery.of(context).textScaleFactor;
-            return new MediaQuery(
-                data: MediaQuery.of(context).copyWith(
-                    textScaleFactor: Mathf.Max(textScaleFactor, 1.0f)
-                ),
+            return  new CupertinoUserInterfaceLevel(
+                data: CupertinoUserInterfaceLevelData.elevatedlayer,
+                child: new MediaQuery(
+                    data: MediaQuery.of(context).copyWith(
+                        textScaleFactor: Mathf.Max(textScaleFactor, 1.0f)
+                    ),
-                        return new Center(
-                            child: new Container(
-                                margin: EdgeInsets.symmetric(vertical: CupertinoDialogUtils._kEdgePadding),
-                                width: isInAccessibilityMode
-                                    ? CupertinoDialogUtils._kAccessibilityCupertinoDialogWidth
-                                    : CupertinoDialogUtils._kCupertinoDialogWidth,
-                                child: new CupertinoPopupSurface(
-                                    isSurfacePainted: false,
-                                    child: new _CupertinoDialogRenderWidget(
-                                        contentSection: _buildContent(),
-                                        actionsSection: _buildActions()
+                        return new AnimatedPadding(
+                            padding: MediaQuery.of(_context).viewInsets + EdgeInsets.symmetric(horizontal: 40.0f, vertical: 24.0f),
+                            duration: insetAnimationDuration,
+                            curve: insetAnimationCurve,
+                            child: MediaQuery.removeViewInsets(
+                                removeLeft: true,
+                                removeTop: true,
+                                removeRight: true,
+                                removeBottom: true,
+                                context: _context,
+                                child: new Center(
+                                child: new Container(
+                                    margin: EdgeInsets.symmetric(vertical: CupertinoDialogUtils._kEdgePadding),
+                                    width: isInAccessibilityMode
+                                        ? CupertinoDialogUtils._kAccessibilityCupertinoDialogWidth
+                                        : CupertinoDialogUtils._kCupertinoDialogWidth,
+                                    child: new CupertinoPopupSurface(
+                                        isSurfacePainted: false,
+                                        child: new _CupertinoDialogRenderWidget(
+                                            contentSection: _buildContent(_context),
+                                            actionsSection: _buildActions()
+                                        )
+                            )
-            );
+            )
+                );
         }
     }
 
                     child: new Container(
                         decoration: CupertinoDialogUtils._kCupertinoDialogBlurOverlayDecoration,
                         child: new Container(
-                            color: isSurfacePainted ? CupertinoDialogUtils._kDialogColor : null,
+                            color: isSurfacePainted ? CupertinoDynamicColor.resolve(CupertinoDialogUtils._kDialogColor, context) : null,
                             child: child
                         )
                     )
 
     class _CupertinoDialogRenderWidget : RenderObjectWidget {
         public _CupertinoDialogRenderWidget(
-            Widget contentSection,
-            Widget actionsSection,
-            Key key = null
+            Key key = null,
+            Widget contentSection = null,
+            Widget actionsSection = null
         ) : base(key: key) {
             this.contentSection = contentSection;
             this.actionsSection = actionsSection;
         public override RenderObject createRenderObject(BuildContext context) {
             return new _RenderCupertinoDialog(
                 dividerThickness: CupertinoDialogUtils._kDividerThickness / MediaQuery.of(context).devicePixelRatio,
-                isInAccessibilityMode: CupertinoDialogUtils._isInAccessibilityMode(context)
+                isInAccessibilityMode: CupertinoDialogUtils._isInAccessibilityMode(context),
+                dividerColor: CupertinoDynamicColor.resolve(CupertinoColors.separator, context)
             );
         }
 
+            ((_RenderCupertinoDialog) renderObject).dividerColor = 
+                CupertinoDynamicColor.resolve(CupertinoColors.separator, context);
         }
 
         public override Element createElement() {
 
         Element _contentElement;
         Element _actionsElement;
+
 
         public new _CupertinoDialogRenderWidget widget {
             get { return base.widget as _CupertinoDialogRenderWidget; }
                 D.assert(_actionsElement == child);
                 _actionsElement = null;
             }
+            base.forgetChild(child);
         }
 
         protected override void removeChildRenderObject(RenderObject child) {
             RenderBox contentSection = null,
             RenderBox actionsSection = null,
             float dividerThickness = 0.0f,
-            bool isInAccessibilityMode = false
+            bool isInAccessibilityMode = false,
+            Color dividerColor = null
+            _dividerPaint = new Paint() {
+                color = dividerColor,
+                style = PaintingStyle.fill
+            };
+
         }
 
         public RenderBox contentSection {
 
         readonly float _dividerThickness;
 
-        readonly Paint _dividerPaint = new Paint() {
-            color = CupertinoDialogUtils._kButtonDividerColor,
-            style = PaintingStyle.fill
-        };
+
+        public readonly Paint _dividerPaint;
+
+        public Color dividerColor {
+            get {
+                return _dividerPaint.color;
+            }
+            set {
+                if (dividerColor == value) {
+                    return;
+                }
+                _dividerPaint.color = value;
+                markNeedsPaint();
+            }
+        }
         public override void attach(object owner) {
             base.attach(owner);
             if (null != contentSection) {
             );
         }
 
-        protected override bool hitTestChildren(BoxHitTestResult result, Offset position = null
-        ) {
+        protected override bool hitTestChildren(BoxHitTestResult result, Offset position = null) {
             BoxParentData contentSectionParentData = contentSection.parentData as BoxParentData;
             BoxParentData actionsSectionParentData = actionsSection.parentData as BoxParentData;
             return result.addWithPaintOffset(
         public readonly ScrollController scrollController;
 
         public override Widget build(BuildContext context) {
+            if (title == null && content == null) {
+                return new SingleChildScrollView(
+                    controller: scrollController,
+                    child: new Container(width: 0.0f, height: 0.0f)
+                );
+            }
+
             float textScaleFactor = MediaQuery.of(context).textScaleFactor;
             List<Widget> titleContentGroup = new List<Widget>();
             if (title != null) {
                         top: CupertinoDialogUtils._kEdgePadding * textScaleFactor
                     ),
                     child: new DefaultTextStyle(
-                        style: CupertinoDialogUtils._kCupertinoDialogTitleStyle,
+                        style: CupertinoDialogUtils._kCupertinoDialogTitleStyle.copyWith(
+                            color: CupertinoDynamicColor.resolve(CupertinoColors.label, context)
+                        ),
                         textAlign: TextAlign.center,
                         child: title
                     )
                             top: title == null ? CupertinoDialogUtils._kEdgePadding : 1.0f
                         ),
                         child: new DefaultTextStyle(
-                            style: CupertinoDialogUtils._kCupertinoDialogContentStyle,
+                            style: CupertinoDialogUtils._kCupertinoDialogContentStyle.copyWith(
+                                color: CupertinoDynamicColor.resolve(CupertinoColors.label, context)
+                            ),
                             textAlign: TextAlign.center,
                             child: content
                         )
 //ParentDataWidget<_DialogActionButtonParentData>
     class _DialogActionButtonParentDataWidget : ParentDataWidget<_ActionButtonParentData> {
         public _DialogActionButtonParentDataWidget(
-            Widget child,
+            Key key = null,
-            Key key = null
+            Widget child = null
         ) : base(key: key, child: child) {
             this.isPressed = isPressed;
         }
                 }
             }
         }
+
+        public override Type debugTypicalAncestorWidgetClass {
+            get {
+                return typeof(_CupertinoDialogActionsRenderWidget);
+            }
+        }
     }
 
     class _DialogActionButtonParentData : MultiChildLayoutParentData {
 
     public class CupertinoDialogAction : StatelessWidget {
         public CupertinoDialogAction(
-            Widget child,
+            Key key = null,
-            TextStyle textStyle = null
-        ) {
+            TextStyle textStyle = null,
+            Widget child = null
+        ):base(key:key) {
             D.assert(child != null);
             this.onPressed = onPressed;
             this.isDefaultAction = isDefaultAction;
         }
 
         public override Widget build(BuildContext context) {
-            TextStyle style = CupertinoDialogUtils._kCupertinoDialogActionStyle;
+            TextStyle style = CupertinoDialogUtils._kCupertinoDialogActionStyle.copyWith(
+                color: CupertinoDynamicColor.resolve(
+                    isDestructiveAction ?  CupertinoColors.systemRed : CupertinoColors.systemBlue,
+                    context
+                )
+            );
-            if (isDestructiveAction) {
-                style = style.copyWith(color: CupertinoColors.destructiveRed);
+            
+            if (isDefaultAction) {
+                style = style.copyWith(fontWeight: FontWeight.w600);
+
 
             if (!enabled) {
                 style = style.copyWith(color: style.color.withOpacity(0.5f));
                 dialogWidth: CupertinoDialogUtils._isInAccessibilityMode(context)
                     ? CupertinoDialogUtils._kAccessibilityCupertinoDialogWidth
                     : CupertinoDialogUtils._kCupertinoDialogWidth,
-                dividerThickness: _dividerThickness
+                dividerThickness: _dividerThickness,
+                dialogColor: CupertinoDynamicColor.resolve(CupertinoDialogUtils._kDialogColor, context),
+                dialogPressedColor: CupertinoDynamicColor.resolve(CupertinoDialogUtils._kDialogPressedColor, context),
+                dividerColor: CupertinoDynamicColor.resolve(CupertinoColors.separator, context)
             );
         }
 
                     ? CupertinoDialogUtils._kAccessibilityCupertinoDialogWidth
                     : CupertinoDialogUtils._kCupertinoDialogWidth;
             (renderObject as _RenderCupertinoDialogActions).dividerThickness = _dividerThickness;
+            (renderObject as _RenderCupertinoDialogActions).dialogColor =
+                CupertinoDynamicColor.resolve( CupertinoDialogUtils._kDialogColor, context);
+            (renderObject as _RenderCupertinoDialogActions).dialogPressedColor =
+                CupertinoDynamicColor.resolve( CupertinoDialogUtils._kDialogPressedColor, context);
+            (renderObject as _RenderCupertinoDialogActions).dividerColor = 
+                CupertinoDynamicColor.resolve(CupertinoColors.separator, context);
         }
     }
 
-            float dialogWidth,
-            float dividerThickness = 0.0f
+            float? dialogWidth = null,
+            float dividerThickness = 0.0f,
+            Color dialogColor = null,
+            Color dialogPressedColor = null,
+            Color dividerColor = null
+            _buttonBackgroundPaint = new Paint() {
+                color = dialogColor,
+                style = PaintingStyle.fill
+            };
+            _pressedButtonBackgroundPaint = new Paint(){
+                color = dialogPressedColor,
+                style = PaintingStyle.fill
+            };
+            _dividerPaint = new Paint(){
+                color = dividerColor,
+                style = PaintingStyle.fill
+            };
-        public float dialogWidth {
+        public float? dialogWidth {
             get { return _dialogWidth; }
             set {
                 if (value != _dialogWidth) {
             }
         }
-
-        float _dialogWidth;
+        float? _dialogWidth;
 
 
         public float dividerThickness {
                 }
             }
         }
+        float _dividerThickness;
+
+        public readonly  Paint _buttonBackgroundPaint;
+
+        public Color dialogColor {
+            set{
+                if (value == _buttonBackgroundPaint.color)
+                    return;
+
+                _buttonBackgroundPaint.color = value;
+                markNeedsPaint();
+            }
+         }
-        float _dividerThickness;
+        public readonly Paint _pressedButtonBackgroundPaint;
-        readonly Paint _buttonBackgroundPaint = new Paint() {
-            color = CupertinoDialogUtils._kDialogColor,
-            style = PaintingStyle.fill
-        };
+        public Color dialogPressedColor {
+            set{
+                if (value == _pressedButtonBackgroundPaint.color)
+                    return;
-        readonly Paint _pressedButtonBackgroundPaint = new Paint() {
-            color = CupertinoDialogUtils._kDialogPressedColor,
-            style = PaintingStyle.fill
-        };
+                _pressedButtonBackgroundPaint.color = value;
+                markNeedsPaint();
+            }
+        }
+        public readonly Paint _dividerPaint;
-        readonly Paint _dividerPaint = new Paint() {
-            color = CupertinoDialogUtils._kButtonDividerColor,
-            style = PaintingStyle.fill
-        };
+        public Color dividerColor{
+            set {
+                if (value == _dividerPaint.color)
+                    return;
+
+                _dividerPaint.color = value;
+                markNeedsPaint();
+            }
+        }
 
         List<RenderBox> _pressedButtons {
             get {
         }
 
         protected internal override float computeMinIntrinsicWidth(float height) {
-            return dialogWidth;
+            return dialogWidth ?? 0.0f;
-            return dialogWidth;
+            return dialogWidth ?? 0.0f;
         }
 
         protected internal override float computeMinIntrinsicHeight(float width) {
             }
             else {
                 float perButtonWidth = (width - dividerThickness) / 2.0f;
-                minHeight = Mathf.Max(firstChild.getMinIntrinsicHeight(perButtonWidth),
+                minHeight = Mathf.Max(
+                    firstChild.getMinIntrinsicHeight(perButtonWidth),
                     lastChild.getMinIntrinsicHeight(perButtonWidth)
                 );
             }
             else if (childCount == 2) {
                 if (_isSingleButtonRow(width)) {
                     float perButtonWidth = (width - dividerThickness) / 2.0f;
-                    maxHeight = Mathf.Max(firstChild.getMaxIntrinsicHeight(perButtonWidth),
+                    maxHeight = Mathf.Max(
+                        firstChild.getMaxIntrinsicHeight(perButtonWidth),
                         lastChild.getMaxIntrinsicHeight(perButtonWidth)
                     );
                 }
                 heightAccumulation += button.getMaxIntrinsicHeight(width);
                 button = childAfter(button);
             }
-
             return heightAccumulation;
         }
 
         }
 
         protected override void performLayout() {
-            if (_isSingleButtonRow(dialogWidth)) {
+            BoxConstraints constraints = this.constraints;
+            if (_isSingleButtonRow(dialogWidth ?? 0.0f)) {
                 if (childCount == 1) {
                     firstChild.layout(
                         constraints,
-                        new Size(dialogWidth, firstChild.size.height)
+                        new Size(dialogWidth ?? 0.0f, firstChild.size.height)
                     );
                 }
                 else {
                     secondButtonParentData.offset =
                         new Offset(firstChild.size.width + dividerThickness, 0.0f);
                     size = constraints.constrain(
-                        new Size(dialogWidth,
-                            Mathf.Max(firstChild.size.height, lastChild.size.height
+                        new Size(
+                            dialogWidth ?? 0.0f,
+                            Mathf.Max(
+                                firstChild.size.height, 
+                                lastChild.size.height
                             )
                         )
                     );
                 }
 
                 size = constraints.constrain(
-                    new Size(dialogWidth, verticalOffset)
+                    new Size(dialogWidth ?? 0.0f, verticalOffset)
                 );
             }
         }
             }
 
             Path backgroundFillPath = new Path();
-
-            // backgroundFillPath.fillType = PathFillType.evenOdd;
+            backgroundFillPath.fillType = PathFillType.evenOdd;
             backgroundFillPath.addRect(Rect.fromLTWH(0.0f, 0.0f, size.width, size.height));
             backgroundFillPath.addRect(verticalDivider);
 
             }
 
             canvas.drawPath(
-                pressedBackgroundFillPath, _pressedButtonBackgroundPaint
+                pressedBackgroundFillPath, 
+                _pressedButtonBackgroundPaint
             );
             Path dividersPath = new Path();
             dividersPath.addRect(verticalDivider);
         void _drawButtonBackgroundsAndDividersStacked(Canvas canvas, Offset offset) {
             Offset dividerOffset = new Offset(0.0f, dividerThickness);
             Path backgroundFillPath = new Path();
-            // ..fillType = PathFillType.evenOdd
+            backgroundFillPath.fillType = PathFillType.evenOdd;
             backgroundFillPath.addRect(Rect.fromLTWH(0.0f, 0.0f, size.width, size.height));
             Path pressedBackgroundFillPath = new Path();
             Path dividersPath = new Path();
             }
         }
 
-        protected override bool hitTestChildren(BoxHitTestResult result,
+        protected override bool hitTestChildren(
+            BoxHitTestResult result,
             Offset position = null
         ) {
             return defaultHitTestChildren(result, position: position);

com.unity.uiwidgets/Runtime/cupertino/icon_theme_data.cs

             Color resolvedColor = CupertinoDynamicColor.resolve(color, context);
             return resolvedColor == color ? this : copyWith(color: resolvedColor);
         }
-        public new CupertinoIconThemeData copyWith(Color color = null , float? opacity = null, float? size = null) 
+        public new CupertinoIconThemeData copyWith(
+            Color color = null , 
+            float? opacity = null, 
+            float? size = null) 
         {
             return new CupertinoIconThemeData(
                 color: color ?? this.color,

com.unity.uiwidgets/Runtime/cupertino/icons.cs

         public static readonly IconData reply_all = new IconData(0xf21d, fontFamily: iconFont);
         public static readonly IconData reply_thick_solid = new IconData(0xf21e, fontFamily: iconFont);
         public static readonly IconData share_up = new IconData(0xf220, fontFamily: iconFont);
+        public static readonly IconData shuffle = new IconData(0xf4a9, fontFamily: iconFont);
+        public static readonly IconData shuffle_medium = new IconData(0xf4a8, fontFamily: iconFont);
         public static readonly IconData shuffle_thick = new IconData(0xf221, fontFamily: iconFont);
         public static readonly IconData photo_camera = new IconData(0xf3f5, fontFamily: iconFont);
         public static readonly IconData photo_camera_solid = new IconData(0xf3f6, fontFamily: iconFont);
         public static readonly IconData bell_solid = new IconData(0xf3e2, fontFamily: iconFont);
         public static readonly IconData news = new IconData(0xf471, fontFamily: iconFont);
         public static readonly IconData news_solid = new IconData(0xf472, fontFamily: iconFont);
+        public static readonly IconData brightness = new IconData(0xf4B6, fontFamily: iconFont);
+        public static readonly IconData brightness_solid = new IconData(0xf4B7, fontFamily: iconFont);
+        
     }
 }

com.unity.uiwidgets/Runtime/cupertino/interface_level.cs

 
         public static CupertinoUserInterfaceLevelData? of(BuildContext context, bool nullOk = false ) {
             D.assert(context != null);
-            D.assert(nullOk != null);
-            //if (nullOk)
-            //  return ;
+            if (nullOk)
+              return null;
             throw new UIWidgetsError(
               "CupertinoUserInterfaceLevel.of() called with a context that does not contain a CupertinoUserInterfaceLevel.\n" +
               "No CupertinoUserInterfaceLevel ancestor could be found starting from the context that was passed "+
           }
 
           public override bool updateShouldNotify(InheritedWidget oldWidget) {
-              //throw new System.NotImplementedException();              
-              //oldWidget._data != _data;
-              /// ????? 
-              if (oldWidget.GetType() == typeof(CupertinoUserInterfaceLevel)) {
-                  return updateShouldNotify(oldWidget);
-              }
-
-              return false;
+              oldWidget = (CupertinoUserInterfaceLevel) oldWidget;
+              return ((CupertinoUserInterfaceLevel) oldWidget)._data != _data;
-          public bool updateShouldNotify(CupertinoUserInterfaceLevel oldWidget) => oldWidget._data != _data;
-
     }
 
 }

com.unity.uiwidgets/Runtime/cupertino/localization.cs

 
         public abstract string postMeridiemAbbreviation { get; }
 
+        public abstract string todayLabel { get; }
+
         public abstract string alertDialogLabel { get; }
 
         public abstract string timerPickerHour(int hour);
 
         public override string postMeridiemAbbreviation {
             get { return "PM"; }
+        }
+
+        public override string todayLabel {
+            get { return "Today"; }
         }
 
         public override string alertDialogLabel {

com.unity.uiwidgets/Runtime/cupertino/nav_bar.cs

 using Rect = Unity.UIWidgets.ui.Rect;
 using TextStyle = Unity.UIWidgets.painting.TextStyle;
 using Brightness = Unity.UIWidgets.ui.Brightness;
+using Transform = Unity.UIWidgets.widgets.Transform;
 
 
 namespace Unity.UIWidgets.cupertino {
 
         public const float _kNavBarBackButtonTapWidth = 50.0f;
 
-        public static readonly TimeSpan _kNavBarTitleFadeDuration = new TimeSpan(0, 0, 0, 0, 150);
+        public static readonly TimeSpan _kNavBarTitleFadeDuration = TimeSpan.FromMilliseconds(150);
 
         public static readonly Color _kDefaultNavBarBorderColor = new Color(0x4C000000);
 
         ) {
             Widget result = child;
             if (updateSystemUiOverlay) {
-                /*bool darkBackground = backgroundColor.computeLuminance() < 0.179f;
-                SystemUiOverlayStyle overlayStyle = darkBackground
-                    ? SystemUiOverlayStyle.light
-                    : SystemUiOverlayStyle.dark;*/
                 bool isDark = backgroundColor.computeLuminance() < 0.179;
                 Brightness newBrightness = brightness ?? (isDark ? Brightness.dark : Brightness.light);
                 SystemUiOverlayStyle overlayStyle;
             BuildContext toHeroContext
         ) => {
             D.assert(animation != null);
-
+            
+            
+            
+            
             D.assert(
                 fromNavBar.componentsKeys.navBarBoxKey.currentContext.owner != null,
                 () => "The from nav bar to Hero must have been mounted in the previous frame"
                         topNavBar: fromNavBar
                     );
             }
-
-            throw new UIWidgetsError($"Unknown flight direction: {flightDirection}");
         };
 
         public static CreateRectTween _linearTranslateWithLargestRectSizeTween = (Rect begin, Rect end) => {
                 end: end.topLeft & largestSize
             );
         };
-//TransitionBuilder 
+
         public static HeroPlaceholderBuilder _navBarHeroLaunchPadBuilder = (
             BuildContext context,
             Size heroSize,
             this.trailing = trailing;
             this.border = border ?? NavBarUtils._kDefaultNavBarBorder;
             this.backgroundColor = backgroundColor;
-            this.brightness = brightness ?? Brightness.dark; //todo ????
+            this.brightness = brightness;
             this.padding = padding;
             this.actionsForegroundColor = actionsForegroundColor;
             this.transitionBetweenRoutes = transitionBetweenRoutes;
         public readonly Widget middle;
 
         public readonly Widget trailing;
-        public readonly Brightness brightness;
+        public readonly Brightness? brightness;
         public readonly Color backgroundColor;
 
         public readonly EdgeInsets padding;
                                           ?? CupertinoTheme.of(context).barBackgroundColor;
             return backgroundColor.alpha == 0xFF;
         }
-
-        /*public override bool? fullObstruction {
-            get { return backgroundColor == null ? null : (bool?) (backgroundColor.alpha == 0xFF); }
-        }*/
-
         public override Size preferredSize {
             get { return Size.fromHeight(NavBarUtils._kNavBarPersistentHeight); }
         }
         }
 
         public override Widget build(BuildContext context) {
-            //Color backgroundColor = widget.backgroundColor ?? CupertinoTheme.of(context).barBackgroundColor;
+            
             Color backgroundColor =
                 CupertinoDynamicColor.resolve(widget.backgroundColor, context) ?? CupertinoTheme.of(context).barBackgroundColor;
 
             );
 
             if (!widget.transitionBetweenRoutes || !NavBarUtils._isTransitionable(context)) {
-                //return NavBarUtils._wrapActiveColor(widget.actionsForegroundColor, context, navBar); // ignore: deprecated_member_use_from_same_package
-                //widget.actionsForegroundColor, // ignore: deprecated_member_use_from_same_package
                 actionsForegroundColor,
                 context,
                 new Builder(
             this.trailing = trailing;
             this.border = border ?? NavBarUtils._kDefaultNavBarBorder;
             this.backgroundColor = backgroundColor;
-            this.brightness = brightness ?? Brightness.dark;
+            this.brightness = brightness;
             this.padding = padding;
             this.actionsForegroundColor = actionsForegroundColor;
             this.transitionBetweenRoutes = transitionBetweenRoutes;
 
         public readonly Color backgroundColor;
 
-        public readonly Brightness brightness;
+        public readonly Brightness? brightness;
 
         public readonly EdgeInsets padding;
 
         }
 
         public override Widget build(BuildContext context) {
-            //Color actionsForegroundColor = widget.actionsForegroundColor ?? CupertinoTheme.of(context).primaryColor; // ignore: deprecated_member_use_from_same_package
             Color actionsForegroundColor = CupertinoDynamicColor.resolve(widget.actionsForegroundColor, context)  // ignore: deprecated_member_use_from_same_package
                                                  ?? CupertinoTheme.of(context).primaryColor;
             _NavigationBarStaticComponents components = new _NavigationBarStaticComponents(
             );
 
             return NavBarUtils._wrapActiveColor(
-                widget.actionsForegroundColor, // ignore: deprecated_member_use_from_same_package
+                actionsForegroundColor,
-                //new SliverPersistentHeader(
                 new MediaQuery(
                     data: MediaQuery.of(context).copyWith(textScaleFactor: 1),
                     child: new SliverPersistentHeader(
                         components: components,
                         userMiddle: widget.middle,
-                        //backgroundColor: widget.backgroundColor ?? CupertinoTheme.of(context).barBackgroundColor,
-                        backgroundColor:CupertinoDynamicColor.resolve(widget.backgroundColor, context) ?? CupertinoTheme.of(context).barBackgroundColor,
+                        backgroundColor: CupertinoDynamicColor.resolve(widget.backgroundColor, context) ?? CupertinoTheme.of(context).barBackgroundColor,
                         brightness: widget.brightness,
                         border: widget.border,
                         padding: widget.padding,
         }
     }
 
-    class _LargeTitleNavigationBarSliverDelegate
-        : SliverPersistentHeaderDelegate {
+    class _LargeTitleNavigationBarSliverDelegate : SliverPersistentHeaderDelegate {
         public _LargeTitleNavigationBarSliverDelegate(
             _NavigationBarStaticComponentsKeys keys = null,
             _NavigationBarStaticComponents components = null,
             float persistentHeight = 0.0f,
             bool alwaysShowMiddle =false
         ) {
-            D.assert(persistentHeight != null);
-            D.assert(alwaysShowMiddle != null);
-            D.assert(transitionBetweenRoutes != null);
-            this.brightness = brightness ?? Brightness.dark;
+            this.brightness = brightness;
             this.padding = padding;
             this.actionsForegroundColor = actionsForegroundColor;
             this.transitionBetweenRoutes = transitionBetweenRoutes;
         public readonly Widget userMiddle;
         public readonly Color backgroundColor;
         public readonly Border border;
-        public Brightness brightness;
+        public readonly Brightness? brightness;
         public readonly EdgeInsets padding;
         public readonly Color actionsForegroundColor;
         public readonly bool transitionBetweenRoutes;
 
             Widget navBar = NavBarUtils._wrapWithBackground(
                 border: border,
-                //backgroundColor: backgroundColor,
                 backgroundColor: CupertinoDynamicColor.resolve(backgroundColor, context),
                 brightness: brightness,
                 child: new DefaultTextStyle(
                                     child: new OverflowBox(
                                         minHeight: 0.0f,
                                         maxHeight: float.PositiveInfinity,
-                                        alignment: Alignment.bottomLeft,
+                                        alignment: AlignmentDirectional.bottomStart,
                                         child: new Padding(
                                             padding: EdgeInsets.only(
                                                 left: NavBarUtils._kNavBarEdgePadding,
                 transitionOnUserGestures: true,
                 child: new _TransitionableNavigationBar(
                     componentsKeys: keys,
-                    //backgroundColor: backgroundColor,
                     backgroundColor: CupertinoDynamicColor.resolve(backgroundColor, context),
                     backButtonTextStyle: CupertinoTheme.of(context).textTheme.navActionTextStyle,
                     titleTextStyle: CupertinoTheme.of(context).textTheme.navTitleTextStyle,
         }
 
         public readonly _NavigationBarStaticComponents components;
-
         public readonly EdgeInsets padding;
         public readonly bool middleVisible;
 
                     style: CupertinoTheme.of(context).textTheme.navTitleTextStyle,
                     child: middle
                 );
-                middle = new AnimatedOpacity(
-                    opacity: middleVisible ? 1.0f : 0.0f,
-                    duration: NavBarUtils._kNavBarTitleFadeDuration,
-                    child: middle
-                );
+                middle = middleVisible == null
+                    ? middle
+                    : new AnimatedOpacity(
+                        opacity: middleVisible ? 1.0f : 0.0f,
+                        duration: NavBarUtils._kNavBarTitleFadeDuration,
+                        child: middle
+                    );
             }
 
             Widget leading = components.leading;
 
     class _NavigationBarStaticComponents {
         public _NavigationBarStaticComponents(
-            _NavigationBarStaticComponentsKeys keys,
-            ModalRoute route,
-            Widget userLeading,
-            string previousPageTitle,
-            Widget userMiddle,
-            Widget userTrailing,
-            Widget userLargeTitle,
-            EdgeInsets padding,
-            bool large
+            bool large,
+            _NavigationBarStaticComponentsKeys keys = null,
+            ModalRoute route = null,
+            Widget userLeading = null,
+            string previousPageTitle = null,
+            Widget userMiddle = null,
+            Widget userTrailing = null,
+            Widget userLargeTitle = null,
+            EdgeInsets padding = null
+           
         ) {
             leading = createLeading(
                 leadingKey: keys.leadingKey,
         }
 
         static Widget _derivedTitle(
-            bool automaticallyImplyTitle,
-            ModalRoute currentRoute
+            bool automaticallyImplyTitle ,
+            ModalRoute currentRoute = null
-                route.title != null) {
+                ((CupertinoPageRoute)route).title != null) {
                 return new Text(route.title);
             }
 
         public readonly KeyedSubtree leading;
 
         static KeyedSubtree createLeading(
-            GlobalKey leadingKey,
-            Widget userLeading,
-            ModalRoute route,
-            EdgeInsets padding
+            GlobalKey leadingKey = null,
+            Widget userLeading = null,
+            ModalRoute route = null,
+            EdgeInsets padding = null
         ) {
             Widget leadingContent = null;
 
         public readonly KeyedSubtree backChevron;
 
         static KeyedSubtree createBackChevron(
-            GlobalKey backChevronKey,
-            Widget userLeading,
-            ModalRoute route,
-            bool automaticallyImplyLeading
+            bool automaticallyImplyLeading,
+            GlobalKey backChevronKey = null,
+            Widget userLeading = null,
+            ModalRoute route = null
         ) {
             if (
                 userLeading != null ||
         public readonly KeyedSubtree backLabel;
 
         static KeyedSubtree createBackLabel(
-            GlobalKey backLabelKey,
-            Widget userLeading,
-            ModalRoute route,
-            string previousPageTitle
+            GlobalKey backLabelKey = null,
+            Widget userLeading = null,
+            ModalRoute route = null,
+            string previousPageTitle = null
         ) {
             if (
                 userLeading != null ||
         public readonly KeyedSubtree middle;
 
         static KeyedSubtree createMiddle(
-            GlobalKey middleKey,
-            Widget userMiddle,
-            Widget userLargeTitle,
-            ModalRoute route
+            GlobalKey middleKey = null,
+            Widget userMiddle = null,
+            Widget userLargeTitle = null, 
+            ModalRoute route = null
         ) {
             Widget middleContent = userMiddle;
 
 
-            middleContent = middleContent ?? _derivedTitle(
-                                automaticallyImplyTitle: automaticallyImplyTitle,
-                                currentRoute: route
-                            );
+            middleContent = middleContent ?? _derivedTitle(automaticallyImplyTitle: automaticallyImplyTitle, currentRoute: route);
 
             if (middleContent == null) {
                 return null;
         public readonly KeyedSubtree trailing;
 
         static KeyedSubtree createTrailing(
-            GlobalKey trailingKey,
-            Widget userTrailing,
-            EdgeInsets padding
+            GlobalKey trailingKey = null,
+            Widget userTrailing = null,
+            EdgeInsets padding = null
         ) {
             if (userTrailing == null) {
                 return null;
         public readonly KeyedSubtree largeTitle;
 
         static KeyedSubtree createLargeTitle(
-            GlobalKey largeTitleKey,
-            Widget userLargeTitle,
-            ModalRoute route
+            GlobalKey largeTitleKey = null,
+            Widget userLargeTitle = null,
+            ModalRoute route = null
         ) {
             if (!large) {
                 return null;
                                            automaticallyImplyTitle: automaticImplyTitle,
-                                           currentRoute: route
-                                       );
-
+                                           currentRoute: route);
-
             return new KeyedSubtree(
                 key: largeTitleKey,
                 child: largeTitleContent
             Color color = null,
             string previousPageTitle = null,
             VoidCallback onPressed = null
-            
         ):base(key:key) {
             _backChevron = null;
             _backLabel = null;
             Widget _backChevron,
             Widget _backLabel
         ) {
-
-            );
-
+            ); 
         }
 
         public readonly Color color;
                     () => "CupertinoNavigationBarBackButton should only be used in routes that can be popped"
                 );
             }
-
-            //    actionTextStyle = actionTextStyle.copyWith(color: color);
                 actionTextStyle = actionTextStyle.copyWith(color: CupertinoDynamicColor.resolve(color, context));
             }
 
                 ),
                 padding: EdgeInsets.zero,
                 onPressed: () => {
-                    //Navigator.maybePop(context);
                     if (onPressed != null) {
                         onPressed();
                     } else {
         public _BackChevron(Key key = null) : base(key: key) { }
 
         public override Widget build(BuildContext context) {
+            TextDirection textDirection = Directionality.of(context);
-                    text: char.ConvertFromUtf32(CupertinoIcons.back.codePoint),
+                    text:new string(new[] {(char) CupertinoIcons.back.codePoint}),
+                        //package: CupertinoIcons.back.fontPackage
+            var matrix = Matrix4.identity();
+            matrix.scale(-1.0f, 1.0f, 1.0f);
+            switch (textDirection) {
+                case TextDirection.rtl:
+                    iconWidget = new Transform(
+                        transform: matrix,
+                        alignment: Alignment.center,
+                        transformHitTests: false,
+                        child: iconWidget
+                    ) as Widget;
+                    break;
+                case TextDirection.ltr:
+                    break;
+            }
 
             return iconWidget;
         }
             string specifiedPreviousTitle = null,
             ModalRoute route = null
         ) : base(key: key) {
-            //D.assert(route != null);
             this.specifiedPreviousTitle = specifiedPreviousTitle;
             this.route = route;
         }
             }
 
             return new Align(
-                alignment: Alignment.centerLeft,
+                alignment: AlignmentDirectional.centerStart,
                 widthFactor: 1.0f,
                 child: textWidget
             );
             if (specifiedPreviousTitle != null) {
                 return _buildPreviousTitleWidget(context, specifiedPreviousTitle, null);
             }
-            //else if (route is CupertinoPageRoute cupertinoRoute) {
             else if (route is CupertinoPageRoute && !route.isFirst) {
                 CupertinoPageRoute cupertinoRoute = route as CupertinoPageRoute;
                 return new ValueListenableBuilder<string>(
             bool? largeExpanded = null,
             Widget child = null
         ) : base(key: componentsKeys.navBarBoxKey) {
+            
-
+            
             this.componentsKeys = componentsKeys;
             this.backgroundColor = backgroundColor;
             this.backButtonTextStyle = backButtonTextStyle;
 
         public RenderBox renderBox {
             get {
-               // RenderBox box = (RenderBox) componentsKeys.navBarBoxKey.currentContext.findRenderObject();
-               RenderBox box = componentsKeys.navBarBoxKey.currentContext.findRenderObject() as RenderBox;
+                RenderBox box = componentsKeys.navBarBoxKey.currentContext.findRenderObject() as RenderBox;
                D.assert(
                     box.attached,
                     () => "_TransitionableNavigationBar.renderBox should be called when building " +
 
     class _NavigationBarTransition : StatelessWidget {
         public _NavigationBarTransition(
-            Animation<float> animation,
-            _TransitionableNavigationBar topNavBar,
-            _TransitionableNavigationBar bottomNavBar
+            Animation<float> animation = null,
+            _TransitionableNavigationBar topNavBar = null,
+            _TransitionableNavigationBar bottomNavBar = null
+            
-                begin: this.bottomNavBar.renderBox.size.height,
-                end: this.topNavBar.renderBox.size.height
+                begin: bottomNavBar.renderBox.size.height,
+                end: topNavBar.renderBox.size.height
-                begin: this.bottomNavBar.backgroundColor,
-                end: this.topNavBar.backgroundColor
+                begin: bottomNavBar.backgroundColor,
+                end: topNavBar.backgroundColor
-                begin: this.bottomNavBar.border,
-                end: this.topNavBar.border
+                begin: bottomNavBar.border,
+                end: topNavBar.border
             );
         }
 

com.unity.uiwidgets/Runtime/cupertino/picker.cs

         public const float _kDefaultDiameterRatio = 1.35f;
         public const float _kDefaultPerspective = 0.004f;
         public const float _kForegroundScreenOpacityFraction = 0.7f;
+        public const float _kOverAndUnderCenterOpacity = 0.447f;
-            float itemExtent,
-            ValueChanged<int> onSelectedItemChanged,
-            List<Widget> children = null,
-            float diameterRatio = CupertinoPickerUtils._kDefaultDiameterRatio,
+            float? diameterRatio = null,
-            bool looping = false,
-            ListWheelChildDelegate childDelegate = null
+            float? squeeze = null,
+            float? itemExtent = null,
+            ValueChanged<int> onSelectedItemChanged = null,
+            List<Widget> children = null, 
+            bool looping = false
-            D.assert(children != null || childDelegate != null);
-            D.assert(diameterRatio > 0.0, () => RenderListWheelViewport.diameterRatioZeroMessage);
+            diameterRatio = diameterRatio == null ? CupertinoPickerUtils._kDefaultDiameterRatio : diameterRatio;
+            squeeze = squeeze == null ? CupertinoDatePickerUtils._kSqueeze : squeeze;
+            D.assert(children != null);
+            D.assert(diameterRatio > 0.0f, ()=>RenderListWheelViewport.diameterRatioZeroMessage);
+            D.assert(itemExtent != null);
-
-            this.childDelegate = childDelegate ?? (looping
-                                     ? (ListWheelChildDelegate) new ListWheelChildLoopingListDelegate(
-                                         children: children)
-                                     : (ListWheelChildDelegate) new ListWheelChildListDelegate(children: children));
-
-            this.itemExtent = itemExtent;
-            this.onSelectedItemChanged = onSelectedItemChanged;
+            D.assert(squeeze > 0);
-            this.backgroundColor = backgroundColor ?? CupertinoPickerUtils._kDefaultBackground;
+            this.backgroundColor = backgroundColor;
+            this.squeeze = squeeze;
+            this.itemExtent = itemExtent;
+            this.onSelectedItemChanged = onSelectedItemChanged;
+            childDelegate = looping
+                ? (ListWheelChildDelegate) new ListWheelChildLoopingListDelegate(children: children)
+                : new ListWheelChildListDelegate(children: children);
+
+
-            float itemExtent,
-            ValueChanged<int> onSelectedItemChanged,
-            IndexedWidgetBuilder itemBuilder,
-            float diameterRatio = CupertinoPickerUtils._kDefaultDiameterRatio,
+            float? diameterRatio = null,
+            float? squeeze = null,
+            float? itemExtent = null,
+            ValueChanged<int> onSelectedItemChanged = null,
+            IndexedWidgetBuilder itemBuilder = null,
+            diameterRatio = diameterRatio == null ? CupertinoPickerUtils._kDefaultDiameterRatio : diameterRatio;
+            squeeze = squeeze == null ? CupertinoDatePickerUtils._kSqueeze : squeeze;
-            D.assert(diameterRatio > 0.0f, () => RenderListWheelViewport.diameterRatioZeroMessage);
+            D.assert(diameterRatio > 0.0f,()=> RenderListWheelViewport.diameterRatioZeroMessage);
+            D.assert(itemExtent != null);
-
-            return new CupertinoPicker(
-                itemExtent: itemExtent,
-                onSelectedItemChanged: onSelectedItemChanged,
-                key: key,
-                diameterRatio: diameterRatio,
-                backgroundColor: backgroundColor,
-                offAxisFraction: offAxisFraction,
-                useMagnifier: useMagnifier,
-                magnification: magnification,
-                scrollController: scrollController,
-                childDelegate: new ListWheelChildBuilderDelegate(builder: itemBuilder, childCount: childCount)
-            );
+            D.assert(squeeze > 0);
+            CupertinoPicker picker = new CupertinoPicker(
+                key, 
+                diameterRatio ,
+                backgroundColor,
+                offAxisFraction ,
+                useMagnifier ,
+                magnification ,
+                scrollController,
+                squeeze ,
+                itemExtent,
+                onSelectedItemChanged);
+                picker.childDelegate = new ListWheelChildBuilderDelegate(builder: itemBuilder, childCount: childCount);
+            return picker;
-        public readonly float diameterRatio;
+        public readonly float? diameterRatio;
-        public readonly float itemExtent;
+        public readonly float? itemExtent;
-        public readonly ListWheelChildDelegate childDelegate;
+        public ListWheelChildDelegate childDelegate;
+        public readonly float? squeeze;
 
         public override State createState() {
             return new _CupertinoPickerState();
     class _CupertinoPickerState : State<CupertinoPicker> {
         FixedExtentScrollController _controller;
-
+        int _lastHapticIndex;
         public override void initState() {
             base.initState();
             if (widget.scrollController == null) {
         }
 
         void _handleSelectedItemChanged(int index) {
+            //bool hasSuitableHapticHardware;
+            /*switch (defaultTargetPlatform) {
+                case TargetPlatform.iOS:
+                    hasSuitableHapticHardware = true;
+                    break;
+                case TargetPlatform.android:
+                case TargetPlatform.fuchsia:
+                case TargetPlatform.linux:
+                case TargetPlatform.macOS:
+                case TargetPlatform.windows:
+                    hasSuitableHapticHardware = false;
+                    break;
+            }*/
+            /*D.assert(hasSuitableHapticHardware != null);
+            if (hasSuitableHapticHardware && index != _lastHapticIndex) {
+                _lastHapticIndex = index;
+                HapticFeedback.selectionClick();
+            }*/
+
-
-        Widget _buildGradientScreen() {
-            if (widget.backgroundColor != null && widget.backgroundColor.alpha < 255) {
-                return new Container();
-            }
+        Widget _buildMagnifierScreen() {
+            Color resolvedBorderColor = CupertinoDynamicColor.resolve(CupertinoPickerUtils._kHighlighterBorder, context);
-            Color widgetBackgroundColor = widget.backgroundColor ?? new Color(0xFFFFFFFF);
-            return Positioned.fill(
-                child: new IgnorePointer(
+            return new IgnorePointer(
+                child: new Center(
-                            gradient: new LinearGradient(
-                                colors: new List<Color> {
-                                    widgetBackgroundColor,
-                                    widgetBackgroundColor.withAlpha(0xF2),
-                                    widgetBackgroundColor.withAlpha(0xDD),
-                                    widgetBackgroundColor.withAlpha(0),
-                                    widgetBackgroundColor.withAlpha(0),
-                                    widgetBackgroundColor.withAlpha(0xDD),
-                                    widgetBackgroundColor.withAlpha(0xF2),
-                                    widgetBackgroundColor,
-                                },
-                                stops: new List<float> {
-                                    0.0f, 0.05f, 0.09f, 0.22f, 0.78f, 0.91f, 0.95f, 1.0f
-                                },
-                                begin: Alignment.topCenter,
-                                end: Alignment.bottomCenter
-                            )
-                        )
-                    )
-                )
-            );
-        }
-
-        Widget _buildMagnifierScreen() {
-            Color foreground = widget.backgroundColor?.withAlpha(
-                (int) (widget.backgroundColor.alpha * CupertinoPickerUtils._kForegroundScreenOpacityFraction)
-            );
-
-            return new IgnorePointer(
-                child: new Column(
-                    children: new List<Widget> {
-                        new Expanded(
-                            child: new Container(
-                                color: foreground
+                            border: new Border(
+                                top: new BorderSide(width: 0.0f, color: resolvedBorderColor),
+                                bottom: new BorderSide(width: 0.0f, color: resolvedBorderColor)
-                        new Container(
-                            decoration: new BoxDecoration(
-                                border: new Border(
-                                    top: new BorderSide(width: 0.0f, color: CupertinoPickerUtils._kHighlighterBorder),
-                                    bottom: new BorderSide(width: 0.0f, color: CupertinoPickerUtils._kHighlighterBorder)
-                                )
-                            ),
-                            constraints: BoxConstraints.expand(
-                                height: widget.itemExtent * widget.magnification
-                            )
-                        ),
-                        new Expanded(
-                            child: new Container(
-                                color: foreground
-                            )
-                        ),
-                    }
-                )
-            );
-        }
-
-        Widget _buildUnderMagnifierScreen() {
-            Color foreground = widget.backgroundColor?.withAlpha(
-                (int) (widget.backgroundColor.alpha * CupertinoPickerUtils._kForegroundScreenOpacityFraction)
-            );
-
-            return new Column(
-                children: new List<Widget> {
-                    new Expanded(child: new Container()),
-                    new Container(
-                        color: foreground,
-                    ),
-                    new Expanded(child: new Container())
-                }
+                    )
+                )
+        public override Widget build(BuildContext context) {
+            Color resolvedBackgroundColor = CupertinoDynamicColor.resolve(widget.backgroundColor, context);
-        Widget _addBackgroundToChild(Widget child) {
-            return new DecoratedBox(
-                decoration: new BoxDecoration(
-                    color: widget.backgroundColor
-                ),
-                child: child
-            );
-        }
-
-        public override Widget build(BuildContext context) {
-            Widget result = new Stack(
-                children: new List<Widget> {
-                    Positioned.fill(
+            Widget result = new DefaultTextStyle(
+                style: CupertinoTheme.of(context).textTheme.pickerTextStyle,
+                child: new Stack(
+                    children: new List<Widget>{
+                Positioned.fill(
+                    child: new _CupertinoPickerSemantics(
+                        scrollController: widget.scrollController ?? _controller,
-                            physics: new FixedExtentScrollPhysics(),
-                            diameterRatio: widget.diameterRatio,
+                            physics: new FixedExtentScrollPhysics(), 
+                            diameterRatio: (float)widget.diameterRatio,
-                            itemExtent: widget.itemExtent,
+                            overAndUnderCenterOpacity: CupertinoPickerUtils._kOverAndUnderCenterOpacity,
+                            itemExtent: (float)widget.itemExtent,
+                            squeeze: (float)widget.squeeze,
+                            )
-                    ),
-                    _buildGradientScreen(),
-                    _buildMagnifierScreen()
-                }
-            );
-            if (widget.backgroundColor != null && widget.backgroundColor.alpha < 255) {
-                result = new Stack(
-                    children: new List<Widget> {
-                        _buildUnderMagnifierScreen(), _addBackgroundToChild(result),
+                    ), 
+                _buildMagnifierScreen(),
+                
+                    )
+            return new DecoratedBox(
+                decoration: new BoxDecoration(color: resolvedBackgroundColor),
+                child: result
+            );
+        }
+
+
+        
+    }
+    public class _CupertinoPickerSemantics : SingleChildRenderObjectWidget { 
+        public _CupertinoPickerSemantics(
+            Key key = null,
+            Widget child = null,
+            FixedExtentScrollController scrollController = null
+            ) : base(key: key, child: child) {
+            this.scrollController = scrollController;
+        }
+    
+        
+        public readonly FixedExtentScrollController scrollController;
+
+        public override RenderObject createRenderObject(BuildContext context) {
+            return new _RenderCupertinoPickerSemantics(scrollController, Directionality.of(context));
+        }
+
+        public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
+            renderObject = (_RenderCupertinoPickerSemantics) renderObject;
+            ((_RenderCupertinoPickerSemantics)renderObject).textDirection = Directionality.of(context);
+            ((_RenderCupertinoPickerSemantics) renderObject).controller = scrollController;
+        }
+    }
+    public class _RenderCupertinoPickerSemantics : RenderProxyBox { 
+        public _RenderCupertinoPickerSemantics(FixedExtentScrollController controller, TextDirection textDirection) { 
+            this.controller = controller;
+            _textDirection = textDirection;
+        }
+
+        public FixedExtentScrollController controller {
+            get { return _controller; }
+            set {
+                if (value == _controller)
+                    return;
+                if (_controller != null)
+                    _controller.removeListener(_handleScrollUpdate);
+                else
+                    _currentIndex = value.initialItem == 0 ? 0 : value.initialItem ;
+                value.addListener(_handleScrollUpdate);
+                _controller = value;
-            else {
-                result = _addBackgroundToChild(result);
+        }
+        FixedExtentScrollController _controller;
+
+        public TextDirection textDirection {
+            get { return _textDirection; }
+            set {
+                if (textDirection == value)
+                    return;
+                _textDirection = value;
+                //markNeedsSemanticsUpdate();
+        }
+        TextDirection _textDirection;
-            return result;
+        int _currentIndex = 0;
+        void _handleIncrease() {
+            controller.jumpToItem(_currentIndex + 1);
+        }
+        void _handleDecrease() { 
+            if (_currentIndex == 0) 
+                return; 
+            controller.jumpToItem(_currentIndex - 1);
+        void _handleScrollUpdate() {
+            if (controller.selectedItem == _currentIndex)
+                return;
+            _currentIndex = controller.selectedItem;
+            //markNeedsSemanticsUpdate();
+        } 
+        
+       
+
 }

com.unity.uiwidgets/Runtime/cupertino/text_field.cs

                 padding: widget.padding,
                 child: new RepaintBoundary(
                     child: new EditableText(
+                        smartDashesType: SmartDashesType.disabled,
+                        smartQuotesType:SmartQuotesType.disabled,
                         key: _editableTextKey,
                         controller: controller,
                         focusNode: _effectiveFocusNode,

com.unity.uiwidgets/Runtime/cupertino/text_selection.cs

             );
         }
 
-        public override Size handleSize {
-            get { return CupertinoTextSelectionUtils._kSelectionOffset; }
-        }
-
         public override Offset getHandleAnchor(TextSelectionHandleType type, float textLineHeight) {
             Size handleSize = getHandleSize(textLineHeight);
             switch (type) {

com.unity.uiwidgets/Runtime/cupertino/text_theme.cs

             TextStyle pickerTextStyle = null,
             TextStyle dateTimePickerTextStyle = null
         ) {
+            _defaults = defaults ?? new _TextThemeDefaultsBuilder(CupertinoColors.label, CupertinoColors.inactiveGray);
+            D.assert((_navActionTextStyle != null && _actionTextStyle != null) || _primaryColor != null);
             _textStyle = textStyle;
             _actionTextStyle = actionTextStyle;
             _tabLabelTextStyle = tabLabelTextStyle;
             _pickerTextStyle = pickerTextStyle;
             _dateTimePickerTextStyle = dateTimePickerTextStyle;
-            _defaults = defaults ??
-                        //new _TextThemeDefaultsBuilder(Color.white,Color.white);
-                        new _TextThemeDefaultsBuilder(CupertinoColors.label, CupertinoColors.inactiveGray);
-            D.assert((_navActionTextStyle != null && _actionTextStyle != null) || _primaryColor != null);
-
         }
         /*public static CupertinoTextThemeData _raw(
             _TextThemeDefaultsBuilder _defaults,
 
 
         public new CupertinoTextThemeData copyWith(
-            Color primaryColor,
-            TextStyle textStyle,
-            TextStyle actionTextStyle,
-            TextStyle tabLabelTextStyle,
-            TextStyle navTitleTextStyle,
-            TextStyle navLargeTitleTextStyle,
-            TextStyle navActionTextStyle,
-            TextStyle pickerTextStyle,
-            TextStyle dateTimePickerTextStyle
+            Color primaryColor = null,
+            TextStyle textStyle = null,
+            TextStyle actionTextStyle = null,
+            TextStyle tabLabelTextStyle = null,
+            TextStyle navTitleTextStyle = null,
+            TextStyle navLargeTitleTextStyle = null,
+            TextStyle navActionTextStyle = null,
+            TextStyle pickerTextStyle = null,
+            TextStyle dateTimePickerTextStyle = null
         ) {
             return new CupertinoTextThemeData(
                 _defaults,

com.unity.uiwidgets/Runtime/gestures/force_press.cs

         }
 
         public GestureForcePressStartCallback onStart;
-        GestureForcePressUpdateCallback onUpdate;
-        GestureForcePressPeakCallback onPeak;
+        public GestureForcePressUpdateCallback onUpdate;
+        public GestureForcePressPeakCallback onPeak;
         public GestureForcePressEndCallback onEnd;
         public readonly float startPressure;
         public readonly float peakPressure;

com.unity.uiwidgets/Runtime/material/dropdown.cs

             return Future.value(false).to<bool>();
         }
 
+        public void didChangeAccessibilityFeatures() {
+            //FIX ME!!!!
+            throw new NotImplementedException();
+        }
+
         public void didChangePlatformBrightness() {
         }
 

com.unity.uiwidgets/Runtime/material/text_field.cs

                     autofocus: widget.autofocus,
                     obscureText: widget.obscureText,
                     autocorrect: widget.autocorrect,
-                    //TODO: update this
-                    // smartDashesType: widget.smartDashesType,
-                    // smartQuotesType: widget.smartQuotesType,
+                    smartDashesType: widget.smartDashesType,
+                    smartQuotesType: widget.smartQuotesType,
                     enableSuggestions: widget.enableSuggestions,
                     maxLines: widget.maxLines,
                     minLines: widget.minLines,
                     onSelectionHandleTapped: _handleSelectionHandleTapped,
                     inputFormatters: formatters,
                     rendererIgnoresPointer: true,
-                    cursorWidth: widget.cursorWidth,
+                    cursorWidth: widget.cursorWidth.Value,
                     cursorRadius: cursorRadius,
                     cursorColor: cursorColor,
                     selectionHeightStyle: widget.selectionHeightStyle,

com.unity.uiwidgets/Runtime/material/text_selection.cs

                 MaterialUtils._kHandleSize);
         }
 
-        public override Size handleSize {
-            get {
-                return new Size(MaterialUtils._kHandleSize,
-                    MaterialUtils._kHandleSize);
-            }
-        }
-
         public override Widget buildToolbar(BuildContext context, Rect globalEditableRegion, float textLineHeight,
             Offset selectionMidpoint, List<TextSelectionPoint> endpoints, TextSelectionDelegate selectionDelegate) {
             D.assert(WidgetsD.debugCheckHasMediaQuery(context));

com.unity.uiwidgets/Runtime/material/user_accounts_drawer_header.cs

                         width: UserAccountsDrawerHeaderUtils._kAccountDetailsHeight,
                         child: new Center(
                             child: Transform.rotate(
-                                degree: _animation.value * Mathf.PI,
+                                angle: _animation.value * Mathf.PI,
                                 child: new Icon(
                                     Icons.arrow_drop_down,
                                     color: widget.arrowColor

com.unity.uiwidgets/Runtime/painting/alignment.cs

         }
 
         public override Alignment resolve(TextDirection? direction) {
-            D.assert(direction != null);
+            direction = direction ?? TextDirection.ltr;
             switch (direction) {
                 case TextDirection.rtl:
                     return new Alignment(_x - _start, _y);

com.unity.uiwidgets/Runtime/painting/basic_types.cs

 using System;
+using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.ui;
 using Unity.UIWidgets.widgets;
 
             Axis axis,
             bool reverse) {
             switch (axis) {
-                case Axis.horizontal:
+                /*case Axis.horizontal:
+                    return reverse ? AxisDirection.up : AxisDirection.down;*/
+                case Axis.horizontal:
+                    D.assert(WidgetsD.debugCheckHasDirectionality(context));
+                    TextDirection textDirection = Directionality.of(context);
+                    AxisDirection axisDirection = (AxisDirection)textDirectionToAxisDirection(textDirection);
+                    return reverse ? flipAxisDirection(axisDirection) : axisDirection;
+                case Axis.vertical:
+            return null;
+        }
+        public static AxisDirection? textDirectionToAxisDirection(TextDirection textDirection) {
+            D.assert(textDirection != null);
+            switch (textDirection) {
+                case TextDirection.rtl:
+                    return AxisDirection.left;
+                case TextDirection.ltr:
+                    return AxisDirection.right;
+            }
+            return null;
+        }
+        public static AxisDirection? flipAxisDirection(AxisDirection axisDirection) {
+            D.assert(axisDirection != null);
+            switch (axisDirection) {
+                case AxisDirection.up:
+                    return AxisDirection.down;
+                case AxisDirection.right:
+                    return AxisDirection.left;
+                case AxisDirection.down:
+                    return AxisDirection.up;
+                case AxisDirection.left:
+                    return AxisDirection.right;
+            }
             return null;
         }
     }

com.unity.uiwidgets/Runtime/painting/edge_insets.cs

         }
 
 
-        float horizontal {
+        public float horizontal {
-        float vertical {
+        public float vertical {
             get { return _top + _bottom; }
         }
 
         public static EdgeInsetsDirectional fromSTEB(float start, float top, float end, float bottom) {
             return new EdgeInsetsDirectional(start, top, end, bottom);
         }
-
-        public static EdgeInsetsDirectional only(float start = 0, float top = 0, float end = 0, float bottom = 0) {
-            return new EdgeInsetsDirectional(start, top, end, bottom);
+        
+        public static EdgeInsetsDirectional only( float start = 0.0f, float top = 0.0f,float end = 0.0f,float bottom = 0.0f) {
+            return new EdgeInsetsDirectional(start,top,end,bottom);
         }
 
         static EdgeInsetsDirectional zero = only();

com.unity.uiwidgets/Runtime/painting/image_cache.cs

             );
         }
 
-        bool containsKey(Object key) {
+        public bool containsKey(Object key) {
             return _pendingImages[key] != null || _cache[key] != null;
         }
 

com.unity.uiwidgets/Runtime/painting/image_provider.cs

             return new ImageStream();
         }
 
-        void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, T key,
+        public virtual void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, T key,
             ImageErrorListener handleError) {
             if (stream.completer != null) {
                 ImageStreamCompleter completerEdge = PaintingBinding.instance.imageCache.putIfAbsent(

com.unity.uiwidgets/Runtime/painting/text_painter.cs

 
     public class TextPainter {
         InlineSpan _text;
-        TextAlign _textAlign;
+        TextAlign? _textAlign;
         TextDirection? _textDirection;
         float _textScaleFactor;
         Paragraph _layoutTemplate;
             _textHeightBehavior = textHeightBehavior;
         }
 
-        void markNeedsLayout() {
+        public void markNeedsLayout() {
             _paragraph = null;
             _needsLayout = true;
             _previousCaretPosition = null;
             }
         }
 
-        public TextAlign textAlign {
+        public TextAlign? textAlign {
             get { return _textAlign; }
             set {
                 if (_textAlign == value) {
             }
         }
 
+        public List<TextBox> inlinePlaceholderBoxes {
+            get {
+                return _inlinePlaceholderBoxes;
+            }
+        }
+
-        List<float> inlinePlaceholderScales {
-            get { return _inlinePlaceholderScales; }
+        public List<float> inlinePlaceholderScales {
+            get {
+                return _inlinePlaceholderScales;
+            }
         }
 
         List<float> _inlinePlaceholderScales;
             }
         }
 
-        void setPlaceholderDimensions(List<PlaceholderDimensions> value) {
+        public void setPlaceholderDimensions(List<PlaceholderDimensions> value) {
             if (value == null || value.isEmpty() || value.equalsList(_placeholderDimensions)) {
                 return;
             }
             return _paragraph.getWordBoundary(position);
         }
 
-        TextRange getLineBoundary(TextPosition position) {
+        public TextRange getLineBoundary(TextPosition position) {
             D.assert(!_needsLayout);
             return _paragraph.getLineBoundary(position);
         }
         bool _isUnicodeDirectionality(int? value) {
             return value == 0x200F || value == 0x200E;
         }
+        
+         public int getOffsetAfter(int offset) {
+            int? nextCodeUnit = _text.codeUnitAt(offset);
+            if (nextCodeUnit == null)
+                return 0;
+            // TODO(goderbauer): doesn't handle extended grapheme clusters with more than one Unicode scalar value (https://github.com/flutter/flutter/issues/13404).
+            return _isUtf16Surrogate(nextCodeUnit.Value) ? offset + 2 : offset + 1;
+        }
+         
+         public int getOffsetBefore(int offset) {
+             int? prevCodeUnit = _text.codeUnitAt(offset - 1);
+             if (prevCodeUnit == null)
+                 return 0;
+             // TODO(goderbauer): doesn't handle extended grapheme clusters with more than one Unicode scalar value (https://github.com/flutter/flutter/issues/13404).
+             return _isUtf16Surrogate(prevCodeUnit.Value) ? offset - 2 : offset - 1;
+         }
+        
     }
 }

com.unity.uiwidgets/Runtime/painting/text_style.cs

         }
 
         public ParagraphStyle getParagraphStyle(
-            TextAlign textAlign,
-            TextDirection textDirection,
+            TextAlign? textAlign = null,
+            TextDirection? textDirection = null,
             float? textScaleFactor = 1.0f,
             string ellipsis = null,
             int? maxLines = null,

com.unity.uiwidgets/Runtime/rendering/animated_size.cs

             TimeSpan? duration = null,
             TimeSpan? reverseDuration = null,
             Curve curve = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null,
-        ) : base(child: child, alignment: alignment ?? Alignment.center) {
+        ) : base(child: child, alignment: alignment ?? Alignment.center, textDirection: textDirection) {
+            curve = curve ?? Curves.linear;
-
-            curve = curve ?? Curves.linear;
             _vsync = vsync;
             _controller = new AnimationController(
                 vsync: this.vsync,
             }
 
             child.layout(constraints, parentUsesSize: true);
-
+            
             switch (_state) {
                 case RenderAnimatedSizeState.start:
                     _layoutStart();

com.unity.uiwidgets/Runtime/rendering/binding.cs

         public void initRenderView() {
             D.assert(renderView == null);
             renderView = new RenderView(configuration: createViewConfiguration());
-            renderView.scheduleInitialFrame();
+            renderView.prepareInitialFrame();
         }
 
         public MouseTracker mouseTracker {
         }
 
         protected virtual void handleMetricsChanged() {
+            D.assert(renderView != null);
             renderView.configuration = createViewConfiguration();
             scheduleForcedFrame();
         }
             _mouseTracker.schedulePostFrameCheck();
         }
 
+        int _firstFrameDeferredCount = 0;
+        bool _firstFrameSent = false;
+        bool sendFramesToEngine {
+            get {
+                return _firstFrameSent || _firstFrameDeferredCount == 0;
+            }
+        }
+        
+        void deferFirstFrame() {
+            D.assert(_firstFrameDeferredCount >= 0);
+            _firstFrameDeferredCount += 1;
+        }
+
+        void allowFirstFrame() {
+            D.assert(_firstFrameDeferredCount > 0);
+            _firstFrameDeferredCount -= 1;
+            if (!_firstFrameSent)
+                scheduleWarmUpFrame();
+        }
+        
+        void resetFirstFrameSent() {
+            _firstFrameSent = false;
+        }
+        
         readonly protected bool inEditorWindow;
         
 
         }*/
 
         protected virtual void drawFrame() {
+            D.assert(renderView != null);
-            renderView.compositeFrame();
+            if (sendFramesToEngine) {
+                renderView.compositeFrame();
+                _firstFrameSent = true;
+            }
         }
 
         public override void hitTest(HitTestResult result, Offset position) {

com.unity.uiwidgets/Runtime/rendering/box.cs

             float maxWidth = float.PositiveInfinity,
             float minHeight = 0.0f,
             float maxHeight = float.PositiveInfinity) {
-            D.assert(minWidth != null);
-            D.assert(maxWidth != null);
-            D.assert(minHeight != null);
-            D.assert (maxHeight != null);
             this.minWidth = minWidth;
             this.maxWidth = maxWidth;
             this.minHeight = minHeight;
         }
 
         public bool addWithRawTransform(
-            Matrix4 transform,
-            Offset position,
-            BoxHitTest hitTest
+            Matrix4 transform = null,
+            Offset position = null,
+            BoxHitTest hitTest = null
         ) {
             D.assert(hitTest != null);
             Offset transformedPosition = position == null || transform == null

com.unity.uiwidgets/Runtime/rendering/custom_layout.cs

 
         MultiChildLayoutDelegate _delegate;
         
-        /*public override void attach(PipelineOwner owner) {
+        public override void attach(object owner) {
             base.attach(owner);
             _delegate?._relayout?.addListener(markNeedsLayout);
         }
             base.detach();
-        }*/
+        }
 
         Size _getSize(BoxConstraints constraints) {
             D.assert(constraints.debugAssertIsValid());

com.unity.uiwidgets/Runtime/rendering/custom_paint.cs

 
                 if (debugNewCanvasSaveCount < debugPreviousCanvasSaveCount) {
                     throw new UIWidgetsError(new List<DiagnosticsNode>{
-                        new ErrorSummary($"The {painter} custom painter called canvas.restore() " +
+                        new ErrorSummary(
+                            $"The {painter} custom painter called canvas.restore() " +
                             $"{debugPreviousCanvasSaveCount - debugNewCanvasSaveCount} more " +
                             "times than it called canvas.save() or canvas.saveLayer()."
                         ),

com.unity.uiwidgets/Runtime/rendering/debug.cs

+using Unity.UIWidgets.painting;
+
+        public static bool debugRepaintTextRainbowEnabled = false;
+        static readonly HSVColor _kDebugDefaultRepaintColor = HSVColor.fromAHSV(0.4f, 60.0f, 1.0f, 1.0f);
+        public static HSVColor debugCurrentRepaintColor = _kDebugDefaultRepaintColor;
     }
 }

com.unity.uiwidgets/Runtime/rendering/debug_overflow_indicator.cs

                 TileMode.repeated
             );
             _labelBackgroundPaint.color = new Color(0xFFFFFFFF);
-            for (int i = 0; i < 4; i++) {
+            _OverflowSide e = new _OverflowSide();
+            var len = Enum.GetNames(e.GetType()).Length;
+            for (int i = 0; i < len; i++) {
                 _indicatorLabel.Add(new TextPainter(textDirection: TextDirection.ltr));
             }
         }
                 );
                 regions.Add(new _OverflowRegionData(
                     rect: markerRect,
-                    label: "LEFT OVERFLOWED BY ${_formatPixels(overflow.left)} PIXELS",
+                    label: $"LEFT OVERFLOWED BY {_formatPixels(overflow.left)} PIXELS",
                     labelOffset: markerRect.centerLeft +
                                  new Offset(_indicatorFontSizePixels + _indicatorLabelPaddingPixels, 0.0f),
                     rotation: Mathf.PI / 2.0f,
         static void _reportOverflow(RenderObject renderObject, RelativeRect overflow, List<DiagnosticsNode> overflowHints) {
             overflowHints = overflowHints ?? new List<DiagnosticsNode>();
             if (overflowHints.isEmpty()) {
-                overflowHints.Add(new ErrorDescription($"The edge of the {renderObject.GetType()} that is " +
-                                                       "overflowing has been marked in the rendering with a yellow and black " +
-                                                       "striped pattern. This is usually caused by the contents being too big " +
-                                                       $"for the {renderObject.GetType()}."));
+                overflowHints.Add(
+                    new ErrorDescription(
+                        $"The edge of the {renderObject.GetType()} that is " +
+                        "overflowing has been marked in the rendering with a yellow and black " +
+                        "striped pattern. This is usually caused by the contents being too big " +
+                        $"for the {renderObject.GetType()}."));
-                overflowHints.Add(new ErrorHint("This is considered an error condition because it indicates that there " +
-                                                "is content that cannot be seen. If the content is legitimately bigger " +
-                                                "than the available space, consider clipping it with a ClipRect widget " +
-                                                $"before putting it in the {renderObject.GetType()}, or using a scrollable " +
-                                                "container, like a ListView."));
+                overflowHints.Add(
+                    new ErrorHint(
+                        "This is considered an error condition because it indicates that there " +
+                        "is content that cannot be seen. If the content is legitimately bigger " +
+                        "than the available space, consider clipping it with a ClipRect widget " +
+                        $"before putting it in the {renderObject.GetType()}, or using a scrollable " +
+                        "container, like a ListView."));
-            List<string> overflows = new List<string> { };
+            List<string> overflows = new List<string>();
             if (overflow.left > 0.0f) {
                 overflows.Add($"{_formatPixels(overflow.left)} pixels on the left");
             }
                 }
 
                 yield return DiagnosticsNode.message($"The specific {renderObject.GetType()} in question is: {renderObject.toStringShallow(joiner: "\n  ")}");
-                yield return DiagnosticsNode.message(string.Concat(Enumerable.Repeat("◢◤", 32)));
+                yield return DiagnosticsNode.message(string.Concat(Enumerable.Repeat("◢◤", 32)),allowWrap: false);
             }
 
             UIWidgetsError.reportError(

com.unity.uiwidgets/Runtime/rendering/editable.cs

 using System;
 using System.Collections.Generic;
+using System.Linq;
+using Unity.UIWidgets.async2;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.services;
 using Unity.UIWidgets.ui;
 using UnityEngine;
 using Canvas = Unity.UIWidgets.ui.Canvas;
         public static readonly float _kCaretHeightOffset = 2.0f;
         public static readonly Offset _kFloatingCaretSizeIncrease = new Offset(0.5f, 1.0f);
         public static readonly float _kFloatingCaretRadius = 1.0f;
+        
+        public static bool _isWhitespace(int codeUnit) {
+            switch (codeUnit) {
+                case 0x9: // horizontal tab
+                case 0xA: // line feed
+                case 0xB: // vertical tab
+                case 0xC: // form feed
+                case 0xD: // carriage return
+                case 0x1C: // file separator
+                case 0x1D: // group separator
+                case 0x1E: // record separator
+                case 0x1F: // unit separator
+                case 0x20: // space
+                case 0xA0: // no-break space
+                case 0x1680: // ogham space mark
+                case 0x2000: // en quad
+                case 0x2001: // em quad
+                case 0x2002: // en space
+                case 0x2003: // em space
+                case 0x2004: // three-per-em space
+                case 0x2005: // four-er-em space
+                case 0x2006: // six-per-em space
+                case 0x2007: // figure space
+                case 0x2008: // punctuation space
+                case 0x2009: // thin space
+                case 0x200A: // hair space
+                case 0x202F: // narrow no-break space
+                case 0x205F: // medium mathematical space
+                case 0x3000: // ideographic space
+                    break;
+                default:
+                    return false;
+            }
+            return true;
+        }
     }
 
     public delegate void SelectionChangedHandler(TextSelection selection, RenderEditable renderObject,
         }
 
         public override string ToString() {
-            return $"Point: {point}, Direction: {direction}";
+            switch (direction) {
+                case TextDirection.ltr:
+                    return $"{point}-ltr";
+                case TextDirection.rtl:
+                    return $"{point}-rtl";
+            }
+
+            return $"{point}";
+            
-    public class RenderEditable : RenderBox {
+    public class RenderEditable : RenderBox, RelayoutWhenSystemFontsChangeMixin {
-            TextSpan text,
-            TextDirection textDirection,
-            TextAlign textAlign = TextAlign.left,
+            TextSpan text = null, 
+            TextDirection? textDirection = null,
+            TextAlign textAlign = TextAlign.start,
+            LayerLink startHandleLayerLink = null,
+            LayerLink endHandleLayerLink = null,
             int? maxLines = 1,
             int? minLines = null,
             bool expands = false,
             SelectionChangedHandler onSelectionChanged = null,
             CaretChangedHandler onCaretChanged = null,
             bool ignorePointer = false,
+            bool readOnly = false,
+            bool forceLine = true,
+            TextWidthBasis textWidthBasis = TextWidthBasis.parent,
+            Locale locale = null,
+            ui.BoxHeightStyle selectionHeightStyle = ui.BoxHeightStyle.tight,
+            ui.BoxWidthStyle selectionWidthStyle = ui.BoxWidthStyle.tight,
-            TextSelectionDelegate textSelectionDelegate = null,
-            GlobalKeyEventHandlerDelegate globalKeyEventHandler = null) {
+            TextSelectionDelegate textSelectionDelegate = null)
+        {
-            D.assert(textSelectionDelegate != null);
+            
+            D.assert(textDirection != null, () => "RenderEditable created without a textDirection.");
+            D.assert(maxLines == null || maxLines > 0);
-            D.assert(maxLines == null || maxLines > 0);
-            D.assert((maxLines == null) || (minLines == null) || maxLines >= minLines,
-                () => "minLines can't be greater than maxLines");
+            D.assert(startHandleLayerLink != null);
+            D.assert(endHandleLayerLink != null);
+            D.assert(
+                (maxLines == null) || (minLines == null) || (maxLines >= minLines), ()=>
+                "minLines can't be greater than maxLines"
+            );
+           
+            D.assert(
+                !expands || (maxLines == null && minLines == null),()=>
+                "minLines and maxLines must be null when expands is true."
+            );
+           
-            D.assert(cursorWidth >= 0.0f);
+           
+            D.assert(textSelectionDelegate != null);
+            D.assert( cursorWidth >= 0.0);
+           
-                textDirection: textDirection,
+                textDirection: textDirection ?? TextDirection.ltr,
-                strutStyle: strutStyle);
+                locale: locale,
+                strutStyle: strutStyle,
+                textWidthBasis: textWidthBasis
+            );
-            _hasFocus = hasFocus ?? false;
-            _obscureText = obscureText;
+            _paintCursorOnTop = paintCursorAboveText;
+            _cursorOffset = cursorOffset;
+            _floatingCursorAddedMargin = floatingCursorAddedMargin;
+            _devicePixelRatio = devicePixelRatio;
+            _selectionHeightStyle = selectionHeightStyle;
+            _selectionWidthStyle = selectionWidthStyle;
+            _startHandleLayerLink = startHandleLayerLink;
+            _endHandleLayerLink = endHandleLayerLink;
+            _obscureText = obscureText;
+            _readOnly = readOnly;
+            _forceLine = forceLine;
+            D.assert(_showCursor != null);
+            D.assert(!_showCursor.value || cursorColor != null);
+            this.hasFocus = hasFocus ?? false;
-            this.globalKeyEventHandler = globalKeyEventHandler;
+           
-
-            _tap = new TapGestureRecognizer(this);
-            _tap.onTapDown = _handleTapDown;
-            _tap.onTap = _handleTap;
-            _longPress = new LongPressGestureRecognizer(debugOwner: this);
-            _longPress.onLongPress = _handleLongPress;
-
-            _paintCursorOnTop = paintCursorAboveText;
-            _cursorOffset = cursorOffset;
-            _floatingCursorAddedMargin = floatingCursorAddedMargin;
-            _devicePixelRatio = devicePixelRatio;
-        float? _textLayoutLastWidth;
+        float? _textLayoutLastMaxWidth;
+        float? _textLayoutLastMinWidth;
+        public TextWidthBasis textWidthBasis {
+            get {
+                return _textPainter.textWidthBasis;
+            }
+            set {
+                D.assert(value != null);
+                if (_textPainter.textWidthBasis == value)
+                    return;
+                _textPainter.textWidthBasis = value;
+                markNeedsTextLayout();
+            }
+        }
+
+        public ui.BoxHeightStyle selectionHeightStyle {
+            get {
+                return _selectionHeightStyle;
+            }
+            set {
+                D.assert(value != null);
+                if (_selectionHeightStyle == value)
+                    return;
+                _selectionHeightStyle = value;
+                markNeedsPaint();
+            }
+        }
+
+        ui.BoxHeightStyle _selectionHeightStyle;
+        
+        public ui.BoxWidthStyle selectionWidthStyle {
+            get {
+                return _selectionWidthStyle;
+            }
+            set {
+                D.assert(value != null);
+                if (_selectionWidthStyle == value)
+                    return;
+                _selectionWidthStyle = value;
+                markNeedsPaint();
+            }
+        }
+
+        ui.BoxWidthStyle _selectionWidthStyle;
+        
+        public LayerLink startHandleLayerLink {
+            get {
+                return _startHandleLayerLink;
+            }
+            set {
+                if (_startHandleLayerLink == value)
+                    return;
+                _startHandleLayerLink = value;
+                markNeedsPaint();
+            }
+        }
+
+        LayerLink _startHandleLayerLink;
+        
+        public LayerLink endHandleLayerLink {
+            get {
+                return _endHandleLayerLink;
+            }
+            set {
+                if (_endHandleLayerLink == value)
+                    return;
+                _endHandleLayerLink = value;
+                markNeedsPaint();
+            }
+        }
+
+        LayerLink _endHandleLayerLink;
+
+        public bool forceLine {
+            get {
+                return _forceLine;
+            }
+            set {
+                D.assert(value != null);
+                if (_forceLine == value)
+                    return;
+                _forceLine = value;
+                markNeedsLayout();
+            }
+        }
+
+        bool _forceLine = false;
+        
+        public bool readOnly {
+            get {
+                return _readOnly;
+            }
+            set {
+                D.assert(value != null);
+                if (_readOnly == value)
+                    return;
+                _readOnly = value;
+            }
+        }
+
+        bool _readOnly = false;
+
         float _devicePixelRatio;
 
         public float devicePixelRatio {
                 }
 
                 _obscureText = value;
-                markNeedsSemanticsUpdate();
             }
         }
 
             Rect visibleRegion = Offset.zero & size;
             Offset startOffset = _textPainter.getOffsetForCaret(
                 new TextPosition(offset: _selection.start, affinity: _selection.affinity),
-                Rect.zero
+                _caretPrototype
             );
 
             float visibleRegionSlop = 0.5f;
 
             Offset endOffset = _textPainter.getOffsetForCaret(
                 new TextPosition(offset: _selection.end, affinity: _selection.affinity),
-                Rect.zero
+                _caretPrototype
             );
             _selectionEndInViewport.value = visibleRegion
                 .inflate(visibleRegionSlop)
 
         bool _resetCursor = false;
 
+        
+        void _handleSelectionChange(
+            TextSelection nextSelection,
+            SelectionChangedCause cause
+        ) {
+            
+            bool focusingEmpty = nextSelection.baseOffset == 0
+                                       && nextSelection.extentOffset == 0
+                                       && !hasFocus;
+            if (nextSelection == selection
+                && cause != SelectionChangedCause.keyboard
+                && !focusingEmpty) {
+                return;
+            }
+
+            onSelectionChanged?.Invoke(nextSelection, this, cause);
+        }
+        
         void _handleKeyEvent(RawKeyEvent keyEvent) {
             if (keyEvent is RawKeyUpEvent) {
                 return;
 
             return newOffset;
         }
+        
 
         int _handleShift(bool rightArrow, bool leftArrow, bool shift, int newOffset) {
             if (onSelectionChanged == null) {
         }
 
         protected void markNeedsTextLayout() {
-            _textLayoutLastWidth = null;
+            _textLayoutLastMaxWidth = null;
+            _textLayoutLastMinWidth = null;
+        
+        public void systemFontsDidChange() {
+            _textPainter.markNeedsLayout();
+            _textLayoutLastMaxWidth = null;
+            _textLayoutLastMinWidth = null;
+        }
+        void _handleSetSelection(TextSelection selection) {
+            _handleSelectionChange(selection, SelectionChangedCause.keyboard);
+        }
+
+        void _handleMoveCursorForwardByCharacter(bool extentSelection) {
+            int extentOffset = _textPainter.getOffsetAfter(_selection.extentOffset);
+            if (extentOffset == null)
+                return;
+            int baseOffset = !extentSelection ? extentOffset : _selection.baseOffset;
+            _handleSelectionChange(
+            new TextSelection(baseOffset: baseOffset, extentOffset: extentOffset), SelectionChangedCause.keyboard
+            );
+        }
+
+        void _handleMoveCursorBackwardByCharacter(bool extentSelection) {
+            int extentOffset = _textPainter.getOffsetBefore(_selection.extentOffset);
+            if (extentOffset == null)
+                return;
+            int baseOffset = !extentSelection ? extentOffset : _selection.baseOffset;
+            _handleSelectionChange(
+                new TextSelection(baseOffset: baseOffset, extentOffset: extentOffset), SelectionChangedCause.keyboard
+            );
+        }
+
+        void _handleMoveCursorForwardByWord(bool extentSelection) {
+            TextRange currentWord = _textPainter.getWordBoundary(_selection.extent);
+            if (currentWord == null)
+                return;
+            TextRange nextWord = _getNextWord(currentWord.end);
+            if (nextWord == null)
+                return;
+            int baseOffset = extentSelection ? _selection.baseOffset : nextWord.start;
+            _handleSelectionChange(
+                new TextSelection(
+                    baseOffset: baseOffset,
+                    extentOffset: nextWord.start
+                ),
+            SelectionChangedCause.keyboard
+            );
+        }
+
+        void _handleMoveCursorBackwardByWord(bool extentSelection) {
+            TextRange currentWord = _textPainter.getWordBoundary(_selection.extent);
+            if (currentWord == null)
+                return;
+            TextRange previousWord = _getPreviousWord(currentWord.start - 1);
+            if (previousWord == null)
+                return;
+            int baseOffset = extentSelection ?  _selection.baseOffset : previousWord.start;
+            _handleSelectionChange(
+                new TextSelection(
+                    baseOffset: baseOffset,
+                    extentOffset: previousWord.start
+                ),
+            SelectionChangedCause.keyboard
+            );
+        }
+        
+        TextRange _getNextWord(int offset) {
+            while (true) {
+                TextRange range = _textPainter.getWordBoundary(new TextPosition(offset: offset));
+                if (range == null || !range.isValid || range.isCollapsed)
+                    return null;
+                if (!_onlyWhitespace(range))
+                    return range;
+                offset = range.end;
+            }
+        }
+
+        TextRange _getPreviousWord(int offset) {
+            while (offset >= 0) {
+                TextRange range = _textPainter.getWordBoundary(new TextPosition(offset: offset));
+                if (range == null || !range.isValid || range.isCollapsed)
+                    return null;
+                if (!_onlyWhitespace(range))
+                    return range;
+                offset = range.start - 1;
+            }
+            return null;
+        }
+        
+        bool _onlyWhitespace(TextRange range) {
+            for (int i = range.start; i < range.end; i++) {
+                int codeUnit = text.codeUnitAt(i).Value;
+                if (!EditableUtils._isWhitespace(codeUnit)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        public void attach(PipelineOwner owner) {
+            _tap = new TapGestureRecognizer(debugOwner: this);
+            _tap.onTapDown = _handleTapDown;
+            _tap.onTap = _handleTap;
+            _longPress = new LongPressGestureRecognizer(debugOwner: this);
+            _longPress.onLongPress = _handleLongPress;
+            _offset.addListener(markNeedsLayout);
+            _showCursor.addListener(markNeedsPaint);
+        }
+        
+        string _cachedPlainText;
+        string _plainText {
+            get {
+                _cachedPlainText = _cachedPlainText ?? _textPainter.text.toPlainText();
+                return _cachedPlainText;
+            }
+        }
+        
         TextPainter _textPainter;
 
         public TextSpan text {
                 }
 
                 _textPainter.text = value;
+                _cachedPlainText = null;
-                markNeedsSemanticsUpdate();
-        public TextAlign textAlign {
+        public TextAlign? textAlign {
             get { return _textPainter.textAlign; }
             set {
                 if (_textPainter.textAlign == value) {
                 _textPainter.textAlign = value;
-                markNeedsPaint();
+                markNeedsTextLayout();
             }
         }
 
 
                 _textPainter.textDirection = value;
                 markNeedsTextLayout();
-                markNeedsSemanticsUpdate();
             }
         }
 
             }
         }
 
+        public Locale locale {
+            get { return _textPainter.locale;
+            }
+            set {
+            if (_textPainter.locale == value)
+                return;
+            _textPainter.locale = value;
+            markNeedsTextLayout();
+            }
+        }
+
+        
+        
+        
+
         Color _backgroundCursorColor;
 
         public Color backgroundCursorColor {
                     RawKeyboard.instance.removeListener(_handleKeyEvent);
                     _listenerAttached = false;
                 }
-
-                markNeedsSemanticsUpdate();
-
+        
         int? _maxLines;
 
         public int? maxLines {
                 _selection = value;
                 _selectionRects = null;
                 markNeedsPaint();
-                markNeedsSemanticsUpdate();
             }
         }
 
 
                 _enableInteractiveSelection = value;
                 markNeedsTextLayout();
-                markNeedsSemanticsUpdate();
             }
         }
 
 
-
+            attach((PipelineOwner)ownerObject);
+            /*_tap = new TapGestureRecognizer(debugOwner: this);
+            _tap.onTapDown = _handleTapDown;
+            _tap.onTap = _handleTap;
+            _longPress = new LongPressGestureRecognizer(debugOwner: this);
+            _longPress.onLongPress = _handleLongPress;
-            _showCursor.addListener(markNeedsPaint);
+            _showCursor.addListener(markNeedsPaint);*/
+            _tap.dispose();
+            _longPress.dispose();
             _offset.removeListener(markNeedsLayout);
             _showCursor.removeListener(markNeedsPaint);
             if (_listenerAttached) {
             return 0.0f;
         }
 
-        float _maxScrollExtent = 0;
+        float  _caretMargin {
+            get {
+                return EditableUtils._kCaretGap + cursorWidth;
+            }
+        }
+        public float  maxScrollExtent {
+            get { return _maxScrollExtent; }
+        }
+
+        float _maxScrollExtent = 0;
-
-
-        /// Returns the local coordinates of the endpoints of the given selection.
-        ///
-        /// If the selection is collapsed (and therefore occupies a single point), the
-        /// returned list is of length one. Otherwise, the selection is not collapsed
-        /// and the returned list is of length two. In this case, however, the two
-        /// points might actually be co-located (e.g., because of a bidirectional
-        /// selection that contains some text but whose ends meet in the middle).
-        ///
+        
-            _layoutText(constraints.maxWidth);
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
             var paintOffset = _paintOffset;
             if (selection.isCollapsed) {
                 var caretOffset = _textPainter.getOffsetForCaret(selection.extendPos, _caretPrototype);
         }
 
         public TextPosition getPositionForPoint(Offset globalPosition) {
-            _layoutText(constraints.maxWidth);
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
-            _layoutText(constraints.maxWidth);
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
             var caretOffset = _textPainter.getOffsetForCaret(caretPosition, _caretPrototype);
             Rect rect = Rect.fromLTWH(0.0f, 0.0f, cursorWidth, preferredLineHeight)
                 .shift(caretOffset + _paintOffset);
         }
 
         protected internal override float computeMinIntrinsicWidth(float height) {
-            _layoutText(float.PositiveInfinity);
+            _layoutText(maxWidth: float.PositiveInfinity);
-            _layoutText(float.PositiveInfinity);
+            _layoutText(maxWidth: float.PositiveInfinity);
             return _textPainter.maxIntrinsicWidth + cursorWidth;
         }
 
             bool minLimited = minLines != null && minLines > 1;
             bool maxLimited = maxLines != null;
             if (minLimited || maxLimited) {
-                _layoutText(width);
+                _layoutText(maxWidth: width);
                 if (minLimited && _textPainter.height < preferredLineHeight * minLines.Value) {
                     return preferredLineHeight * minLines.Value;
                 }
             }
 
             if (!width.isFinite()) {
-                var text = _textPainter.text.toPlainText();
+                var text = _plainText;
                 int lines = 1;
                 for (int index = 0; index < text.Length; ++index) {
                     if (text[index] == 0x0A) {
                 return preferredLineHeight * lines;
             }
 
-            _layoutText(width);
+            _layoutText(maxWidth: width);
             return Mathf.Max(preferredLineHeight, _textPainter.height);
         }
 
         }
 
         public override float? computeDistanceToActualBaseline(TextBaseline baseline) {
-            _layoutText(constraints.maxWidth);
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
             return _textPainter.computeDistanceToActualBaseline(baseline);
         }
 
             D.assert(cause != null);
             D.assert(from != null);
 
-            _layoutText(constraints.maxWidth);
-            if (onSelectionChanged != null) {
-                TextPosition fromPosition =
-                    _textPainter.getPositionForOffset(globalToLocal(from - _paintOffset));
-                TextPosition toPosition = to == null
-                    ? null
-                    : _textPainter.getPositionForOffset(globalToLocal(to - _paintOffset));
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
+            if (onSelectionChanged == null) {
+                return;
+            }
+            TextPosition fromPosition =
+                _textPainter.getPositionForOffset(globalToLocal(from - _paintOffset));
+            TextPosition toPosition = to == null
+                ? null
+                : _textPainter.getPositionForOffset(globalToLocal(to - _paintOffset));
-                int baseOffset = fromPosition.offset;
-                int extentOffset = fromPosition.offset;
-                if (toPosition != null) {
-                    baseOffset = Mathf.Min(fromPosition.offset, toPosition.offset);
-                    extentOffset = Mathf.Max(fromPosition.offset, toPosition.offset);
-                }
+            int baseOffset = fromPosition.offset;
+            int extentOffset = fromPosition.offset;
+            if (toPosition != null) {
+                baseOffset = Mathf.Min(fromPosition.offset, toPosition.offset);
+                extentOffset = Mathf.Max(fromPosition.offset, toPosition.offset);
+            }
-                TextSelection newSelection = new TextSelection(
-                    baseOffset: baseOffset,
-                    extentOffset: extentOffset,
-                    affinity: fromPosition.affinity);
+            TextSelection newSelection = new TextSelection(
+                baseOffset: baseOffset,
+                extentOffset: extentOffset,
+                affinity: fromPosition.affinity);
-                onSelectionChanged(newSelection, this, cause.Value);
-            }
+            _handleSelectionChange(newSelection, cause.Value);
         }
 
         public void selectPosition(SelectionChangedCause? cause = null) {
         public void selectWordsInRange(Offset from = null, Offset to = null, SelectionChangedCause? cause = null) {
             D.assert(cause != null);
             D.assert(from != null);
-            _layoutText(constraints.maxWidth);
-            if (onSelectionChanged != null) {
-                TextPosition firstPosition =
-                    _textPainter.getPositionForOffset(globalToLocal(from - _paintOffset));
-                TextSelection firstWord = _selectWordAtOffset(firstPosition);
-                TextSelection lastWord = to == null
-                    ? firstWord
-                    : _selectWordAtOffset(
-                        _textPainter.getPositionForOffset(globalToLocal(to - _paintOffset)));
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
+            if (onSelectionChanged == null) {
+                return;
+            }
+            TextPosition firstPosition =
+                _textPainter.getPositionForOffset(globalToLocal(from - _paintOffset));
+            TextSelection firstWord = _selectWordAtOffset(firstPosition);
+            TextSelection lastWord = to == null
+                ? firstWord
+                : _selectWordAtOffset(
+                    _textPainter.getPositionForOffset(globalToLocal(to - _paintOffset)));
-                onSelectionChanged(
-                    new TextSelection(
-                        baseOffset: firstWord.baseOffset,
-                        extentOffset: lastWord.extentOffset,
-                        affinity: firstWord.affinity),
-                    this,
-                    cause.Value);
-            }
+            _handleSelectionChange(
+                new TextSelection(
+                    baseOffset: firstWord.baseOffset,
+                    extentOffset: lastWord.extentOffset,
+                    affinity: firstWord.affinity),
+                cause.Value);
-            _layoutText(constraints.maxWidth);
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
-            if (onSelectionChanged != null) {
-                TextPosition position =
-                    _textPainter.getPositionForOffset(
-                        globalToLocal(_lastTapDownPosition - _paintOffset));
-                TextRange word = _textPainter.getWordBoundary(position);
-                if (position.offset - word.start <= 1) {
-                    onSelectionChanged(
-                        TextSelection.collapsed(offset: word.start, affinity: TextAffinity.downstream),
-                        this,
-                        cause
-                    );
-                }
-                else {
-                    onSelectionChanged(
-                        TextSelection.collapsed(offset: word.end, affinity: TextAffinity.upstream),
-                        this,
-                        cause
-                    );
-                }
+            if (onSelectionChanged == null) {
+                return;
+            }
+            TextPosition position =
+                _textPainter.getPositionForOffset(
+                    globalToLocal(_lastTapDownPosition - _paintOffset));
+            TextRange word = _textPainter.getWordBoundary(position);
+            if (position.offset - word.start <= 1) {
+                _handleSelectionChange(
+                    TextSelection.collapsed(offset: word.start, affinity: TextAffinity.downstream),
+                    cause
+                );
+            }
+            else {
+                _handleSelectionChange(
+                    TextSelection.collapsed(offset: word.end, affinity: TextAffinity.upstream),
+                    cause
+                );
-            D.assert(_textLayoutLastWidth == constraints.maxWidth);
+            D.assert(_textLayoutLastMaxWidth == constraints.maxWidth &&
+                   _textLayoutLastMinWidth == constraints.minWidth,
+                () => $"Last width ({_textLayoutLastMinWidth}, {_textLayoutLastMaxWidth}) not the same as max width constraint ({constraints.minWidth}, {constraints.maxWidth}).");
-
+            if (obscureText) {
+                return new TextSelection(baseOffset: 0, extentOffset: _plainText.Length);
+            }
+        TextSelection _selectLineAtOffset(TextPosition position) {
+            D.assert(_textLayoutLastMaxWidth == constraints.maxWidth &&
+                   _textLayoutLastMinWidth == constraints.minWidth,
+                () => $"Last width ({_textLayoutLastMinWidth}, {_textLayoutLastMaxWidth}) not the same as max width constraint ({constraints.minWidth}, {constraints.maxWidth}).");
+            TextRange line = _textPainter.getLineBoundary(position);
+            if (position.offset >= line.end)
+                return TextSelection.fromPosition(position);
+            // If text is obscured, the entire string should be treated as one line.
+            if (obscureText) {
+                return new TextSelection(baseOffset: 0, extentOffset: _plainText.Length);
+            }
+            return new TextSelection(baseOffset: line.start, extentOffset: line.end);
+        }
+        
-        void _layoutText(float constraintWidth) {
-            if (_textLayoutLastWidth == constraintWidth) {
+        void _layoutText( float minWidth = 0.0f, float maxWidth = float.PositiveInfinity ) {
+            D.assert(maxWidth != null && minWidth != null);
+            if (_textLayoutLastMaxWidth == maxWidth && _textLayoutLastMinWidth == minWidth)
-            }
-
-            var caretMargin = EditableUtils._kCaretGap + cursorWidth;
-            var avialableWidth = Mathf.Max(0.0f, constraintWidth - caretMargin);
-            var maxWidth = _isMultiline ? avialableWidth : float.PositiveInfinity;
-            _textPainter.layout(minWidth: avialableWidth, maxWidth: maxWidth);
-            _textLayoutLastWidth = constraintWidth;
+            float availableMaxWidth = Mathf.Max(0.0f, maxWidth - _caretMargin);
+            float availableMinWidth = Mathf.Min(minWidth, availableMaxWidth);
+            float textMaxWidth = _isMultiline ? availableMaxWidth : float.PositiveInfinity;
+            float textMinWidth = forceLine ? availableMaxWidth : availableMinWidth;
+            _textPainter.layout(
+                minWidth: textMinWidth,
+                maxWidth: textMaxWidth
+            );
+            _textLayoutLastMinWidth = minWidth;
+            _textLayoutLastMaxWidth = maxWidth;
         }
 
         Rect _getCaretPrototype {
                         return Rect.fromLTWH(0.0f, EditableUtils._kCaretHeightOffset, cursorWidth,
                             preferredLineHeight - 2.0f * EditableUtils._kCaretHeightOffset);
                 }
+                return null;
-            _layoutText(constraints.maxWidth);
+            BoxConstraints constraints = this.constraints;
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
-            size = new Size(constraints.maxWidth,
-                constraints.constrainHeight(_preferredHeight(constraints.maxWidth)));
-            var contentSize = new Size(textPainterSize.width + EditableUtils._kCaretGap + cursorWidth,
-                textPainterSize.height);
+            float width = forceLine ? constraints.maxWidth : constraints
+                .constrainWidth(_textPainter.size.width + _caretMargin);
+            size = new Size(width, constraints.constrainHeight(_preferredHeight(constraints.maxWidth)));
+            Size contentSize = new Size(textPainterSize.width + _caretMargin, textPainterSize.height);
             _maxScrollExtent = _getMaxScrollExtent(contentSize);
             offset.applyViewportDimension(_viewportExtent);
             offset.applyContentDimensions(0.0f, _maxScrollExtent);
         }
 
         void _paintCaret(Canvas canvas, Offset effectiveOffset, TextPosition textPosition) {
-            D.assert(_textLayoutLastWidth == constraints.maxWidth);
+            D.assert(_textLayoutLastMaxWidth == constraints.maxWidth &&
+                   _textLayoutLastMinWidth == constraints.minWidth,
+                () => $"Last width ({_textLayoutLastMinWidth}, {_textLayoutLastMaxWidth}) not the same as max width constraint ({constraints.minWidth}, {constraints.maxWidth}).");
             var paint = new Paint() {color = _floatingCursorOn ? backgroundCursorColor : _cursorColor};
             var caretOffset = _textPainter.getOffsetForCaret(textPosition, _caretPrototype) + effectiveOffset;
             Rect caretRect = _caretPrototype.shift(caretOffset);
             if (caretHeight != null) {
                 switch (Application.platform) {
                     case RuntimePlatform.IPhonePlayer:
-                        float heightDiff = caretHeight.Value - caretRect.height;
+                        float? heightDiff = caretHeight - caretRect.height;
-                            caretRect.top + heightDiff / 2f,
+                            (caretRect.top + heightDiff / 2).Value,
                             caretRect.width,
                             caretRect.height
                         );
         // describeSemanticsConfiguration todo
 
         void _paintFloatingCaret(Canvas canvas, Offset effectiveOffset) {
-            D.assert(_textLayoutLastWidth == constraints.maxWidth);
+            D.assert(_textLayoutLastMaxWidth == constraints.maxWidth &&
+                     _textLayoutLastMinWidth == constraints.minWidth,
+                () => $"Last width ({_textLayoutLastMinWidth}, {_textLayoutLastMaxWidth}) not the same as max width constraint ({constraints.minWidth}, {constraints.maxWidth}).");
             D.assert(_floatingCursorOn);
 
             Paint paint = new Paint() {color = _cursorColor.withOpacity(0.75f)};
         }
 
         void _paintSelection(Canvas canvas, Offset effectiveOffset) {
-            D.assert(_textLayoutLastWidth == constraints.maxWidth);
+            D.assert(_textLayoutLastMaxWidth == constraints.maxWidth &&
+                     _textLayoutLastMinWidth == constraints.minWidth,
+                () => $"Last width ({_textLayoutLastMinWidth}, {_textLayoutLastMaxWidth}) not the same as max width constraint ({constraints.minWidth}, {constraints.maxWidth}).");
             D.assert(_selectionRects != null);
             var paint = new Paint() {color = _selectionColor};
 
         }
 
         void _paintContents(PaintingContext context, Offset offset) {
-            D.assert(_textLayoutLastWidth == constraints.maxWidth);
+            D.assert(_textLayoutLastMaxWidth == constraints.maxWidth &&
+                     _textLayoutLastMinWidth == constraints.minWidth,
+                () => $"Last width ({_textLayoutLastMinWidth}, {_textLayoutLastMaxWidth}) not the same as max width constraint ({constraints.minWidth}, {constraints.maxWidth}).");
             var effectiveOffset = offset + _paintOffset;
 
             bool showSelection = false;
             }
 
             if (showSelection) {
-                _selectionRects = _selectionRects ?? _textPainter.getBoxesForSelection(_selection);
+                _selectionRects = _selectionRects ?? _textPainter.getBoxesForSelection(_selection, boxHeightStyle: _selectionHeightStyle, boxWidthStyle: _selectionWidthStyle);
                 _paintSelection(context.canvas, effectiveOffset);
             }
 
             }
         }
 
-        void markNeedsSemanticsUpdate() {
-            // todo
+        void _paintHandleLayers(PaintingContext context, List<TextSelectionPoint> endpoints) {
+            Offset startPoint = endpoints[0].point;
+            startPoint = new Offset(
+                startPoint.dx.clamp(0.0f, size.width),
+                startPoint.dy.clamp(0.0f, size.height)
+            );
+            context.pushLayer(
+                new LeaderLayer(link: startHandleLayerLink, offset: startPoint),
+                base.paint,
+                Offset.zero
+            );
+            if (endpoints.Count == 2) {
+                Offset endPoint = endpoints[1].point;
+                endPoint = new Offset(
+                    endPoint.dx.clamp(0.0f, size.width),
+                    endPoint.dy.clamp(0.0f, size.height)
+                );
+                context.pushLayer(
+                    new LeaderLayer(link: endHandleLayerLink, offset: endPoint),
+                    base.paint,
+                    Offset.zero
+                );
+            }
-
+        
+        
-            _layoutText(constraints.maxWidth);
+            _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
+                _paintHandleLayers(context, getEndpointsForSelection(selection));
-            properties.add(new DiagnosticsProperty<Color>("cursorColor", cursorColor));
+            properties.add(new ColorProperty("cursorColor", cursorColor));
-            properties.add(new DiagnosticsProperty<Color>("selectionColor", selectionColor));
+            properties.add(new ColorProperty("selectionColor", selectionColor));
+            properties.add(new DiagnosticsProperty<Locale>("locale", locale, defaultValue: null));
         }
 
         public override List<DiagnosticsNode> debugDescribeChildren() {

com.unity.uiwidgets/Runtime/rendering/flex.cs

         public int flex;
 
         public FlexFit fit;
+
+        public override string ToString() => $"{base.ToString()}; flex={flex}; fit={fit}";
     }
 
     public enum MainAxisSize {
 
         public TextBaseline _textBaseline;
 
+        bool _debugHasNecessaryDirections {
+            get  {
+                if (firstChild != null && lastChild != firstChild) {
+                    // i.e. there's more than one child
+                    switch (direction) {
+                        case Axis.horizontal:
+                            D.assert(textDirection != null, () => "Horizontal $runtimeType with multiple children has a null textDirection, so the layout order is undefined.");
+                            break;
+                        case Axis.vertical:
+                            D.assert(verticalDirection != null, () => "Vertical $runtimeType with multiple children has a null verticalDirection, so the layout order is undefined.");
+                            break;
+                    }
+                }
+                if (mainAxisAlignment == MainAxisAlignment.start ||
+                mainAxisAlignment == MainAxisAlignment.end) {
+                    switch (direction) {
+                        case Axis.horizontal:
+                            D.assert(textDirection != null, () => "Horizontal $runtimeType with $mainAxisAlignment has a null textDirection, so the alignment cannot be resolved.");
+                            break;
+                        case Axis.vertical:
+                            D.assert(verticalDirection != null, () => "Vertical $runtimeType with $mainAxisAlignment has a null verticalDirection, so the alignment cannot be resolved.");
+                            break;
+                    }
+                }
+                if (crossAxisAlignment == CrossAxisAlignment.start ||
+                crossAxisAlignment == CrossAxisAlignment.end) {
+                    switch (direction) {
+                        case Axis.horizontal:
+                            D.assert(verticalDirection != null, () => "Horizontal $runtimeType with $crossAxisAlignment has a null verticalDirection, so the alignment cannot be resolved.");
+                            break;
+                        case Axis.vertical:
+                            D.assert(textDirection != null, () => "Vertical $runtimeType with $crossAxisAlignment has a null textDirection, so the alignment cannot be resolved.");
+                            break;
+                    }
+                }
+                return true;
+            }
+        }
+        
+        
+        
         public float _overflow;
         
         bool _hasOverflow {
         }
 
         public float _getIntrinsicSize(
-            Axis sizingDirection,
-            float extent,
-            _ChildSizingFunction childSize
+            Axis? sizingDirection = null,
+            float? extent = null,
+            _ChildSizingFunction childSize = null
         ) {
             if (_direction == sizingDirection) {
                 float totalFlex = 0.0f;
                     int flex = _getFlex(child);
                     totalFlex += flex;
                     if (flex > 0) {
-                        float flexFraction = childSize(child, extent) / _getFlex(child);
+                        float flexFraction = childSize(child, extent.Value) / _getFlex(child);
-                        inflexibleSpace += childSize(child, extent);
+                        inflexibleSpace += childSize(child, extent.Value);
                     }
 
                     var childParentData = (FlexParentData) child.parentData;
                 return maxFlexFractionSoFar * totalFlex + inflexibleSpace;
             }
             else {
-                float availableMainSpace = extent;
+                float? availableMainSpace = extent;
                 int totalFlex = 0;
                 float inflexibleSpace = 0.0f;
                 float maxCrossSize = 0.0f;
                     child = childParentData.nextSibling;
                 }
 
-                float spacePerFlex = Mathf.Max(0.0f, (availableMainSpace - inflexibleSpace) / totalFlex);
+                float spacePerFlex = Mathf.Max(0.0f, ((availableMainSpace - inflexibleSpace) / totalFlex).Value);
 
                 child = firstChild;
                 while (child != null) {
         }
 
         protected override void performLayout() {
+            D.assert(_debugHasNecessaryDirections);
+            BoxConstraints constraints = this.constraints;
+            D.assert(constraints != null);
             float maxMainSize = _direction == Axis.horizontal
                 ? constraints.maxWidth
                 : constraints.maxHeight;
                     allocatedSize += _getMainSize(child);
                     crossSize = Mathf.Max(crossSize, _getCrossSize(child));
                 }
-
+                D.assert(child.parentData == childParentData);
                 child = childParentData.nextSibling;
             }
 
                 ),
                 new ErrorDescription(
                     $"The edge of the {GetType()} that is overflowing has been marked " +
-                "in the rendering with a yellow and black striped pattern. This is " +
-                "usually caused by the contents being too big for the $runtimeType."
-                    ),
+                    "in the rendering with a yellow and black striped pattern. This is " +
+                    "usually caused by the contents being too big for the $runtimeType."
+                ),
-                    ),
+                ),
                 new ErrorHint(
                     "This is considered an error condition because it indicates that there " +
                     "is content that cannot be seen. If the content is legitimately bigger " +
-                    )
-                    };
+                )};
                 
                 Rect overflowChildRect;
                 switch (_direction) {
 
         protected override bool hitTestChildren(BoxHitTestResult result, Offset position = null) {
             return defaultHitTestChildren(result, position: position);
+        }
+        
+        public override Rect describeApproximatePaintClip(RenderObject child) => _hasOverflow ? Offset.zero & size : null;
+        
+        
+        public override string toStringShort() {
+            String header = base.toStringShort();
+            if (_overflow is float && _hasOverflow)
+                header += " OVERFLOWING";
+            return header;
+        }
+        
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+            base.debugFillProperties(properties);
+            properties.add(new EnumProperty<Axis>("direction", direction));
+            properties.add(new EnumProperty<MainAxisAlignment>("mainAxisAlignment", mainAxisAlignment));
+            properties.add(new EnumProperty<MainAxisSize>("mainAxisSize", mainAxisSize));
+            properties.add(new EnumProperty<CrossAxisAlignment>("crossAxisAlignment", crossAxisAlignment));
+            properties.add(new EnumProperty<TextDirection>("textDirection", textDirection, defaultValue: null));
+            properties.add(new EnumProperty<VerticalDirection>("verticalDirection", verticalDirection, defaultValue: null));
+            properties.add(new EnumProperty<TextBaseline>("textBaseline", textBaseline, defaultValue: null));
         }
     }
 }

com.unity.uiwidgets/Runtime/rendering/image.cs

             Color color = null,
             BlendMode colorBlendMode = BlendMode.srcIn,
             BoxFit? fit = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            bool matchTextDirection = false,
+            TextDirection? textDirection = null,
+            D.assert(alignment != null);
             _image = image;
             _width = width;
             _height = height;
             _alignment = alignment ?? Alignment.center;
             _invertColors = invertColors;
             _filterQuality = filterQuality;
+            _textDirection = textDirection;
+            _matchTextDirection = matchTextDirection;
+        }
+        Alignment _resolvedAlignment;
+        bool _flipHorizontally;
+        void _resolve() {
+            if (_resolvedAlignment != null)
+                return;
+            _resolvedAlignment = alignment.resolve(textDirection);
+            _flipHorizontally = matchTextDirection && textDirection == TextDirection.rtl;
+        }
+
+        
+        void _markNeedResolution() {
+            _resolvedAlignment = null;
+            _flipHorizontally = false;
+            markNeedsPaint();
         }
 
         Image _image;
             }
         }
 
-        Alignment _alignment;
+        AlignmentGeometry _alignment;
-        public Alignment alignment {
+        public AlignmentGeometry alignment {
             get { return _alignment; }
             set {
                 if (value == _alignment) {
             }
         }
 
+        public bool matchTextDirection {
+            get { return _matchTextDirection; }
+            set {
+                D.assert(value != null);
+                if (value == _matchTextDirection)
+                    return;
+                _matchTextDirection = value;
+                _markNeedResolution();
+            }
+        }
+        bool _matchTextDirection;
+
+        public TextDirection? textDirection {
+            get { return _textDirection; }
+            set {
+                if (_textDirection == value)
+                    return;
+                _textDirection = value;
+                _markNeedResolution();
+            }
+        }
+        TextDirection? _textDirection;
+       
+       
+
         Size _sizeForConstraints(BoxConstraints constraints) {
             constraints = BoxConstraints.tightFor(
                 _width,
             if (_image == null) {
                 return;
             }
-
+            _resolve();
+            D.assert(_resolvedAlignment != null);
+            D.assert(_flipHorizontally != null);
             painting_.paintImage(
                 canvas: context.canvas,
                 rect: offset & size,
                 fit: _fit,
-                alignment: _alignment,
+                alignment: _resolvedAlignment,
-                invertColors: _invertColors,
+                flipHorizontally: _flipHorizontally,
+                invertColors: invertColors,
                 filterQuality: _filterQuality
             );
         }
             properties.add(new EnumProperty<BlendMode>("colorBlendMode", colorBlendMode,
                 defaultValue: foundation_.kNullDefaultValue));
             properties.add(new EnumProperty<BoxFit?>("fit", fit, defaultValue: foundation_.kNullDefaultValue));
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment,
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment,
                 defaultValue: foundation_.kNullDefaultValue));
             properties.add(new EnumProperty<ImageRepeat>("repeat", repeat, defaultValue: ImageRepeat.noRepeat));
             properties.add(new DiagnosticsProperty<Rect>("centerSlice", centerSlice,
+            properties.add(new FlagProperty("matchTextDirection", value: matchTextDirection, ifTrue: "match text direction"));
+            properties.add(new EnumProperty<TextDirection?>("textDirection", textDirection, defaultValue: null));
+
         }
     }
 }

com.unity.uiwidgets/Runtime/rendering/layer.cs

 using UnityEngine;
 using Canvas = Unity.UIWidgets.ui.Canvas;
 using Color = Unity.UIWidgets.ui.Color;
+using Object = System.Object;
 using Rect = Unity.UIWidgets.ui.Rect;
 using Shader = Unity.UIWidgets.ui.Shader;
 namespace Unity.UIWidgets.rendering {
         protected void markNeedsAddToScene() {
             D.assert(
                 !alwaysNeedsAddToScene,()=>
-                GetType().ToString() +" with alwaysNeedsAddToScene set called markNeedsAddToScene.\n" + 
+                GetType() +" with alwaysNeedsAddToScene set called markNeedsAddToScene.\n" + 
                 "The layer's alwaysNeedsAddToScene is set to true, and therefore it should not call markNeedsAddToScene."
                 );
             if (_needsAddToScene) {
         }
 
         public virtual void remove() {
-            if (parent != null) {
-                parent._removeChild(this);
-            }
+            parent?._removeChild(this);
         }
 
         public virtual bool findAnnotations<S>(
         S find<S>(Offset localPosition) {
             AnnotationResult<S> result = new AnnotationResult<S>();
             findAnnotations<S>(result, localPosition, onlyFirst: true);
-            return result.entries.Count() == 0 ?  default : result.entries.First().annotation;
+            return !result.entries.Any() ?  default : result.entries.First().annotation;
         }
 
         AnnotationResult<S> findAllAnnotations<S>(Offset localPosition) {
                 defaultValue: foundation_.kNullDefaultValue));
             properties.add(new DiagnosticsProperty<object>("creator", debugCreator,
                 defaultValue: foundation_.kNullDefaultValue, level: DiagnosticLevel.debug));
+            properties.add(new DiagnosticsProperty<string>("engine layer", foundation_.describeIdentity(_engineLayer)));
         }
         public void replaceWith(Layer newLayer) {
             D.assert(parent != null);
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new DiagnosticsProperty<Rect>("paint bounds", canvasBounds));
-            properties.add(new DiagnosticsProperty<string>("picture", _picture.GetType().ToString));
+            properties.add(new DiagnosticsProperty<string>("picture", foundation_.describeIdentity(_picture)));
-                    "isComplex =" + isComplexHint + "willChange ="+ willChangeHint)
+                    $"isComplex = {isComplexHint} willChange = {willChangeHint}")
             );
         }
 
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
             layerOffset = layerOffset ?? Offset.zero;
 
-            Rect shiftedRect = rect.shift(layerOffset);
+            Rect shiftedRect = layerOffset == Offset.zero ? rect : rect.shift(layerOffset);
             builder.addTexture(
                 textureId,
                 offset: shiftedRect.topLeft,
             get { return _lastChild; }
         }
         internal Layer _lastChild;
-        
+        internal bool hasChildren {
+            get { return _firstChild != null; }
+        }
+
         public ui.Scene buildScene(ui.SceneBuilder builder) {
             List<PictureLayer> temporaryLayers =  new List<PictureLayer>();
             D.assert(()=> {
             
             UIWidgetsError.reportError(new UIWidgetsErrorDetails(
                 exception: new UIWidgetsError("Painting order is out of order with respect to elevation.\n" +
-                                              "See https://api.flutter.dev/flutter/rendering/debugCheckElevations.html " +
+                                              "See https://api.flutter.dev/flutter/rendering/debugCheckElevationsEnabled.html " +
                                               "for more details."),
                 library: "rendering library",
                 context: new ErrorDescription("during compositing"),
                 bool isAbsorbed = child.findAnnotations<S>(result, localPosition, onlyFirst: onlyFirst);
                 if (isAbsorbed)
                     return true;
-                if (onlyFirst && result.entries.Count() != 0)
+                if (onlyFirst && result.entries.Any())
                     return isAbsorbed;
             }
             return false;
         }
 
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
+            layerOffset = layerOffset ?? Offset.zero;
             addChildrenToScene(builder, layerOffset);
         }
 
             properties.add(new DiagnosticsProperty<Offset>("offset", offset));
         }
 
-        public Scene buildScene(SceneBuilder builder) {
+        /*public Scene buildScene(SceneBuilder builder) {
             List<PictureLayer> temporaryLayers = null;
             D.assert(() => {
                 if (RenderingDebugUtils.debugCheckElevationsEnabled) {
                 return true;
             });
             return scene;
-        }
+        }*/
-            D.assert(pixelRatio != null);
             ui.SceneBuilder builder = new SceneBuilder();
             Matrix4 transform = Matrix4.translationValues(
                 (-bounds.left  - offset.dx) * pixelRatio,
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
             layerOffset = layerOffset ?? Offset.zero;
             D.assert(clipRect != null);
-            D.assert(clipBehavior != null);
 
             bool enabled = true;
             D.assert(() => {
     public class ClipRRectLayer : ContainerLayer {
         public ClipRRectLayer(
             RRect clipRRect = null,
-            Clip clipBehavior = Clip.hardEdge
+            Clip clipBehavior = Clip.antiAlias
         ) {
             D.assert(clipRRect != null);
             D.assert(clipBehavior != Clip.none);
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
             layerOffset = layerOffset ?? Offset.zero;
             D.assert(clipRRect != null);
-            D.assert(clipBehavior != null);
             bool enabled = true;
             D.assert(() => {
                 enabled = !D.debugDisableClipLayers;
     public class ClipPathLayer : ContainerLayer {
         public ClipPathLayer(
             Path clipPath = null,
-            Clip clipBehavior = Clip.hardEdge
+            Clip clipBehavior = Clip.antiAlias
         ) {
             D.assert(clipPath != null);
             D.assert(clipBehavior != Clip.none);
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
             layerOffset = layerOffset ?? Offset.zero;
             D.assert(clipPath != null);
-            D.assert(clipBehavior != null);
 
             bool enabled = true;
             D.assert(() => {
         ColorFilter _colorFilter;
         
         
-        //[!!!]builder.pushColorFilter?
-        /*public override void addToScene(ui.SceneBuilder builder, Offset layerOffset = null ) {
+        public override void addToScene(ui.SceneBuilder builder, Offset layerOffset = null ) {
             D.assert(colorFilter != null);
             engineLayer =  builder.pushColorFilter(
                 colorFilter,
             builder.pop();
-        }*/
+        }
         
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
 
     ui.ImageFilter _imageFilter;
     
-    //[!!!] builder.pushImageFilter?
-    /*public override void addToScene(ui.SceneBuilder builder,  Offset layerOffset = null) {
+    public override void addToScene(ui.SceneBuilder builder,  Offset layerOffset = null) {
         D.assert(imageFilter != null);
         engineLayer = builder.pushImageFilter(
             imageFilter,
         builder.pop();
-    }*/
+    }
     
     public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
         base.debugFillProperties(properties);
     
     public class TransformLayer : OffsetLayer {
         public TransformLayer(Matrix4 transform = null, Offset offset = null) : base(offset) {
+            offset = offset ?? Offset.zero;
             _transform = transform ?? Matrix4.identity();
         }
 
                 D.assert(value != null);
-                //D.assert(value.storage.Each((float component) => ));
+                bool componentIsFinite = true;
+                foreach (var component in value.storage) {
+                    if (!component.isFinite()) {
+                        componentIsFinite = false;
+                        break;
+                    }
+                }
+                D.assert(componentIsFinite);
                 if (value == _transform)
                     return;
                 _transform = value;
             }
 
             engineLayer = builder.pushTransform(
-                _lastEffectiveTransform._m4storage,
+                _lastEffectiveTransform.storage,
                 oldLayer: engineLayer as TransformEngineLayer);
             
             addChildrenToScene(builder);
         public int alpha {
             get { return _alpha; }
             set {
+                D.assert(value != null);
                 if (value != _alpha) {
                     _alpha = value;
                     markNeedsAddToScene();
         }
 
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
+            layerOffset = layerOffset ?? Offset.zero;
             D.assert(filter != null);
             engineLayer = builder.pushBackdropFilter(
                 filter: filter,
                 D.assert(value != null);
                 _link = value;
             }
-
         }
         LayerLink _link;
         
         public override void addToScene(SceneBuilder builder, Offset layerOffset = null) {
             layerOffset = layerOffset ?? Offset.zero;
             D.assert(link != null);
-            D.assert(showWhenUnlinked != null);
             D.assert(link != null);
             if (link.leader == null && !showWhenUnlinked) {
                 _lastTransform = null;
                 defaultValue: foundation_.kNullDefaultValue));
         }
     }
+    
+    /*public class PlatformViewLayer : Layer {
+        public PlatformViewLayer(
+            Rect rect = null,
+            int viewId = default,
+            MouseTrackerAnnotation hoverAnnotation = null
+        ) {
+            D.assert(rect != null);
+        }
+        
+        public readonly Rect rect;
+
+  
+        public readonly int viewId;
+  
+        public readonly MouseTrackerAnnotation hoverAnnotation;
+
+  
+        public override void addToScene(ui.SceneBuilder builder,  Offset layerOffset = null) {
+            Rect shiftedRect = layerOffset == Offset.zero ? rect : rect.shift(layerOffset);
+            builder.addPlatformView(
+                viewId,
+                offset: shiftedRect.topLeft,
+                width: shiftedRect.width,
+                height: shiftedRect.height
+            );
+        }
+
+  
+        public override bool findAnnotations<S>(AnnotationResult<S> result, Offset localPosition, bool onlyFirst ) {
+            if (hoverAnnotation == null || !rect.contains(localPosition)) {
+                return false;
+            }
+            if (typeof(S) == typeof(MouseTrackerAnnotation)) {
+                Object untypedValue = hoverAnnotation;
+                S typedValue = (S)untypedValue;
+                result.add(new AnnotationEntry<S>(
+                    annotation: typedValue,
+                    localPosition: localPosition
+                ));
+                return true;
+            }
+            return false;
+        }
+    }*/
-            int? optionsMask = null,
-            int? rasterizerThreshold = null,
-            bool? checkerboardRasterCacheImages = null,
-            bool? checkerboardOffscreenLayers = null
+            int optionsMask = default,
+            int rasterizerThreshold = default,
+            bool checkerboardRasterCacheImages = default,
+            bool checkerboardOffscreenLayers = default
             
         ) {
             _overlayRect = overlayRect;
         }
         Rect _overlayRect;
 
-        public readonly int? optionsMask;
-        public readonly int? rasterizerThreshold;
-        public readonly bool? checkerboardRasterCacheImages;
-        public readonly bool? checkerboardOffscreenLayers;
+        public readonly int optionsMask;
+        public readonly int rasterizerThreshold;
+        public readonly bool checkerboardRasterCacheImages;
+        public readonly bool checkerboardOffscreenLayers;
 
         public override bool findAnnotations<S>(AnnotationResult<S> result, Offset localPosition,  bool onlyFirst ) {
             return false;
             layerOffset = layerOffset ?? Offset.zero;
             
             var shiftedOverlayRect = layerOffset == Offset.zero ? overlayRect : overlayRect.shift(layerOffset);
-            builder.addPerformanceOverlay((int)optionsMask, shiftedOverlayRect);
+            builder.addPerformanceOverlay(optionsMask, shiftedOverlayRect);
             //TODO: add implementations
             //builder.setRasterizerTracingThreshold(rasterizerThreshold);
             //builder.setCheckerboardRasterCacheImages(checkerboardRasterCacheImages);
             ) {
             offset = offset ?? Offset.zero;
             D.assert(value != null);
-            D.assert(opaque != null);
             this.value = value;
             this.size = size;
             this.offset = offset;
 
         public override bool findAnnotations<S>(AnnotationResult<S> result, Offset localPosition, bool onlyFirst ) {
             bool isAbsorbed = base.findAnnotations(result, localPosition, onlyFirst: onlyFirst);
-            if (result.entries.Count() != 0 && onlyFirst)
+            if (result.entries.Any() && onlyFirst)
                 return isAbsorbed;
             if (size != null && !(offset & size).contains(localPosition)) {
                 return isAbsorbed;
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new FloatProperty("elevation", elevation));
-            properties.add(new DiagnosticsProperty<Color>("color", color));
+            properties.add(new ColorProperty("color", color));
         }
     }
 }

com.unity.uiwidgets/Runtime/rendering/list_body.cs

         }
 
         protected override void performLayout() {
+            BoxConstraints constraints = this.constraints;
             D.assert(() => {
                 switch (mainAxis) {
                     case Axis.horizontal:
                         break;
                 }
 
-                throw new UIWidgetsError(
-                    "RenderListBody must have unlimited space along its main axis.\n" +
-                    "RenderListBody does not clip or resize its children, so it must be " +
-                    "placed in a parent that does not constrain the main " +
-                    "axis. You probably want to put the RenderListBody inside a " +
-                    "RenderViewport with a matching main axis.");
+                throw new UIWidgetsError(new List<DiagnosticsNode>{
+                    new ErrorSummary("RenderListBody must have unlimited space along its main axis."),
+                    new ErrorDescription(
+                        "RenderListBody does not clip or resize its children, so it must be " +
+                        "placed in a parent that does not constrain the main axis."
+                    ),
+                    new ErrorHint(
+                        "You probably want to put the RenderListBody inside a " +
+                        "RenderViewport with a matching main axis."
+                    )
+                });
             });
 
             D.assert(() => {
                         break;
                 }
 
-                throw new UIWidgetsError(
-                    "RenderListBody must have a bounded constraint for its cross axis.\n" +
-                    "RenderListBody forces its children to expand to fit the RenderListBody\"s container, " +
-                    "so it must be placed in a parent that constrains the cross " +
-                    "axis to a finite dimension. If you are attempting to nest a RenderListBody with " +
-                    "one direction inside one of another direction, you will want to " +
-                    "wrap the inner one inside a box that fixes the dimension in that direction, " +
-                    "for example, a RenderIntrinsicWidth or RenderIntrinsicHeight object. " +
-                    "This is relatively expensive, however."
-                );
+                throw new UIWidgetsError(new List<DiagnosticsNode>{
+                    new ErrorSummary("RenderListBody must have a bounded constraint for its cross axis."),
+                    new ErrorDescription(
+                        "RenderListBody forces its children to expand to fit the RenderListBody's container, " +
+                        "so it must be placed in a parent that constrains the cross " +
+                        "axis to a finite dimension."
+                    ),
+                    // TODO(jacobr): this hint is a great candidate to promote to being an
+                    // automated quick fix in the future.
+                    new ErrorHint(
+                        "If you are attempting to nest a RenderListBody with " +
+                        "one direction inside one of another direction, you will want to " +
+                        "wrap the inner one inside a box that fixes the dimension in that direction, " +
+                        "for example, a RenderIntrinsicWidth or RenderIntrinsicHeight object. " +
+                        "This is relatively expensive, however." // (that's why we don't do it automatically)
+                    )
+                });
             });
 
             float mainAxisExtent = 0.0f;
                 case Axis.vertical:
                     return _getIntrinsicCrossAxis((RenderBox child) => child.getMinIntrinsicWidth(height));
             }
-
             D.assert(false);
             return 0.0f;
         }

com.unity.uiwidgets/Runtime/rendering/list_wheel_viewport.cs

     public interface IListWheelChildManager {
         int? childCount { get; }
         bool childExistsAt(int index);
-        void createChild(int index, RenderBox after);
+        void createChild(int index, RenderBox after = null);
         void removeChild(RenderBox child);
     }
 
             D.assert(perspective > 0);
             D.assert(perspective <= 0.01f, () => perspectiveTooHighMessage);
             D.assert(magnification > 0);
-            D.assert(overAndUnderCenterOpacity != null);
-            D.assert(squeeze != null);
             D.assert(squeeze > 0);
             D.assert(
                 !renderChildrenOutsideViewport || !clipToSize,
                 return _overAndUnderCenterOpacity;
             }
             set {
-                D.assert(value != null);
                 D.assert(value >= 0 && value <= 1);
                 if (value == _overAndUnderCenterOpacity)
                     return;
                 return _squeeze;
             }
             set {
-                D.assert(value != null);
                 D.assert(value > 0);
                 if (value == _squeeze)
                     return;
                 minWidth: 0.0f
             );
 
-            float visibleHeight = size.height;
+            float visibleHeight = size.height * _squeeze;
             if (renderChildrenOutsideViewport) {
                 visibleHeight *= 2;
             }
 
             float fractionalY = (untransformedPaintingCoordinates.dy + _itemExtent / 2.0f) / size.height;
 
-            float angle = -(fractionalY - 0.5f) * 2.0f * _maxVisibleRadian;
+            float angle = -(fractionalY - 0.5f) * 2.0f * _maxVisibleRadian / squeeze;
             if (angle > Mathf.PI / 2.0f || angle < -Mathf.PI / 2.0f) {
                 return;
             }
             Offset offsetToCenter =
                 new Offset(untransformedPaintingCoordinates.dx, -deltaY - _topScrollMarginExtent);
 
-            if (!useMagnifier) {
+            bool shouldApplyOffCenterDim = overAndUnderCenterOpacity < 1;
+            if (useMagnifier || shouldApplyOffCenterDim) {
+                _paintChildWithMagnifier(context, offset, child, transform, offsetToCenter, untransformedPaintingCoordinates);
+            } else {
-            else {
-                _paintChildWithMagnifier(
-                    context,
-                    offset,
-                    child,
-                    transform,
-                    offsetToCenter,
-                    untransformedPaintingCoordinates
-                );
-            }
         }
 
         void _paintChildWithMagnifier(
-            // Matrix4x4 cylindricalTransform,
             Matrix4 cylindricalTransform,
             Offset offsetToCenter,
             Offset untransformedPaintingCoordinates
             if (isAfterMagnifierTopLine && isBeforeMagnifierBottomLine) {
                 Rect centerRect = Rect.fromLTWH(
                     0.0f,
-                    magnifierTopLinePosition, size.width, _itemExtent * _magnification);
+                    magnifierTopLinePosition, 
+                    size.width, 
+                    _itemExtent * _magnification);
                 Rect topHalfRect = Rect.fromLTWH(
                     0.0f,
                     0.0f, size.width,
-                    magnifierBottomLinePosition, size.width,
+                    magnifierBottomLinePosition, 
+                    size.width,
-                    false,
+                    needsCompositing,
-                            false,
+                            needsCompositing,
-                                context2.paintChild(
-                                    child,
-                                    offset2 + untransformedPaintingCoordinates);
+                                context2.paintChild(child, offset2 + untransformedPaintingCoordinates);
-                    false,
+                    needsCompositing,
                     offset,
                     untransformedPaintingCoordinates.dy <= magnifierTopLinePosition
                         ? topHalfRect
             PaintingContext context,
             Offset offset,
             RenderBox child,
-            // Matrix4x4 cylindricalTransform,
+            PaintingContextCallback painter = (PaintingContext _context, Offset _offset) => {
+                _context.paintChild(
+                    child,
+                    _offset + offsetToCenter
+                );
+            };
+            PaintingContextCallback opacityPainter = (PaintingContext context2, Offset offset2) =>{
+                context2.pushOpacity(offset2, (overAndUnderCenterOpacity * 255).round(), painter);
+            };
+
-                false,
+                needsCompositing,
-                cylindricalTransform,
-                // this._centerOriginTransform(cylindricalTransform),
-                (PaintingContext _context, Offset _offset) => { _context.paintChild(child, _offset + offsetToCenter); }
+                _centerOriginTransform(cylindricalTransform),
+                // Pre-transform painting function.
+                overAndUnderCenterOpacity == 1 ? painter : opacityPainter
+        Matrix4 _centerOriginTransform(Matrix4 originalMatrix) {
+            Matrix4 result = Matrix4.identity();
+            Offset centerOriginTranslation = Alignment.center.alongSize(size);
+            result.translate(centerOriginTranslation.dx * (-_offAxisFraction * 2 + 1),
+                centerOriginTranslation.dy);
+            result.multiply(originalMatrix);
+            result.translate(-centerOriginTranslation.dx * (-_offAxisFraction * 2 + 1),
+                -centerOriginTranslation.dy);
+            return result;
+        }
+        
+        Matrix4 _magnifyTransform() {
+            Matrix4 magnify = Matrix4.identity();
+            magnify.translate(size.width * (-_offAxisFraction + 0.5), size.height / 2);
+            magnify.scale(_magnification, _magnification, _magnification);
+            magnify.translate(-size.width * (-_offAxisFraction + 0.5), -size.height / 2);
+            return magnify;
+        }
+        
+        
         public override Rect describeApproximatePaintClip(RenderObject child) {
             if (child != null && _shouldClipAtCurrentOffset()) {
                 return Offset.zero & size;
         }
 
-        protected override bool hitTestChildren(BoxHitTestResult result, Offset position = null
-        ) {
+        protected override bool hitTestChildren(BoxHitTestResult result, Offset position = null) {
             return false;
         }
 
 
             ListWheelParentData parentData = (ListWheelParentData) child.parentData;
             float targetOffset = parentData.offset.dy;
-            Matrix4 transform = target.getTransformTo(this);
+            Matrix4 transform = target.getTransformTo(child);
             Rect bounds = MatrixUtils.transformRect(transform, rect);
             Rect targetRect = bounds.translate(0.0f, (size.height - itemExtent) / 2);
 

com.unity.uiwidgets/Runtime/rendering/object.cs

 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
-using UnityEngine;
+using Debug = UnityEngine.Debug;
 using Rect = Unity.UIWidgets.ui.Rect;
 
 namespace Unity.UIWidgets.rendering {
                 D.assert(debugAlsoPaintedParent || child._layer.attached);
                 child._layer.removeAllChildren();
             }
-
+            D.assert(child._layer is OffsetLayer);
             D.assert(() => {
                 child._layer.debugCreator = child.debugCreator ?? child.GetType().ToString();
                 return true;
 
         public void pushLayer(ContainerLayer childLayer, PaintingContextCallback painter, Offset offset,
             Rect childPaintBounds = null) {
-            D.assert(!childLayer.attached);
-            D.assert(childLayer.parent == null);
-
+            if (childLayer.hasChildren) {
+                childLayer.removeAllChildren();
+            }
             stopRecordingIfNeeded();
             appendLayer(childLayer);
 
             return new PaintingContext(childLayer, bounds);
         }
 
-        public void pushClipRect(bool needsCompositing, Offset offset, Rect clipRect, PaintingContextCallback painter,
-            Clip clipBehavior = Clip.hardEdge) {
+        public ClipRectLayer pushClipRect(
+            bool needsCompositing, 
+            Offset offset, 
+            Rect clipRect, 
+            PaintingContextCallback painter,
+            Clip clipBehavior = Clip.hardEdge, 
+            ClipRectLayer oldLayer = null) {
-                pushLayer(new ClipRectLayer(offsetClipRect, clipBehavior: clipBehavior),
-                    painter, offset, childPaintBounds: offsetClipRect);
+                ClipRectLayer layer = oldLayer ?? new ClipRectLayer();
+                layer.clipRect = offsetClipRect;
+                layer.clipBehavior = clipBehavior;
+                pushLayer(layer, painter, offset, childPaintBounds: offsetClipRect);
+                return layer;
+                return null;
-        public void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, RRect clipRRect,
-            PaintingContextCallback painter, Clip clipBehavior = Clip.antiAlias) {
+        public ClipRRectLayer pushClipRRect(
+            bool needsCompositing, 
+            Offset offset, 
+            Rect bounds, 
+            RRect clipRRect,
+            PaintingContextCallback painter, 
+            Clip clipBehavior = Clip.antiAlias,
+            ClipRRectLayer oldLayer = null) {
-                pushLayer(new ClipRRectLayer(offsetClipRRect, clipBehavior: clipBehavior),
-                    painter, offset, childPaintBounds: offsetBounds);
+                ClipRRectLayer layer = oldLayer ?? new ClipRRectLayer();
+                layer.clipRRect = offsetClipRRect;
+                layer.clipBehavior = clipBehavior;
+                pushLayer(layer, painter, offset, childPaintBounds: offsetBounds);
+                return layer;
+                return null;
-        public void pushClipPath(bool needsCompositing, Offset offset, Rect bounds, Path clipPath,
-            PaintingContextCallback painter, Clip clipBehavior = Clip.antiAlias) {
+        public ClipPathLayer pushClipPath(
+            bool needsCompositing, 
+            Offset offset, 
+            Rect bounds, 
+            Path clipPath,
+            PaintingContextCallback painter, 
+            Clip clipBehavior = Clip.antiAlias,
+            ClipPathLayer oldLayer = null) {
-                pushLayer(new ClipPathLayer(clipPath: offsetClipPath, clipBehavior: clipBehavior), painter, offset,
-                    childPaintBounds: offsetBounds);
+                ClipPathLayer layer = oldLayer ?? new ClipPathLayer();
+                layer.clipPath = offsetClipPath;
+                layer.clipBehavior = clipBehavior;
+                pushLayer(layer, painter, offset, childPaintBounds: offsetBounds);
+                return layer;
+                return null;
+        
+        public ColorFilterLayer pushColorFilter(Offset offset, ColorFilter colorFilter, PaintingContextCallback painter, ColorFilterLayer oldLayer = null) {
+            D.assert(colorFilter != null);
+            ColorFilterLayer layer = oldLayer ?? new ColorFilterLayer();
+            layer.colorFilter = colorFilter;
+            pushLayer(layer, painter, offset);
+            return layer;
+        }
-        public void pushTransform(bool needsCompositing, Offset offset, Matrix4 transform,
-            PaintingContextCallback painter) {
+        public TransformLayer pushTransform(
+            bool needsCompositing, 
+            Offset offset, 
+            Matrix4 transform,
+            PaintingContextCallback painter,
+            TransformLayer oldLayer = null) {
             Matrix4 effectiveTransform;
             if (offset == null || offset == Offset.zero) {
                 effectiveTransform = transform;
             }
 
             if (needsCompositing) {
-                // it could just be "scale == 0", ignore the assertion.
-                // D.assert(invertible);
+                TransformLayer layer = oldLayer ?? new TransformLayer();
+                layer.transform = effectiveTransform;
-                    new TransformLayer(effectiveTransform),
+                    layer,
+                return layer;
             }
             else {
                 canvas.save();
+                return null;
-
-        public void pushOpacity(Offset offset, int alpha, PaintingContextCallback painter) {
-            pushLayer(new OpacityLayer(alpha: alpha), painter, offset);
-        }
+        
         public OpacityLayer pushOpacity(Offset offset, int alpha, PaintingContextCallback painter,  OpacityLayer oldLayer = null) {
             OpacityLayer layer = oldLayer ?? new OpacityLayer();
             layer.alpha = alpha;
                 $"{GetType()}#{GetHashCode()}(layer: {_containerLayer}, canvas bounds: {estimatedBounds}";
         }
         
-        public ColorFilterLayer pushColorFilter(Offset offset, ColorFilter colorFilter, PaintingContextCallback painter, ColorFilterLayer oldLayer = null) {
-            D.assert(colorFilter != null);
-            ColorFilterLayer layer = oldLayer ?? new ColorFilterLayer();
-            layer.colorFilter = colorFilter;
-            pushLayer(layer, painter, offset);
-            return layer;
-        }
+        
+        protected Constraints(){}
         public abstract bool isTight { get; }
 
         public abstract bool isNormalized { get; }
             _needsCompositing = isRepaintBoundary || alwaysNeedsCompositing;
         }
 
+        void reassemble() {
+            markNeedsLayout();
+            markNeedsCompositingBitsUpdate();
+            markNeedsPaint();
+            visitChildren((RenderObject child) =>{
+                child.reassemble();
+            });
+        }
+        
         public ParentData parentData;
 
         public virtual void setupParentData(RenderObject child) {
             D.assert(node._relayoutBoundary == node);
             return true;
         }
-        // TODO
-        /*void markNeedsSemanticsUpdate() { 
-            D.assert(!attached || !owner._debugDoingSemantics);
-            if (!attached || owner._semanticsOwner == null) {
-              _cachedSemanticsConfiguration = null;
-              return;
-            }
-
-            bool wasSemanticsBoundary = _semantics != null && _cachedSemanticsConfiguration?.isSemanticBoundary == true;
-            _cachedSemanticsConfiguration = null;
-            bool isEffectiveSemanticsBoundary = _semanticsConfiguration.isSemanticBoundary && wasSemanticsBoundary;
-            RenderObject node = this;
-
-            while (!isEffectiveSemanticsBoundary && node.parent is RenderObject) {
-                if (node != this && node._needsSemanticsUpdate)
-                    break;
-                node._needsSemanticsUpdate = true;
-
-                node = node.parent as RenderObject;
-                isEffectiveSemanticsBoundary = node._semanticsConfiguration.isSemanticBoundary;
-                if (isEffectiveSemanticsBoundary && node._semantics == null) {
-                    return;
-                }
-            }
-            if (node != this && _semantics != null && _needsSemanticsUpdate) {
-
-                owner._nodesNeedingSemantics.remove(this);
-            }
-            if (!node._needsSemanticsUpdate) {
-                node._needsSemanticsUpdate = true;
-                if (owner != null) {
-                    D.assert(node._semanticsConfiguration.isSemanticBoundary || node.parent is! RenderObject);
-                    owner._nodesNeedingSemantics.add(node);
-                    owner.requestVisualUpdate();
-                }
-            }
-        }*/
+        
         public virtual void markNeedsLayout() {
             D.assert(_debugCanPerformMutations);
             if (_needsLayout) {
             if (_relayoutBoundary != this) {
                 _relayoutBoundary = null;
                 _needsLayout = true;
-                visitChildren(child => { child._cleanRelayoutBoundary(); });
+                visitChildren(_cleanChildRelayoutBoundary);
+        }
+        
+        static void _cleanChildRelayoutBoundary(RenderObject child) {
+            child._cleanRelayoutBoundary();
         }
 
         public void scheduleInitialLayout() {
             D.assert(!_debugDoingThisLayout);
 
             RenderObject relayoutBoundary;
-            if (!parentUsesSize || sizedByParent || constraints.isTight || !(this.parent is RenderObject)) {
+            if (!parentUsesSize || sizedByParent || constraints.isTight || !(parent is RenderObject)) {
-                RenderObject parent = (RenderObject) this.parent;
-                relayoutBoundary = parent._relayoutBoundary;
+                relayoutBoundary = (parent as RenderObject)._relayoutBoundary;
             }
 
             D.assert(() => {
             }
 
             _constraints = constraints;
+            if (_relayoutBoundary != null && relayoutBoundary != _relayoutBoundary) {
+                visitChildren(_cleanChildRelayoutBoundary);
+            }
             _relayoutBoundary = relayoutBoundary;
 
             D.assert(!_debugMutationsLocked);
             }
         }
 
+        /// Rotate this render object (not yet implemented).
+        void rotate(
+            int oldAngle, // 0..3
+            int newAngle, // 0..3
+            TimeSpan time
+        ) { }
+        
         public bool debugDoingThisPaint {
             get { return _debugDoingThisPaint; }
         }
                 return _layer;
             }
             set {
-                D.assert(!isRepaintBoundary);
+                D.assert(
+                    !isRepaintBoundary,
+                    () => "Attempted to set a layer to a repaint boundary render object.\n" +
+                "The framework creates and assigns an OffsetLayer to a repaint " +
+                "boundary automatically."
+                    );
-
-        public void setLayer(ContainerLayer newLayer) {
-            D.assert(
-                !isRepaintBoundary,()=>
-                "Attempted to set a layer to a repaint boundary render object.\n" +
-                "The framework creates and assigns an OffsetLayer to a repaint "+
-                "boundary automatically.");
-            _layer = newLayer;
-        }
+        
         public ContainerLayer debugLayer {
             get {
                 ContainerLayer result = null;
                     return true;
                 });
 
-                D.assert(_layer != null);
+                D.assert(_layer is OffsetLayer);
 
                 if (owner != null) {
                     owner._nodesNeedingPaint.Add(this);
             else if (this.parent is RenderObject) {
-                D.assert(_layer == null);
-                var parent = (RenderObject) this.parent;
+                RenderObject parent = this.parent as RenderObject;
+                D.assert(parent == this.parent);
             }
             else {
                 D.assert(() => {
         internal void _paintWithContext(PaintingContext context, Offset offset) {
             D.assert(() => {
                 if (_debugDoingThisPaint) {
-                    throw new UIWidgetsError(
-                        "Tried to paint a RenderObject reentrantly.\n" +
-                        "The following RenderObject was already being painted when it was " +
-                        "painted again:\n" +
-                        "  " + toStringShallow(joiner: "\n    ") + "\n" +
-                        "Since this typically indicates an infinite recursion, it is " +
-                        "disallowed."
-                    );
+                    throw new UIWidgetsError(new List<DiagnosticsNode>{
+                        new ErrorSummary("Tried to paint a RenderObject reentrantly."),
+                        describeForError(
+                            "The following RenderObject was already being painted when it was " +
+                            "painted again"
+                        ),
+                        new ErrorDescription(
+                            "Since this typically indicates an infinite recursion, it is " +
+                            "disallowed."
+                        )
+                    });
                 }
 
                 return true;
 
             D.assert(() => {
                 if (_needsCompositingBitsUpdate) {
-                    throw new UIWidgetsError(
-                        "Tried to paint a RenderObject before its compositing bits were " +
-                        "updated.\n" +
-                        "The following RenderObject was marked as having dirty compositing " +
-                        "bits at the time that it was painted:\n" +
-                        "  " + toStringShallow(joiner: "\n    ") + "\n" +
-                        "A RenderObject that still has dirty compositing bits cannot be " +
-                        "painted because this indicates that the tree has not yet been " +
-                        "properly configured for creating the layer tree.\n" +
-                        "This usually indicates an error in the Flutter framework itself."
-                    );
+                    throw new UIWidgetsError(new List<DiagnosticsNode>{
+                        new ErrorSummary(
+                            "Tried to paint a RenderObject before its compositing bits were " +
+                            "updated."
+                        ),
+                        describeForError(
+                            "The following RenderObject was marked as having dirty compositing " +
+                            "bits at the time that it was painted"
+                        ),
+                        new ErrorDescription(
+                            "A RenderObject that still has dirty compositing bits cannot be " +
+                            "painted because this indicates that the tree has not yet been " +
+                            "properly configured for creating the layer tree."
+                        ),
+                        new ErrorHint(
+                            "This usually indicates an error in the Flutter framework itself."
+                        )
+                    });
                 }
 
                 return true;
         }
 
         public Matrix4 getTransformTo(RenderObject ancestor) {
+            bool ancestorSpecified = ancestor != null;
             D.assert(attached);
 
             if (ancestor == null) {
                 D.assert(renderer != null);
                 renderers.Add(renderer);
             }
-
+            if (ancestorSpecified)
+                renderers.Add(ancestor);
             var transform = Matrix4.identity();
             for (int index = renderers.Count - 1; index > 0; index -= 1) {
                 renderers[index].applyPaintTransform(renderers[index - 1], transform);
                 header += " NEEDS-PAINT";
             }
 
+            if (_needsCompositingBitsUpdate)
+                header += " NEEDS-COMPOSITING-BITS-UPDATE";
+            
             if (!attached) {
                 header += " DETACHED";
             }
 
-        public override string toString(DiagnosticLevel minLevel = DiagnosticLevel.debug) {
+        public override string toString(DiagnosticLevel minLevel = DiagnosticLevel.info) {
             return toStringShort();
         }
 
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
+            properties.add(new FlagProperty("needsCompositing", value: _needsCompositing, ifTrue: "needs compositing"));
             properties.add(new DiagnosticsProperty<object>(
                 "creator", debugCreator, defaultValue: foundation_.kNullDefaultValue,
                 level: DiagnosticLevel.debug));
                 defaultValue: foundation_.kNullDefaultValue));
         }
 
+        public override List<DiagnosticsNode> debugDescribeChildren() => new List<DiagnosticsNode>();
+        
         public virtual void showOnScreen(
             RenderObject descendant = null,
             Rect rect = null,
                 );
             }
         }
-    public DiagnosticsNode describeForError(String name, DiagnosticsTreeStyle style = DiagnosticsTreeStyle.shallow) {
+    public DiagnosticsNode describeForError(string name, DiagnosticsTreeStyle style = DiagnosticsTreeStyle.shallow) {
             return toDiagnosticsNode(name: name, style: style);
         }
     }
         RenderObject childAfter(RenderObject child);
     }
 
+    public interface RelayoutWhenSystemFontsChangeMixin {
+        void systemFontsDidChange();
+        void attach(PipelineOwner owner);
+        void detach();
+    }
+
+            StackTrace stack = null,
             string library = null,
             DiagnosticsNode context = null,
             RenderObject renderObject = null,

com.unity.uiwidgets/Runtime/rendering/paragraph.cs

 
 namespace Unity.UIWidgets.rendering {
     public enum TextOverflow {
-        /// Clip the overflowing text to fix its container.
-
-        /// Fade the overflowing text to transparent.
-
-        /// Use an ellipsis to indicate that the text has overflowed.
-        
-        /// Render overflowing text outside of its container.
-        visible,
+        visible
-    
-    public class RenderParagraph : RenderBox{
-        // ContainerRenderObjectMixin<RenderBox, TextParentData>,
-        //RenderBoxContainerDefaultsMixin<RenderBox, TextParentData>,
-        //RelayoutWhenSystemFontsChangeMixin
+    public class TextParentData : ContainerBoxParentData<RenderBox> {
+        public float scale;
+        public override string ToString() {
+            List<string> values = new List<string>();
+            if (offset != null) values.Add("offset=$offset");
+            if (scale != null) values.Add("scale=$scale");
+            values.Add(base.ToString());
+            return string.Join("; ", values);
+        }
+    }
+    public class RenderParagraph : RenderBoxContainerDefaultsMixinContainerRenderObjectMixinRenderBox<RenderBox, TextParentData> {
         static readonly string _kEllipsis = "\u2026";
 
         bool _softWrap;
 
         public RenderParagraph(
             InlineSpan text = null,
-            TextAlign textAlign = TextAlign.left,
+            TextAlign textAlign = TextAlign.start,
             TextDirection textDirection = TextDirection.ltr,
             bool softWrap = true,
             TextOverflow overflow = TextOverflow.clip,
             TextWidthBasis textWidthBasis = TextWidthBasis.parent,
             ui.TextHeightBehavior textHeightBehavior = null,
             List<RenderBox> children = null
-            //Action onSelectionChanged = null,
-            //Color selectionColor = null
-            D.assert(textAlign != null);
-            D.assert(textDirection != null);
-            D.assert(softWrap != null);
-            D.assert(overflow != null);
-            D.assert(textScaleFactor != null);
-            D.assert(textWidthBasis != null);
             _softWrap = softWrap;
             _overflow = overflow;
             _textPainter = new TextPainter(
                 textWidthBasis: textWidthBasis,
                 textHeightBehavior: textHeightBehavior
             );
-
-            _selection = null;
-            this.onSelectionChanged = onSelectionChanged;
-            this.selectionColor = selectionColor;
-            //addAll(children);
+            //addAll(children);[!!!]?
-            //_resetHoverHandler();
+        public override void setupParentData(RenderObject child) {
+            if (!(child.parentData is TextParentData))
+                child.parentData = new TextParentData();
+        }
+        
+        
         public Action onSelectionChanged;
         public Color selectionColor;
 
                         _textPainter.text = value;
                         _extractPlaceholderSpans(value);
                         markNeedsPaint();
-                        //markNeedsSemanticsUpdate();
                         break;
                     case RenderComparison.layout:
                         _textPainter.text = value;
                         break;
-                    /*case RenderComparison.function:
-                        _textPainter.text = value;
-                        markNeedsPaint();
-                        break;
-                    case RenderComparison.paint:
-                        _textPainter.text = value;
-                        markNeedsPaint();
-                        break;
-                    case RenderComparison.layout:
-                        _textPainter.text = value;
-                        markNeedsLayout();
-                        break;*/
                 }
 
                 
         }
 
         public TextAlign textAlign {
-            get { return _textPainter.textAlign; }
+            get { return _textPainter.textAlign.Value; }
             set {
                 if (_textPainter.textAlign == value) {
                     return;
                     return;
                 }
 
-                _textPainter.textDirection = textDirection;
+                _textPainter.textDirection = value;
                 markNeedsLayout();
             }
         }
             return _textPainter.getOffsetForCaret(position, caretPrototype);
         }
+        
+        List<ui.TextBox> getBoxesForSelection(TextSelection selection) {
+            D.assert(!debugNeedsLayout);
+            _layoutTextWithConstraints(constraints);
+            return _textPainter.getBoxesForSelection(selection);
+        }
+        
+        TextPosition getPositionForOffset(Offset offset) {
+            D.assert(!debugNeedsLayout);
+            _layoutTextWithConstraints(constraints);
+            return _textPainter.getPositionForOffset(offset);
+        }
+        
+        TextRange getWordBoundary(TextPosition position) {
+            D.assert(!debugNeedsLayout);
+            _layoutTextWithConstraints(constraints);
+            return _textPainter.getWordBoundary(position);
+        }
 
         public bool softWrap {
             get { return _softWrap; }
 
                 _overflow = value;
                 _textPainter.ellipsis = value == TextOverflow.ellipsis ? _kEllipsis : null;
-                // _textPainter.e
                 markNeedsLayout();
             }
         }
                 }
 
                 _textPainter.textScaleFactor = value;
+                _overflowShader = null;
                 markNeedsLayout();
             }
         }
                 }
 
                 _textPainter.maxLines = value;
+                _overflowShader = null;
                 markNeedsLayout();
             }
         }
         public TextWidthBasis textWidthBasis {
             get { return _textPainter.textWidthBasis; }
             set {
-                D.assert(value != null);
                 if (_textPainter.textWidthBasis == value)
                     return;
                 _textPainter.textWidthBasis = value;
         }
 
         protected internal override float computeMinIntrinsicWidth(float height) {
-            _layoutText();
+            if (!_canComputeIntrinsics()) {
+                return 0.0f;
+            }
+            _computeChildrenWidthWithMinIntrinsics(height);
+            _layoutText(); // layout with infinite width.
-            _layoutText();
+            if (!_canComputeIntrinsics()) {
+                return 0.0f;
+            }
+            _computeChildrenWidthWithMaxIntrinsics(height);
+            _layoutText(); // layout with infinite width.
+            if (!_canComputeIntrinsics()) {
+                return 0.0f;
+            }
+            _computeChildrenHeightWithMinIntrinsics(width);
             _layoutText(minWidth: width, maxWidth: width);
             return _textPainter.height;
         }
         }
 
         public override float? computeDistanceToActualBaseline(TextBaseline baseline) {
+            D.assert(!debugNeedsLayout);
+            D.assert(constraints != null);
+            D.assert(constraints.debugAssertIsValid());
-            return _textPainter.computeDistanceToActualBaseline(baseline);
+            return _textPainter.computeDistanceToActualBaseline(TextBaseline.alphabetic);
+        }
+
+        bool _canComputeIntrinsics() {
+            foreach (PlaceholderSpan span in _placeholderSpans) {
+                switch (span.alignment) {
+                    case ui.PlaceholderAlignment.baseline:
+                    case ui.PlaceholderAlignment.aboveBaseline:
+                    case ui.PlaceholderAlignment.belowBaseline: {
+                        D.assert(RenderObject.debugCheckingIntrinsics,
+                        () => "Intrinsics are not available for PlaceholderAlignment.baseline, " +
+                        "PlaceholderAlignment.aboveBaseline, or PlaceholderAlignment.belowBaseline,");
+                        return false;
+                    }
+                    case ui.PlaceholderAlignment.top:
+                    case ui.PlaceholderAlignment.middle:
+                    case ui.PlaceholderAlignment.bottom: {
+                        continue;
+                    }
+                }
+            }
+            return true;
+        }
+
+        void _computeChildrenWidthWithMaxIntrinsics(float height) {
+            RenderBox child = firstChild;
+            List<PlaceholderDimensions> placeholderDimensions = new List<PlaceholderDimensions>(childCount);
+            int childIndex = 0;
+            while (child != null) {
+                placeholderDimensions[childIndex] = new PlaceholderDimensions(
+                size: new Size(child.getMaxIntrinsicWidth(height), height),
+                alignment: _placeholderSpans[childIndex].alignment,
+                baseline: _placeholderSpans[childIndex].baseline.Value,
+                baselineOffset:0.0f
+            );
+            child = childAfter(child);
+            childIndex += 1;
+            }
+            _textPainter.setPlaceholderDimensions(placeholderDimensions);
+        }
+
+        void _computeChildrenWidthWithMinIntrinsics(float height) {
+            RenderBox child = firstChild;
+            List<PlaceholderDimensions> placeholderDimensions = new List<PlaceholderDimensions>(childCount);
+            int childIndex = 0;
+            while (child != null) {
+                float intrinsicWidth = child.getMinIntrinsicWidth(height);
+                float intrinsicHeight = child.getMinIntrinsicHeight(intrinsicWidth);
+                placeholderDimensions[childIndex] = new PlaceholderDimensions(
+                    size: new Size(intrinsicWidth, intrinsicHeight),
+                    alignment: _placeholderSpans[childIndex].alignment,
+                    baseline: _placeholderSpans[childIndex].baseline.Value,
+                    baselineOffset:0.0f
+                );
+                child = childAfter(child);
+                childIndex += 1;
+            }
+            _textPainter.setPlaceholderDimensions(placeholderDimensions);
+        void _computeChildrenHeightWithMinIntrinsics(float width) {
+            RenderBox child = firstChild;
+            List<PlaceholderDimensions> placeholderDimensions = new List<PlaceholderDimensions>(childCount);
+            int childIndex = 0;
+            while (child != null) {
+                float intrinsicHeight = child.getMinIntrinsicHeight(width);
+                float intrinsicWidth = child.getMinIntrinsicWidth(intrinsicHeight);
+                placeholderDimensions[childIndex] = new PlaceholderDimensions(
+                    size: new Size(intrinsicWidth, intrinsicHeight),
+                    alignment: _placeholderSpans[childIndex].alignment,
+                    baseline: _placeholderSpans[childIndex].baseline.Value,
+                    baselineOffset:0.0f
+                );
+                child = childAfter(child);
+                childIndex += 1;
+            }
+            _textPainter.setPlaceholderDimensions(placeholderDimensions);
+        }
+        
+        protected override bool hitTestChildren(BoxHitTestResult boxHitTestResult, Offset position = null) {
+            RenderBox child = firstChild;
+            while (child != null) {
+                TextParentData textParentData = child.parentData as TextParentData;
+                Matrix4 transform = Matrix4.translationValues(
+                    textParentData.offset.dx,
+                    textParentData.offset.dy,
+                    0.0f
+                );
+                    transform.scale(
+                    textParentData.scale,
+                    textParentData.scale,
+                    textParentData.scale
+                );
+                bool isHit = boxHitTestResult.addWithPaintTransform(
+                    transform: transform,
+                    position: position,
+                    hitTest: (BoxHitTestResult result, Offset transformed) => {
+                        D.assert(() => {
+                            Offset manualPosition = (position - textParentData.offset) / textParentData.scale;
+                            return (transformed.dx - manualPosition.dx).abs() < foundation_.precisionErrorTolerance
+                                   && (transformed.dy - manualPosition.dy).abs() < foundation_.precisionErrorTolerance;
+                        });
+                        return child.hitTest(result, position: transformed);
+                    }
+                );
+                if (isHit) {
+                    return true;
+                }
+                child = childAfter(child);
+            }
+            return false;
+        }
 
         bool _hasFocus = false;
         bool _listenerAttached = false;
             Offset offset = ((BoxHitTestEntry) entry).localPosition;
             TextPosition position = _textPainter.getPositionForOffset(offset);
             InlineSpan span = _textPainter.text.getSpanForPosition(position);
-            (span as TextSpan)?.recognizer?.addPointer((PointerDownEvent) evt);
+            if (span == null) {
+                return;
+            }
+            if (span is TextSpan) {
+                TextSpan textSpan = (TextSpan)span;
+                textSpan.recognizer?.addPointer(evt as PointerDownEvent);
+            }
+        }
+        
+        bool debugHasOverflowShader {
+            get { return _overflowShader != null; }
+
+        void _layoutChildren(BoxConstraints constraints) {
+            if (childCount == 0) {
+                return;
+            }
+            RenderBox child = firstChild;
+            _placeholderDimensions = new List<PlaceholderDimensions>(childCount);
+            int childIndex = 0;
+            while (child != null) {
+                child.layout(
+                    new BoxConstraints(
+                        maxWidth: constraints.maxWidth
+                    ),
+                    parentUsesSize: true
+                );
+                float baselineOffset;
+                switch (_placeholderSpans[childIndex].alignment) {
+                    case ui.PlaceholderAlignment.baseline: {
+                        baselineOffset = child.getDistanceToBaseline(
+                        _placeholderSpans[childIndex].baseline.Value
+                        ).Value;
+                        break;
+                    }
+                    default: {
+                        baselineOffset = 0.0f;
+                        break;
+                    }
+                }
+                _placeholderDimensions[childIndex] = new PlaceholderDimensions(
+                    size: child.size,
+                    alignment: _placeholderSpans[childIndex].alignment,
+                    baseline: _placeholderSpans[childIndex].baseline.Value,
+                    baselineOffset: baselineOffset
+                );
+                child = childAfter(child);
+                childIndex += 1;
+            }
+        }
+        
+        void _setParentData() {
+            RenderBox child = firstChild;
+            int childIndex = 0;
+            while (child != null && childIndex < _textPainter.inlinePlaceholderBoxes.Count) {
+                TextParentData textParentData = child.parentData as TextParentData;
+                textParentData.offset = new Offset(
+                    _textPainter.inlinePlaceholderBoxes[childIndex].left,
+                    _textPainter.inlinePlaceholderBoxes[childIndex].top
+                );
+                textParentData.scale = _textPainter.inlinePlaceholderScales[childIndex];
+                child = childAfter(child);
+                childIndex += 1;
+            }
+        }
+        
+             BoxConstraints constraints = this.constraints;
+             _layoutChildren(constraints);
+             _setParentData();
             var textSize = _textPainter.size;
             var textDidExceedMaxLines = _textPainter.didExceedMaxLines;
             size = constraints.constrain(textSize);
             var hasVisualOverflow = didOverflowWidth || didOverflowHeight;
             if (hasVisualOverflow) {
+                /*switch (_overflow) {
+                    case TextOverflow.visible:
+                        _needsClipping = false;
+                        break;
+                    case TextOverflow.clip:
+                    case TextOverflow.ellipsis:
+                    case TextOverflow.fade:
+                        _needsClipping = true;
+                        break;
+                }*/
-                case TextOverflow.visible:
-                    _needsClipping = false;
-                    break;
-                case TextOverflow.clip:
-                case TextOverflow.ellipsis:
-                case TextOverflow.fade:
-                    _needsClipping = true;
-                    break;
+                    case TextOverflow.visible:
+                        _needsClipping = false;
+                        _overflowShader = null;
+                        break;
+                    case TextOverflow.clip:
+                    case TextOverflow.ellipsis:
+                        _needsClipping = true;
+                        _overflowShader = null;
+                        break;
+                    case TextOverflow.fade:
+                        D.assert(textDirection != null);
+                        _needsClipping = true;
+                        TextPainter fadeSizePainter = new TextPainter(
+                            text: new TextSpan(style: _textPainter.text.style, text: "\u2026"),
+                            textDirection: textDirection.Value,
+                            textScaleFactor: textScaleFactor,
+                            locale: locale
+                        );
+                        fadeSizePainter.layout();
+                        if (didOverflowWidth) {
+                            float fadeEnd = 0, fadeStart = 0;
+                            switch (textDirection) {
+                                case TextDirection.rtl:
+                                    fadeEnd = 0.0f;
+                                    fadeStart = fadeSizePainter.width;
+                                    break;
+                                case TextDirection.ltr:
+                                    fadeEnd = size.width;
+                                    fadeStart = fadeEnd - fadeSizePainter.width;
+                                    break;
+                            }
+                            _overflowShader = ui.Gradient.linear(
+                                    new Offset(fadeStart, 0.0f),
+                                    new Offset(fadeEnd, 0.0f),
+                                    new List<Color>{new Color(0xFFFFFFFF), new Color(0x00FFFFFF)}
+                                );
+                        } else {
+                            float fadeEnd = size.height;
+                            float fadeStart = fadeEnd - fadeSizePainter.height / 2.0f;
+                            _overflowShader = ui.Gradient.linear(
+                                new Offset(0.0f, fadeStart),
+                                new Offset(0.0f, fadeEnd),
+                                new List<Color> {new Color(0xFFFFFFFF), new Color(0x00FFFFFF)}
+                            );
+                        }
+                        break;
+                _overflowShader = null;
-
-            _selectionRects = null;
-        void paintParagraph(PaintingContext context, Offset offset) {
+        /*void paintParagraph(PaintingContext context, Offset offset) {
             _layoutTextWithConstraints(constraints);
             var canvas = context.canvas;
 
             else {
                 paintParagraph(context, offset);
             }
+        } */
+        
+        public override void paint(PaintingContext context2, Offset offset2) {
+              _layoutTextWithConstraints(constraints);
+
+            D.assert(() => {
+              if (RenderingDebugUtils.debugRepaintTextRainbowEnabled) {
+                  Paint paint = new Paint();
+                  paint.color = RenderingDebugUtils.debugCurrentRepaintColor.toColor();
+                context2.canvas.drawRect(offset2 & size, paint);
+              }
+              return true;
+            });
+
+            if (_needsClipping) {
+              Rect bounds = offset2 & size;
+              if (_overflowShader != null) {
+                  context2.canvas.saveLayer(bounds, new Paint());
+              } else {
+                context2.canvas.save();
+              }
+              context2.canvas.clipRect(bounds);
+            }
+            _textPainter.paint(context2.canvas, offset2);
+
+            RenderBox child = firstChild;
+            int childIndex = 0;
+            while (child != null && childIndex < _textPainter.inlinePlaceholderBoxes.Count) {
+                TextParentData textParentData = child.parentData as TextParentData;
+
+                float scale = textParentData.scale;
+                context2.pushTransform(
+                    needsCompositing,
+                    offset2 + textParentData.offset,
+                    Matrix4.diagonal3Values(scale, scale, scale),
+                    (PaintingContext context, Offset offset) => {
+                    context.paintChild(
+                        child,
+                        offset
+                    );
+                }
+                );
+                child = childAfter(child);
+                childIndex += 1;
+            }
+            if (_needsClipping) {
+                if (_overflowShader != null) {
+                    context2.canvas.translate(offset2.dx, offset2.dy);
+                    Paint paint = new Paint();
+                    paint.blendMode = BlendMode.modulate;
+                    paint.shader = _overflowShader;
+                    context2.canvas.drawRect(Offset.zero & size, paint);
+                }
+                context2.canvas.restore();
+            }
         }
 
 
             _textPainter.layout(minWidth, widthMatters ? maxWidth : float.PositiveInfinity);
         }
 
+        List<PlaceholderDimensions> _placeholderDimensions;
+        
+            _textPainter.setPlaceholderDimensions(_placeholderDimensions);
             _layoutText(minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
         }
 
                 ifFalse: "no wrapping except at line break characters", showName: true));
             properties.add(new EnumProperty<TextOverflow>("overflow", overflow));
             properties.add(new FloatProperty("textScaleFactor", textScaleFactor, defaultValue: 1.0f));
+            properties.add(new DiagnosticsProperty<Locale>("locale", locale, defaultValue: null));
             properties.add(new IntProperty("maxLines", maxLines, ifNull: "unlimited"));
         }
     }

com.unity.uiwidgets/Runtime/rendering/performance_overlay.cs

 
 namespace Unity.UIWidgets.rendering {
     public enum PerformanceOverlayOption {
-        drawFPS, //default
-        drawFrameCost
+        displayRasterizerStatistics,
+        visualizeRasterizerStatistics,
+        displayEngineStatistics,
+        visualizeEngineStatistics,
-            int optionsMask = 0
+            int optionsMask = 0,
+            int rasterizerThreshold = 0,
+            bool checkerboardRasterCacheImages = false,
+            bool checkerboardOffscreenLayers = false
-            _optionMask = optionsMask;
+            D.assert(optionsMask != null);
+            D.assert(rasterizerThreshold != null);
+            D.assert(checkerboardRasterCacheImages != null);
+            D.assert(checkerboardOffscreenLayers != null);
+            _optionsMask = optionsMask;
+            _rasterizerThreshold = rasterizerThreshold;
+            _checkerboardRasterCacheImages = checkerboardRasterCacheImages;
+            _checkerboardOffscreenLayers = checkerboardOffscreenLayers;
-            get { return _optionMask; }
+            get { return _optionsMask; }
-                if (value == _optionMask) {
+                if (value == _optionsMask) {
-                _optionMask = value;
+                _optionsMask = value;
+                markNeedsPaint();
+            }
+        }
+
+        int _optionsMask;
+
+        public int rasterizerThreshold {
+            get {
+                return _rasterizerThreshold;
+            }
+            set {
+                D.assert(value != null);
+                if (value == _rasterizerThreshold)
+                    return;
+                _rasterizerThreshold = value;
+                markNeedsPaint();
+            }
+        }
+        int _rasterizerThreshold;
+
+        public bool checkerboardRasterCacheImages {
+            get {
+                return _checkerboardRasterCacheImages;
+            }
+            set {
+                D.assert(value != null);
+                if (value == _checkerboardRasterCacheImages)
+                    return;
+                _checkerboardRasterCacheImages = value;
+        bool _checkerboardRasterCacheImages;
-        int _optionMask;
+        public bool checkerboardOffscreenLayers {
+            get { return _checkerboardOffscreenLayers; }
+            set {
+                D.assert(value != null);
+                if (value == _checkerboardOffscreenLayers)
+                    return;
+                _checkerboardOffscreenLayers = value;
+                markNeedsPaint();
+            }
+        }
+        bool _checkerboardOffscreenLayers;
+        
+        
 
         protected override bool sizedByParent {
             get { return true; }
         float _intrinsicHeight {
             get {
                 const float kDefaultGraphHeight = 80.0f;
-                float result = 20f;
-
-                if ((optionsMask | (1 << (int) PerformanceOverlayOption.drawFrameCost)) > 0) {
+                
+                float result = 0.0f;
+                if (
+                    ((optionsMask | (1 << (int) PerformanceOverlayOption.displayRasterizerStatistics)) > 0) ||
+                    ((optionsMask | (1 << (int) PerformanceOverlayOption.visualizeRasterizerStatistics)) > 0)
+                        )
-                }
+                if (((optionsMask | (1 << (int) PerformanceOverlayOption.displayEngineStatistics)) > 0) ||
+                    ((optionsMask | (1 << (int) PerformanceOverlayOption.visualizeEngineStatistics)) > 0))
+                    result += kDefaultGraphHeight;
+                return result;
 
                 return result;
             }
             D.assert(needsCompositing);
             context.addLayer(new PerformanceOverlayLayer(
                 overlayRect: Rect.fromLTWH(offset.dx, offset.dy, size.width, size.height),
-                optionsMask: optionsMask
+                optionsMask: optionsMask,
+                rasterizerThreshold: rasterizerThreshold,
+                checkerboardRasterCacheImages: checkerboardRasterCacheImages,
+                checkerboardOffscreenLayers: checkerboardOffscreenLayers
             ));
         }
     }

com.unity.uiwidgets/Runtime/rendering/proxy_box.cs

     }
 
     public class RenderAspectRatio : RenderProxyBox {
-        public RenderAspectRatio(float aspectRatio, RenderBox child = null) : base(child) {
+        public RenderAspectRatio(
+            float aspectRatio, 
+            RenderBox child = null) : base(child) {
             _aspectRatio = aspectRatio;
         }
 
 
     public class ShapeBorderClipper : CustomClipper<Path> {
         public ShapeBorderClipper(
-            ShapeBorder shape = null) {
+            ShapeBorder shape = null,
+            TextDirection? textDirection = null
+            ) {
+            this.textDirection = textDirection;
+        public readonly TextDirection? textDirection;
-            return shape.getOuterPath(Offset.zero & size);
+            return shape.getOuterPath(Offset.zero & size, textDirection: textDirection);
-            if (oldClipper.GetType() != GetType()) {
+            if (oldClipper.GetType() != typeof(ShapeBorderClipper))
-            }
-
-            ShapeBorderClipper typedOldClipper = (ShapeBorderClipper) oldClipper;
-            return typedOldClipper.shape != shape;
+            ShapeBorderClipper typedOldClipper = oldClipper as ShapeBorderClipper;
+            return typedOldClipper.shape != shape
+                   || typedOldClipper.textDirection != textDirection;
+        
         }
     }
 
 
     public class RenderTransform : RenderProxyBox {
         public RenderTransform(
-            Matrix4 transform,
+            Matrix4 transform ,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null,
             bool transformHitTests = true,
             RenderBox child = null
         ) : base(child) {
+            this.textDirection = textDirection;
             this.transformHitTests = transformHitTests;
         }
 
 
         Offset _origin;
 
-        public Alignment alignment {
+        public AlignmentGeometry alignment {
             get { return _alignment; }
             set {
                 if (_alignment == value) {
             }
         }
 
-        Alignment _alignment;
+        AlignmentGeometry _alignment;
+
+
+        public TextDirection? textDirection {
+            get { return _textDirection; }
+            set {
+                if (_textDirection == value)
+                    return;
+                _textDirection = value;
+                markNeedsPaint();
+                //markNeedsSemanticsUpdate();
+            }
+        }
+
+        TextDirection? _textDirection; 
+        
 
         public bool transformHitTests;
 
 
         Matrix4 _effectiveTransform {
             get {
-                Alignment resolvedAlignment = alignment;
+                Alignment resolvedAlignment = alignment?.resolve(textDirection);
                 if (_origin == null && resolvedAlignment == null) {
                     return _transform;
                 }
             base.debugFillProperties(properties);
             properties.add(new DiagnosticsProperty<Matrix4>("transform matrix", _transform));
             properties.add(new DiagnosticsProperty<Offset>("origin", origin));
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment));
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment));
+            properties.add(new EnumProperty<TextDirection>("textDirection", (TextDirection)textDirection, defaultValue: null));
         }
     }
 
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null,
+            _textDirection = textDirection;
         }
 
         Alignment _resolvedAlignment;
                 return;
             }
-
-            _resolvedAlignment = alignment;
+            _resolvedAlignment = alignment.resolve(textDirection);
         }
 
         void _markNeedResolution() {
 
         BoxFit _fit;
 
-        public Alignment alignment {
+        public AlignmentGeometry alignment {
             get { return _alignment; }
             set {
                 D.assert(value != null);
                 _markNeedResolution();
             }
         }
+        AlignmentGeometry _alignment;
-        Alignment _alignment;
+        public TextDirection? textDirection {
+            get {
+                return _textDirection;
+            }
+            set {
+                if (_textDirection == value)
+                    return;
+                _textDirection = value;
+                _clearPaintData();
+                _markNeedResolution();
+            }
+        }
+        TextDirection? _textDirection;
+        
 
         protected override void performLayout() {
             if (child != null) {
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new EnumProperty<BoxFit>("fit", fit));
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment));
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment));
+            properties.add(new EnumProperty<TextDirection>("textDirection", (TextDirection)textDirection, defaultValue: null));
         }
     }
 

com.unity.uiwidgets/Runtime/rendering/proxy_sliver.cs

     public class RenderSliverAnimatedOpacity :RenderAnimatedOpacityMixinRenderSliver<RenderSliver>{
         public RenderSliverAnimatedOpacity(
             Animation<float> opacity ,
-            RenderSliver sliver = null,
-            bool alwaysIncludeSemantics = false
+            RenderSliver sliver = null
-            this.alwaysIncludeSemantics = alwaysIncludeSemantics;
             child = sliver;
         }
     }
-            float opacity = 1.0f, 
-            bool alwaysIncludeSemantics = false
+            float opacity = 1.0f
-            D.assert(alwaysIncludeSemantics != null);
-            _alwaysIncludeSemantics = alwaysIncludeSemantics;
             _alpha = ui.Color.getAlphaFromOpacity(opacity);
             child = sliver;
         }
             }
         }
         float _opacity;
-
-        public bool alwaysIncludeSemantics {
-            get { return _alwaysIncludeSemantics;}
-            set { 
-                if (value == _alwaysIncludeSemantics)
-                    return;
-                _alwaysIncludeSemantics = value;
-               // markNeedsSemanticsUpdate(); 
-            }
-        }
-        bool _alwaysIncludeSemantics;
+        
-                    setLayer(null);
+                    layer = null;
-                    setLayer(null);
+                    layer = null;
                     context.paintChild(child, offset);
                     return;
                 }
                     base.paint,
                     oldLayer: layer as OpacityLayer
                 );
-                setLayer(opacity);
+                layer = opacity;
             }
         }
         /*public override void visitChildrenForSemantics(RenderObject visitor) {
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) { 
             base.debugFillProperties(properties);
             properties.add(new FloatProperty("opacity", opacity));
-            properties.add(new FlagProperty("alwaysIncludeSemantics", value: alwaysIncludeSemantics, ifTrue: "alwaysIncludeSemantics"));
         }
     }
 
                 child = sliver;
                 D.assert(ignoring != null);
                 _ignoring = ignoring;
-                _ignoringSemantics = ignoringSemantics;
         }
 
 
         }
         bool _ignoring;
 
-
-        public bool? ignoringSemantics {
-            get { return _ignoringSemantics; }
-            set {
-                if (value == _ignoringSemantics)
-                    return ;
-                bool oldEffectiveValue = _effectiveIgnoringSemantics;
-                _ignoringSemantics = value;
-                //if (oldEffectiveValue != _effectiveIgnoringSemantics)
-                //    markNeedsSemanticsUpdate();
-                
-            }
-        }
-        bool? _ignoringSemantics;
-
-
-        bool _effectiveIgnoringSemantics {
-            get { return ignoringSemantics ?? ignoring; }
-        }
-
         public override bool hitTest(SliverHitTestResult result, float mainAxisPosition = 0, float crossAxisPosition = 0) { 
             return !ignoring && base.hitTest(
                 result,
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new DiagnosticsProperty<bool>("ignoring", ignoring));
-            properties.add(new DiagnosticsProperty<bool>("ignoringSemantics", _effectiveIgnoringSemantics, description: ignoringSemantics == null ? $"implicitly {_effectiveIgnoringSemantics}" : null));
         }
     }
     public class RenderSliverOffstage : RenderProxySliver {

com.unity.uiwidgets/Runtime/rendering/shifted_box.cs

 
     public class RenderPadding : RenderShiftedBox {
         public RenderPadding(
-            EdgeInsets padding = null,
+            EdgeInsetsGeometry padding = null,
+            TextDirection? textDirection = null,
-
+            _textDirection = textDirection;
+        EdgeInsets _resolvedPadding;
+        
+        void _resolve() {
+            if (_resolvedPadding != null)
+                return;
+            _resolvedPadding = padding.resolve(textDirection);
+            D.assert(_resolvedPadding.isNonNegative);
+        }
-        public EdgeInsets padding {
+        void _markNeedResolution() {
+            _resolvedPadding = null;
+            markNeedsLayout();
+        }
+        public EdgeInsetsGeometry padding {
             get { return _padding; }
             set {
                 D.assert(value != null);
                 markNeedsLayout();
             }
         }
+        EdgeInsetsGeometry _padding;
-        EdgeInsets _padding;
+        public TextDirection? textDirection {
+            get { return _textDirection; }
+            set {if (_textDirection == value)
+                    return;
+                _textDirection = value;
+                _markNeedResolution(); }
+        }
+        TextDirection? _textDirection;
+       
-            if (child != null) {
-                return child.getMinIntrinsicWidth(Mathf.Max(0.0f, height - _padding.vertical)) +
-                       _padding.horizontal;
-            }
-
-            return _padding.horizontal;
+            _resolve();
+            float totalHorizontalPadding = _resolvedPadding.left + _resolvedPadding.right;
+            float totalVerticalPadding = _resolvedPadding.top + _resolvedPadding.bottom;
+            if (child != null) // next line relies on double.infinity absorption
+                return child.getMinIntrinsicWidth(Mathf.Max(0.0f, height - totalVerticalPadding)) + totalHorizontalPadding;
+            return totalHorizontalPadding;
-            if (child != null) {
-                return child.getMaxIntrinsicWidth(Mathf.Max(0.0f, height - _padding.vertical)) +
-                       _padding.horizontal;
-            }
-
-            return _padding.horizontal;
+            _resolve();
+            float totalHorizontalPadding = _resolvedPadding.left + _resolvedPadding.right;
+            float totalVerticalPadding = _resolvedPadding.top + _resolvedPadding.bottom;
+            if (child != null) // next line relies on double.infinity absorption
+                return child.getMaxIntrinsicWidth(Mathf.Max(0.0f, height - totalVerticalPadding)) + totalHorizontalPadding;
+            return totalHorizontalPadding;
-            if (child != null) {
-                return child.getMinIntrinsicHeight(Mathf.Max(0.0f, width - _padding.horizontal)) +
-                       _padding.vertical;
-            }
-
-            return _padding.vertical;
+            _resolve();
+            float totalHorizontalPadding = _resolvedPadding.left + _resolvedPadding.right;
+            float totalVerticalPadding = _resolvedPadding.top + _resolvedPadding.bottom;
+            if (child != null) // next line relies on double.infinity absorption
+                return child.getMinIntrinsicHeight(Mathf.Max(0.0f, width - totalHorizontalPadding)) + totalVerticalPadding;
+            return totalVerticalPadding;
-            if (child != null) {
-                return child.getMaxIntrinsicHeight(Mathf.Max(0.0f, width - _padding.horizontal)) +
-                       _padding.vertical;
-            }
-
-            return _padding.vertical;
+            _resolve();
+            float totalHorizontalPadding = _resolvedPadding.left + _resolvedPadding.right;
+            float totalVerticalPadding = _resolvedPadding.top + _resolvedPadding.bottom;
+            if (child != null) // next line relies on double.infinity absorption
+                return child.getMaxIntrinsicHeight(Mathf.Max(0.0f, width - totalHorizontalPadding)) + totalVerticalPadding;
+            return totalVerticalPadding;
+             BoxConstraints constraints = this.constraints;
+            _resolve();
+            D.assert(_resolvedPadding != null);
-                size = constraints.constrain(_padding.inflateSize(Size.zero));
+                size = constraints.constrain(new Size(
+                    _resolvedPadding.left + _resolvedPadding.right,
+                    _resolvedPadding.top + _resolvedPadding.bottom
+                ));
-
-            var innerConstraints = constraints.deflate(_padding);
+             BoxConstraints innerConstraints = constraints.deflate(_resolvedPadding);
-
-            var childParentData = (BoxParentData) child.parentData;
-            childParentData.offset = _padding.topLeft;
-            size = constraints.constrain(_padding.inflateSize(child.size));
+             BoxParentData childParentData = child.parentData as BoxParentData;
+            childParentData.offset = new Offset(_resolvedPadding.left, _resolvedPadding.top);
+            size = constraints.constrain(new Size(
+                _resolvedPadding.left + child.size.width + _resolvedPadding.right,
+                _resolvedPadding.top + child.size.height + _resolvedPadding.bottom
+            ));
-            D.assert(() => {
+            D.assert(()=> {
-                D.debugPaintPadding(context.canvas, outerRect,
-                    child != null ? _padding.deflateRect(outerRect) : null);
+                D.debugPaintPadding(context.canvas, outerRect, child != null ? _resolvedPadding.deflateRect(outerRect) : null);
                 return true;
             });
         }
-            properties.add(new DiagnosticsProperty<EdgeInsets>("padding", padding));
+            properties.add(new DiagnosticsProperty<EdgeInsetsGeometry>("padding", padding));
+            properties.add(new EnumProperty<TextDirection>("textDirection", (TextDirection)textDirection, defaultValue: null));
-            Alignment alignment = null,
-            RenderBox child = null,
-            //TODO : update textdirection
-            TextDirection? textDirection = null
+            AlignmentGeometry  alignment = null,
+            TextDirection? textDirection = null,
+            RenderBox child = null
+            _textDirection = textDirection;
+        }
+        
+        Alignment _resolvedAlignment;
+
+        void _resolve() {
+            if (_resolvedAlignment != null)
+                return;
+            _resolvedAlignment = alignment.resolve(textDirection);
-        public Alignment alignment {
+        void _markNeedResolution() {
+            _resolvedAlignment = null;
+            markNeedsLayout();
+        }
+
+        public AlignmentGeometry alignment {
             get { return _alignment; }
             set {
                 D.assert(value != null);
             }
         }
 
-        Alignment _alignment;
-
-        TextDirection _textDirection;
-
-        public TextDirection textDirection {
-            get { return _textDirection; }
+        AlignmentGeometry _alignment;
+        public TextDirection? textDirection {
+            get { return _textDirection;}
-                //TODO: complete _markNeedResolution
-                // _markNeedResolution();
+                _markNeedResolution();
-
+        TextDirection? _textDirection;
+        
+            _resolve();
-
+            D.assert(_resolvedAlignment != null);
-            childParentData.offset = _alignment.alongOffset(size - child.size);
+            childParentData.offset = _resolvedAlignment.alongOffset(size - child.size);
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment));
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment));
+            properties.add(new EnumProperty<TextDirection>("textDirection", (TextDirection)textDirection, defaultValue: null));
+        
         }
     }
 
             float? widthFactor = null,
             float? heightFactor = null,
-            Alignment alignment = null
-        ) : base(alignment, child) {
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null
+        ) : base(child: child, alignment: alignment ?? Alignment.center, textDirection: textDirection){
-
             _widthFactor = widthFactor;
             _heightFactor = heightFactor;
         }
         float? _heightFactor;
 
         protected override void performLayout() {
+            BoxConstraints constraints = this.constraints;
             bool shrinkWrapWidth = _widthFactor != null || float.IsPositiveInfinity(constraints.maxWidth);
             bool shrinkWrapHeight = _heightFactor != null || float.IsPositiveInfinity(constraints.maxHeight);
 
             float? maxWidth = null,
             float? minHeight = null,
             float? maxHeight = null,
-            Alignment alignment = null
-        ) : base(alignment, child) {
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null
+        ) : base(child: child, alignment: alignment ?? Alignment.center, textDirection: textDirection){
             _minWidth = minWidth;
             _maxWidth = maxWidth;
             _minHeight = minHeight;
                 alignChild();
             }
         }
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+            base.debugFillProperties(properties);
+            properties.add(new FloatProperty("minWidth", minWidth, ifNull: "use parent minWidth constraint"));
+            properties.add(new FloatProperty("maxWidth", maxWidth, ifNull: "use parent maxWidth constraint"));
+            properties.add(new FloatProperty("minHeight", minHeight, ifNull: "use parent minHeight constraint"));
+            properties.add(new FloatProperty("maxHeight", maxHeight, ifNull: "use parent maxHeight constraint"));
+        }
-    public class RenderUnconstrainedBox : RenderAligningShiftedBox {
+    public class RenderUnconstrainedBox : RenderAligningShiftedBox {//, DebugOverflowIndicatorMixin
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null,
-        ) : base(alignment, child) {
+        ) : base(alignment , textDirection ,child) {
+            D.assert(alignment != null);
             _constrainedAxis = constrainedAxis;
         }
 
                 markNeedsLayout();
             }
         }
-
         public Axis? _constrainedAxis;
 
         public Rect _overflowContainerRect = Rect.zero;
         protected override void performLayout() {
+            BoxConstraints constraints = this.constraints;
             if (child != null) {
                 BoxConstraints childConstraints = null;
                 if (constrainedAxis != null) {
                 return true;
             });
         }
+        public override Rect describeApproximatePaintClip(RenderObject child) {
+            return _isOverflowing ? Offset.zero & size : null;
+        }
+
+        public override string toStringShort() {
+            string header = base.toStringShort();
+            if (_isOverflowing)
+                header += "OVERFLOWING";
+            return header;
+        }
     }
 
     public class RenderSizedOverflowBox : RenderAligningShiftedBox {
-            Alignment alignment = null
-        ) : base(alignment, child) {
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null
+        ) : base(child: child, alignment: alignment ?? Alignment.center, textDirection: textDirection) {
+            D.assert(requestedSize != null);
             _requestedSize = requestedSize;
         }
 
             RenderBox child = null,
             float? widthFactor = null,
             float? heightFactor = null,
-            Alignment alignment = null
-        ) : base(alignment, child) {
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null
+        ) : base(child: child, alignment: alignment ?? Alignment.center, textDirection: textDirection){
+            D.assert(_widthFactor == null || _widthFactor >= 0.0);
+            D.assert(_heightFactor == null || _heightFactor >= 0.0);
+                D.assert(value == null || value >= 0.0f);
                 if (_widthFactor == value) {
                     return;
                 }
         public float? heightFactor {
             get { return _heightFactor; }
             set {
+                D.assert(value == null || value >= 0.0);
                 if (_heightFactor == value) {
                     return;
                 }
                 size = constraints.constrain(
                     _getInnerConstraints(constraints).constrain(Size.zero));
             }
+        }
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+            base.debugFillProperties(properties);
+            properties.add(new FloatProperty("widthFactor", _widthFactor, ifNull: "pass-through"));
+            properties.add(new FloatProperty("heightFactor", _heightFactor, ifNull: "pass-through"));
         }
     }
 
     }
 
     public class RenderCustomSingleChildLayoutBox : RenderShiftedBox {
-        public RenderCustomSingleChildLayoutBox(RenderBox child = null,
-            SingleChildLayoutDelegate layoutDelegate = null) : base(child) {
+        public RenderCustomSingleChildLayoutBox(
+            RenderBox child = null,
+            SingleChildLayoutDelegate layoutDelegate = null
+            ) : base(child) {
             D.assert(layoutDelegate != null);
             _delegate = layoutDelegate;
         }
         public float baseline {
             get { return _baseline; }
             set {
+                D.assert(value != null);
-
                 _baseline = value;
                 markNeedsLayout();
             }
         public TextBaseline baselineType {
             get { return _baselineType; }
             set {
+                D.assert(value != null);
                 if (_baselineType == value) {
                     return;
                 }
             else {
                 performResize();
             }
+        }
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+            base.debugFillProperties(properties);
+            properties.add(new FloatProperty("baseline", baseline));
+            properties.add(new EnumProperty<TextBaseline>("baselineType", baselineType));
         }
     }
 }

com.unity.uiwidgets/Runtime/rendering/sliver_multi_box_adaptor.cs

 
         public bool debugChildIntegrityEnabled {
             get { return _debugChildIntegrityEnabled;}
+            set {
+                D.assert(value != null);
+                D.assert(() =>{
+                    _debugChildIntegrityEnabled = value;
+                    return _debugVerifyChildOrder() &&
+                           (!_debugChildIntegrityEnabled || _debugDanglingKeepAlives.isEmpty());
+                });
+            }
         }
         public void setDebugChildIntegrityEnabled(bool enabled) {
             D.assert(enabled != null);

com.unity.uiwidgets/Runtime/rendering/stack.cs

     public class RenderStack : RenderBoxContainerDefaultsMixinContainerRenderObjectMixinRenderBox<RenderBox,
         StackParentData> {
         public RenderStack(
-            StackFit? fit,
-            Overflow? overflow,
-            TextDirection textDirection,
-            Alignment alignment = null) {
-            this.textDirection = textDirection;
-            _alignment = alignment ?? Alignment.topLeft;
-            _fit = fit ?? StackFit.loose;
-            _overflow = overflow ?? Overflow.clip;
+            AlignmentGeometry alignment =  null,
+            TextDirection? textDirection = null,
+            StackFit fit = StackFit.loose,
+            Overflow overflow = Overflow.clip
+            ) {
+            _textDirection = textDirection;
+            _alignment = alignment ?? AlignmentDirectional.topStart;
+            _fit = fit;
+            _overflow = overflow;
             addAll(children);
         }
 
                 child.parentData = new StackParentData();
             }
         }
+        void _resolve() {
+            if (_resolvedAlignment != null)
+                return;
+            _resolvedAlignment = alignment.resolve(textDirection);
+        }
         
         Alignment _resolvedAlignment;
 
         }
         
-        public TextDirection  textDirection {
+        public TextDirection?  textDirection {
             get {
                 return _textDirection;
             }
             }
         }
 
-        TextDirection _textDirection;
+        TextDirection? _textDirection;
-        Alignment _alignment;
+        AlignmentGeometry _alignment;
-        public Alignment alignment {
+        public AlignmentGeometry alignment {
             get { return _alignment; }
             set {
                 if (_alignment == value) {
         }
 
         protected override void performLayout() {
+            BoxConstraints constraints = this.constraints;
+            _resolve();
+            D.assert(_resolvedAlignment != null);
-                size = constraints.biggest;
-                return;
+              size = constraints.biggest;
+              D.assert(size.isFinite);
+              return;
             }
 
             float width = constraints.minWidth;
+            D.assert(fit != null);
-                case StackFit.loose:
-                    nonPositionedConstraints = constraints.loosen();
-                    break;
-                case StackFit.expand:
-                    nonPositionedConstraints = BoxConstraints.tight(constraints.biggest);
-                    break;
-                case StackFit.passthrough:
-                    nonPositionedConstraints = constraints;
-                    break;
+              case StackFit.loose:
+                nonPositionedConstraints = constraints.loosen();
+                break;
+              case StackFit.expand:
+                nonPositionedConstraints = BoxConstraints.tight(constraints.biggest);
+                break;
+              case StackFit.passthrough:
+                nonPositionedConstraints = constraints;
+                break;
-
+            D.assert(nonPositionedConstraints != null);
-                StackParentData childParentData = (StackParentData) child.parentData;
+              StackParentData childParentData = child.parentData as StackParentData;
-                if (!childParentData.isPositioned) {
-                    hasNonPositionedChildren = true;
+              if (!childParentData.isPositioned) {
+                hasNonPositionedChildren = true;
-                    child.layout(nonPositionedConstraints, parentUsesSize: true);
+                child.layout(nonPositionedConstraints, parentUsesSize: true);
-                    Size childSize = child.size;
-                    width = Mathf.Max(width, childSize.width);
-                    height = Mathf.Max(height, childSize.height);
-                }
+                Size childSize = child.size;
+                width = Mathf.Max(width, childSize.width);
+                height =  Mathf.Max(height, childSize.height);
+              }
-                child = childParentData.nextSibling;
+              child = childParentData.nextSibling;
-                size = new Size(width, height);
-                D.assert(size.width == constraints.constrainWidth(width));
-                D.assert(size.height == constraints.constrainHeight(height));
-            }
-            else {
-                size = constraints.biggest;
+              size = new Size(width, height);
+              D.assert(size.width == constraints.constrainWidth(width));
+              D.assert(size.height == constraints.constrainHeight(height));
+            } else {
+              size = constraints.biggest;
+            D.assert(size.isFinite);
+
-                StackParentData childParentData = (StackParentData) child.parentData;
-
-                if (!childParentData.isPositioned) {
-                    childParentData.offset = _alignment.alongOffset(size - child.size);
-                }
-                else {
-                    BoxConstraints childConstraints = new BoxConstraints();
-
-                    if (childParentData.left != null && childParentData.right != null) {
-                        childConstraints =
-                            childConstraints.tighten(
-                                width: size.width - childParentData.right - childParentData.left);
-                    }
-                    else if (childParentData.width != null) {
-                        childConstraints = childConstraints.tighten(width: childParentData.width);
-                    }
-
-                    if (childParentData.top != null && childParentData.bottom != null) {
-                        childConstraints =
-                            childConstraints.tighten(
-                                height: size.height - childParentData.bottom - childParentData.top);
-                    }
-                    else if (childParentData.height != null) {
-                        childConstraints = childConstraints.tighten(height: childParentData.height);
-                    }
-
-                    child.layout(childConstraints, parentUsesSize: true);
-
-                    float x;
-                    if (childParentData.left != null) {
-                        x = childParentData.left.Value;
-                    }
-                    else if (childParentData.right != null) {
-                        x = size.width - childParentData.right.Value - child.size.width;
-                    }
-                    else {
-                        x = _alignment.alongOffset(size - child.size).dx;
-                    }
-
-                    if (x < 0.0 || x + child.size.width > size.width) {
-                        _hasVisualOverflow = true;
-                    }
-
-                    float y;
-                    if (childParentData.top != null) {
-                        y = childParentData.top.Value;
-                    }
-                    else if (childParentData.bottom != null) {
-                        y = size.height - childParentData.bottom.Value - child.size.height;
-                    }
-                    else {
-                        y = _alignment.alongOffset(size - child.size).dy;
-                    }
+              StackParentData childParentData = child.parentData as StackParentData;
-                    if (y < 0.0 || y + child.size.height > size.height) {
-                        _hasVisualOverflow = true;
-                    }
-
-                    childParentData.offset = new Offset(x, y);
-                }
+              if (!childParentData.isPositioned) {
+                childParentData.offset = _resolvedAlignment.alongOffset(size - child.size as Offset);
+              } else {
+                _hasVisualOverflow = layoutPositionedChild(child, childParentData, size, _resolvedAlignment) || _hasVisualOverflow;
+              }
-                D.assert(child.parentData == childParentData);
-                child = childParentData.nextSibling;
+              D.assert(child.parentData == childParentData);
+              child = childParentData.nextSibling;
             }
         }
 
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment));
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment));
             properties.add(new EnumProperty<StackFit>("fit", fit));
             properties.add(new EnumProperty<Overflow>("overflow", overflow));
         }
         public RenderIndexedStack(
             List<RenderBox> children = null,
-            Alignment alignment = null,
-            TextDirection textDirection = default,
-            int? index = 0
-        ) : base(fit: null, overflow: null, textDirection: textDirection, children: children, alignment: alignment ?? Alignment.topLeft) {
+            AlignmentGeometry alignment = null,
+            TextDirection? textDirection = null,
+            int index = 0
+        ) :  base(
+            children: children,
+            alignment: alignment ?? AlignmentDirectional.topStart,
+            textDirection: textDirection) {
-        public int? index {
+        public int index {
             get { return _index; }
             set {
                 if (_index != value) {
             }
         }
 
-        int? _index;
+        int _index;
 
         RenderBox _childAtIndex() {
             D.assert(index != null);

com.unity.uiwidgets/Runtime/rendering/tweens.cs

             return Alignment.lerp(begin, end, t);
         }
     }
+    public class AlignmentGeometryTween : Tween<AlignmentGeometry> {
+        public AlignmentGeometryTween(
+            AlignmentGeometry begin = null,
+            AlignmentGeometry end = null
+        ) : base(begin: begin, end: end) {
+            
+        }
+        public override AlignmentGeometry lerp(float t) {
+            return AlignmentGeometry.lerp(begin, end, t);
+        }
+    }
+    
 }

com.unity.uiwidgets/Runtime/rendering/view.cs

             owner.requestVisualUpdate();
         }
 
+        public void prepareInitialFrame() {
+            D.assert(owner != null);
+            D.assert(_rootTransform == null);
+            scheduleInitialLayout();
+            scheduleInitialPaint((OffsetLayer)_updateMatricesAndCreateNewRootLayer());
+            D.assert(_rootTransform != null);
+        }
+        
         Matrix4 _rootTransform;
 
         public Layer _updateMatricesAndCreateNewRootLayer() {

com.unity.uiwidgets/Runtime/scheduler2/ticker.cs

             return _future;
         }
 
-        DiagnosticsNode describeForError(string name) {
+        public DiagnosticsNode describeForError(string name) {
             return new DiagnosticsProperty<Ticker>(name, this, description: toString(debugIncludeStack: true));
         }
 

com.unity.uiwidgets/Runtime/services/text_editing.cs

         public TextPosition endPos {
             get { return new TextPosition(offset: end, affinity: affinity); }
         }
+        
+        public TextPosition  extent {
+            get { return new TextPosition(offset: extentOffset, affinity: affinity); }
+        }
 
         public bool Equals(TextSelection other) {
             if (ReferenceEquals(null, other)) {

com.unity.uiwidgets/Runtime/ui2/compositing.cs

             return layer;
         }
 
+        public ColorFilterEngineLayer pushColorFilter(ColorFilter colorFilter, ColorFilterEngineLayer oldLayer = null) {
+            D.assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, "pushColorFilter"));
+            ColorFilterEngineLayer layer = new ColorFilterEngineLayer(SceneBuilder_pushColorFilter(_ptr, colorFilter._toNativeColorFilter()._ptr));
+            return layer;
+        }
+
+        public ImageFilterEngineLayer pushImageFilter(ImageFilter imageFilter, ImageFilterEngineLayer oldLayer = null) {
+            D.assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, "pushImageFilter"));
+            ImageFilterEngineLayer layer = new ImageFilterEngineLayer(SceneBuilder_pushImageFilter(_ptr, imageFilter._toNativeImageFilter()._ptr));
+            return layer;
+        }
+        
         public BackdropFilterEngineLayer pushBackdropFilter(
             ImageFilter filter,
             BackdropFilterEngineLayer oldLayer = null) {
 
         [DllImport(NativeBindings.dllName)]
         static extern IntPtr SceneBuilder_pushOpacity(IntPtr ptr, int alpha, float dx, float dy);
+
+        [DllImport(NativeBindings.dllName)]
+        static extern IntPtr SceneBuilder_pushColorFilter(IntPtr ptr, IntPtr filter);
+
+        [DllImport(NativeBindings.dllName)]
+        static extern IntPtr SceneBuilder_pushImageFilter(IntPtr ptr, IntPtr filter);
 
         [DllImport(NativeBindings.dllName)]
         static extern IntPtr SceneBuilder_pushBackdropFilter(IntPtr ptr, IntPtr filter);

com.unity.uiwidgets/Runtime/widgets/actions.cs

     public delegate void OnInvokeCallback(FocusNode node, Intent tag);
     public class Intent : Diagnosticable {
         public Intent(LocalKey key) : base() {
-            this.key = key;
+            this.key = key;
         }
 
         public static readonly Intent doNothing = new Intent(DoNothingAction.key);
     public abstract class UiWidgetAction : Diagnosticable {
 
         public UiWidgetAction(LocalKey intentKey) {
-            this.intentKey = intentKey;
+            this.intentKey = intentKey;
         }
 
         public readonly LocalKey intentKey;
     class CallbackAction : UiWidgetAction  {
         public CallbackAction(LocalKey intentKey, OnInvokeCallback onInvoke) : base(intentKey: intentKey) {
             D.assert(onInvoke != null);
+            this.onInvoke = onInvoke;
         }
         protected readonly OnInvokeCallback onInvoke;
 
     }
 
     class Actions : InheritedWidget {
-
         public Actions(
             Key key = null,
             ActionDispatcher dispatcher = null,
                 if (nullOk) {
                     return true;
                 }
-
                 if (inherited == null) {
                     throw new UIWidgetsError("Unable to find an $Actions widget in the context.\n" +
                                              "Actions.of() was called with a context that does not contain an " +
                 if (!(element.widget is Actions)) {
                     return true;
                 }
-
                 actionsElement = element;
                 Actions actions = element.widget as Actions;
                 action = actions.actions[intent.key]?.Invoke();
 
             return _findDispatcher(actionsElement).invokeAction(action, intent, focusNode: focusNode);
         }
-
+       
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new DiagnosticsProperty<ActionDispatcher>("dispatcher", dispatcher));
         }
 
         public override void didUpdateWidget(StatefulWidget oldWidget) {
-            //oldWidget =(FocusableActionDetector) oldWidget;
+            oldWidget =(FocusableActionDetector) oldWidget;
             base.didUpdateWidget(oldWidget);
             if (widget.enabled != ((FocusableActionDetector)oldWidget).enabled) {
               SchedulerBinding.instance.addPostFrameCallback((TimeSpan timespan)=> {
     }
 
     public abstract class ActivateAction : UiWidgetAction {
-
         public ActivateAction() : base(key) {
         }
         public readonly static LocalKey key = new ValueKey<Type>(typeof(ActivateAction));

com.unity.uiwidgets/Runtime/widgets/animated_cross_fade.cs

         showSecond
     }
 
-    public delegate Widget AnimatedCrossFadeBuilder(Widget topChild, Key topChildKey, Widget bottomChild,
-        Key bottomChildKey);
+    public delegate Widget AnimatedCrossFadeBuilder(Widget topChild, Key topChildKey, Widget bottomChild, Key bottomChildKey);
 
 
     public class AnimatedCrossFade : StatefulWidget {
 
 
     public class _AnimatedCrossFadeState : TickerProviderStateMixin<AnimatedCrossFade> {
+        
-
 
         public override void initState() {
             base.initState();
         public override Widget build(BuildContext context) {
             Key kFirstChildKey = new ValueKey<CrossFadeState>(CrossFadeState.showFirst);
             Key kSecondChildKey = new ValueKey<CrossFadeState>(CrossFadeState.showSecond);
-            bool transitioningForwards = _controller.status == AnimationStatus.completed ||
-                                         _controller.status == AnimationStatus.forward;
+            bool transitioningForwards = _controller.status == AnimationStatus.completed || _controller.status == AnimationStatus.forward;
 
             Key topKey;
             Widget topChild;
             Animation<float> bottomAnimation;
+            
             if (transitioningForwards) {
                 topKey = kSecondChildKey;
                 topChild = widget.secondChild;

com.unity.uiwidgets/Runtime/widgets/animated_size.cs

         public AnimatedSize(
             Key key = null,
             Widget child = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
             Curve curve = null,
             TimeSpan? duration = null,
             TimeSpan? reverseDuration = null,
             this.vsync = vsync;
         }
 
-        public readonly Alignment alignment;
+        public readonly AlignmentGeometry alignment;
 
         public readonly Curve curve;
 
                 duration: duration,
                 reverseDuration: reverseDuration,
                 curve: curve,
-                vsync: vsync);
+                vsync: vsync,
+                textDirection: Directionality.of(context)
+                );
         }
 
         public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
             _renderObject.reverseDuration = reverseDuration;
             _renderObject.curve = curve;
             _renderObject.vsync = vsync;
+            _renderObject.textDirection = Directionality.of(context);
         }
         
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {

com.unity.uiwidgets/Runtime/widgets/animated_switcher.cs

 namespace Unity.UIWidgets.widgets {
     class _ChildEntry {
         public _ChildEntry(
-            AnimationController controller,
-            Animation<float> animation,
-            Widget transition,
-            Widget widgetChild
+            AnimationController controller = null,
+            Animation<float> animation = null,
+            Widget transition = null,
+            Widget widgetChild = null
         ) {
             D.assert(animation != null);
             D.assert(transition != null);
         public Widget widgetChild;
 
         public override string ToString() {
-            return "Entry#${shortHash(this)}($widgetChild)";
+            return $"Entry#{foundation_.shortHash(this)}({widgetChild})";
         }
     }
 
             AnimatedSwitcherLayoutBuilder layoutBuilder = null
         ) : base(key: key) {
             D.assert(duration != null);
+            this.child = child;
+            this.duration = duration;
+            this.reverseDuration = reverseDuration;
-            this.child = child;
-            this.duration = duration;
-            this.reverseDuration = reverseDuration;
         }
 
         public readonly Widget child;
         }
 
         _ChildEntry _newEntry(
-            Widget child,
-            AnimatedSwitcherTransitionBuilder builder,
-            AnimationController controller,
-            Animation<float> animation
+            Widget child = null,
+            AnimatedSwitcherTransitionBuilder builder = null,
+            AnimationController controller = null,
+            Animation<float> animation = null
         ) {
             _ChildEntry entry = new _ChildEntry(
                 widgetChild: child,

com.unity.uiwidgets/Runtime/widgets/annotated_region.cs

 using Unity.UIWidgets.rendering;
 
 namespace Unity.UIWidgets.widgets {
-    public class AnnotatedRegion<T> : SingleChildRenderObjectWidget
-        where T : class {
+    public class AnnotatedRegion<T> : SingleChildRenderObjectWidget where T : class
+    {
-            T value = null,
+            T value = default,
             bool sized = true
         ) : base(key: key, child: child) {
             D.assert(value != null);

com.unity.uiwidgets/Runtime/widgets/app.cs

                       "will know what kind of PageRoute transition to build."
             );
         } 
-        // [!!!]too many errors here
-        /*public static readonly Dictionary<LogicalKeySet, Intent> _defaultShortcuts = new Dictionary<LogicalKeySet, Intent>(){
-    // Activation
-    {new LogicalKeySet(LogicalKeyboardKey.enter), new Intent(ActivateAction.key)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.space), new Intent(ActivateAction.key)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.gameButtonA), new Intent(ActivateAction.key)},
+        
+        public static readonly Dictionary<LogicalKeySet, Intent> _defaultShortcuts = new Dictionary<LogicalKeySet, Intent>(){
+            // Activation
+            {new LogicalKeySet(LogicalKeyboardKey.enter), new Intent(ActivateAction.key)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.space), new Intent(ActivateAction.key)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.gameButtonA), new Intent(ActivateAction.key)},
-    // Keyboard traversal.
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.tab), new Intent(NextFocusAction.key)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.shift, LogicalKeyboardKey.tab), new Intent(PreviousFocusAction.key)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowLeft), new DirectionalFocusIntent(TraversalDirection.left)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowRight), new DirectionalFocusIntent(TraversalDirection.right)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowDown), new DirectionalFocusIntent(TraversalDirection.down)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowUp), new DirectionalFocusIntent(TraversalDirection.up)},
+            // Keyboard traversal.
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.tab), new Intent(NextFocusAction.key)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.shift, LogicalKeyboardKey.tab), new Intent(PreviousFocusAction.key)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowLeft), new DirectionalFocusIntent(TraversalDirection.left)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowRight), new DirectionalFocusIntent(TraversalDirection.right)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowDown), new DirectionalFocusIntent(TraversalDirection.down)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowUp), new DirectionalFocusIntent(TraversalDirection.up)},
-    // Scrolling
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowUp), new ScrollIntent(direction: AxisDirection.up)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowDown), new ScrollIntent(direction: AxisDirection.down)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowLeft), new ScrollIntent(direction: AxisDirection.left)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowRight), new ScrollIntent(direction: AxisDirection.right)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.pageUp), new ScrollIntent(direction: AxisDirection.up, type: ScrollIncrementType.page)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.pageDown), new ScrollIntent(direction: AxisDirection.down, type: ScrollIncrementType.page)},
-  };
+            // Scrolling
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowUp), new ScrollIntent(direction: AxisDirection.up)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowDown), new ScrollIntent(direction: AxisDirection.down)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowLeft), new ScrollIntent(direction: AxisDirection.left)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.control, LogicalKeyboardKey.arrowRight), new ScrollIntent(direction: AxisDirection.right)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.pageUp), new ScrollIntent(direction: AxisDirection.up, type: ScrollIncrementType.page)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.pageDown), new ScrollIntent(direction: AxisDirection.down, type: ScrollIncrementType.page)},
+        };
-  // Default shortcuts for the web platform.
-  public static readonly Dictionary<LogicalKeySet, Intent> _defaultWebShortcuts = new Dictionary<LogicalKeySet, Intent>(){
-    // Activation
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.space), new Intent(ActivateAction.key)},
+        // Default shortcuts for the web platform.
+        public static readonly Dictionary<LogicalKeySet, Intent> _defaultWebShortcuts = new Dictionary<LogicalKeySet, Intent>(){
+            // Activation
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.space), new Intent(ActivateAction.key)},
-    // Keyboard traversal.
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.tab), new Intent(NextFocusAction.key)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.shift, LogicalKeyboardKey.tab),new Intent(PreviousFocusAction.key)},
+            // Keyboard traversal.
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.tab), new Intent(NextFocusAction.key)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.shift, LogicalKeyboardKey.tab),new Intent(PreviousFocusAction.key)},
-    // Scrolling
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowUp), new ScrollIntent(direction: AxisDirection.up)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowDown), new ScrollIntent(direction: AxisDirection.down)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowLeft), new ScrollIntent(direction: AxisDirection.left)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowRight), new ScrollIntent(direction: AxisDirection.right)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.pageUp), new ScrollIntent(direction: AxisDirection.up, type: ScrollIncrementType.page)},
-    {new widgets.LogicalKeySet(LogicalKeyboardKey.pageDown), new ScrollIntent(direction: AxisDirection.down, type: ScrollIncrementType.page)},
-  };
+            // Scrolling
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowUp), new ScrollIntent(direction: AxisDirection.up)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowDown), new ScrollIntent(direction: AxisDirection.down)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowLeft), new ScrollIntent(direction: AxisDirection.left)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.arrowRight), new ScrollIntent(direction: AxisDirection.right)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.pageUp), new ScrollIntent(direction: AxisDirection.up, type: ScrollIncrementType.page)},
+            {new widgets.LogicalKeySet(LogicalKeyboardKey.pageDown), new ScrollIntent(direction: AxisDirection.down, type: ScrollIncrementType.page)},
+        };
-  // Default shortcuts for the macOS platform.
-  public static readonly Dictionary<LogicalKeySet, Intent> _defaultMacOsShortcuts = new Dictionary<LogicalKeySet, Intent>(){
-    // Activation
-    new LogicalKeySet(LogicalKeyboardKey.enter), new Intent(ActivateAction.key),
-    new LogicalKeySet(LogicalKeyboardKey.space), new Intent(ActivateAction.key),
+        // Default shortcuts for the macOS platform.
+        public static readonly Dictionary<LogicalKeySet, Intent> _defaultMacOsShortcuts = new Dictionary<LogicalKeySet, Intent>(){
+            // Activation
+            {new LogicalKeySet(LogicalKeyboardKey.enter), new Intent(ActivateAction.key)},
+            {new LogicalKeySet(LogicalKeyboardKey.space), new Intent(ActivateAction.key)},
-    // Keyboard traversal
-    {new LogicalKeySet(LogicalKeyboardKey.tab), new Intent(NextFocusAction.key)},
-    {new LogicalKeySet(LogicalKeyboardKey.shift, LogicalKeyboardKey.tab), new Intent(PreviousFocusAction.key)},
-    {new LogicalKeySet(LogicalKeyboardKey.arrowLeft), new DirectionalFocusIntent(TraversalDirection.left)},
-    {new LogicalKeySet(LogicalKeyboardKey.arrowRight), new DirectionalFocusIntent(TraversalDirection.right)},
-    {new LogicalKeySet(LogicalKeyboardKey.arrowDown), new DirectionalFocusIntent(TraversalDirection.down)},
-    {new LogicalKeySet(LogicalKeyboardKey.arrowUp), new DirectionalFocusIntent(TraversalDirection.up)},
+            // Keyboard traversal
+            {new LogicalKeySet(LogicalKeyboardKey.tab), new Intent(NextFocusAction.key)},
+            {new LogicalKeySet(LogicalKeyboardKey.shift, LogicalKeyboardKey.tab), new Intent(PreviousFocusAction.key)},
+            {new LogicalKeySet(LogicalKeyboardKey.arrowLeft), new DirectionalFocusIntent(TraversalDirection.left)},
+            {new LogicalKeySet(LogicalKeyboardKey.arrowRight), new DirectionalFocusIntent(TraversalDirection.right)},
+            {new LogicalKeySet(LogicalKeyboardKey.arrowDown), new DirectionalFocusIntent(TraversalDirection.down)},
+            {new LogicalKeySet(LogicalKeyboardKey.arrowUp), new DirectionalFocusIntent(TraversalDirection.up)},
-    // Scrolling
-    {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowUp), new  ScrollIntent(direction: AxisDirection.up)},
-    {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowDown), new ScrollIntent(direction: AxisDirection.down)},
-    {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowLeft), new ScrollIntent(direction: AxisDirection.left)},
-    {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowRight), new ScrollIntent(direction: AxisDirection.right)},
-    {new LogicalKeySet(LogicalKeyboardKey.pageUp), new ScrollIntent(direction: AxisDirection.up, type: ScrollIncrementType.page)},
-    {new LogicalKeySet(LogicalKeyboardKey.pageDown), new ScrollIntent(direction: AxisDirection.down, type: ScrollIncrementType.page)},
-  };
+            // Scrolling
+            {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowUp), new  ScrollIntent(direction: AxisDirection.up)},
+            {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowDown), new ScrollIntent(direction: AxisDirection.down)},
+            {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowLeft), new ScrollIntent(direction: AxisDirection.left)},
+            {new LogicalKeySet(LogicalKeyboardKey.meta, LogicalKeyboardKey.arrowRight), new ScrollIntent(direction: AxisDirection.right)},
+            {new LogicalKeySet(LogicalKeyboardKey.pageUp), new ScrollIntent(direction: AxisDirection.up, type: ScrollIncrementType.page)},
+            {new LogicalKeySet(LogicalKeyboardKey.pageDown), new ScrollIntent(direction: AxisDirection.down, type: ScrollIncrementType.page)},
+        };
-  /// Generates the default shortcut key bindings based on the
-  /// [defaultTargetPlatform].
-  ///
-  /// Used by [WidgetsApp] to assign a default value to [WidgetsApp.shortcuts].
-  public static Dictionary<LogicalKeySet, Intent> defaultShortcuts {
-      get {
-          if (kIsWeb) {
-              return _defaultWebShortcuts;
-          }
-          switch (defaultTargetPlatform) {
-              case TargetPlatform.android:
-              case TargetPlatform.fuchsia:
-              case TargetPlatform.linux:
-              case TargetPlatform.windows:
-                  return _defaultShortcuts;
-              case TargetPlatform.macOS:
-                  return _defaultMacOsShortcuts;
-              case TargetPlatform.iOS:
-                  // No keyboard support on iOS yet.
-                  break;
-          }
-          return new Dictionary<LogicalKeySet, Intent>();
-      }
-  }
+  
+        public static Dictionary<LogicalKeySet, Intent> defaultShortcuts {
+            get {
+                if (foundation_.kIsWeb) {
+                    return _defaultWebShortcuts;
+                }
+                switch (Application.platform) {
+                    case RuntimePlatform.Android:
+                    //case TargetPlatform.fuchsia:
+                    case RuntimePlatform.LinuxPlayer:
+                    case RuntimePlatform.WindowsPlayer:
+                        return _defaultShortcuts;
+                    case RuntimePlatform.OSXPlayer:
+                        return _defaultMacOsShortcuts;
+                    case RuntimePlatform.IPhonePlayer:
+                        // No keyboard support on iOS yet.
+                        break;
+                }
+                return new Dictionary<LogicalKeySet, Intent>();
+            }
+        }
-  /// The default value of [WidgetsApp.actions].
-  public static readonly Dictionary<LocalKey, ActionFactory> defaultActions = new Dictionary<LocalKey, ActionFactory>(){
-      {DoNothingAction.key, () => new  DoNothingAction()},
-      {RequestFocusAction.key, () => new RequestFocusAction()},
-      {NextFocusAction.key, () => new NextFocusAction()},
-      {PreviousFocusAction.key, () => new PreviousFocusAction()},
-      {DirectionalFocusAction.key, () => new DirectionalFocusAction()},
-      {ScrollAction.key, () => new ScrollAction()},
-  };*/
+    /// The default value of [WidgetsApp.actions].
+    public static readonly Dictionary<LocalKey, ActionFactory> defaultActions = new Dictionary<LocalKey, ActionFactory>(){
+        {DoNothingAction.key, () => new  DoNothingAction()},
+        {RequestFocusAction.key, () => new RequestFocusAction()},
+        {NextFocusAction.key, () => new NextFocusAction()},
+        {PreviousFocusAction.key, () => new PreviousFocusAction()},
+        {DirectionalFocusAction.key, () => new DirectionalFocusAction()},
+        {ScrollAction.key, () => new ScrollAction()},
+    };
         
         public override State createState() {
             return new _WidgetsAppState();
             navigator.pushNamed<bool>(route);
             return Future.value(true).to<bool>();
         }
+
+        public void didChangeAccessibilityFeatures() {}
 
         Route<object> _onUnknownRoute(RouteSettings settings) {
             D.assert(() => {
 
     public class _MediaQueryFromWindow : StatefulWidget {
         public _MediaQueryFromWindow(Key key = null, Widget child = null) : base(key: key) {
+            this.child = child;
         }
         public readonly Widget child;
 

com.unity.uiwidgets/Runtime/widgets/automatic_keep_alive.cs

         }
 
         public override void didUpdateWidget(StatefulWidget oldWidget) {
+            oldWidget = (AutomaticKeepAlive)oldWidget;
             base.didUpdateWidget(oldWidget);
             _updateChild();
         }
                     handle.removeListener(_handles[handle]);
                 }
             }
-
             base.dispose();
         }
 
-
-                //ParentDataElement 
                 ParentDataElement<KeepAliveParentDataMixin> childElement = _getChildElement();
                 if (childElement != null) {
                     _updateParentDataOfChild(childElement);
                         if (!mounted) {
                             return;
                         }
-
                         ParentDataElement<KeepAliveParentDataMixin> childElement1 = _getChildElement();
                         D.assert(childElement1 != null);
                         _updateParentDataOfChild(childElement1);

com.unity.uiwidgets/Runtime/widgets/banner.cs

 
     public class BannerPainter : AbstractCustomPainter {
         public BannerPainter(
-            string message,
-            BannerLocation? location,
+            string message = null,
+            TextDirection? textDirection = null,
+            BannerLocation? location = null,
+            TextDirection? layoutDirection = null,
+            D.assert(textDirection != null);
-            this.color = color ?? BannerConstants._kColor;
+
+            this.textDirection = textDirection;
+            this.layoutDirection = layoutDirection;
+            this.color = color ?? BannerConstants._kColor;
+        
+        public readonly TextDirection? textDirection;
+        
+        public readonly TextDirection? layoutDirection;
 
         public readonly Color color;
 
             _paintBanner.color = color;
             _textPainter = new TextPainter(
                 text: new TextSpan(style: textStyle, text: message),
-                textAlign: TextAlign.center
+                textAlign: TextAlign.center,
+                textDirection: textDirection ?? TextDirection.ltr
             );
             _prepared = true;
         }
         }
 
         float _translationX(float width) {
-            switch (location) {
-                case BannerLocation.bottomEnd:
-                    return width - BannerConstants._kBottomOffset;
-                case BannerLocation.topEnd:
-                    return width;
-                case BannerLocation.bottomStart:
-                    return BannerConstants._kBottomOffset;
-                case BannerLocation.topStart:
-                    return 0.0f;
-                default:
-                    throw new Exception("Unknown location: " + location);
+            D.assert(location != null);
+            D.assert(layoutDirection != null);
+            switch (layoutDirection) {
+                case TextDirection.rtl:
+                    switch (location) {
+                        case BannerLocation.bottomEnd:
+                            return BannerConstants._kBottomOffset;
+                        case BannerLocation.topEnd:
+                            return 0.0f;
+                        case BannerLocation.bottomStart:
+                            return width - BannerConstants._kBottomOffset;
+                        case BannerLocation.topStart:
+                            return width;
+                    }
+                    break;
+                case TextDirection.ltr:
+                    switch (location) {
+                        case BannerLocation.bottomEnd:
+                            return width - BannerConstants._kBottomOffset;
+                        case BannerLocation.topEnd:
+                            return width;
+                        case BannerLocation.bottomStart:
+                            return BannerConstants._kBottomOffset;
+                        case BannerLocation.topStart:
+                            return 0.0f;
+                    }
+                    break;
+                
+            return 0.0f;
         }
 
         float _translationY(float height) {
 
         float _rotation {
             get {
-                switch (location) {
-                    case BannerLocation.bottomStart:
-                    case BannerLocation.topEnd:
-                        return Mathf.PI / 4.0f;
-                    case BannerLocation.bottomEnd:
-                    case BannerLocation.topStart:
-                        return -Mathf.PI / 4.0f;
-                    default:
-                        throw new Exception("Unknown location: " + location);
+                D.assert(location != null);
+                D.assert(layoutDirection != null);
+                switch (layoutDirection) {
+                    case TextDirection.rtl:
+                        switch (location) {
+                            case BannerLocation.bottomStart:
+                            case BannerLocation.topEnd:
+                                return -Mathf.PI / 4.0f;
+                            case BannerLocation.bottomEnd:
+                            case BannerLocation.topStart:
+                                return Mathf.PI / 4.0f;
+                        }
+                        break;
+                    case TextDirection.ltr:
+                        switch (location) {
+                            case BannerLocation.bottomStart:
+                            case BannerLocation.topEnd:
+                                return Mathf.PI / 4.0f;
+                            case BannerLocation.bottomEnd:
+                            case BannerLocation.topStart:
+                                return -Mathf.PI / 4.0f;
+                        }
+                        break;
+                return 0.0f;
             }
         }
     }
             Key key = null,
             Widget child = null,
             string message = null,
+            TextDirection? textDirection = null,
+            TextDirection? layoutDirection = null,
+            D.assert(location != null);
+            this.layoutDirection = layoutDirection;
+            this.textDirection = textDirection;
             this.location = location;
             this.color = color ?? BannerConstants._kColor;
             this.textStyle = textStyle ?? BannerConstants._kTextStyle;
 
         public readonly string message;
+        
+        public readonly TextDirection? textDirection;
+        
+        public readonly TextDirection? layoutDirection;
 
         public readonly BannerLocation? location;
 
 
         public override Widget build(BuildContext context) {
-            D.assert(WidgetsD.debugCheckHasDirectionality(context));
+            D.assert((textDirection != null && layoutDirection != null)|| WidgetsD.debugCheckHasDirectionality(context));
+                    textDirection: textDirection ?? Directionality.of(context),
+                    layoutDirection: layoutDirection ?? Directionality.of(context),
                     color: color,
                     textStyle: textStyle
                 ),
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new StringProperty("message", message, showName: false));
-            properties.add(new EnumProperty<BannerLocation?>("location", location));
+            properties.add(new EnumProperty<TextDirection>("textDirection", (TextDirection)textDirection, defaultValue: null));
+            properties.add(new EnumProperty<BannerLocation>("location", (BannerLocation)location));
+            properties.add(new EnumProperty<TextDirection>("layoutDirection", (TextDirection)layoutDirection, defaultValue: null));
-            textStyle?.debugFillProperties(properties);
+            textStyle?.debugFillProperties(properties, prefix: "text ");
         }
     }
 
                 result = new Banner(
                     child: result,
                     message: "DEBUG",
+                    textDirection: TextDirection.ltr,
                     location: BannerLocation.topEnd
                 );
                 return true;

com.unity.uiwidgets/Runtime/widgets/binding.cs

         Future<bool> didPopRoute();
 
         Future<bool> didPushRoute(string route);
+
+        void didChangeAccessibilityFeatures();
     }
 
     public static partial class ui_ {

com.unity.uiwidgets/Runtime/widgets/color_filter.cs

 namespace Unity.UIWidgets.widgets {
     
         public class ColorFiltered : SingleChildRenderObjectWidget {
-            protected ColorFiltered(ColorFilter colorFilter = null, Widget child = null, Key key = null)
+            protected ColorFiltered(
+                ColorFilter colorFilter = null, 
+                Widget child = null, 
+                Key key = null)
+                this.colorFilter = colorFilter;
-            
-            public override RenderObject createRenderObject(BuildContext context) => new _ColorFilterRenderObject(colorFilter);
-            
+
+            public override RenderObject createRenderObject(BuildContext context) {
+                return  new _ColorFilterRenderObject(colorFilter);
+            }
+
             public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
                 ((_ColorFilterRenderObject)renderObject).colorFilter = colorFilter;
             }
                 properties.add(new DiagnosticsProperty<ColorFilter>("colorFilter", colorFilter));
             }
         }
+        public class _ColorFilterRenderObject : RenderProxyBox {
+            public _ColorFilterRenderObject(ColorFilter _colorFilter) {
+                this._colorFilter = _colorFilter;
+            }
-    public class _ColorFilterRenderObject : RenderProxyBox {
-        public _ColorFilterRenderObject(ColorFilter _colorFilter) {
-            this._colorFilter = _colorFilter;
-        }
+            public ColorFilter colorFilter {
+                get { return _colorFilter; }
+                set {
+                    D.assert(value != null);
+                    if (value != _colorFilter) {
+                        _colorFilter = value;
+                        markNeedsPaint();
+                    }
+                }
+            }
-    public ColorFilter colorFilter {
-        get { return _colorFilter; }
-        set {
-            D.assert(value != null);
-            if (value != _colorFilter) {
-                _colorFilter = value;
-                markNeedsPaint();
+            ColorFilter _colorFilter;
+            
+            public  bool alwaysNeedsCompositing {
+                get { return child != null; }
+            }
+            
+            public override void paint(PaintingContext context, Offset offset) {
+                layer = context.pushColorFilter(offset, colorFilter, base.paint, oldLayer: layer as ColorFilterLayer);
-    }
-
-    ColorFilter _colorFilter;
-    
-    public  bool alwaysNeedsCompositing {
-        get { return child != null; }
-    }
-    
-    public override void paint(PaintingContext context, Offset offset) {
-        layer = context.pushColorFilter(offset, colorFilter, base.paint, oldLayer: layer as ColorFilterLayer);
-    }
-    }
 
     
 }

com.unity.uiwidgets/Runtime/widgets/container.cs

     public class Container : StatelessWidget {
         public Container(
             Key key = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
-            Decoration forgroundDecoration = null,
+            Decoration foregroundDecoration = null,
-            Matrix4 transfrom = null,
+            Matrix4 transform = null,
             Widget child = null,
             Clip clipBehavior = Clip.none
         ) : base(key: key) {
             
             this.alignment = alignment;
             this.padding = padding;
-            foregroundDecoration = forgroundDecoration;
-            this.margin = margin;
-            transform = transfrom;
-            this.child = child;
+            this.foregroundDecoration = foregroundDecoration;
-            this.decoration = decoration ?? (color != null ? new BoxDecoration(color) : null);
+            this.decoration = decoration;// ?? (color != null ? new BoxDecoration(color) : null);
+            this.margin = margin;
+            this.transform = transform;
+            this.child = child;
+            this.clipBehavior = clipBehavior ;
-            this.clipBehavior = clipBehavior;
+           
-        public readonly Alignment alignment;
+        public readonly AlignmentGeometry alignment;
         public readonly EdgeInsets padding;
         public readonly Decoration decoration;
         public readonly Decoration foregroundDecoration;
                 if (decoration == null || decoration.padding == null) {
                     return padding;
                 }
-
-                Debug.LogError("EdgeInsets needs to be update to EdgeInsetsGeometry");
+                //Debug.LogError("EdgeInsets needs to be update to EdgeInsetsGeometry");
-
                 return padding.add(decorationPadding);
             }
         }
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
-            properties.add(new DiagnosticsProperty<Alignment>("alignment",
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment",
                 alignment, showName: false, defaultValue: foundation_.kNullDefaultValue));
             properties.add(new DiagnosticsProperty<EdgeInsets>("padding",
                 padding, defaultValue: foundation_.kNullDefaultValue));
     /// A clipper that uses [Decoration.getClipPath] to clip.
     public class _DecorationClipper : CustomClipper<Path> {
         public _DecorationClipper(
-            TextDirection textDirection = TextDirection.rtl,
+            TextDirection? textDirection = null,
-            textDirection =  TextDirection.ltr;
+            this.textDirection =  textDirection ?? TextDirection.ltr;
+            this.decoration = decoration;
         } 
 
         public readonly TextDirection textDirection;

com.unity.uiwidgets/Runtime/widgets/debug.cs

         public static bool debugPrintGlobalKeyedWidgetLifecycle = false;
 
         public static bool debugPrintScheduleBuildForStacks = false;
+        
+        public static bool debugProfileBuildsEnabled = false;
+
+       
+        public static bool debugHighlightDeprecatedWidgets = false;
 
         static Key _firstNonUniqueKey(IEnumerable<Widget> widgets) {
             var keySet = new HashSet<Key>();
                     throw new UIWidgetsError(
                         "Duplicate keys found.\n" +
                         "If multiple keyed nodes exist as children of another node, they must have unique keys.\n" +
-                        parent + " has multiple children with key " + children + "."
+                        parent + " has multiple children with key " + nonUniqueKey + "."
                     );
                 }
 
                 if (widget == built) {
                     throw new UIWidgetsError(
                         "A build function returned context.widget.\n" +
-                        "The offending widget is: $widget\n" +
+                        $"The offending widget is: {widget}\n" +
                         "Build functions must never return their BuildContext parameter\'s widget or a child that contains 'context.widget'. " +
                         "Doing so introduces a loop in the widget tree that can cause the app to crash."
                     );
                     context.findAncestorWidgetOfExactType<Directionality>() == null) {
                     throw new UIWidgetsError(new List<DiagnosticsNode>{
                         new ErrorSummary("No Directionality widget found."),
-                        new ErrorDescription("${context.widget.runtimeType} widgets require a Directionality widget ancestor.\n"),
+                        new ErrorDescription($"{context.widget.GetType()} widgets require a Directionality widget ancestor.\n"),
                         context.describeWidget("The specific widget that could not find a Directionality ancestor was"),
                         context.describeOwnershipChain("The ownership chain for the affected widget is"),
                         new ErrorHint(
         }
 
         internal static UIWidgetsErrorDetails _debugReportException(
+            DiagnosticsNode context,
+            Exception exception,
+            InformationCollector informationCollector = null
+        ) {
+            var details = new UIWidgetsErrorDetails(
+                exception: exception,
+                library: "widgets library",
+                context: context,
+                informationCollector: informationCollector
+            );
+            UIWidgetsError.reportError(details);
+            return details;
+        }
+
+        internal static UIWidgetsErrorDetails _debugReportException(
             string context,
             Exception exception,
             InformationCollector informationCollector = null
             UIWidgetsError.reportError(details);
             return details;
         }
+        
+        /// See [the widgets library](widgets/widgets-library.html) for a complete list.
+        public static bool debugAssertAllWidgetVarsUnset(string reason) {
+            D.assert(()=> {
+                if (debugPrintRebuildDirtyWidgets ||
+                    debugPrintBuildScope ||
+                    debugPrintScheduleBuildForStacks ||
+                    debugPrintGlobalKeyedWidgetLifecycle ||
+                    debugProfileBuildsEnabled ||
+                    debugHighlightDeprecatedWidgets) {
+                    throw new UIWidgetsError(reason);
+                }
+                return true;
+            });
+            return true;
+        }
+
     }
 }

com.unity.uiwidgets/Runtime/widgets/dismissible.cs

             Axis axis,
             Animation<Offset> moveAnimation
         ) : base(reclip: moveAnimation) {
-            D.assert(moveAnimation != null);
             this.axis = axis;
             this.moveAnimation = moveAnimation;
         }
         }
 
         public override bool shouldReclip(CustomClipper<Rect> oldClipper) {
-            D.assert(oldClipper is _DismissibleClipper);
+            //D.assert(oldClipper is _DismissibleClipper);
             _DismissibleClipper clipper = oldClipper as _DismissibleClipper;
             return clipper.axis != axis
                    || clipper.moveAnimation.value != moveAnimation.value;
         }
 
         _FlingGestureKind _describeFlingGesture(Velocity velocity) {
+            D.assert(widget.direction != null);
             if (_dragExtent == 0.0f) {
                 return _FlingGestureKind.none;
             }
             );
 
             if (background != null) {
-                List<Widget> children = new List<Widget> { };
+                List<Widget> children = new List<Widget>();
 
                 if (!_moveAnimation.isDismissed) {
                     children.Add(Positioned.fill(
 
                 children.Add(content);
                 content = new Stack(children: children);
+                
             }
 
             return new GestureDetector(

com.unity.uiwidgets/Runtime/widgets/disposable_build_context.cs

 using Unity.UIWidgets.foundation;
 
 namespace Unity.UIWidgets.widgets {
-    
-    public class DisposableBuildContext<T> where T : State{
-        public DisposableBuildContext(T _state) {
-            D.assert(_state != null);
-            D.assert(_state.mounted, () => "A DisposableBuildContext was given a BuildContext for an Element that is not mounted.");
-            this._state = _state;
-        }
-
-        T _state;
-        
+    public class DisposableBuildContext {
+        State _state;
         public BuildContext context {
             get {
                 D.assert(_debugValidate());
         public bool _debugValidate() {
             D.assert(
                 _state == null || _state.mounted,() =>
-                "A DisposableBuildContext tried to access the BuildContext of a disposed " +
-            "State object. This can happen when the creator of this " +
-            "DisposableBuildContext fails to call dispose when it is disposed."
-                );
+                    "A DisposableBuildContext tried to access the BuildContext of a disposed " +
+                    "State object. This can happen when the creator of this " +
+                    "DisposableBuildContext fails to call dispose when it is disposed."
+            );
             return true;
         }
         
+    }
+
+    public class DisposableBuildContext<T> : DisposableBuildContext where T : State{
+
+        public DisposableBuildContext(T _state) {
+            D.assert(_state != null);
+            D.assert(_state.mounted, () => "A DisposableBuildContext was given a BuildContext for an Element that is not mounted.");
+            this._state = _state;
+        }
+
+        T _state;
+        
+        
     }
 }

com.unity.uiwidgets/Runtime/widgets/drag_target.cs

 
     public class Draggable<T> : StatefulWidget {
         public Draggable(
-            T data,
+            T data = default,
             Axis? axis = null,
             Widget childWhenDragging = null,
             Offset feedbackOffset = null,
             VoidCallback onDragStarted = null,
             DraggableCanceledCallback onDraggableCanceled = null,
             DragEndCallback onDragEnd = null,
-            VoidCallback onDragCompleted = null) : base(key) {
+            VoidCallback onDragCompleted = null
+            ) : base(key) {
             D.assert(child != null);
             D.assert(feedback != null);
             D.assert(maxSimultaneousDrags == null || maxSimultaneousDrags >= 0);
             this.data = data;
             this.axis = axis;
             this.childWhenDragging = childWhenDragging;
-            if (feedbackOffset == null) {
-                feedbackOffset = Offset.zero;
-            }
-
-            this.feedbackOffset = feedbackOffset;
+            this.feedbackOffset = feedbackOffset ?? Offset.zero;
             this.dragAnchor = dragAnchor;
             this.affinity = affinity;
             this.maxSimultaneousDrags = maxSimultaneousDrags;
 
     public class LongPressDraggable<T> : Draggable<T> {
         public LongPressDraggable(
-            T data,
+            T data = default,
             Axis? axis = null,
             Widget childWhenDragging = null,
             Offset feedbackOffset = null,
             if (_activeCount > 0) {
                 return;
             }
-
             _recognizer.dispose();
             _recognizer = null;
         }
 
     public class _DragAvatar<T> : Drag {
         public _DragAvatar(
-            T data,
+            T data = default,
             Axis? axis = null,
             Offset initialPosition = null,
             Offset dragStartPoint = null,
         ) {
-            if (initialPosition == null) {
-                initialPosition = Offset.zero;
-            }
-
-            if (dragStartPoint == null) {
-                dragStartPoint = Offset.zero;
-            }
+           
+           
             if (feedbackOffset == null) {
                 feedbackOffset = Offset.zero;
             }
             this.data = data;
             this.axis = axis;
-            this.dragStartPoint = dragStartPoint;
+            this.dragStartPoint = dragStartPoint ?? Offset.zero;
-            this.feedbackOffset = feedbackOffset;
+            this.feedbackOffset = feedbackOffset ?? Offset.zero;
-
-            _position = initialPosition;
+            _position = initialPosition ?? Offset.zero;
             updateDrag(initialPosition);
         }
 

com.unity.uiwidgets/Runtime/widgets/editable_text.cs

         public void clearComposing() {
             value = value.copyWith(composing: TextRange.empty);
         }
+        
+        public bool isSelectionWithinTextBounds(TextSelection selection) {
+            return selection.start <= text.Length && selection.end <= text.Length;
+        }
     }
     public class ToolbarOptions {
         
             bool paste = false,
             bool selectAll = false
         ) {
-            D.assert(copy != null);
-            D.assert(cut != null);
-            D.assert(paste != null);
-            D.assert(selectAll != null);
             this.copy = copy;
             this.cut = cut;
             this.paste = paste;
     
     public class EditableText : StatefulWidget {
         public EditableText(
+            SmartDashesType smartDashesType,
+            SmartQuotesType smartQuotesType,
             Key key = null,
             TextEditingController controller = null,
             FocusNode focusNode = null,
-            //SmartDashesType smartDashesType,
-            //SmartQuotesType smartQuotesType,
-            TextAlign textAlign = TextAlign.left,
+            TextAlign textAlign = TextAlign.start,
             TextDirection? textDirection = null,
             Locale locale = null,
             float? textScaleFactor = null,
-            bool forceLine = false,
+            bool forceLine = true,
             TextWidthBasis textWidthBasis = TextWidthBasis.parent,
             bool autofocus = false,
             bool? showCursor = null,
             VoidCallback onSelectionHandleTapped = null,
             List<TextInputFormatter> inputFormatters = null,
             bool rendererIgnoresPointer = false,
-            float? cursorWidth = 2.0f,
+            float cursorWidth = 2.0f,
             Radius cursorRadius = null,
             bool cursorOpacityAnimates = false,
             Offset cursorOffset = null,
             ToolbarOptions toolbarOptions = null,
             bool unityTouchKeyboard = false
         ) : base(key) {
-            toolbarOptions = toolbarOptions ?? new ToolbarOptions(
-                copy: true,
-                cut: true,
-                paste: true,
-                selectAll: true
-            );
-            D.assert(obscureText != null);
-            D.assert(autocorrect != null);
-           //smartDashesType = smartDashesType ?? (obscureText ? SmartDashesType.disabled : SmartDashesType.enabled),
-           //smartQuotesType = smartQuotesType ?? (obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled),
-            D.assert(enableSuggestions != null);
-            D.assert(showSelectionHandles != null);
+            smartDashesType = (obscureText ? SmartDashesType.disabled : SmartDashesType.enabled);
+            smartQuotesType = (obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled);
-            D.assert(readOnly != null);
-            D.assert(forceLine != null);
-            D.assert(cursorOpacityAnimates != null);
-            D.assert(paintCursorAboveText != null);
-            D.assert(selectionHeightStyle != null);
-            D.assert(selectionWidthStyle != null);
-            D.assert(textAlign != null);
             D.assert(maxLines == null || maxLines > 0);
             D.assert(minLines == null || minLines > 0);
             D.assert(
-            D.assert(expands != null);
-            D.assert(autofocus != null);
-            D.assert(rendererIgnoresPointer != null);
-            D.assert(dragStartBehavior != null);
-            D.assert(toolbarOptions != null);
-            _strutStyle = strutStyle;
+            toolbarOptions = toolbarOptions ?? new ToolbarOptions(
+                copy: true,
+                cut: true,
+                paste: true,
+                selectAll: true
+            );
             inputFormatters = inputFormatters ?? new List<TextInputFormatter>();
             keyboardType = keyboardType ?? (maxLines == 1 ? TextInputType.text : TextInputType.multiline);
             List<TextInputFormatter> formatters = new List<TextInputFormatter>();
                 }
             }
             this.readOnly = readOnly;
-            this.showCursor = showCursor ?? !readOnly;
+            this.showCursor = !readOnly;
             this.keyboardType = keyboardType ?? (maxLines == 1 ? TextInputType.text : TextInputType.multiline);
             this.locale = locale;
             this.scrollPadding = scrollPadding ?? EdgeInsets.all(20.0f);
             this.autocorrect = autocorrect;
             this.style = style;
-            
+            this.smartDashesType = smartDashesType;
+            this.smartQuotesType = smartQuotesType;
+            this.showCursor = showCursor;
             this.textWidthBasis = textWidthBasis;
             this.onSelectionHandleTapped = onSelectionHandleTapped;
             this.scrollController = scrollController;
             this.keyboardAppearance = keyboardAppearance;
             this.enableInteractiveSelection = enableInteractiveSelection;
             this.dragStartBehavior = dragStartBehavior;
-            this.scrollPhysics = scrollPhysics;
-           // this.globalKeyEventHandler = globalKeyEventHandler;
+            this.scrollPhysics = scrollPhysics; 
         }
 
         public readonly bool readOnly;
         public readonly bool obscureText;
         public readonly bool autocorrect;
+        public readonly SmartDashesType smartDashesType;
+        public readonly SmartQuotesType smartQuotesType;
-
-        public readonly bool showCursor;
+        public readonly bool? showCursor;
         public readonly ui.BoxHeightStyle selectionHeightStyle;
         public readonly ui.BoxWidthStyle selectionWidthStyle;
         public readonly bool forceLine;
                 if (_strutStyle == null) {
                     return style != null
                         ? StrutStyle.fromTextStyle(style, forceStrutHeight: true)
-                        : StrutStyle.disabled;
+                        :  new StrutStyle();
                 }
 
                 return _strutStyle.inheritFromTextStyle(style);
             properties.add( new DiagnosticsProperty<FocusNode>("focusNode", focusNode));
             properties.add( new DiagnosticsProperty<bool>("obscureText", obscureText, defaultValue: false));
             properties.add( new DiagnosticsProperty<bool>("autocorrect", autocorrect, defaultValue: true));
-           // properties.add( new EnumProperty<SmartDashesType>("smartDashesType", smartDashesType, defaultValue: obscureText ? SmartDashesType.disabled : SmartDashesType.enabled));
-           // properties.add( new EnumProperty<SmartQuotesType>("smartQuotesType", smartQuotesType, defaultValue: obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled));
+            properties.add( new EnumProperty<SmartDashesType>("smartDashesType", smartDashesType, defaultValue: obscureText ? SmartDashesType.disabled : SmartDashesType.enabled));
+            properties.add( new EnumProperty<SmartQuotesType>("smartQuotesType", smartQuotesType, defaultValue: obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled));
             properties.add( new DiagnosticsProperty<bool>("enableSuggestions", enableSuggestions, defaultValue: true));
             style?.debugFillProperties(properties);
             properties.add( new EnumProperty<TextAlign>("textAlign", textAlign, defaultValue: null));
 
     public class EditableTextState : AutomaticKeepAliveClientWithTickerProviderStateMixin<EditableText>,
         WidgetsBindingObserver, TextInputClient,
-        TextSelectionDelegate {
+        TextSelectionDelegate 
+    {
-
+        const float kMinInteractiveDimension = 48.0f;
+        public readonly LayerLink _toolbarLayerLink = new LayerLink();
+        public readonly LayerLink _startHandleLayerLink = new LayerLink();
+        public readonly LayerLink _endHandleLayerLink = new LayerLink();
         GlobalKey _editableKey = GlobalKey.key();
 
         TextInputConnection _textInputConnection;
         AnimationController _cursorBlinkOpacityController;
-
-        LayerLink _layerLink = new LayerLink();
+        
         bool _didAutoFocus = false;
         FocusAttachment _focusAttachment;
         
             widget.controller.addListener(_didChangeTextEditingValue);
             _focusAttachment = widget.focusNode.attach(context);
             widget.focusNode.addListener(_handleFocusChanged);
+            _scrollController = widget.scrollController ?? new ScrollController();
+            _cursorVisibilityNotifier.value = widget.showCursor ?? false;
-                FocusScope.of(context).autofocus(widget.focusNode);
+                SchedulerBinding.instance.addPostFrameCallback((_) => {
+                    if (mounted) {
+                        FocusScope.of(context).autofocus(widget.focusNode);
+                    }
+                });
             }
         }
 
                 oldWidget.controller.removeListener(_didChangeTextEditingValue);
                 widget.controller.addListener(_didChangeTextEditingValue);
                 _updateRemoteEditingValueIfNeeded();
-                //_updateImePosIfNeed();
+            }
+            if (widget.controller.selection != oldWidget.controller.selection) {
+                _selectionOverlay?.update(_value);
-
+            _selectionOverlay.handlesVisible = widget.showSelectionHandles;
             if (widget.focusNode != oldWidget.focusNode) {
                 oldWidget.focusNode.removeListener(_handleFocusChanged);
                 _focusAttachment?.detach();
             }
+            if (widget.readOnly) {
+                _closeInputConnectionIfNeeded();
+            } else {
+                if (oldWidget.readOnly && _hasFocus)
+                    _openInputConnection();
+            }
+            if (widget.style != oldWidget.style) {
+                TextStyle style = widget.style;
+                if (_textInputConnection != null && _textInputConnection.attached) {
+                    _textInputConnection.setStyle(
+                        fontFamily: style.fontFamily,
+                        fontSize: style.fontSize,
+                        fontWeight: style.fontWeight,
+                        textDirection: (TextDirection)_textDirection,
+                        textAlign: widget.textAlign
+                    );
+                }
+            }
         }
 
         public override void dispose() {
             widget.focusNode.removeListener(_handleFocusChanged);
             base.dispose();
         }
-
+            if (widget.readOnly) {
+                return;
+            }
+            _receivedRemoteTextEditingValue = value;
-                _hideSelectionOverlayIfNeeded();
+                hideToolbar();
                 _showCaretOnScreen();
                 if (widget.obscureText && value.text.Length == _value.text.Length + 1) {
                     _obscureShowCharTicksPending = !_unityKeyboard() ? _kObscureShowLatestCharCursorTicks : 0;
-
-            _lastKnownRemoteTextEditingValue = value;
-
             _stopCursorTimer(resetCharTicks: false);
             _startCursorTimer();
         }
 
                     break;
                 case FloatingCursorDragState.End:
-                    _floatingCursorResetController.setValue(0.0f);
-                    _floatingCursorResetController.animateTo(1.0f, duration: _floatingCursorResetTime,
-                        curve: Curves.decelerate);
+                    if (_lastTextPosition != null && _lastBoundedOffset != null) {
+                        _floatingCursorResetController.setValue(0.0f);
+                        _floatingCursorResetController.animateTo(1.0f, duration: _floatingCursorResetTime,
+                            curve: Curves.decelerate);
+                    }
+
                     break;
             }
         }
             }
 
             var localValue = _value;
-            if (localValue == _lastKnownRemoteTextEditingValue) {
+            if (localValue == _receivedRemoteTextEditingValue) {
-
-            _lastKnownRemoteTextEditingValue = localValue;
+            
             _textInputConnection.setEditingState(localValue);
         }
 
             float caretStart;
             float caretEnd;
             if (_isMultiline) {
-                // The caret is vertically centered within the line. Expand the caret's
-                // height so that it spans the line because we're going to ensure that the entire
-                // expanded caret is scrolled into view.
                 float lineHeight = renderEditable.preferredLineHeight;
                 float caretOffset = (lineHeight - caretRect.height) / 2;
                 caretStart = caretRect.top - caretOffset;
             else if (caretEnd >= viewportExtent) {
                 scrollOffset += caretEnd - viewportExtent;
             }
-
+            if (_isMultiline) {
+                scrollOffset = scrollOffset.clamp(0.0f, renderEditable.maxScrollExtent);
+            }
             return scrollOffset;
         }
 
                         inputType: widget.keyboardType,
                         obscureText: widget.obscureText,
                         autocorrect: widget.autocorrect,
-                        //smartDashesType: widget.smartDashesType ?? (widget.obscureText ? SmartDashesType.disabled : SmartDashesType.enabled),
-                        //smartQuotesType: widget.smartQuotesType ?? (widget.obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled),
+                        smartDashesType: widget.obscureText ? SmartDashesType.disabled : SmartDashesType.enabled,
+                        smartQuotesType: widget.obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled,
                         enableSuggestions: widget.enableSuggestions,
                         inputAction: widget.textInputAction ?? (widget.keyboardType == TextInputType.multiline
                             ? TextInputAction.newline
             if (_hasInputConnection) {
                 _textInputConnection.close();
                 _textInputConnection = null;
-                _lastKnownRemoteTextEditingValue = null;
+                _lastFormattedUnmodifiedTextEditingValue = null;
+                _receivedRemoteTextEditingValue = null;
             }
         }
 
                 widget.controller.clearComposing();
             }
         }
-
         public void requestKeyboard() {
             if (_hasFocus) {
                 _openInputConnection();
 
         void _handleSelectionChanged(TextSelection selection, RenderEditable renderObject,
             SelectionChangedCause cause) {
+            if (!widget.controller.isSelectionWithinTextBounds(selection))
+                return;
-            _hideSelectionOverlayIfNeeded();
+            _selectionOverlay?.hide();
+            _selectionOverlay = null;
 
             if (widget.selectionControls != null && Application.isMobilePlatform && !_unityKeyboard()) {
                 _selectionOverlay = new TextSelectionOverlay(
-                    layerLink: _layerLink,
+                    toolbarLayerLink: _toolbarLayerLink,
+                    startHandleLayerLink: _startHandleLayerLink,
+                    endHandleLayerLink: _endHandleLayerLink,
-                    dragStartBehavior: widget.dragStartBehavior
+                    dragStartBehavior: widget.dragStartBehavior,
+                    onSelectionHandleTapped: widget.onSelectionHandleTapped
-                bool longPress = cause == SelectionChangedCause.longPress;
-                if (cause != SelectionChangedCause.keyboard && (_value.text.isNotEmpty() || longPress)) {
-                    _selectionOverlay.showHandles();
+                _selectionOverlay.handlesVisible = widget.showSelectionHandles;
+                _selectionOverlay.showHandles();
+                if (widget.onSelectionChanged != null) {
+                    widget.onSelectionChanged(selection, cause);
-
-                if (longPress || cause == SelectionChangedCause.doubleTap) {
-                    _selectionOverlay.showToolbar();
-                }
-            }
-
-            if (widget.onSelectionChanged != null) {
-                widget.onSelectionChanged(selection, cause);
             }
         }
 
                     curve: _caretAnimationCurve);
 
                 Rect newCaretRect = _getCaretRectAtScrollOffset(_currentCaretRect, scrollOffsetForCaret);
-                // Enlarge newCaretRect by scrollPadding to ensure that caret is not positioned directly at the edge after scrolling.
+                float bottomSpacing = widget.scrollPadding.bottom;
+                if (_selectionOverlay?.selectionControls != null) {
+                    float handleHeight = _selectionOverlay.selectionControls
+                        .getHandleSize(renderEditable.preferredLineHeight).height;
+                    float interactiveHandleHeight = Mathf.Max(
+                        handleHeight,
+                        kMinInteractiveDimension
+                    );
+                    Offset anchor = _selectionOverlay.selectionControls
+                        .getHandleAnchor(
+                            TextSelectionHandleType.collapsed,
+                            renderEditable.preferredLineHeight
+                        );
+                    float handleCenter = handleHeight / 2 - anchor.dy;
+                    bottomSpacing = Mathf.Max(
+                        handleCenter + interactiveHandleHeight / 2,
+                        bottomSpacing
+                    );
+                }
-                    newCaretRect.bottom + widget.scrollPadding.bottom
+                    newCaretRect.bottom + bottomSpacing
                 );
                 _editableKey.currentContext.findRenderObject().showOnScreen(
                     rect: inflatedRect,
             return Future.value(false).to<bool>();
         }
 
+        public void didChangeAccessibilityFeatures() {}
+
+        //_WhitespaceDirectionalityFormatter _whitespaceFormatter;
+            //whitespaceFormatter ??= new _WhitespaceDirectionalityFormatter(textDirection: _textDirection);
+
+            bool textChanged = _value?.text != value?.text;
+            bool isRepeatText = value?.text == _lastFormattedUnmodifiedTextEditingValue?.text;
+            bool isRepeatSelection = value?.selection == _lastFormattedUnmodifiedTextEditingValue?.selection; 
+            bool isRepeatComposing = value?.composing == _lastFormattedUnmodifiedTextEditingValue?.composing;
+           
+            if (!isRepeatText && textChanged && widget.inputFormatters != null && widget.inputFormatters.isNotEmpty()) {
+                foreach (TextInputFormatter formatter in widget.inputFormatters) {
+                    value = formatter.formatEditUpdate(_value, value);
+                }
+                //value = _whitespaceFormatter.formatEditUpdate(_value, value);
+                _lastFormattedValue = value;
+            }
+
+            _value = value;
+           
+            if (isRepeatText && isRepeatSelection && isRepeatComposing && textChanged && _lastFormattedValue != null) {
+                _value = _lastFormattedValue;
+            }
+
+          
+            _updateRemoteEditingValueIfNeeded();
+
+            if (textChanged && widget.onChanged != null)
+                widget.onChanged(value.text);
+            _lastFormattedUnmodifiedTextEditingValue = _receivedRemoteTextEditingValue;
+            /*
             var textChanged = _value?.text != value?.text || isIMEInput;
             if (textChanged && widget.inputFormatters != null && widget.inputFormatters.isNotEmpty()) {
                 foreach (var formatter in widget.inputFormatters) {
 
             if (textChanged && widget.onChanged != null) {
                 widget.onChanged(value.text);
-            }
+            }*/
-            _cursorVisibilityNotifier.value = _cursorBlinkOpacityController.value > 0;
+            _cursorVisibilityNotifier.value = widget.showCursor.Value && _cursorBlinkOpacityController.value > 0;
         }
 
         public bool cursorCurrentlyVisible {
             updateKeepAlive();
         }
 
-
         TextDirection? _textDirection {
             get {
                 TextDirection? result = widget.textDirection ?? Directionality.of(context);
             }
         }
         public bool showToolbar() {
-            if (_selectionOverlay == null) {
+            if (foundation_.kIsWeb) {
+                return false;
+            }
+
+            if (_selectionOverlay == null || _selectionOverlay.toolbarIsVisible) {
                 return false;
             }
 
         public override Widget build(BuildContext context) {
             D.assert(WidgetsD.debugCheckHasMediaQuery(context));
             _focusAttachment.reparent();
-            //FocusScope.of(context).reparentIfNeeded(widget.focusNode);
-            base.build(context); // See AutomaticKeepAliveClientMixin.
+            base.build(context);
 
             return new Scrollable(
                 axisDirection: _isMultiline ? AxisDirection.down : AxisDirection.right,
                 viewportBuilder: (BuildContext _context, ViewportOffset offset) =>
                     new CompositedTransformTarget(
-                        link: _layerLink,
+                        link: _toolbarLayerLink,
-                            textSpan: buildTextSpan(),
-                            value: _value,
-                            cursorColor: _cursorColor,
-                            backgroundCursorColor: widget.backgroundCursorColor,
-                            showCursor: EditableText.debugDeterministicCursor
-                                ? new ValueNotifier<bool>(true)
-                                : _cursorVisibilityNotifier,
-                            hasFocus: _hasFocus,
-                            maxLines: widget.maxLines,
-                            minLines: widget.minLines,
-                            expands: widget.expands,
-                            strutStyle: widget.strutStyle,
-                            selectionColor: widget.selectionColor,
-                            textScaleFactor: widget.textScaleFactor ?? MediaQuery.textScaleFactorOf(context),
-                            textAlign: widget.textAlign,
-                            textDirection: _textDirection,
-                            obscureText: widget.obscureText,
-                            autocorrect: widget.autocorrect,
-                            offset: offset,
-                            onSelectionChanged: _handleSelectionChanged,
-                            onCaretChanged: _handleCaretChanged,
-                            rendererIgnoresPointer: widget.rendererIgnoresPointer,
-                            cursorWidth: widget.cursorWidth,
-                            cursorRadius: widget.cursorRadius,
-                            cursorOffset: widget.cursorOffset,
-                            paintCursorAboveText: widget.paintCursorAboveText,
-                            enableInteractiveSelection: widget.enableInteractiveSelection == true,
-                            textSelectionDelegate: this,
-                            devicePixelRatio: _devicePixelRatio,
-                            globalKeyEventHandler : widget.globalKeyEventHandler
+                              startHandleLayerLink: _startHandleLayerLink,
+                              endHandleLayerLink: _endHandleLayerLink,
+                              textSpan: buildTextSpan(),
+                              value: _value,
+                              cursorColor: _cursorColor,
+                              backgroundCursorColor: widget.backgroundCursorColor,
+                              showCursor: EditableText.debugDeterministicCursor
+                                  ? new ValueNotifier<bool>(widget.showCursor ?? false)
+                                  : _cursorVisibilityNotifier,
+                              forceLine: widget.forceLine,
+                              readOnly: widget.readOnly,
+                              hasFocus: _hasFocus,
+                              maxLines: widget.maxLines,
+                              minLines: widget.minLines,
+                              expands: widget.expands,
+                              strutStyle: widget.strutStyle,
+                              selectionColor: widget.selectionColor,
+                              textScaleFactor: widget.textScaleFactor ?? MediaQuery.textScaleFactorOf(context),
+                              textAlign: widget.textAlign,
+                              textDirection: _textDirection,
+                              locale: widget.locale,
+                              textWidthBasis: widget.textWidthBasis,
+                              obscureText: widget.obscureText,
+                              autocorrect: widget.autocorrect,
+                              smartDashesType: widget.smartDashesType,
+                              smartQuotesType: widget.smartQuotesType,
+                              enableSuggestions: widget.enableSuggestions,
+                              offset: offset,
+                              onSelectionChanged: _handleSelectionChanged,
+                              onCaretChanged: _handleCaretChanged,
+                              rendererIgnoresPointer: widget.rendererIgnoresPointer,
+                              cursorWidth: widget.cursorWidth,
+                              cursorRadius: widget.cursorRadius,
+                              cursorOffset: widget.cursorOffset,
+                              selectionHeightStyle: widget.selectionHeightStyle,
+                              selectionWidthStyle: widget.selectionWidthStyle,
+                              paintCursorAboveText: widget.paintCursorAboveText,
+                              enableInteractiveSelection: widget.enableInteractiveSelection ?? true,
+                              textSelectionDelegate: this,
+                              devicePixelRatio: _devicePixelRatio
+
                         )
                     )
             );
-            if (!widget.obscureText && _value.composing.isValid) {
-                TextStyle composingStyle = widget.style.merge(
-                    new TextStyle(decoration: TextDecoration.underline)
-                );
-
-                return new TextSpan(
-                    style: widget.style,
-                    children: new List<InlineSpan> {
-                        new TextSpan(text: _value.composing.textBefore(_value.text)),
-                        new TextSpan(
-                            style: composingStyle,
-                            text: _value.composing.textInside(_value.text)
-                        ),
-                        new TextSpan(text: _value.composing.textAfter(_value.text)),
-                    });
-            }
-
-            var text = _value.text;
-                text = new string(RenderEditable.obscuringCharacter, text.Length);
-                int o = _obscureShowCharTicksPending > 0 ? _obscureLatestCharIndex : -1;
-                if (o >= 0 && o < text.Length) {
-                    text = text.Substring(0, o) + _value.text.Substring(o, 1) + text.Substring(o + 1);
+                var text = _value.text;
+                if (widget.obscureText) {
+                    text = new string(RenderEditable.obscuringCharacter, text.Length);
+                    int o = _obscureShowCharTicksPending > 0 ? _obscureLatestCharIndex : -1;
+                    if (o >= 0 && o < text.Length) {
+                        text = text.Substring(0, o) + _value.text.Substring(o, 1) + text.Substring(o + 1);
+                    }
+                return new TextSpan(style: widget.style, text: text);
-
-            return new TextSpan(style: widget.style, text: text);
+            
+            return widget.controller.buildTextSpan(
+                style: widget.style,
+                withComposing: !widget.readOnly
+            );
-        // unity keyboard has a preview view with editing function, text selection & cursor function of this widget is disable
-        // in the case
+       
-        /*Offset _getImePos() {
-            if (_hasInputConnection && _textInputConnection.imeRequired()) {
-                var localPos = renderEditable.getLocalRectForCaret(_value.selection.basePos).bottomLeft;
-                return renderEditable.localToGlobal(localPos);
-            }
-
-            return null;
-        }*/
+        
-        /*void _updateImePosIfNeed() {
-            if (!_hasInputConnection || !_textInputConnection.imeRequired()) {
-                return;
-            }
-
-            if (_imePosUpdateScheduled) {
-                return;
-            }
-
-            _imePosUpdateScheduled = true;
-            SchedulerBinding.instance.addPostFrameCallback(_ => {
-                _imePosUpdateScheduled = false;
-                if (!_hasInputConnection) {
-                    return;
-                }
-
-                _textInputConnection.setIMEPos(_getImePos());
-            });
-        }*/
+        
+    
+        public readonly LayerLink startHandleLayerLink;
+        public readonly LayerLink endHandleLayerLink;
+        public readonly bool forceLine;
+        public readonly bool readOnly;
         public readonly bool hasFocus;
         public readonly int? maxLines;
         public readonly int? minLines;
         public readonly float textScaleFactor;
-        public readonly TextAlign textAlign;
+        public readonly TextAlign? textAlign;
+        public readonly TextWidthBasis textWidthBasis;
+        public readonly SmartDashesType smartDashesType;
+        public readonly SmartQuotesType smartQuotesType;
+        public readonly bool? enableSuggestions;
         public readonly ViewportOffset offset;
         public readonly SelectionChangedHandler onSelectionChanged;
         public readonly CaretChangedHandler onCaretChanged;
         public readonly Offset cursorOffset;
+        public readonly ui.BoxHeightStyle selectionHeightStyle;
+        public readonly ui.BoxWidthStyle selectionWidthStyle;
-        public readonly GlobalKeyEventHandlerDelegate globalKeyEventHandler;
-
-        public _Editable(TextSpan textSpan = null,
+        //public readonly GlobalKeyEventHandlerDelegate globalKeyEventHandler;
+        public readonly Locale locale;
+        public _Editable(
+            Key key = null,
+            TextSpan textSpan = null,
+            LayerLink startHandleLayerLink = null,
+            LayerLink endHandleLayerLink = null,
+            bool forceLine = false,
+            bool readOnly = false,
+            TextWidthBasis textWidthBasis = TextWidthBasis.parent,
             bool hasFocus = false,
             int? maxLines = null,
             int? minLines = null,
             float textScaleFactor = 1.0f,
+            TextAlign? textAlign = null,
+            Locale locale = null,
-            TextAlign textAlign = TextAlign.left,
+            SmartDashesType smartDashesType = SmartDashesType.disabled,
+            SmartQuotesType smartQuotesType = SmartQuotesType.disabled,
+            bool? enableSuggestions = null,
-            Key key = null,
-            TextSelectionDelegate textSelectionDelegate = null,
+            bool? paintCursorAboveText = null,
+            ui.BoxHeightStyle selectionHeightStyle = ui.BoxHeightStyle.tight,
+            ui.BoxWidthStyle selectionWidthStyle = ui.BoxWidthStyle.tight,
-            bool? paintCursorAboveText = null,
-            float? devicePixelRatio = null,
-            GlobalKeyEventHandlerDelegate globalKeyEventHandler = null) : base(key) {
+            TextSelectionDelegate textSelectionDelegate = null,
+            float? devicePixelRatio = null
+            //GlobalKeyEventHandlerDelegate globalKeyEventHandler = null
+            ) : base(key) {
+            this.startHandleLayerLink = startHandleLayerLink;
+            this.endHandleLayerLink = endHandleLayerLink;
+            this.locale = locale;
+            this.forceLine = forceLine;
+            this.readOnly = readOnly;
+            this.textWidthBasis = textWidthBasis;
             this.hasFocus = hasFocus;
             this.maxLines = maxLines;
             this.minLines = minLines;
             this.textDirection = textDirection;
             this.obscureText = obscureText;
             this.autocorrect = autocorrect;
+            this.smartDashesType = smartDashesType;
+            this.smartQuotesType = smartQuotesType;
+            this.enableSuggestions = enableSuggestions;
             this.offset = offset;
             this.onSelectionChanged = onSelectionChanged;
             this.onCaretChanged = onCaretChanged;
             this.cursorRadius = cursorRadius;
             this.cursorOffset = cursorOffset;
+            this.paintCursorAboveText = paintCursorAboveText;
+            this.selectionHeightStyle = selectionHeightStyle;
+            this.selectionWidthStyle = selectionWidthStyle;
-            this.paintCursorAboveText = paintCursorAboveText;
-            this.globalKeyEventHandler = globalKeyEventHandler;
+            //this.globalKeyEventHandler = globalKeyEventHandler;
-                textDirection: textDirection ?? TextDirection.ltr,
-                offset: offset,
-                showCursor: showCursor,
+                startHandleLayerLink: startHandleLayerLink,
+                endHandleLayerLink: endHandleLayerLink,
+                showCursor: showCursor,
+                forceLine: forceLine,
+                readOnly: readOnly,
                 hasFocus: hasFocus,
                 maxLines: maxLines,
                 minLines: minLines,
                 textScaleFactor: textScaleFactor,
-                textAlign: textAlign,
+                textAlign: textAlign ?? TextAlign.start,
+                textDirection: textDirection,
+                locale: locale ?? Localizations.localeOf(context, nullOk: true),
-                obscureText: obscureText,
+                offset: offset,
+                obscureText: obscureText,
+                textWidthBasis: textWidthBasis,
+                paintCursorAboveText: paintCursorAboveText ?? false,
+                selectionHeightStyle: selectionHeightStyle,
+                selectionWidthStyle: selectionWidthStyle,
-                paintCursorAboveText: paintCursorAboveText == true,
-                devicePixelRatio: devicePixelRatio ?? 1.0f,
-                globalKeyEventHandler : globalKeyEventHandler
+                devicePixelRatio: devicePixelRatio ?? 1.0f
             );
         }
 
             edit.cursorColor = cursorColor;
-            edit.backgroundCursorColor = backgroundCursorColor;
+            edit.startHandleLayerLink = startHandleLayerLink;
+            edit.endHandleLayerLink = endHandleLayerLink;
+            edit.forceLine = forceLine;
+            edit.readOnly = readOnly;
+            edit.minLines = minLines;
+            edit.expands = expands;
+            edit.locale = locale ?? Localizations.localeOf(context, nullOk: true);
+            edit.textWidthBasis = textWidthBasis;
-            edit.textSelectionDelegate = textSelectionDelegate;
-            edit.cursorWidth = cursorWidth ?? 1.0f;
+            edit.cursorWidth = cursorWidth ?? 0.0f;
-            edit.enableInteractiveSelection = enableInteractiveSelection;
-            edit.paintCursorAboveText = paintCursorAboveText == true;
+            edit.selectionHeightStyle = selectionHeightStyle;
+            edit.selectionWidthStyle = selectionWidthStyle;
+            edit.textSelectionDelegate = textSelectionDelegate;
-            edit.globalKeyEventHandler = globalKeyEventHandler;
+            edit.paintCursorAboveText = paintCursorAboveText ?? false;
         }
     }
 }

com.unity.uiwidgets/Runtime/widgets/fade_in_image.cs

             ImageProvider placeholder,
             ImageErrorWidgetBuilder placeholderErrorBuilder,
             ImageProvider image,
-            ImageErrorWidgetBuilder imageErrorBuilder,
+            ImageErrorWidgetBuilder imageErrorBuilder = null,
             TimeSpan? fadeOutDuration = null,
             Curve fadeOutCurve = null,
             TimeSpan? fadeInDuration = null,
             BoxFit? fit = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
-            Key key = null
+            Key key = null,
+            bool matchTextDirection = false
-            D.assert(placeholder != null);
+           
             D.assert(image != null);
             D.assert(fadeOutDuration != null);
             D.assert(fadeOutCurve != null);
             this.fadeInCurve = fadeInCurve ?? Curves.easeIn;
             this.alignment = alignment ?? Alignment.center;
             this.repeat = repeat;
+            this.matchTextDirection = matchTextDirection;
-            byte[] placeholder,
-            ImageErrorWidgetBuilder placeholderErrorBuilder,
-            string image,
-            ImageErrorWidgetBuilder imageErrorBuilder,
+            byte[] placeholder ,
+            string image ,
+            Key key = null,
+            ImageErrorWidgetBuilder placeholderErrorBuilder = null,
+            ImageErrorWidgetBuilder imageErrorBuilder = null,
             float placeholderScale = 1.0f,
             float imageScale = 1.0f,
             TimeSpan? fadeOutDuration = null,
             float? width = null,
             float? height = null,
             BoxFit? fit = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
-            Key key = null,
-            int placeholderCacheWidth = default,
-            int placeholderCacheHeight = default,
-            int imageCacheWidth = default,
-            int imageCacheHeight = default
+            bool matchTextDirection = false,
+            int? placeholderCacheWidth = null,
+            int? placeholderCacheHeight = null,
+            int? imageCacheWidth = null,
+            int? imageCacheHeight = null
-            D.assert(placeholder != null);
-            D.assert(image != null);
-            D.assert(fadeOutDuration != null);
-            D.assert(fadeOutCurve != null);
-            D.assert(fadeInDuration != null);
-            D.assert(fadeInCurve != null);
-            D.assert(alignment != null);
-            var memoryImage = new MemoryImage(placeholder, placeholderScale);
-            var networkImage = new NetworkImage(image, imageScale);
-            /*placeholder = ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight,
-                new MemoryImage(placeholder, scale: placeholderScale));
-            image = ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight,
-                new NetworkImage(image, scale: imageScale));*/
+            alignment = alignment ?? Alignment.center;
+            fadeOutDuration = fadeOutDuration  ?? TimeSpan.FromMilliseconds( 300 );
+            fadeOutCurve = fadeOutCurve ?? Curves.easeOut;
+            fadeInDuration = fadeInDuration ?? TimeSpan.FromMilliseconds( 700 );
+            fadeInCurve = fadeInCurve ?? Curves.easeIn;
+            ImageProvider memoryImage = new MemoryImage(placeholder, placeholderScale);
+            ImageProvider networkImage = new NetworkImage(image, imageScale);
+            
+            //placeholder = ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight, memoryImage);
+            //image = ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight, networkImage);
-                placeholder: memoryImage,
+                placeholder: ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight, memoryImage),
-                image: networkImage,
+                image: ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight, networkImage),
                 imageErrorBuilder: imageErrorBuilder,
                 fadeOutDuration: fadeOutDuration,
                 fadeOutCurve: fadeOutCurve,
                 fit: fit,
                 alignment: alignment,
                 repeat: repeat,
+                matchTextDirection: matchTextDirection,
                 key: key
             );
         }
-            ImageErrorWidgetBuilder placeholderErrorBuilder,
-            ImageErrorWidgetBuilder imageErrorBuilder,
+            ImageErrorWidgetBuilder placeholderErrorBuilder = null,
+            ImageErrorWidgetBuilder imageErrorBuilder = null,
             AssetBundle bundle = null,
             float? placeholderScale = null,
             float imageScale = 1.0f,
             float? width = null,
             float? height = null,
             BoxFit? fit = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            bool matchTextDirection = false,
-            int placeholderCacheWidth = default,
-            int placeholderCacheHeight = default,
-            int imageCacheWidth = default,
-            int imageCacheHeight = default
+            int? placeholderCacheWidth = null,
+            int? placeholderCacheHeight = null,
+            int? imageCacheWidth = null,
+            int? imageCacheHeight = null
-            D.assert(placeholder != null);
-            D.assert(image != null);
+           
-            var imageProvider = placeholderScale != null
-                ? new ExactAssetImage(placeholder, bundle: bundle, scale: placeholderScale ?? 1.0f)
-                : (ImageProvider) new AssetImage(placeholder, bundle: bundle);
-            /*placeholder = placeholderScale != null
-                ? ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight, ExactAssetImage(placeholder, bundle: bundle, scale: placeholderScale))
-                : ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight, AssetImage(placeholder, bundle: bundle));*/
-            var networkImage = new NetworkImage(image, imageScale);
+            var holder = placeholderScale ?? 1.0f;
+            var _placeholder = placeholderScale != null
+                ? ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight,
+                    new ExactAssetImage(placeholder, bundle: bundle, scale: holder))
+                : ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight,
+                    new AssetImage(placeholder, bundle: bundle));
-                placeholder: imageProvider,
+                placeholder: _placeholder,
-                image: networkImage,
+                image: ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight, new NetworkImage(image, scale: imageScale)),
                 imageErrorBuilder: imageErrorBuilder,
                 fadeOutDuration: fadeOutDuration,
                 fadeOutCurve: fadeOutCurve,
                 fit: fit,
                 alignment: alignment,
                 repeat: repeat,
+                matchTextDirection: matchTextDirection,
                 key: key
             );
         }
         public readonly float? width;
         public readonly float? height;
         public readonly BoxFit? fit;
-        public readonly Alignment alignment;
+        public readonly AlignmentGeometry alignment;
+        public readonly bool matchTextDirection;
 
         public Image _image(
             ImageProvider image = null,
             D.assert(image != null);
             return new Image(
                 image: image,
-                //errorBuilder: errorBuilder,
-                //frameBuilder: frameBuilder,
+                errorBuilder: errorBuilder,
+                frameBuilder: frameBuilder,
-                //matchTextDirection: matchTextDirection,
+                matchTextDirection: matchTextDirection,
+                
             );
         }
 
                 errorBuilder: imageErrorBuilder,
-                frameBuilder: (BuildContext context1, Widget child, int frame, bool wasSynchronouslyLoaded) => {
-                    if (wasSynchronouslyLoaded)
-                        return child;
-                    return new _AnimatedFadeOutFadeIn(
-                        key: key,
-                        target: child,
-                        placeholder: _image(
-                            image: placeholder,
-                            errorBuilder: placeholderErrorBuilder
-                        ),
-                        isTargetLoaded: frame != null,
-                        fadeInDuration: fadeInDuration,
-                        fadeOutDuration: fadeOutDuration,
-                        fadeInCurve: fadeInCurve,
-                        fadeOutCurve: fadeOutCurve
-                    );
-                }
+                frameBuilder: (BuildContext context1, Widget child, int frame, bool wasSynchronouslyLoaded)=> {
+                if (wasSynchronouslyLoaded)
+                    return child;
+                return new _AnimatedFadeOutFadeIn(
+                    target: child,
+                    placeholder: _image(image: placeholder, errorBuilder: placeholderErrorBuilder),
+                    isTargetLoaded: frame != null,
+                    fadeInDuration: fadeInDuration,
+                    fadeOutDuration: fadeOutDuration,
+                    fadeInCurve: fadeInCurve,
+                    fadeOutCurve: fadeOutCurve
+                );
+            }
             );
             return result;
         }
         public _AnimatedFadeOutFadeIn(
-            Key key,
-            Widget target,
-            Widget placeholder,
-            bool isTargetLoaded,
+            Widget target ,
+            Widget placeholder ,
+            bool isTargetLoaded ,
-            Curve fadeInCurve
+            Curve fadeInCurve,
+            Key key = null
-            D.assert(target != null);
-            D.assert(placeholder != null);
-            D.assert(isTargetLoaded != null);
-            D.assert(fadeOutDuration != null);
-            D.assert(fadeOutCurve != null);
-            D.assert(fadeInDuration != null);
-            D.assert(fadeInCurve != null);
+            
             this.target = target;
             this.placeholder = placeholder;
             this.isTargetLoaded = isTargetLoaded;
             Animation<float> _targetOpacityAnimation;
             Animation<float> _placeholderOpacityAnimation;
 
-            /*@override
-            void forEachTween(TweenVisitor<dynamic> visitor) {
-                _targetOpacity = visitor(
-                    _targetOpacity,
-                    widget.isTargetLoaded ? 1.0 : 0.0,
-                    (dynamic value) => Tween<double>(begin: value as double),
-                ) as Tween<double>;
-                _placeholderOpacity = visitor(
-                    _placeholderOpacity,
-                    widget.isTargetLoaded ? 0.0 : 1.0,
-                    (dynamic value) => Tween<double>(begin: value as double),
-                ) as Tween<double>;
-            }*/
-
             protected override void forEachTween(TweenVisitor visitor) {
                 _targetOpacity = (FloatTween) visitor.visit(
                     state: this,
                     weight: (float) widget.fadeInDuration?.Milliseconds
                 ));
 
-                //[!!!] drive
-                /*_placeholderOpacityAnimation = animation.drive(list).addStatusListener((AnimationStatus status) =>{
+                
+                _placeholderOpacityAnimation = animation.drive(new TweenSequence<float>(list));
+                _placeholderOpacityAnimation.addStatusListener((AnimationStatus status) =>{
-                        // Need to rebuild to remove placeholder now that it is invisibile.
-                });*/
+                });
 
                 List<TweenSequenceItem<float>> list2 = new List<TweenSequenceItem<float>>();
                 list2.Add(new TweenSequenceItem<float>(
                     tween: _targetOpacity.chain(new CurveTween(curve: widget.fadeInCurve)),
                     weight: (float) widget.fadeInDuration?.Milliseconds
                 ));
-                //_targetOpacityAnimation = animation.drive(list2);[!!!] animation.cs drive
+                _targetOpacityAnimation = animation.drive(new TweenSequence<float>(list2));
-                    //controller.value = controller.upperBound;[!!!] animation_controller.cs value set
+                    controller.setValue(controller.upperBound);
                 }
             }
 
 
                 return new Stack(
                     fit: StackFit.passthrough,
-                    alignment: Alignment.center,//AlignmentDirectional.center,[!!!]
+                    alignment: AlignmentDirectional.center,
                     textDirection: TextDirection.ltr,
                     children: new List<Widget>() {
                         target,

com.unity.uiwidgets/Runtime/widgets/focus_manager.cs

                 if (_descendants == null) {
                     List<FocusNode> result = new List<FocusNode>();
                     foreach (FocusNode child in _children) {
-                        foreach (var childDescendant in child.descendants) {
-                            result.Add(childDescendant);
-                        }
-
-                        //result.addAll(child.descendants);
+                        result.AddRange(child.descendants);
                         result.Add(child);
                     }
 
                     if (!node.skipTraversal && node.canRequestFocus) {
                         nodes.Add(node);
                     }
-
-
-                // descendants.where((FocusNode node) => !node.skipTraversal && node.canRequestFocus);
+                
                 return nodes;
             }
 
 
         public void _notify() {
             if (_parent == null) {
-
                 return;
             }
 
-
             notifyListeners();
         }
 
                 }
             }
         }
-
-
+        
-    
-    
+        
-    
-    
+        
-
-
+        
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
             properties.add(new DiagnosticsProperty<BuildContext>("context", context, defaultValue: null));
         }
-
-
+        
-              return child.toDiagnosticsNode(name: "Child ${count++}");
+              return child.toDiagnosticsNode(name: $"Child {count++}");
-
-
+        
         public override string toStringShort() {//override
             bool hasDebugLabel = debugLabel != null && debugLabel.isNotEmpty();
             string nullStr = "";
             onKey: onKey,
             canRequestFocus: canRequestFocus,
             skipTraversal: skipTraversal
-        ) {
-            D.assert(skipTraversal != null);
-            D.assert(canRequestFocus != null);
-            
-        }
+        ) {}
-            get { return enclosingScope; }
+            get { return this; }
         }
 
         public bool isFirstFocus {
             // It is possible that a previously focused child is no longer focusable.
             while (focusedChild != null && !focusedChild.canRequestFocus)
               _focusedChildren.removeLast();
-
-
+            
             if (!findFirstFocus) {
               if (canRequestFocus) {
                 _setAsFocusedChildForScope();
                 _markNextFocus(this);
               }
             } else {
-              
-              primaryFocus._doRequestFocus(findFirstFocus: findFirstFocus);
+                primaryFocus._doRequestFocus(findFirstFocus: findFirstFocus);
             }
         }
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             childList = _focusedChildren.Select((FocusNode child)=> {
               return child.toStringShort();
             }).ToList();
-           // properties.add(new IEnumerableProperty<string>("focusedChildren", childList, defaultValue: new List<string>()));
+            properties.add(new EnumerableProperty<string>("focusedChildren", childList, defaultValue: new List<string>()));
-        {
+        { 
             rootScope._manager = this;
             RawKeyboard.instance.addListener(_handleRawKeyEvent);
             GestureBinding.instance.pointerRouter.addGlobalRoute(_handlePointerEvent);

com.unity.uiwidgets/Runtime/widgets/focus_scope.cs

 using Unity.UIWidgets.foundation;
 
 namespace Unity.UIWidgets.widgets {
-    class _FocusScopeMarker : InheritedWidget {
-        public _FocusScopeMarker(FocusScopeNode node, Widget child, Key key = null) : base(key, child) {
-            D.assert(node != null);
-            this.node = node;
-        }
-
-        public readonly FocusScopeNode node;
-
-        public override bool updateShouldNotify(InheritedWidget oldWidget) {
-            return node != ((_FocusScopeMarker) oldWidget).node;
-        }
-    }
 
     public class FocusScope : Focus {
         public FocusScope(
             onKey: onKey,
             debugLabel: debugLabel) {
             D.assert(child != null);
-            D.assert(autofocus != null);
         }
         public static FocusScopeNode of(BuildContext context) {
             D.assert(context != null);
             bool includeSemantics = true
           )  :base(key:key) {
             D.assert(child != null);
-            D.assert(autofocus != null);
-            D.assert(includeSemantics != null);
             this.child = child;
             this.focusNode = focusNode;
             this.autofocus = autofocus;
 
         public static FocusNode of(BuildContext context,  bool nullOk = false, bool scopeOk = false ) {
             D.assert(context != null);
-            D.assert(nullOk != null);
-            D.assert(scopeOk != null);
             _FocusMarker marker = context.dependOnInheritedWidgetOfExactType<_FocusMarker>();
             FocusNode node = marker?.notifier;
             if (node == null) {
         public override Widget build(BuildContext context) {
             _focusAttachment.reparent();
             Widget child = widget.child;
-            /*if (widget.includeSemantics) {
-              child = Semantics(
-                focusable: _canRequestFocus,
-                focused: _hasPrimaryFocus,
-                child: widget.child,
-              );
-            }*/
             return new _FocusMarker(
               node: focusNode,
               child: child

com.unity.uiwidgets/Runtime/widgets/focus_traversal.cs

             FocusTraversalPolicy policy = null,
             Widget child = null
         ) : base(key: key) {
-            policy = policy ?? new ReadingOrderTraversalPolicy();
+            this.policy = policy ?? new ReadingOrderTraversalPolicy();
             this.child = child;
         }
 
             ) {
                 groupNode = marker?.focusNode;
                 policy = marker?.policy ?? defaultPolicy ?? new ReadingOrderTraversalPolicy();
-                members = members ?? new List<FocusNode>();
+                this.members = members ?? new List<FocusNode>();
             }
             public readonly FocusNode groupNode;
             public readonly FocusTraversalPolicy policy;
             D.assert(currentNode != null);
             FocusScopeNode scope = currentNode.nearestScope;
             FocusNode candidate = scope.focusedChild;
-            if (candidate == null && scope.descendants.Count() != 0) {
-                List<FocusNode> sorted = _sortAllDescendants(scope);
-                candidate = sorted.isNotEmpty() ? sorted.First() : null;
+            if (candidate == null && scope.descendants.Any()) {
+                IEnumerable<FocusNode> sorted = _sortAllDescendants(scope);
+                candidate = sorted.Any() ? sorted.First() : null;
             }
 
             candidate = candidate ?? currentNode;
             }
             HashSet<FocusNode> groupKeys = new HashSet<FocusNode>(groups.Keys);
             foreach ( FocusNode key in groups.Keys) { 
-                List<FocusNode> sortedMembers = groups[key].policy.sortDescendants(groups[key].members).ToList(); 
+                List<FocusNode> sortedMembers = groups.getOrDefault(key).policy.sortDescendants(groups.getOrDefault(key).members).ToList(); 
                 groups[key].members.Clear(); 
                 groups[key].members.AddRange(sortedMembers); 
             }
             FocusNode node ) {
             this.direction = direction;
             this.node = node;
-
         } 
         public readonly TraversalDirection direction;
         public readonly FocusNode node;
     public class _DirectionalPolicyData {
         public _DirectionalPolicyData(List<_DirectionalPolicyDataEntry> history) {
             D.assert(history != null);
+            this.history = history;
         }
 
 
     public class OrderedTraversalPolicy : DirectionalFocusTraversalPolicyMixinFocusTraversalPolicy {
 
         public OrderedTraversalPolicy(FocusTraversalPolicy secondary) {
+            this.secondary = secondary;
         }
 
         public readonly FocusTraversalPolicy secondary;
     public class FocusTraversalOrder : InheritedWidget {
         public FocusTraversalOrder(Key key = null, FocusOrder order = null, Widget child = null)
             : base(key: key, child: child) {
-            
+            this.order = order;
         }
 
         public readonly FocusOrder order;
-            D.assert(nullOk != null); 
             FocusTraversalOrder marker = context.getElementForInheritedWidgetOfExactType<FocusTraversalOrder>()?.widget as FocusTraversalOrder; 
             FocusOrder order = marker?.order;
             if (order == null && !nullOk) {
             properties.add(new DiagnosticsProperty<FocusNode>("previous", _previousFocus));
         }
     }
+    
+    public class RequestFocusAction : _RequestFocusActionBase {
+        /// Creates a [RequestFocusAction] with a fixed [key].
+        public RequestFocusAction() : base(key) {
+        }
+
+        public static readonly LocalKey key = new ValueKey<Type>(typeof(RequestFocusAction));
+    
+        public override void invoke(FocusNode node, Intent intent) => FocusTravesalUtils._focusAndEnsureVisible(node);
+    }
+    
     public class NextFocusAction : _RequestFocusActionBase {
         public NextFocusAction() : base(key) {
             

com.unity.uiwidgets/Runtime/widgets/form.cs

             Widget child = null,
             FormState formState = null,
             int? generation = null
-        ) :
-            base(key: key, child: child) {
+        ) : base(key: key, child: child) {
             _formState = formState;
             _generation = generation;
         }
             get { return _errorText != null; }
         }
 
-        //[!!!] call?
-        /*public bool isValid {
+        public bool isValid {
-                return widget.validator?.call(_value) == null;
+                return widget.validator?.Invoke(_value) == null;
-        }*/
+        }
 
         public void save() {
             if (widget.onSaved != null) {

com.unity.uiwidgets/Runtime/widgets/framework.cs

                                 error = new UIWidgetsError(new List<DiagnosticsNode>{
                                     new ErrorSummary("Multiple widgets used the same GlobalKey."),
                                     new ErrorDescription(
-                                        "The key $key was used by multiple widgets. The parents of those widgets were " +
+                                        $"The key {key} was used by multiple widgets. The parents of those widgets were " +
-                                        "  ${parent.toString()}\n" +
+                                        $"  {parent.toString()}\n" +
                                         "A GlobalKey can only be specified on one widget at a time in the widget tree."
                                     )
                                 });
                         D.assert(element.widget.key != null);
                         GlobalKey key = (GlobalKey) element.widget.key;
                         CompositeKey compKey = new CompositeKey(Window.instance, key);
-
+
                         duplicates = duplicates ?? new Dictionary<GlobalKey, HashSet<Element>>();
                         var elements = duplicates.putIfAbsent(key, () => new HashSet<Element>());
                         elements.Add(element);
         public abstract Element createElement();
 
         public override string toStringShort() {
-            return key == null ? GetType().ToString() : GetType() + "-" + key;
+            return key == null ? GetType().ToString() : $"{GetType()}-{key}";
         }
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
         public virtual void didUpdateWidget(StatefulWidget oldWidget) {
         }
 
+        public virtual void reassemble() {
+        }
+
         public void setState(VoidCallback fn = null) {
             D.assert(() => {
                 if (_debugLifecycleState == _StateLifecycle.defunct) {
                 return true;
             });
 
+            
             if (fn != null) {
                 fn();
             }
 
                 return true;
             });
-            D.assert(!children.Any(child => child == null));
             this.children = children;
         }
 
     public delegate bool ElementVisitorBool(Element element);
 
     public interface BuildContext {
-        bool debugDoingBuild { get; }
-
+        
+        bool debugDoingBuild { get; }
 
         RenderObject findRenderObject();
 
         
         State rootAncestorStateOfType(TypeMatcher matcher);
 
-        T findRootAncestorStateOfType<T>() where T: State ;//: State<StatefulWidget>;
+        T findRootAncestorStateOfType<T>() where T: State;
 
         RenderObject ancestorRenderObjectOfType(TypeMatcher matcher);
 
             D.assert(element.owner == this);
             D.assert(() => {
                 if (WidgetsD.debugPrintScheduleBuildForStacks) {
-                    Debug.Log("scheduleBuildFor() called for " + element +
+                    Debug.LogFormat("scheduleBuildFor() called for {0} {1}", element,
                               (_dirtyElements.Contains(element) ? " (ALREADY IN LIST)" : ""));
                 }
 
                           "calling scheduleBuildFor()."),
                           new ErrorHint(
                               "If you did not attempt to call scheduleBuildFor() yourself, then this probably " +
-                          "indicates a bug in the widgets framework. Please report it:\n" +
-                          "  https://github.com/flutter/flutter/issues/new?template=BUG.md"
+                          "indicates a bug in the widgets framework."
                           ),
                       }
                     );
         }
 
         int _debugStateLockLevel = 0;
-
         internal bool _debugStateLocked {
             get { return _debugStateLockLevel > 0; }
         }
         }
-
         bool _debugBuilding = false;
 
         internal Element _debugCurrentBuildTarget;
                     }
                     catch (Exception ex) {
                         IEnumerable<DiagnosticsNode> infoCollector() {
-                            //yield return new DiagnosticsDebugCreator(new DebugCreator(_dirtyElements[index]));
+                            yield return new DiagnosticsDebugCreator(new DebugCreator(_dirtyElements[index]));
-                            "while rebuilding dirty elements", ex,
+                            new ErrorDescription("while rebuilding dirty elements"), 
+                            ex,
                             informationCollector: infoCollector
                         );
                     }
         }
 
         internal void _debugElementWasRebuilt(Element node) {
-            if (_debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans != null) {
-                _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.Remove(node);
-            }
+            _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans?.Remove(node);
         }
 
         public void finalizeTree() {
 
                                 D.assert(keyLabels.isNotEmpty());
 
+                                string the = keys.Count == 1 ? " the" : "";
+                                string s = keys.Count == 1 ? "" : "s";
+                                string were = keys.Count == 1 ? "was" : "were";
+                                string their = keys.Count == 1 ? "its" : "their";
+                                string respective = elementLabels.Count == 1 ? "" : " respective";
+                                string those = keys.Count == 1 ? "that" : "those";
+                                string s2 = elementLabels.Count == 1 ? "" : "s";
+                                string those2 = elementLabels.Count == 1 ? "that" : "those";
+                                string they = elementLabels.Count == 1 ? "it" : "they";
+                                string think = elementLabels.Count == 1 ? "thinks" : "think";
+                                string are = elementLabels.Count == 1 ? "is" : "are"; 
+
-                                            "The following GlobalKeys were specified multiple times in the widget tree. This will lead to " +
+                                            $"The following GlobalKey{s} {were} specified multiple times in the widget tree. This will lead to " +
-                                        "the previous instance is moved to the new location. The keys were:\n" +  "- " +
+                                        $"the previous instance is moved to the new location. The key{s} {were}:\n" +  "- " +
-                                        "This was determined by noticing that after$the widgets with the above global keys were moved " +
-                                        "out of their respective previous parent, those previous parents never updated during this frame, meaning " +
-                                        "that they either did not update at all or updated before the widgets were moved, in either case " +
-                                        "implying that they still think that they should have a child with those global keys.\n" + 
-                                        "The specific parent that did not update after having one or more children forcibly removed " +
-                                        "due to GlobalKey reparenting are:\n" +
+                                        $"This was determined by noticing that after {the} widget{s} with the above global key{s} {were} moved " +
+                                        $"out of {their} {respective} previous parent{s2}, {those2} previous parent{s2} never updated during this frame, meaning " +
+                                        $"that {they} either did not update at all or updated before the widget{s} {were} moved, in either case " +
+                                        $"implying that {they} still {think} that {they} should have a child with {those} global key{s}.\n" + 
+                                        $"The specific parent{s2} that did not update after having one or more children forcibly removed " +
+                                        $"due to GlobalKey reparenting {are}:\n" +
-                                        ),
+                                        )
-                        if (_debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans != null) {
-                            _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.Clear();
-                        }
+                        _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans?.Clear();
                     }
 
                     return true;
-                WidgetsD._debugReportException("while finalizing the widget tree", ex);
+                WidgetsD._debugReportException(new ErrorSummary("while finalizing the widget tree"), ex);
+            }
+        }
+
+        void reassemble(Element root) {
+            try {
+                D.assert(root._parent == null);
+                D.assert(root.owner == this);
+                root.reassemble();
+            }
+            finally {
+                
             }
         }
     }
         }
 
         internal Widget _widget;
-
-        public virtual bool debugDoingBuild { get; }
-
+        
-
+        
         internal BuildOwner _owner;
 
         public BuildOwner owner {
         public bool _active = false;
+
+        public virtual void reassemble() {
+            markNeedsBuild();
+            visitChildren((Element child) => {
+                child.reassemble();
+            });
+        }
+
+        public virtual bool debugDoingBuild { get; }
 
         internal bool _debugIsInScope(Element target) {
             Element current = this;
         }
 
         protected virtual Element updateChild(Element child, Widget newWidget, object newSlot) {
-            /*D.assert(() => {
-                if (newWidget != null && newWidget.key is GlobalKey) {
-                    GlobalKey key = (GlobalKey) newWidget.key;
-                    key._debugReserveFor(this);
-                }
-
-                return true;
-            });*/
-
-                if (child != null)
+                if (child != null) {
+                }
                 return null;
             }
 
                     return true;
                 });
                 if (hasSameSuperclass && child.widget == newWidget) {
-                    if (child.slot != newSlot)
+                    if (child.slot != newSlot) {
+                    }
+
-                    if (child.slot != newSlot)
+                    if (child.slot != newSlot) {
+                    }
+
                     child.update(newWidget);
                     D.assert(child.widget == newWidget);
                     D.assert(() => {
             bool hadDependencies = (_dependencies != null && _dependencies.isNotEmpty()) ||
                                    _hadUnsatisfiedDependencies;
             _active = true;
-            if (_dependencies != null) {
-                _dependencies.Clear();
-            }
-
+            
+            _dependencies?.Clear();
             _hadUnsatisfiedDependencies = false;
             _updateInheritance();
             D.assert(() => {
                                 new ErrorHint(
                                     "If you need some sizing information during build to decide which " + 
                                 "widgets to build, consider using a LayoutBuilder widget, which can " + 
-                                "tell you the layout constraints at a given location in the tree. See " + 
-                                "<https://api.flutter.dev/flutter/widgets/LayoutBuilder-class.html> " + 
-                                "for more details."
+                                "tell you the layout constraints at a given location in the tree."
                                 ),
                                 new ErrorSpacer(),
                                 describeElement("The size getter was called for the following element"),
         }
 
         public virtual InheritedWidget inheritFromElement(InheritedElement ancestor, object aspect = null) {
-            D.assert(ancestor != null);
-            _dependencies = _dependencies ?? new HashSet<InheritedElement>();
-            _dependencies.Add(ancestor);
-            ancestor.updateDependencies(this, aspect);
-            return ancestor.widget;
+            return dependOnInheritedElement(ancestor, aspect: aspect);
         }
 
         public virtual InheritedWidget dependOnInheritedElement(InheritedElement ancestor, object aspect = null) {
 
         internal virtual void _updateInheritance() {
             D.assert(_active);
-            _inheritedWidgets = _parent == null ? null : _parent._inheritedWidgets;
+            _inheritedWidgets = _parent?._inheritedWidgets;
         }
 
         public virtual Widget ancestorWidgetOfExactType(Type targetType) {
                 ancestor = ancestor._parent;
             }
 
-            return ancestor == null ? null : ancestor.widget;
+            return ancestor?.widget;
-            while (ancestor != null && ancestor.widget.GetType() != typeof(T))
+            while (ancestor != null && ancestor.widget.GetType() != typeof(T)) {
+            }
+
             return ancestor?.widget as T;
         }
 
             }
 
             var statefulAncestor = ancestor as StatefulElement;
-            return statefulAncestor == null ? null : statefulAncestor.state;
+            return statefulAncestor?.state;
         }
 
         public T findAncestorStateOfType<T>() where T : State{
-                if (ancestor is StatefulElement stateAncestor && stateAncestor.state is T)
+                if (ancestor is StatefulElement stateAncestor && stateAncestor.state is T) {
+                }
+
                 ancestor = ancestor._parent;
             }
 
                 ancestor = ancestor._parent;
             }
 
-            return statefulAncestor == null ? null : statefulAncestor.state;
+            return statefulAncestor?.state;
-        public T findRootAncestorStateOfType<T>() where T : State{//<StatefulWidget> {
+        public T findRootAncestorStateOfType<T>() where T : State {
-                if (ancestor is StatefulElement stateAncestor && stateAncestor.state is T)
+                if (ancestor is StatefulElement stateAncestor && stateAncestor.state is T) {
+                }
+
                 ancestor = ancestor._parent;
             }
 
             D.assert(_debugCheckStateIsActiveForAncestorLookup());
             Element ancestor = _parent;
             while (ancestor != null) {
-                if (ancestor is RenderObjectElement && ancestor.renderObject is T)
+                if (ancestor is RenderObjectElement && ancestor.renderObject is T) {
+                }
+
                 ancestor = ancestor._parent;
             }
 
         }
 
         public List<Element> debugGetDiagnosticChain() {
-            var chain = new List<Element>();
+            var chain = new List<Element>() {this};
             Element node = _parent;
             while (node != null) {
                 chain.Add(node);
                     }
 
                     if (!_debugAllowIgnoredCallsToMarkNeedsBuild) {
-                        throw new UIWidgetsError(
-                            new List<DiagnosticsNode>(){
+                        List<DiagnosticsNode> information = new List<DiagnosticsNode>() {
                             new ErrorSummary("setState() or markNeedsBuild() called during build.\n"),
                             new ErrorDescription("This " + widget.GetType() +
                                                  " widget cannot be marked as needing to build because the framework " +
                                                  "builds parent widgets before children, which means a dirty descendant " +
                                                  "will always be built. Otherwise, the framework might not visit this " +
-                                                 "widget during this build phase.\n" +
-                                                 "The widget on which setState() or markNeedsBuild() was called was:\n" +
-                                                 "  " + this + "\n" +
-                                                 (owner._debugCurrentBuildTarget == null
-                                                     ? ""
-                                                     : "The widget which was currently being built when the offending call was made was:\n  " +
-                                                       owner._debugCurrentBuildTarget))
-                            
-                            }
+                                                 "widget during this build phase.\n"),
+                            describeElement("The widget on which setState() or markNeedsBuild() was called was")
+                        };
+                        if (owner._debugCurrentBuildTarget != null) {
+                            information.Add(owner._debugCurrentBuildTarget.describeWidget("The widget which was currently being built when the offending call was made was"));
+                        }
+                        throw new UIWidgetsError(
+                            information
                         );
                     }
 
             }
 
             D.assert(() => {
+                
                 if (WidgetsD.debugPrintRebuildDirtyWidgets) {
                     if (!_debugBuiltOnce) {
                         Debug.Log("Building " + this);
         protected abstract void performRebuild();
     }
 
-    public delegate Widget ErrorWidgetBuilder(UIWidgetsErrorDetails details);
-
     internal class _ElementDiagnosticableTreeNode : DiagnosticableTreeNode {
         internal _ElementDiagnosticableTreeNode(
             Element value,
         }
 
         readonly bool stateful;
-
-        /*public override Dictionary<string, object> toJsonMap() {
-            Dictionary<string, object> json = base.toJsonMap();
-            Element element = value as Element;
-            json["widgetRuntimeType"] = element.widget?.GetType()?.ToString();
-            json["stateful"] = stateful;
-            return json;
-        }*/
+        
         public override Dictionary<string, object> toJsonMap(DiagnosticsSerializationDelegate Delegate) {
             Dictionary<string, object> json = base.toJsonMap(Delegate);
             Element element = value as Element;
         }
     }
+    
+    public delegate Widget ErrorWidgetBuilder(UIWidgetsErrorDetails details);
 
     public class ErrorWidget : LeafRenderObjectWidget {
         public ErrorWidget(Exception exception, string message = null) : base(key: new UniqueKey()) {
             return new ErrorWidget(error, message);
         }
 
-        public static ErrorWidgetBuilder builder = (details) => new ErrorWidget(details.exception);
+        public static ErrorWidgetBuilder builder = _defaultErrorWidgetBuilder;
 
         static Widget _defaultErrorWidgetBuilder(UIWidgetsErrorDetails details) {
             string message = "";
             }
             catch (Exception e) {
                 _debugDoingBuild = false;
-                built = ErrorWidget.builder(WidgetsD._debugReportException("building " + this, e));
+
+                IEnumerable<DiagnosticsNode> informationCollector() {
+                    yield return new DiagnosticsDebugCreator(new DebugCreator(this));
+                }
+                built = ErrorWidget.builder(WidgetsD._debugReportException("building " + this, e, informationCollector));
             }
             finally {
                 _dirty = false;
                 D.assert(_child != null);
             }
             catch (Exception e) {
-                built = ErrorWidget.builder(WidgetsD._debugReportException("building " + this, e));
+                IEnumerable<DiagnosticsNode> informationCollector() {
+                    yield return new DiagnosticsDebugCreator(new DebugCreator(this));
+                }
+                built = ErrorWidget.builder(WidgetsD._debugReportException("building " + this, e, informationCollector));
                 _child = updateChild(null, built, slot);
             }
         }
             });
             D.assert(_state._element == null);
             _state._element = this;
-            D.assert(_state._widget == null);
+            D.assert(_state._widget == null, () => $"The createState function for {widget} returned an old or invalid state " +
+                                                   $"instance: {_state._widget}, which is not null, violating the contract " +
+                                                   "for createState.");
+        protected override Widget build() {
+            return _state.build(this);
+        }
+
-        protected override Widget build() {
-            return _state.build(this);
-        }
-
+
+        public override void reassemble() {
+            state.reassemble();
+            base.reassemble();
+        }
 
         protected override void _firstBuild() {
             D.assert(_state._debugLifecycleState == _StateLifecycle.created);
         internal readonly Dictionary<Element, object> _dependents = new Dictionary<Element, object>();
 
         internal override void _updateInheritance() {
-            Dictionary<Type, InheritedElement> incomingWidgets =
-                _parent == null ? null : _parent._inheritedWidgets;
+            D.assert(_active);
+            Dictionary<Type, InheritedElement> incomingWidgets = _parent?._inheritedWidgets;
 
             if (incomingWidgets != null) {
                 _inheritedWidgets = new Dictionary<Type, InheritedElement>(incomingWidgets);
         }
 
         RenderObject _renderObject;
+        
+        public override RenderObject renderObject {
+            get { return _renderObject; }
+        }
 
         bool _debugDoingBuild = false;
 
 
-        public override RenderObject renderObject {
-            get { return _renderObject; }
-        }
-
         RenderObjectElement _ancestorRenderObjectElement;
 
         RenderObjectElement _findAncestorRenderObjectElement() {
         ParentDataElement _findAncestorParentDataElement() {
             Element ancestor = _parent;
             ParentDataElement result = null;
-            //ParentData> 
             while (ancestor != null && !(ancestor is RenderObjectElement)) {
                 if (ancestor is ParentDataElement parentDataElement) {
                     result = parentDataElement;
                 if (result == null || ancestor == null) {
                     return true;
                 }
-
-                // Check that no other ParentDataWidgets want to provide parent data.
+                
                 List<ParentDataElement> badAncestors = new List<ParentDataElement>();
                 ancestor = ancestor._parent;
                 while (ancestor != null && !(ancestor is RenderObjectElement)) {
                     badAncestors.Insert(0, result);
                     try {
                         List<ErrorDescription> errors = new List<ErrorDescription>();
-                        foreach (ParentDataElement<ParentData> parentDataElement in badAncestors)
+                        foreach (ParentDataElement<ParentData> parentDataElement in badAncestors) {
+                        }
 
                         List<DiagnosticsNode> results = new List<DiagnosticsNode>();
                         results.Add( new ErrorSummary("Incorrect use of ParentDataWidget."));
                 }
             }
 
-            // Update the middle of the list.
             while (newChildrenTop <= newChildrenBottom) {
                 Element oldChild = null;
                 Widget newWidget = newWidgets[newChildrenTop];
                     }
                 }
                 catch (UIWidgetsError e) {
-                    UIWidgetsError.reportError(new UIWidgetsErrorDetails(
-                        context: new ErrorDescription("while apply parent data"),
-                        exception: e
-                    ));
+                    WidgetsD._debugReportException(new ErrorSummary("while apply parent data"), e);
                 }
 
                 return true;
             D.assert(_ancestorRenderObjectElement == null);
             _slot = newSlot;
             _ancestorRenderObjectElement = _findAncestorRenderObjectElement();
-            if (_ancestorRenderObjectElement != null) {
-                _ancestorRenderObjectElement.insertChildRenderObject(renderObject, newSlot);
-            }
+            _ancestorRenderObjectElement?.insertChildRenderObject(renderObject, newSlot);
 
             ParentDataElement parentDataElement = _findAncestorParentDataElement();
             if (parentDataElement != null) {
     }
 
     public class DebugCreator {
-        public DebugCreator(RenderObjectElement element) {
+        public DebugCreator(Element element) {
-        public readonly RenderObjectElement element;
+        public readonly Element element;
 
         public override string ToString() {
             return element.debugGetCreatorChain(12);

com.unity.uiwidgets/Runtime/widgets/gesture_detector.cs

     public delegate void GestureRecognizerFactoryInitializer<T>(T instance) where T : GestureRecognizer;
 
     public class GestureRecognizerFactoryWithHandlers<T> : GestureRecognizerFactory<T> where T : GestureRecognizer {
-        public GestureRecognizerFactoryWithHandlers(GestureRecognizerFactoryConstructor<T> constructor,
+        public GestureRecognizerFactoryWithHandlers(
+            GestureRecognizerFactoryConstructor<T> constructor,
             GestureRecognizerFactoryInitializer<T> initializer) {
             D.assert(constructor != null);
             D.assert(initializer != null);
             GestureDragUpdateCallback onHorizontalDragUpdate = null,
             GestureDragEndCallback onHorizontalDragEnd = null,
             GestureDragCancelCallback onHorizontalDragCancel = null,
+            GestureForcePressStartCallback onForcePressStart = null,
+            GestureForcePressPeakCallback onForcePressPeak = null,
+            GestureForcePressUpdateCallback onForcePressUpdate = null,
+            GestureForcePressEndCallback onForcePressEnd = null,
             GestureDragDownCallback onPanDown = null,
             GestureDragStartCallback onPanStart = null,
             GestureDragUpdateCallback onPanUpdate = null,
             this.onHorizontalDragUpdate = onHorizontalDragUpdate;
             this.onHorizontalDragEnd = onHorizontalDragEnd;
             this.onHorizontalDragCancel = onHorizontalDragCancel;
+            this.onForcePressEnd = onForcePressEnd;
+            this.onForcePressPeak = onForcePressPeak;
+            this.onForcePressStart = onForcePressStart;
+            this.onForcePressUpdate = onForcePressUpdate;
             this.onPanDown = onPanDown;
             this.onPanStart = onPanStart;
             this.onPanUpdate = onPanUpdate;
         public readonly GestureScaleEndCallback onScaleEnd;
         public readonly HitTestBehavior behavior;
         public readonly DragStartBehavior dragStartBehavior;
+        public readonly GestureForcePressStartCallback onForcePressStart;
+        public readonly GestureForcePressPeakCallback onForcePressPeak;
+        public readonly GestureForcePressUpdateCallback onForcePressUpdate;
+        public readonly GestureForcePressEndCallback onForcePressEnd;
 
         public override Widget build(BuildContext context) {
             var gestures = new Dictionary<Type, GestureRecognizerFactory>();
                         }
                     );
             }
+            if (onForcePressStart != null ||
+                onForcePressPeak != null ||
+                onForcePressUpdate != null ||
+                onForcePressEnd != null) {
+                gestures[typeof(ForcePressGestureRecognizer)] = 
+                    new GestureRecognizerFactoryWithHandlers<ForcePressGestureRecognizer>(
+                    () => new ForcePressGestureRecognizer(debugOwner: this),
+                    (ForcePressGestureRecognizer instance) => {
+                        instance.onStart = onForcePressStart;
+                        instance.onPeak = onForcePressPeak;
+                        instance.onUpdate = onForcePressUpdate;
+                        instance.onEnd = onForcePressEnd;
+                    }
+                );
+            }
+
 
             return new RawGestureDetector(
                 gestures: gestures,
         public override Widget build(BuildContext context) {
             Widget result = new Listener(
                 onPointerDown: _handlePointerDown,
-                onPointerScroll: _handlePointerScroll,
+           
             return result;
         }
 

com.unity.uiwidgets/Runtime/widgets/heroes.cs

     }
 
     class HeroUtils {
-        /*public static Rect _globalBoundingBoxFor(BuildContext context) {
-            RenderBox box = (RenderBox) context.findRenderObject();
-            D.assert(box != null && box.hasSize);
-            return MatrixUtils.transformRect( box.getTransformTo(null), Offset.zero & box.size);
-        }*/
         public  static Rect _boundingBoxFor(BuildContext context, BuildContext ancestorContext = null) {
             RenderBox box = context.findRenderObject() as RenderBox;
             D.assert(box != null && box.hasSize);
 
 
         public readonly object tag;
-
-
-
         public readonly HeroFlightShuttleBuilder flightShuttleBuilder;
         public readonly HeroPlaceholderBuilder placeholderBuilder;
         
             BuildContext context, 
             bool isUserGestureTransition, 
             NavigatorState navigator) {
+            
+            
             Dictionary<object, _HeroState> result = new Dictionary<object, _HeroState> { };
             
             void inviteHero(StatefulElement hero, object tag) {
     }
 
     class _HeroState : State<Hero> {
+        
         GlobalKey _key = GlobalKey.key();
         Size _placeholderSize;
         bool _shouldIncludeChild = true;
             _HeroState toHero = null,
             CreateRectTween createRectTween = null,
             HeroFlightShuttleBuilder shuttleBuilder = null,
-            bool isUserGestureTransition = false,
-            bool isDiverted = false
+            bool? isUserGestureTransition = null,
+            bool? isDiverted = null
         ) {
             D.assert(fromHero.widget.tag.Equals(toHero.widget.tag));
             this.type = type;
             this.toHero = toHero;
             this.createRectTween = createRectTween;
             this.shuttleBuilder = shuttleBuilder;
-            this.isUserGestureTransition = isUserGestureTransition;
-            this.isDiverted = isDiverted;
+            this.isUserGestureTransition = isUserGestureTransition ?? false;
+            this.isDiverted = isDiverted ?? false;
         }
 
         public readonly HeroFlightDirection type;
             get {
                 return new CurvedAnimation(
                     parent: (type == HeroFlightDirection.push) ? toRoute.animation : fromRoute.animation,
-                    curve: Curves.fastOutSlowIn
-                    , reverseCurve: isDiverted ? null : Curves.fastOutSlowIn.flipped
+                    curve: Curves.fastOutSlowIn, 
+                    reverseCurve: isDiverted ? null : Curves.fastOutSlowIn.flipped
                 );
             }
         }
         public void _handleAnimationUpdate(AnimationStatus status) {
             if (status == AnimationStatus.completed || status == AnimationStatus.dismissed) {
                 _proxyAnimation.parent = null;
-
                 D.assert(overlayEntry != null);
                 overlayEntry.remove();
                 overlayEntry = null;
                 HeroFlightDirection type = initialManifest.type;
                 switch (type) {
                     case HeroFlightDirection.pop:
-                        return initial.value == 1.0f && initialManifest.isUserGestureTransition
+                        return initial.value == 1.0f && 
+                               initialManifest.isUserGestureTransition 
                             ? initial.status == AnimationStatus.completed
                             : initial.status == AnimationStatus.reverse;
                     case HeroFlightDirection.push:
             RouteSettings from = manifest.fromRoute.settings;
             RouteSettings to = manifest.toRoute.settings;
             object tag = manifest.tag;
-            return $"HeroFlight(for: {tag}, from: {from}, to: {to} ${_proxyAnimation.parent})";
+            return $"HeroFlight(for: {tag}, from: {from}, to: {to} {_proxyAnimation.parent})";
         }
     }
 
                 if (toHeroes.ContainsKey(tag)) {
                     HeroFlightShuttleBuilder fromShuttleBuilder = fromHeroes[tag].widget.flightShuttleBuilder;
                     HeroFlightShuttleBuilder toShuttleBuilder = toHeroes[tag].widget.flightShuttleBuilder;
-                    //bool isDiverted = _flights[tag] != null;
                     bool isDiverted = _flights.ContainsKey(tag);
                     _HeroFlightManifest manifest = new _HeroFlightManifest(
                         type: flightType,

com.unity.uiwidgets/Runtime/widgets/icon.cs

 
 namespace Unity.UIWidgets.widgets {
     public class Icon : StatelessWidget {
-        public Icon(IconData icon,
+        public Icon(
+            IconData icon,
-            Color color = null
+            Color color = null,
+            TextDirection? textDirection = null
+            this.textDirection = textDirection;
         }
 
         public readonly IconData icon;
         public readonly Color color;
 
+        public readonly TextDirection? textDirection;
+            D.assert(this.textDirection != null || WidgetsD.debugCheckHasDirectionality(context)); 
+            TextDirection textDirection = this.textDirection ?? Directionality.of(context);
             IconThemeData iconTheme = IconTheme.of(context);
             float iconSize = size ?? iconTheme.size.Value;
 
             if (iconOpacity != 1.0) {
                 iconColor = iconColor.withOpacity(iconColor.opacity * iconOpacity);
             }
-
-                overflow: TextOverflow.visible,
+                overflow: TextOverflow.visible, // Never clip.
+                textDirection: textDirection, // Since we already fetched it for the assert...
                 text: new TextSpan(
                     text: new string(new[] {(char) icon.codePoint}),
                     style: new TextStyle(
                 )
             );
 
+            var matrix = Matrix4.identity();
+            matrix.scale(-1.0f, 1.0f, 1.0f);
+            if (icon.matchTextDirection) {
+                switch (textDirection) {
+                    case TextDirection.rtl:
+                        iconWidget = new Transform(
+                            transform: matrix,
+                            alignment: Alignment.center,
+                            transformHitTests: false,
+                            child: iconWidget
+                        );
+                        break;
+                    case TextDirection.ltr:
+                        break;
+                }
+            }
             return new SizedBox(
                 width: iconSize,
                 height: iconSize,

com.unity.uiwidgets/Runtime/widgets/icon_data.cs

     public class IconData : IEquatable<IconData> {
         public IconData(
             int codePoint,
-            string fontFamily = null
+            string fontFamily = null,
+            string fontPackage = null,
+            bool matchTextDirection = false
+            this.fontPackage = fontPackage;
+            this.matchTextDirection = matchTextDirection;
+
+        public readonly string fontPackage;
+
+        public readonly bool matchTextDirection;
 
         public bool Equals(IconData other) {
             if (ReferenceEquals(null, other)) {
             }
 
             return codePoint == other.codePoint &&
-                   string.Equals(fontFamily, other.fontFamily);
+                   string.Equals(fontFamily, other.fontFamily) && 
+                   string.Equals(fontPackage, other.fontPackage) && 
+                matchTextDirection == other.matchTextDirection;
         }
 
         public override bool Equals(object obj) {
 
         public override int GetHashCode() {
             unchecked {
-                return (codePoint * 397) ^ (fontFamily != null ? fontFamily.GetHashCode() : 0);
+                var hashCode = 
+                     (codePoint * 397) ^ (fontFamily != null ? fontFamily.GetHashCode() : 0);
+                hashCode = (hashCode * 397) ^ (fontPackage != null ? fontPackage.GetHashCode() : 0);
+                hashCode = (hashCode * 397) ^ matchTextDirection.GetHashCode();
+                return hashCode;
             }
         }
 
-
         public static bool operator !=(IconData left, IconData right) {
             return !Equals(left, right);
         }
     
     public class IconDataProperty : DiagnosticsProperty<IconData> {
         public IconDataProperty(
-            String name,
+            string name,
-            String ifNull = null,
+            string ifNull = null,
-        ) : base(name, value,
+        ) : base(name, 
+            value,
-            D.assert(showName != null);
-            D.assert(style != null);
-            D.assert(level != null);
+           
+           
-        public override Dictionary<String, Object> toJsonMap(DiagnosticsSerializationDelegate _delegate) {
-            Dictionary<String, Object> json = base.toJsonMap(_delegate);
+        public override Dictionary<string, object> toJsonMap(DiagnosticsSerializationDelegate _delegate) {
+            Dictionary<string, object> json = base.toJsonMap(_delegate);
-            json["valueProperties"] = new Dictionary<String, Object>(){
+            json["valueProperties"] = new Dictionary<string, object>(){
                 {"codePoint", value.codePoint},
             };
         }

com.unity.uiwidgets/Runtime/widgets/icon_theme.cs

         ) : base(key: key, child: child) {
             D.assert(data != null);
             D.assert(child != null);
-
             this.data = data;
         }
 
             Widget child = null
         ) {
             return new Builder(
-                builder: context => new IconTheme(
+                builder: (BuildContext context)=> {
+                return new IconTheme(
-                )
+                );
+            }
             );
         }
 
-            IconThemeData iconThemeData = _getInheritedIconThemeData(context);
-            return iconThemeData.isConcrete ? iconThemeData : 
-                iconThemeData.copyWith(
+            IconThemeData iconThemeData = _getInheritedIconThemeData(context).resolve(context);
+            return iconThemeData.isConcrete
+                ? iconThemeData
+                : iconThemeData.copyWith(
-                    color: iconThemeData.color ??  IconThemeData.fallback().color,
-                    opacity: iconThemeData.opacity ??  IconThemeData.fallback().opacity
+            color: iconThemeData.color ?? IconThemeData.fallback().color,
+            opacity: iconThemeData.opacity ?? IconThemeData.fallback().opacity
-            if (iconTheme != null) {
-                return iconTheme.data;
-            }
-
-            return IconThemeData.fallback();
+            
+            return iconTheme?.data ?? IconThemeData.fallback();
         }
 
         public override bool updateShouldNotify(InheritedWidget oldWidget) {

com.unity.uiwidgets/Runtime/widgets/icon_theme_data.cs

                 size: other.size
             );
         }
-        
-        IconThemeData resolve(BuildContext context) => this;
+
+        public IconThemeData resolve(BuildContext context) => this;
         
         public bool isConcrete {
             get { return color != null && opacity != null && size != null; }

com.unity.uiwidgets/Runtime/widgets/image.cs

             );
         }
 
-        public Future precacheImage(
+        public static Future precacheImage(
             ImageProvider provider,
             BuildContext context,
             Size size = null,
-            var completer = Completer.create();
+            Completer completer = Completer.create();
-
-            void listener(ImageInfo image, bool sync) {
-                // TODO: update 
-                // if (!completer.isCompleted) {
-                //     stream.removeListener(listener);
-                // }
-                //
-                // SchedulerBinding.instance.addPostFrameCallback(timeStamp => { stream.removeListener(listener); });
-            }
-
-            void errorListener(Exception exception) {
+            ImageStreamListener listener = null;
+            listener = new ImageStreamListener(
+                (ImageInfo image, bool sync)=> {
-
-                // TODO: update 
-                // stream.removeListener(listener);
-                if (onError != null) {
-                    onError(exception);
+                
+                SchedulerBinding.instance.addPostFrameCallback((TimeSpan timeStamp)=> {
+                    stream.removeListener(listener);
+                });
+            },
+            onError: (Exception error) =>{
+                if (!completer.isCompleted) {
+                    completer.complete();
-                else {
-                    UIWidgetsError.reportError(new UIWidgetsErrorDetails(
-                        context: new ErrorDescription("image failed to precache"),
-                        library: "image resource service",
-                        exception: exception,
-                        silent: true
-                    ));
+                stream.removeListener(listener);
+                UIWidgetsError.reportError(new UIWidgetsErrorDetails(
+                    context: new ErrorDescription("image failed to precache"),
+                    library: "image resource service",
+                    silent: true));
-            }
-
-            // TODO: update 
-            // stream.addListener(listener, onError: errorListener);
+            );
+            stream.addListener(listener);
+            
         }
     }
 
             Color color = null,
             BlendMode colorBlendMode = BlendMode.srcIn,
             BoxFit? fit = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            bool matchTextDirection = false,
             bool gaplessPlayback = false,
             FilterQuality filterQuality = FilterQuality.low
         ) : base(key: key) {
             this.centerSlice = centerSlice;
             this.gaplessPlayback = gaplessPlayback;
             this.filterQuality = filterQuality;
+            this.matchTextDirection = matchTextDirection;
         }
 
         public static Image network(
             Color color = null,
             BlendMode colorBlendMode = BlendMode.srcIn,
             BoxFit? fit = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
+            bool matchTextDirection = false,
             FilterQuality filterQuality = FilterQuality.low,
             IDictionary<string, string> headers = null,
             int? cacheWidth = null,
                 alignment: alignment,
                 repeat: repeat,
                 centerSlice: centerSlice,
+                matchTextDirection : matchTextDirection,
                 gaplessPlayback: gaplessPlayback,
                 filterQuality: filterQuality
             );
             Color color = null,
             BlendMode colorBlendMode = BlendMode.srcIn,
             BoxFit? fit = null,
-            Alignment alignment = null,
-            ImageRepeat repeat = ImageRepeat.noRepeat,
+            AlignmentGeometry alignment = null,
+            ImageRepeat repeat = ImageRepeat.noRepeat, 
+            bool matchTextDirection = false,
             Rect centerSlice = null,
             bool gaplessPlayback = false,
             FilterQuality filterQuality = FilterQuality.low,
                 alignment: alignment,
                 repeat: repeat,
                 centerSlice: centerSlice,
+                matchTextDirection: matchTextDirection,
                 gaplessPlayback: gaplessPlayback,
                 filterQuality: filterQuality
             );
             Alignment alignment = null,
             ImageRepeat repeat = ImageRepeat.noRepeat,
             Rect centerSlice = null,
+            bool matchTextDirection = false,
+            string package = null,
-            /*image = ResizeImage.resizeIfNeeded(cacheWidth, cacheHeight, scale != null
-                ? ExactAssetImage(name, bundle: bundle, scale: scale, package: package)
-                : AssetImage(name, bundle: bundle, package: package)
-            );*/
-            var image = scale != null
-                ? (AssetBundleImageProvider) new ExactAssetImage(name, bundle: bundle, scale: scale.Value)
+            var _scale = scale ?? 1.0f;
+            var _image = scale != null
+                ? (AssetBundleImageProvider) new ExactAssetImage(name, bundle: bundle, scale: _scale)
-
+            var _Image = ResizeImage.resizeIfNeeded(cacheWidth, cacheHeight, _image);
+            
-                image: image,
+                image: _Image,
                 frameBuilder: frameBuilder,
                 loadingBuilder: null,
                 errorBuilder: errorBuilder,
                 alignment: alignment,
                 repeat: repeat,
                 centerSlice: centerSlice,
+                matchTextDirection: matchTextDirection,
                 gaplessPlayback: gaplessPlayback,
                 filterQuality: filterQuality
             );
             Alignment alignment = null,
             ImageRepeat repeat = ImageRepeat.noRepeat,
             Rect centerSlice = null,
+            bool matchTextDirection = false,
             bool gaplessPlayback = false,
             FilterQuality filterQuality = FilterQuality.low,
             int? cacheWidth = default,
             var memoryImage = new MemoryImage(bytes, scale);
             return new Image(
                 key: key,
-                image: memoryImage,
+                image: ResizeImage.resizeIfNeeded(cacheWidth, cacheHeight, new MemoryImage(bytes, scale: scale)),
                 frameBuilder: frameBuilder,
                 loadingBuilder: null,
                 errorBuilder: errorBuilder,
                 alignment: alignment,
                 repeat: repeat,
                 centerSlice: centerSlice,
+                matchTextDirection : matchTextDirection,
                 gaplessPlayback: gaplessPlayback,
                 filterQuality: filterQuality
             );
         public readonly FilterQuality filterQuality;
         public readonly BlendMode colorBlendMode;
         public readonly BoxFit? fit;
-        public readonly Alignment alignment;
+        public readonly AlignmentGeometry alignment;
+        public readonly bool matchTextDirection;
 
         public override State createState() {
             return new _ImageState();
             properties.add(new EnumProperty<BlendMode>("colorBlendMode", colorBlendMode,
                 defaultValue: foundation_.kNullDefaultValue));
             properties.add(new EnumProperty<BoxFit?>("fit", fit, defaultValue: foundation_.kNullDefaultValue));
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment,
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment,
                 defaultValue: foundation_.kNullDefaultValue));
             properties.add(new EnumProperty<ImageRepeat>("repeat", repeat, defaultValue: ImageRepeat.noRepeat));
             properties.add(new DiagnosticsProperty<Rect>("centerSlice", centerSlice,
+            properties.add(new FlagProperty("matchTextDirection", value: matchTextDirection, ifTrue: "match text direction"));
         }
     }
 
         }
 
 
-        /*public override void didChangeAccessibilityFeatures() {
-            base.didChangeAccessibilityFeatures();
+        public void didChangeAccessibilityFeatures() {
-        }*/
+        }
+        public override void reassemble() {
+            _resolveImage(); // in case the image cache was flushed
+            base.reassemble();
+        }
+
 
         void _updateInvertColors() {
             _invertColors = MediaQuery.of(context, nullOk: true)?.invertColors
         void _resolveImage() {
-            /*ScrollAwareImageProvider provider = new ScrollAwareImageProvider<dynamic>(
+            /*ScrollAwareImageProvider<object> provider = new ScrollAwareImageProvider<object>(
-                imageProvider: widget.image
-            );
-            ImageStream newStream =
-                provider.resolve(ImageUtils.createLocalImageConfiguration(
-                    context,
-                    size: widget.width != null && widget.height != null
-                        ? new Size(widget.width.Value, widget.height.Value)
-                        : null
-                ));*/
+                imageProvider: (ImageProvider<object>)widget.image
+            );*/
             ImageStream newStream =
                 widget.image.resolve(ImageUtils.createLocalImageConfiguration(
                     context,
                 setState(() => { _imageInfo = null; });
             }
 
+            setState(()=> {
+                _loadingProgress = null;
+                _frameNumber = 0;
+                _wasSynchronouslyLoaded = false;
+            });
+
-            if (_isListeningToStream) {
+            if (_isListeningToStream)
-            }
         }
 
         void _listenToStream() {
                 alignment: widget.alignment,
                 repeat: widget.repeat,
                 centerSlice: widget.centerSlice,
+                matchTextDirection: widget.matchTextDirection,
                 invertColors: _invertColors,
                 filterQuality: widget.filterQuality
             );

com.unity.uiwidgets/Runtime/widgets/image_filter.cs

     public class ImageFiltered : SingleChildRenderObjectWidget {
     
         protected ImageFiltered(
-            Key key,
-            ImageFilter imageFilter,
-            Widget child
-        ) : 
-        base(key: key, child: child) {
+            Key key = null,
+            ImageFilter imageFilter = null,
+            Widget child = null
+        ) : base(key: key, child: child) {
+            this.imageFilter = imageFilter;
-        
-        public override RenderObject createRenderObject(BuildContext context) => new _ImageFilterRenderObject(imageFilter);
+
+        public override RenderObject createRenderObject(BuildContext context) {
+                return new _ImageFilterRenderObject(imageFilter);
+        }
 
         public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
             ((_ImageFilterRenderObject) renderObject).imageFilter = imageFilter;
                 }
             }
         }
-
         ImageFilter _imageFilter;
         
         protected override bool alwaysNeedsCompositing {

com.unity.uiwidgets/Runtime/widgets/implicit_animations.cs

             return EdgeInsets.lerp(begin, end, t);
         }
     }
+    public class EdgeInsetsGeometryTween : Tween<EdgeInsetsGeometry> {
+        public EdgeInsetsGeometryTween(
+            EdgeInsetsGeometry begin = null,
+            EdgeInsetsGeometry end = null) : base(begin: begin, end: end) {
+        }
+        public override EdgeInsetsGeometry lerp(float t) {
+            return EdgeInsetsGeometry.lerp(begin, end, t);
+        }
+    }
 
 
     public class BorderRadiusTween : Tween<BorderRadius> {
         protected AnimationController controller {
             get { return _controller; }
         }
-
-
         Animation<float> _animation;
 
         public override void initState() {
     public class AnimatedContainer : ImplicitlyAnimatedWidget {
         public AnimatedContainer(
             Key key = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
             EdgeInsets padding = null,
             Color color = null,
             Decoration decoration = null,
 
         public readonly Widget child;
 
-        public readonly Alignment alignment;
+        public readonly AlignmentGeometry alignment;
 
         public readonly EdgeInsets padding;
 
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", alignment, showName: false,
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", alignment, showName: false,
                 defaultValue: null));
             properties.add(new DiagnosticsProperty<EdgeInsets>("padding", padding, defaultValue: null));
             properties.add(new DiagnosticsProperty<Decoration>("bg", decoration, defaultValue: null));
     }
 
     class _AnimatedContainerState : AnimatedWidgetBaseState<AnimatedContainer> {
-        AlignmentTween _alignment;
+        AlignmentGeometryTween _alignment;
         EdgeInsetsTween _padding;
         DecorationTween _decoration;
         DecorationTween _foregroundDecoration;
 
 
         protected override void forEachTween(TweenVisitor visitor) {
-            _alignment = (AlignmentTween) visitor.visit(this, _alignment, widget.alignment,
-                (Alignment value) => new AlignmentTween(begin: value));
+            _alignment = (AlignmentGeometryTween) visitor.visit(this, _alignment, widget.alignment,
+                (AlignmentGeometry value) => new AlignmentGeometryTween(begin: value));
             _padding = (EdgeInsetsTween) visitor.visit(this, _padding, widget.padding,
                 (EdgeInsets value) => new EdgeInsetsTween(begin: value));
             _decoration = (DecorationTween) visitor.visit(this, _decoration, widget.decoration,
                 alignment: _alignment?.evaluate(animation),
                 padding: _padding?.evaluate(animation),
                 decoration: _decoration?.evaluate(animation),
-                forgroundDecoration: _foregroundDecoration?.evaluate(animation),
+                foregroundDecoration: _foregroundDecoration?.evaluate(animation),
-                transfrom: _transform?.evaluate(animation)
+                transform: _transform?.evaluate(animation)
             );
         }
 
-            description.add(new DiagnosticsProperty<AlignmentTween>("alignment", _alignment, showName: false,
+            description.add(new DiagnosticsProperty<AlignmentGeometryTween>("alignment", _alignment, showName: false,
                 defaultValue: null));
             description.add(new DiagnosticsProperty<EdgeInsetsTween>("padding", _padding, defaultValue: null));
             description.add(new DiagnosticsProperty<DecorationTween>("bg", _decoration, defaultValue: null));
     public class AnimatedPadding : ImplicitlyAnimatedWidget {
         public AnimatedPadding(
             Key key = null,
-            EdgeInsets padding = null,
+            EdgeInsetsGeometry padding = null,
             Widget child = null,
             Curve curve = null,
             TimeSpan? duration = null,
             this.child = child;
         }
 
-        public readonly EdgeInsets padding;
+        public readonly EdgeInsetsGeometry padding;
 
         public readonly Widget child;
 
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties);
-            properties.add(new DiagnosticsProperty<EdgeInsets>("padding", padding));
+            properties.add(new DiagnosticsProperty<EdgeInsetsGeometry>("padding", padding));
-        EdgeInsetsTween _padding;
+        EdgeInsetsGeometryTween _padding;
-            _padding = (EdgeInsetsTween) visitor.visit(this, _padding, widget.padding,
-                (EdgeInsets value) => new EdgeInsetsTween(begin: value));
+            _padding = (EdgeInsetsGeometryTween) visitor.visit(this, _padding, widget.padding,
+                (EdgeInsetsGeometry value) => new EdgeInsetsGeometryTween(begin: value));
         }
 
         public override Widget build(BuildContext context) {
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder description) {
             base.debugFillProperties(description);
-            description.add(new DiagnosticsProperty<EdgeInsetsTween>("padding", _padding,
+            description.add(new DiagnosticsProperty<EdgeInsetsGeometryTween>("padding", _padding,
                 defaultValue: foundation_.kNullDefaultValue));
         }
     }
             Key key = null,
-            Alignment alignment = null,
+            AlignmentGeometry alignment = null,
             Widget child = null,
             Curve curve = null,
             TimeSpan? duration = null,
             this.child = child;
         }
 
-        public readonly Alignment alignment;
+        public readonly AlignmentGeometry alignment;
 
         public readonly Widget child;
 
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
             base.debugFillProperties(properties: properties);
-            properties.add(new DiagnosticsProperty<Alignment>("alignment", value: alignment));
+            properties.add(new DiagnosticsProperty<AlignmentGeometry>("alignment", value: alignment));
-        AlignmentTween _alignment;
+        AlignmentGeometryTween _alignment;
-            _alignment = (AlignmentTween) visitor.visit(this, tween: _alignment,
-                targetValue: widget.alignment, constructor: value => new AlignmentTween(begin: value));
+            _alignment = (AlignmentGeometryTween) visitor.visit(this, tween: _alignment,
+                targetValue: widget.alignment, constructor: value => new   AlignmentGeometryTween(begin: value));
         }
 
         public override Widget build(BuildContext context) {
 
         public override void debugFillProperties(DiagnosticPropertiesBuilder description) {
             base.debugFillProperties(properties: description);
-            description.add(new DiagnosticsProperty<AlignmentTween>("alignment", value: _alignment, defaultValue: null));
+            description.add(new DiagnosticsProperty<AlignmentGeometryTween>("alignment", value: _alignment, defaultValue: null));
         }
     }
 
             Curve curve = null,
             TimeSpan? duration = null,
             VoidCallback onEnd = null
-        ) : base(key: key, curve: curve, duration: duration, onEnd: onEnd) {
+        ) : base(key: key, curve: curve ?? Curves.linear, duration: duration, onEnd: onEnd) {
             D.assert(start == null || end == null || width == null);
             D.assert(top == null || bottom == null || height == null);
             this.child = child;
             base(key: key, curve: curve ?? Curves.linear, duration: duration, onEnd: onEnd) {
             D.assert(opacity != null && opacity >= 0.0 && opacity <= 1.0);
             this.child = child;
-            this.opacity = opacity ?? 1.0f;
+            this.opacity = opacity;
-        public readonly float opacity;
+        public readonly float? opacity;
 
         public override State createState() {
             return new _AnimatedOpacityState();
         protected SliverAnimatedOpacity(
             Key key = null,
             Widget sliver = null,
-            float opacity = default,
-            Curve curve = null,//Curve curve = Curve.linear
+            float? opacity = null,
+            Curve curve = null,
-        ) : base(key: key, curve: curve, duration: duration, onEnd: onEnd) {
+        ) : base(key: key, curve: curve ?? Curves.linear, duration: duration, onEnd: onEnd) {
+            this.opacity = opacity;
+            this.sliver = sliver;
-      public readonly float opacity;
+      public readonly float? opacity;
       
       public override State createState() {
           return new _SliverAnimatedOpacityState();
         Animation<float> _opacityAnimation;
         
       protected override void forEachTween(TweenVisitor visitor) {
-        _opacity = (FloatTween) visitor.visit(this,_opacity, widget.opacity, (float value) => new FloatTween(begin: value, 0));
+        _opacity = (FloatTween) visitor.visit(this, _opacity, widget.opacity ?? 0.0f, (float value) => new FloatTween(begin: value, 0));
       }
       
       protected override void didUpdateTweens() {
             bool softWrap = true,
             TextOverflow? overflow = null,
             int? maxLines = null,
+            TextWidthBasis textWidthBasis = TextWidthBasis.parent,
+            ui.TextHeightBehavior textHeightBehavior = null,
-            TimeSpan? duration = null
-        ) : base(key: key, curve: curve ?? Curves.linear, duration: duration) {
+            TimeSpan? duration = null,
+            VoidCallback onEnd = null
+        ) : base(key: key, curve: curve ?? Curves.linear, duration: duration, onEnd: onEnd) {
+            D.assert(overflow != null);
+           
             this.child = child;
             this.style = style;
             this.textAlign = textAlign;
+            this.textHeightBehavior = textHeightBehavior;
+            this.textWidthBasis = textWidthBasis;
+            
         }
 
         public readonly Widget child;
         public readonly bool softWrap;
 
         public readonly TextAlign? textAlign;
+        
+        public readonly ui.TextHeightBehavior textHeightBehavior;
+
+        public readonly TextWidthBasis textWidthBasis;
+
+        public readonly VoidCallback onEnd;
 
         public override State createState() {
             return new _AnimatedDefaultTextStyleState();
             base.debugFillProperties(properties);
+           
-            properties.add(new EnumProperty<TextAlign>("textAlign", textAlign ?? TextAlign.center,
-                defaultValue: null));
-            properties.add(new FlagProperty("softWrap", value: softWrap, ifTrue: "wrapping at box width",
-                ifFalse: "no wrapping except at line break characters", showName: true));
+            properties.add(new EnumProperty<TextAlign>("textAlign", textAlign ?? TextAlign.start, defaultValue: null));
+            properties.add(new FlagProperty("softWrap", value: softWrap, ifTrue: "wrapping at box width", ifFalse: "no wrapping except at line break characters", showName: true));
+            properties.add(new EnumProperty<TextWidthBasis>("textWidthBasis", textWidthBasis, defaultValue: TextWidthBasis.parent));
+            properties.add(new DiagnosticsProperty<ui.TextHeightBehavior>("textHeightBehavior", textHeightBehavior, defaultValue: null));
         }
     }
 
                 softWrap: widget.softWrap,
                 overflow: widget.overflow,
                 maxLines: widget.maxLines,
-                child: widget.child);
+                textWidthBasis: widget.textWidthBasis,
+                textHeightBehavior: widget.textHeightBehavior,
+                child: widget.child
+            );
         }
     }
 
             Color shadowColor = null,
             bool animateShadowColor = true,
             Curve curve = null,
-            TimeSpan? duration = null
-        ) : base(key: key, curve: curve ?? Curves.linear, duration: duration) {
+            TimeSpan? duration = null,
+            VoidCallback onEnd = null
+        ) : base(key: key, curve: curve ?? Curves.linear, duration: duration,onEnd: onEnd) {
-            D.assert(duration != null);
             this.child = child;
             this.shape = shape ?? BoxShape.circle;
             this.clipBehavior = clipBehavior;
             properties.add(new DiagnosticsProperty<bool>("animateColor", animateColor));
             properties.add(new DiagnosticsProperty<Color>("shadowColor", shadowColor));
             properties.add(new DiagnosticsProperty<bool>("animateShadowColor", animateShadowColor));
+        
         }
     }
 

com.unity.uiwidgets/Runtime/widgets/inherited_theme.cs

         ) : base(key: key) {
             D.assert(themes != null);
             D.assert(child != null);
+            this.child = child;
+            this.themes = themes;
         }
 
         public readonly List<InheritedTheme> themes;

com.unity.uiwidgets/Runtime/widgets/list_wheel_scroll_view.cs

 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using JetBrains.Annotations;
 using Unity.UIWidgets.animation;
 using Unity.UIWidgets.async2;
 using Unity.UIWidgets.foundation;
 
     class ListWheelScrollViewUtils {
         public static int _getItemFromOffset(
-            float offset,
-            float itemExtent,
-            float minScrollExtent,
-            float maxScrollExtent
+            float? offset = null,
+            float? itemExtent = null,
+            float? minScrollExtent = null,
+            float? maxScrollExtent = null
-            return (_clipOffsetToScrollableRange(offset, minScrollExtent, maxScrollExtent) / itemExtent).round();
+            var _itemExtent = itemExtent ?? 1.0f;
+            return (_clipOffsetToScrollableRange(offset ?? 0.0f , minScrollExtent ?? 0.0f, maxScrollExtent ?? 0.0f) / _itemExtent).round();
-
         public static float _clipOffsetToScrollableRange(
             float offset,
             float minScrollExtent,
 
         public Future animateToItem(
             int itemIndex,
-            TimeSpan duration,
-            Curve curve
-        ) {///////
+            TimeSpan? duration = null,
+            Curve curve = null
+        ) {
             if (!hasClients) {
                 return null;
             }
                     itemIndex * position.itemExtent,
-                    duration: duration,
+                    duration: duration ?? new TimeSpan(0,0,0,0,0),
                     curve: curve
                 ));
             }
             }
         }
 
-        public override ScrollPosition createScrollPosition(ScrollPhysics physics, ScrollContext context,
+        public override ScrollPosition createScrollPosition(
+            ScrollPhysics physics, 
+            ScrollContext context,
             ScrollPosition oldPosition) {
             return new _FixedExtentScrollPosition(
                 physics: physics,
 
     public class FixedExtentMetrics : FixedScrollMetrics, IFixedExtentMetrics {
         public FixedExtentMetrics(
-            int itemIndex,
-            float minScrollExtent = 0.0f,
-            float maxScrollExtent = 0.0f,
-            float pixels = 0.0f,
-            float viewportDimension = 0.0f,
-            AxisDirection axisDirection = AxisDirection.down
+            float? minScrollExtent = null,
+            float? maxScrollExtent = null,
+            float? pixels = null,
+            float? viewportDimension = null,
+            AxisDirection axisDirection = AxisDirection.down,
+            int? itemIndex = null
-            minScrollExtent: minScrollExtent,
-            maxScrollExtent: maxScrollExtent,
-            pixels: pixels,
-            viewportDimension: viewportDimension,
+            minScrollExtent: minScrollExtent ?? 0.0f,
+            maxScrollExtent: maxScrollExtent ?? 0.0f,
+            pixels: pixels ?? 0.0f,
+            viewportDimension: viewportDimension ?? 0.0f,
-            this.itemIndex = itemIndex;
+            this.itemIndex = itemIndex ?? 0;
         }
 
         public int itemIndex { get; set; }
                 itemIndex: itemIndex ?? this.itemIndex
             );
         }
+       
+
-            ScrollPhysics physics,
-            ScrollContext context,
-            int initialItem,
+            ScrollPhysics physics = null,
+            ScrollContext context = null,
+            int? initialItem = null,
             bool keepScrollOffset = true,
             ScrollPosition oldPosition = null,
             string debugLabel = null
 
         static float _getItemExtentFromScrollContext(ScrollContext context) {
             _FixedExtentScrollableState scrollable = (_FixedExtentScrollableState) context;
-            return scrollable.itemExtent;
+            return scrollable.itemExtent ?? 0.0f;
         }
 
         public float itemExtent {
 
     class _FixedExtentScrollable : Scrollable {
         public _FixedExtentScrollable(
-            float itemExtent,
-            ViewportBuilder viewportBuilder,
-            ScrollPhysics physics = null
+            ScrollPhysics physics = null,
+            float? itemExtent = null,
+            ViewportBuilder viewportBuilder = null
         ) : base(
             key: key,
             axisDirection: axisDirection,
             this.itemExtent = itemExtent;
         }
 
-        public readonly float itemExtent;
+        public readonly float? itemExtent;
 
         public override State createState() {
             return new _FixedExtentScrollableState();
     class _FixedExtentScrollableState : ScrollableState {
-        public float itemExtent {
+        public float? itemExtent {
             get {
                 _FixedExtentScrollable actualWidget = (_FixedExtentScrollable) widget;
                 return actualWidget.itemExtent;
             }
 
             if (settlingItemIndex == metrics.itemIndex) {
-                return new SpringSimulation(spring,
+                return new SpringSimulation(
+                    spring,
                     metrics.pixels,
                     settlingPixels,
                     velocity,
             return FrictionSimulation.through(
                 metrics.pixels,
                 settlingPixels,
-                velocity, tolerance.velocity * velocity.sign()
+                velocity, 
+                tolerance.velocity * velocity.sign()
             );
         }
     }
-            float itemExtent,
-            List<Widget> children = null,
             Key key = null,
             ScrollController controller = null,
             ScrollPhysics physics = null,
             bool useMagnifier = false,
             float magnification = 1.0f,
             float overAndUnderCenterOpacity = 1.0f,
+            float? itemExtent = null,
-            ListWheelChildDelegate childDelegate = null
+            List<Widget> children = null
         ) : base(key: key) {
             D.assert(children != null || childDelegate != null);
             D.assert(diameterRatio > 0.0, () => RenderListWheelViewport.diameterRatioZeroMessage);
-            D.assert(overAndUnderCenterOpacity != null);
-            D.assert(squeeze != null);
             D.assert(squeeze > 0);
             D.assert(
                 !renderChildrenOutsideViewport || !clipToSize,
-            this.childDelegate = childDelegate ?? new ListWheelChildListDelegate(children: children);
+            childDelegate = new ListWheelChildListDelegate(children: children);
             this.overAndUnderCenterOpacity = overAndUnderCenterOpacity;
             this.itemExtent = itemExtent;
             this.squeeze = squeeze;
         }
 
         public static ListWheelScrollView useDelegate(
-            float itemExtent,
-            float overAndUnderCenterOpacity = 1.0f,
-            float squeeze = 1.0f,
-            List<Widget> children = null,
-            ListWheelChildDelegate childDelegate = null,
             Key key = null,
             ScrollController controller = null,
             ScrollPhysics physics = null,
             bool useMagnifier = false,
             float magnification = 1.0f,
+            float? itemExtent = null,
+            float squeeze = 1.0f,
+            float overAndUnderCenterOpacity = 1.0f,
-            bool renderChildrenOutsideViewport = false
+            bool renderChildrenOutsideViewport = false,
+            ListWheelChildDelegate childDelegate = null
-            return new ListWheelScrollView(
+            D.assert(childDelegate != null);
+            D.assert(diameterRatio > 0.0, ()=>RenderListWheelViewport.diameterRatioZeroMessage);
+            D.assert(perspective > 0);
+            D.assert(perspective <= 0.01,()=> RenderListWheelViewport.perspectiveTooHighMessage);
+            D.assert(magnification > 0);
+            D.assert(overAndUnderCenterOpacity >= 0 && overAndUnderCenterOpacity <= 1);
+            D.assert(itemExtent != null);
+            D.assert(itemExtent > 0);
+            D.assert(squeeze > 0);
+            D.assert(
+                !renderChildrenOutsideViewport || !clipToSize,()=>
+                RenderListWheelViewport.clipToSizeAndRenderChildrenOutsideViewportConflict
+            );
+            var view =  new ListWheelScrollView(
-                children: children,
-                childDelegate: childDelegate,
                 key: key,
                 controller: controller,
                 physics: physics,
                 clipToSize: clipToSize,
                 renderChildrenOutsideViewport: renderChildrenOutsideViewport
             );
+            view.childDelegate = childDelegate;
+            return view;
         }
 
         public readonly ScrollController controller;
         public readonly float offAxisFraction;
         public readonly bool useMagnifier;
         public readonly float magnification;
-        public readonly float itemExtent;
+        public readonly float? itemExtent;
-        public readonly ListWheelChildDelegate childDelegate;
+        public ListWheelChildDelegate childDelegate;
 
         public override State createState() {
             return new _ListWheelScrollViewState();
                         && notification is ScrollUpdateNotification
                         && notification.metrics is FixedExtentMetrics metrics) {
                         int currentItemIndex = metrics.itemIndex;
-
                         if (currentItemIndex != _lastReportedItemIndex) {
                             _lastReportedItemIndex = currentItemIndex;
                             int trueIndex = widget.childDelegate.trueIndexOf(currentItemIndex);
                             useMagnifier: widget.useMagnifier,
                             magnification: widget.magnification,
                             overAndUnderCenterOpacity: widget.overAndUnderCenterOpacity,
-                            itemExtent: widget.itemExtent,
+                            itemExtent: widget.itemExtent ?? 0.0f,
                             squeeze: widget.squeeze,
                             clipToSize: widget.clipToSize,
                             renderChildrenOutsideViewport: widget.renderChildrenOutsideViewport,
             owner.buildScope(this, () => {
                 bool insertFirst = after == null;
                 D.assert(insertFirst || _childElements[index - 1] != null);
-                // Debug.Log($"{index}: {this._childElements.getOrDefault(index)}");
-
-
-                // Debug.Log(newChild);
                 if (newChild != null) {
                     _childElements[index] = newChild;
                 }
         protected override void insertChildRenderObject(RenderObject child, object slot) {
             RenderListWheelViewport renderObject = this.renderObject;
             D.assert(renderObject.debugValidateChild(child));
-
-            renderObject.insert((RenderBox) child,
-                (RenderBox) _childElements.getOrDefault((int) slot - 1)?.renderObject);
-            // Debug.Log($"insert: {this._childElements.getOrDefault((int) slot - 1)}");
-
-
+            renderObject.insert(child as RenderBox, after: _childElements[(int)slot - 1]?.renderObject as RenderBox);
             D.assert(renderObject == this.renderObject);
         }
 
 
     public class ListWheelViewport : RenderObjectWidget {
         public ListWheelViewport(
-            float itemExtent,
-            ViewportOffset offset,
-            ListWheelChildDelegate childDelegate,
             Key key = null,
             float diameterRatio = RenderListWheelViewport.defaultDiameterRatio,
             float perspective = RenderListWheelViewport.defaultPerspective,
+            float overAndUnderCenterOpacity = 1.0f,
+            float? itemExtent = null,
+            float squeeze = 1.0f,
-            float overAndUnderCenterOpacity = 1.0f,
-            float squeeze = 1.0f
+            ViewportOffset offset = null,
+            ListWheelChildDelegate childDelegate = null
         ) : base(key: key) {
             D.assert(childDelegate != null);
             D.assert(offset != null);
-            D.assert(overAndUnderCenterOpacity != null);
+            D.assert(itemExtent != null);
             D.assert(itemExtent > 0);
             D.assert(
                 !renderChildrenOutsideViewport || !clipToSize,
         public readonly bool useMagnifier;
         public readonly float magnification;
         public readonly float overAndUnderCenterOpacity;
-        public readonly float itemExtent;
+        public readonly float? itemExtent;
         public readonly float squeeze;
         public readonly bool clipToSize;
         public readonly bool renderChildrenOutsideViewport;
                 useMagnifier: useMagnifier,
                 magnification: magnification,
                 overAndUnderCenterOpacity: overAndUnderCenterOpacity,
-                itemExtent: itemExtent,
+                itemExtent: itemExtent ?? 0.0f,
                 squeeze: squeeze,
                 clipToSize: clipToSize,
                 renderChildrenOutsideViewport: renderChildrenOutsideViewport
             viewport.useMagnifier = useMagnifier;
             viewport.magnification = magnification;
             viewport.overAndUnderCenterOpacity = overAndUnderCenterOpacity;
-            viewport.itemExtent = itemExtent;
+            viewport.itemExtent = itemExtent ?? 0.0f;
             viewport.squeeze = squeeze;
             viewport.clipToSize = clipToSize;
             viewport.renderChildrenOutsideViewport = renderChildrenOutsideViewport;

com.unity.uiwidgets/Runtime/widgets/localizations.cs

 
 namespace Unity.UIWidgets.widgets {
     class _Pending {
-        public _Pending(LocalizationsDelegate del, Future<object> futureValue) {
+        public _Pending(
+            LocalizationsDelegate del, 
+            Future<object> futureValue) {
             this.del = del;
             this.futureValue = futureValue;
         }
 
-        internal static Future<Dictionary<Type, object>> _loadAll(Locale locale,
+        internal static Future<Dictionary<Type, object>> _loadAll(
+            Locale locale,
             IEnumerable<LocalizationsDelegate> allDelegates) {
             Dictionary<Type, object> output = new Dictionary<Type, object>();
             List<_Pending> pendingList = null;
             }
 
             foreach (LocalizationsDelegate del in delegates) {
-                //Future<WidgetsLocalizations> inputValue = del.load(locale);
+                
-               /* Future<object> futureValue = inputValue.then_<object>(value => {
-                    completedValue = value;
-                    return FutureOr.value(completedValue);
-                })();*/
+                
                 if (completedValue != null) {
                     Type type = del.type;
                     D.assert(!output.ContainsKey(type));
 
             return Future.wait<object>(pendingList.Select(p => p.futureValue))
                 .then(values => {
-                    //TODO : check values is list
+                    
                     var list = (List<object>)values;
                     D.assert(list.Count == pendingList.Count);
                     for (int i = 0; i < list.Count; i += 1) {
     }
 
     public abstract class LocalizationsDelegate<T> : LocalizationsDelegate {
+        //public abstract Future<T> load(Locale locale);
         public override Type type {
             get { return typeof(T); }
         }
+        public TextDirection textDirection { get; }
+
         static WidgetsLocalizations of(BuildContext context) {
             return Localizations.of<WidgetsLocalizations>(context, typeof(WidgetsLocalizations));
         }
 
     class _LocalizationsScope : InheritedWidget {
         public _LocalizationsScope(
-            Key key,
-            Locale locale,
-            _LocalizationsState localizationsState,
-            Dictionary<Type, object> typeToResources,
-            Widget child
+            Key key = null,
+            Locale locale = null,
+            _LocalizationsState localizationsState = null,
+            Dictionary<Type, object> typeToResources = null,
+            Widget child = null
         ) : base(key: key, child: child) {
             D.assert(locale != null);
             D.assert(localizationsState != null);
         public Locale locale {
             get { return _locale; }
         }
-
         Locale _locale;
 
         public override void initState() {
             return resources;
         }
 
+        TextDirection _textDirection {
+            get {
+                WidgetsLocalizations resources = (WidgetsLocalizations)_typeToResources.getOrDefault(typeof(WidgetsLocalizations)) ;
+                D.assert(resources != null);
+                return resources.textDirection;
+            }
+        }
         public override Widget build(BuildContext context) {
             if (_locale == null) {
                 return new Container();
                 locale: _locale,
                 localizationsState: this,
                 typeToResources: _typeToResources,
-                child: widget.child
+                child: new Directionality(
+                    textDirection: _textDirection,
+                    child: widget.child
+                )
             );
         }
     }

com.unity.uiwidgets/Runtime/widgets/media_query.cs

                 size: window.physicalSize / window.devicePixelRatio,
                 devicePixelRatio: window.devicePixelRatio,
                 textScaleFactor: window.textScaleFactor,
-                //platformBrightness: window.platformBrightness, // TODO: remove comment when window.platformBrightness is ready
+                platformBrightness: window.platformBrightness, // TODO: remove comment when window.platformBrightness is ready
                 padding: EdgeInsets.fromWindowPadding(window.padding, window.devicePixelRatio),
                 viewPadding : EdgeInsets.fromWindowPadding(window.viewPadding, window.devicePixelRatio),
                 viewInsets: EdgeInsets.fromWindowPadding(window.viewInsets, window.devicePixelRatio),
             float? physicalDepth = null,
             
             bool? alwaysUse24HourFormat = null,
-            bool? accessibleNavigation = null,
-            bool? invertColors = null,
+            bool? invertColors = null,
+            bool? accessibleNavigation = null,
             bool? boldText = null
         ) {
             return new MediaQueryData(
             bool removeRight = false,
             bool removeBottom = false
         ) {
-            if (!(removeLeft || removeTop || removeRight || removeBottom)) {
+            
+            if (!(removeLeft || removeTop || removeRight || removeBottom))
-            }
-
             return new MediaQueryData(
                 size: size,
                 devicePixelRatio: devicePixelRatio,
-                    left: removeLeft ? (float?) 0.0 : null,
-                    top: removeTop ? (float?) 0.0 : null,
-                    right: removeRight ? (float?) 0.0 : null,
-                    bottom: removeBottom ? (float?) 0.0 : null
+                    left: removeLeft ? (float?)0.0f : null,
+                    top: removeTop ?(float?) 0.0f : null,
+                    right: removeRight ? (float?)0.0f : null,
+                    bottom: removeBottom ?(float?) 0.0f : null
                 ),
                 viewPadding: viewPadding.copyWith(
                     left: removeLeft ? (float?)Mathf.Max(0.0f, viewPadding.left - padding.left) : null,
                 accessibleNavigation: accessibleNavigation,
                 boldText: boldText
             );
+            
         }
 
         public MediaQueryData removeViewInsets(
 
         public static MediaQueryData of(BuildContext context, bool nullOk = false) {
             D.assert(context != null);
-            //MediaQuery query = context.dependOnInheritedWidgetOfExactType<MediaQuery>();
-
             MediaQuery query = (MediaQuery) context.dependOnInheritedWidgetOfExactType<MediaQuery>();
             if (query != null) {
                 return query.data;

com.unity.uiwidgets/Runtime/widgets/modal_barrier.cs

         public readonly Color color;
         public readonly bool dismissible;
 
-        public ModalBarrier(Key key = null, Color color = null, bool dismissible = true) : base(key) {
+        public ModalBarrier(
+            Key key = null, 
+            Color color = null, 
+            bool dismissible = true) : base(key) {
             this.color = color;
             this.dismissible = dismissible;
         }
     public class AnimatedModalBarrier : AnimatedWidget {
         public readonly bool dismissible;
 
-        public AnimatedModalBarrier(Key key = null, Animation<Color> color = null,
-            bool dismissible = true) : base(key, color) {
+        public AnimatedModalBarrier(
+            Key key = null, 
+            Animation<Color> color = null,
+            bool dismissible = true
+            ) : base(key, color) {
             this.dismissible = dismissible;
         }
 
 
         protected internal override Widget build(BuildContext context) {
-            return new ModalBarrier(color: color?.value, dismissible: dismissible);
+            return new ModalBarrier(
+                color: color?.value, 
+                dismissible: dismissible);
-        public _AnyTapGestureRecognizer( Object debugOwner = null) : base(debugOwner: debugOwner) {}
+        public _AnyTapGestureRecognizer( object debugOwner = null) : base(debugOwner: debugOwner) {}
-        protected override bool isPointerAllowed(PointerDownEvent _event) {
+        protected override bool isPointerAllowed(PointerDownEvent _event ) {
             if (onAnyTapUp == null)
               return false;
             return base.isPointerAllowed(_event);
         ) : base(key: key) {
             D.assert(child != null);
             D.assert(onDismiss != null);
+            this.child = child;
+            this.onDismiss = onDismiss;
         }
         
         public readonly Widget child;

com.unity.uiwidgets/Runtime/widgets/navigation_toolbar.cs

 
 namespace Unity.UIWidgets.widgets {
     public class NavigationToolbar : StatelessWidget {
-        public NavigationToolbar(Key key = null, Widget leading = null, Widget middle = null,
-            Widget trailing = null, bool centerMiddle = true, float middleSpacing = kMiddleSpacing) : base(key) {
+        public NavigationToolbar(
+            Key key = null,
+            Widget leading = null, 
+            Widget middle = null,
+            Widget trailing = null, 
+            bool centerMiddle = true, 
+            float middleSpacing = kMiddleSpacing
+            ) : base(key) {
             this.leading = leading;
             this.middle = middle;
             this.trailing = trailing;
 
     class _ToolbarLayout : MultiChildLayoutDelegate {
         public _ToolbarLayout(
-            bool? centerMiddle = true,
+            bool? centerMiddle = null,
             float? middleSpacing = null,
             TextDirection? textDirection = null
         ) {
-            this.middleSpacing = middleSpacing ?? 0.0f;
+            this.middleSpacing = middleSpacing  ?? 0.0f;
             this.textDirection = textDirection ?? TextDirection.ltr;
         }
 
                 float middleStartMargin = leadingWidth + middleSpacing;
                 float middleStart = middleStartMargin;
                 float middleY = (size.height - middleSize.height) / 2.0f;
-                // If the centered middle will not fit between the leading and trailing
-                // widgets, then align its left or right edge with the adjacent boundary.
+                
                 if (centerMiddle) {
                     middleStart = (size.width - middleSize.width) / 2.0f;
                     if (middleStart + middleSize.width > size.width - trailingWidth) {

com.unity.uiwidgets/Runtime/widgets/navigator.cs

             return other.GetType() == GetType() &&
                    other.key == key;
         }
-
-        //public abstract Route createRoute(BuildContext context);
-
         public override string ToString() {
             return $"{GetType()}(\"{name}\",{key},{arguments})";
         }
         public _RouteEntry(
             Route route,
             _RouteLifecycle initialState
-
         ) {
             D.assert(
                 initialState == _RouteLifecycle.staging ||

com.unity.uiwidgets/Runtime/widgets/nested_scroll_view.cs

                             reverse: widget.reverse,
                             physics: widget.physics != null
                                 ? widget.physics.applyTo(new ClampingScrollPhysics())
-                                : new ClampingScrollPhysics(),
-                            controller: _coordinator._outerController,
-                            slivers: widget._buildSlivers(
-                                _context, _coordinator._innerController, _lastHasScrolledBody
-                            ),
-                            handle: _absorberHandle
-                        );
+                            : new ClampingScrollPhysics(),
+                        controller: _coordinator._outerController,
+                        slivers: widget._buildSlivers(
+                            context,
+                            _coordinator._innerController,
+                            _lastHasScrolledBody
+                        ),
+                        handle: _absorberHandle
+                            );
                     }
                 )
             );
     class _NestedScrollViewCustomScrollView : CustomScrollView {
         public _NestedScrollViewCustomScrollView(
-            Axis scrollDirection,
+            Axis scrollDirection, 
             bool reverse,
             ScrollPhysics physics,
             ScrollController controller,
                 if (!_outerController.hasClients) {
                     return null;
                 }
-
                 return _outerController.nestedPositions.Single();
             }
         }
             if (userScrollDirection == value) {
                 return;
             }
-
             _userScrollDirection = value;
             _outerPosition.didUpdateScrollDirection(value);
             foreach (_NestedScrollPosition position in _innerPositions) {
         }
 
         public void goBallistic(float velocity) {
-            beginActivity(createOuterBallisticScrollActivity(velocity),
+            beginActivity(
+                createOuterBallisticScrollActivity(velocity),
                 (_NestedScrollPosition position) => createInnerBallisticScrollActivity(position, velocity)
             );
         }
             _outerPosition.updateCanDrag(maxInnerExtent);
         }
 
-        public Future animateTo(float to,
+        public Future animateTo(
+            float to,
             TimeSpan duration,
             Curve curve
         ) {
         }
 
         public override string ToString() {
-            return "$GetType()(outer=$_outerController; inner=$_innerController)";
+            return $"{GetType()}(outer={_outerController}; inner={_innerController})";
         }
     }
 

com.unity.uiwidgets/Runtime/widgets/overlay.cs

 
 namespace Unity.UIWidgets.widgets {
     public class OverlayEntry {
-        public OverlayEntry(WidgetBuilder builder = null, bool opaque = false, bool maintainState = false) {
+        public OverlayEntry(
+            WidgetBuilder builder = null, 
+            bool opaque = false, 
+            bool maintainState = false) {
             D.assert(builder != null);
             _opaque = opaque;
             _maintainState = maintainState;
 
                 _maintainState = value;
                 D.assert(_overlay != null);
-                _overlay._didChangeEntryOpacity();
+                _overlay?._didChangeEntryOpacity();
             }
         }
 
     }
 
     class _OverlayEntryWidgetState : State<_OverlayEntryWidget> {
-        public override Widget build(BuildContext context) {
+        public override Widget build(
+            BuildContext context) {
             return new TickerMode(
                 enabled: widget.tickerEnabled,
                 child: widget.entry.builder(context)
 
     class _RenderTheatre : ContainerRenderObjectMixinRenderBox<RenderBox, StackParentData> {
         internal _RenderTheatre(
-            TextDirection textDirection,
+            TextDirection textDirection ,
             List<RenderBox> children = null,
             int skipCount = 0
         ) {
             if (_resolvedAlignment != null) {
                 return;
             }
-            //FIXME: wait for changes on painting/alignment.cs (by Siyao)
-            //then uncomment the line below and remove the switch clauses
-            //_resolvedAlignment = AlignmentDirectional.topStart.resolve(textDirection);
-            switch (textDirection) {
-                case TextDirection.rtl:
-                    _resolvedAlignment = new Alignment(-1, -1);
-                    break;
-                case TextDirection.ltr:
-                    _resolvedAlignment = new Alignment(1, -1);
-                    break;
-            }
+            _resolvedAlignment = AlignmentDirectional.topStart.resolve(textDirection);
         }
 
         void _markNeedResolution() {

com.unity.uiwidgets/Runtime/widgets/page_storage.cs

 
         public static PageStorageBucket of(BuildContext context) {
             PageStorage widget = context.findAncestorWidgetOfExactType<PageStorage>();
-            return widget == null ? null : widget.bucket;
+            return widget?.bucket;
         }
 
         public override Widget build(BuildContext context) {

com.unity.uiwidgets/Runtime/widgets/page_view.cs

             this.initialPage = initialPage;
             this.keepPage = keepPage;
             this.viewportFraction = viewportFraction;
-            D.assert(viewportFraction > 0.0);
+            D.assert(viewportFraction > 0.0f);
         }
 
         public readonly int initialPage;
             }
         }
 
-        public Future animateToPage(int page, TimeSpan duration, Curve curve) {
+        public Future animateToPage(
+            int page, 
+            TimeSpan duration, 
+            Curve curve ) {
             _PagePosition position = (_PagePosition) this.position;
             return position.animateTo(
                 position.getPixelsFromPage(page),
         }
+        
+        
 
         public void jumpToPage(int page) {
             _PagePosition position = (_PagePosition) this.position;
-        public Future nextPage(TimeSpan duration, Curve curve) {
+        public Future nextPage(
+            TimeSpan duration, Curve curve) {
             return animateToPage(page.round() + 1, duration: duration, curve: curve);
         }
 
 
-        public override ScrollPosition createScrollPosition(ScrollPhysics physics, ScrollContext context,
+        public override ScrollPosition createScrollPosition(
+            ScrollPhysics physics, 
+            ScrollContext context,
             ScrollPosition oldPosition) {
             return new _PagePosition(
                 physics: physics,
         }
 
         public readonly float _viewportFraction;
+        
+        public PageMetrics copyWith(
+            float? minScrollExtent = null,
+            float? maxScrollExtent = null,
+            float? pixels = null,
+            float? viewportDimension = null,
+            AxisDirection? axisDirection = null,
+            float? viewportFraction = null
+        ) {
+            return new PageMetrics(
+                minScrollExtent: minScrollExtent ?? this.minScrollExtent,
+                maxScrollExtent: maxScrollExtent ?? this.maxScrollExtent,
+                pixels: pixels ?? this.pixels,
+                viewportDimension: viewportDimension ?? this.viewportDimension,
+                axisDirection: axisDirection ?? this.axisDirection,
+                viewportFraction: viewportFraction ?? this.viewportFraction
+            );
+        }
 
         public float page {
             get {
             bool keepPage = true,
             float viewportFraction = 1.0f,
             ScrollPosition oldPosition = null
-        ) :
-            base(
+        ) : base(
                 physics: physics,
                 context: context,
                 initialPixels: null,
         }
 
         public float getPageFromPixels(float pixels, float viewportDimension) {
-            return (Mathf.Max(0.0f, pixels) / Mathf.Max(1.0f, viewportDimension * viewportFraction));
+            float actual = Mathf.Max(0.0f, pixels - _initialPageOffset) / Mathf.Max(1.0f, viewportDimension * viewportFraction);
+            float round = (int)actual * 1.0f;
+            if ((actual - round).abs() < 1e-10) {
+                return round;
+            }
+            return actual;
         }
 
         public float getPixelsFromPage(float page) {
         }
 
         public override bool applyViewportDimension(float viewportDimension) {
-            float oldViewportDimensions = 0.0f;
-            if (haveDimensions) {
-                oldViewportDimensions = this.viewportDimension;
-            }
-
+            float oldViewportDimensions = this.viewportDimension;
-
             float page = (oldPixels == null || oldViewportDimensions == 0.0f)
                 ? _pageToUseOnStartup
                 : getPageFromPixels(oldPixels.Value, oldViewportDimensions);
                 return false;
             }
-
             return result;
         }
         
-            return base.applyContentDimensions(
+             return base.applyContentDimensions(
+        public PageMetrics copyWith(
+            float? minScrollExtent = null,
+            float? maxScrollExtent = null,
+            float? pixels = null,
+            float? viewportDimension = null,
+            AxisDirection? axisDirection = null,
+            float? viewportFraction = null
+        ) {
+            return new PageMetrics(
+                minScrollExtent: minScrollExtent ?? this.minScrollExtent,
+                maxScrollExtent: maxScrollExtent ?? this.maxScrollExtent,
+                pixels: pixels ?? this.pixels,
+                viewportDimension: viewportDimension ?? this.viewportDimension,
+                axisDirection: axisDirection ?? this.axisDirection,
+                viewportFraction: viewportFraction ?? this.viewportFraction
+            );
+        }
     }
     
     public class _ForceImplicitScrollPhysics : ScrollPhysics {
         ) : base(parent: parent) {
             D.assert(allowImplicitScrolling != null);
+            this.allowImplicitScrolling = allowImplicitScrolling;
         }
         
         public override ScrollPhysics applyTo(ScrollPhysics ancestor) {
             ValueChanged<int> onPageChanged = null,
             List<Widget> children = null,
             DragStartBehavior dragStartBehavior = DragStartBehavior.start,
-            IndexedWidgetBuilder itemBuilder = null,
-            SliverChildDelegate childDelegate = null,
-            int itemCount = 0,
             bool allowImplicitScrolling = false
         ) : base(key: key) {
             this.scrollDirection = scrollDirection;
             this.dragStartBehavior = dragStartBehavior;
             this.controller = controller ?? PageViewUtils._defaultPageController;
             this.allowImplicitScrolling = allowImplicitScrolling;
-            if (itemBuilder != null) {
-                childrenDelegate = new SliverChildBuilderDelegate(itemBuilder, childCount: itemCount);
-            }
-            else if (childDelegate != null) {
-                childrenDelegate = childDelegate;
-            }
-            else {
-                childrenDelegate = new SliverChildListDelegate(children ?? new List<Widget>());
-            }
+            childrenDelegate = new SliverChildListDelegate(children);
-            IndexedWidgetBuilder itemBuilder,
             Key key = null,
             Axis scrollDirection = Axis.horizontal,
             bool reverse = false,
             ValueChanged<int> onPageChanged = null,
+            IndexedWidgetBuilder itemBuilder = null,
-            bool allowImplicitScrolling = false,
-            DragStartBehavior dragStartBehavior = DragStartBehavior.start
+            DragStartBehavior dragStartBehavior = DragStartBehavior.start,
+            bool allowImplicitScrolling = false
+        ) {
+            var page =  new PageView(
+                key: key,
+                scrollDirection: scrollDirection,
+                reverse: reverse,
+                controller: controller ?? PageViewUtils._defaultPageController,
+                physics: physics,
+                pageSnapping: pageSnapping,
+                onPageChanged: onPageChanged,
+                allowImplicitScrolling: allowImplicitScrolling, 
+                dragStartBehavior: dragStartBehavior
+            );
+            page.childrenDelegate = new SliverChildBuilderDelegate(itemBuilder, childCount: itemCount);
+            return page;
+        }
+        
+        public static PageView custom(
+            Key key = null,
+            Axis scrollDirection = Axis.horizontal,
+            bool reverse = false,
+            PageController controller = null,
+            ScrollPhysics physics = null,
+            bool pageSnapping = true,
+            ValueChanged<int> onPageChanged = null,
+            SliverChildDelegate childrenDelegate = null,
+            DragStartBehavior dragStartBehavior = DragStartBehavior.start,
+            bool allowImplicitScrolling = false
-            return new PageView(
-                itemBuilder: itemBuilder,
+            D.assert(childrenDelegate != null);
+            var page =  new PageView(
-                controller: controller,
+                controller: controller ?? PageViewUtils._defaultPageController,
-                itemCount: itemCount,
-                allowImplicitScrolling: allowImplicitScrolling,
+                allowImplicitScrolling: allowImplicitScrolling, 
+            page.childrenDelegate = childrenDelegate;
+            return page;
         }
 
         // TODO: PageView.custom
 
         public readonly ValueChanged<int> onPageChanged;
 
-        public readonly SliverChildDelegate childrenDelegate;
+        public SliverChildDelegate childrenDelegate;
 
         public readonly DragStartBehavior dragStartBehavior;
         

com.unity.uiwidgets/Runtime/widgets/pages.cs

     }
 
     public abstract class PageRoute : ModalRoute {
-        public readonly bool fullscreenDialog;
-
-        public PageRoute() {}
-
+        
-            bool fullscreenDialog = false) : base(settings) {
+            bool fullscreenDialog = false
+        ) : base(settings) {
+        
+        public readonly bool fullscreenDialog;
 
         public override bool opaque {
             get { return true; }
             bool fullscreenDialog = false
         ) : base(settings,fullscreenDialog) {
             D.assert(pageBuilder != null);
-
             this.opaque = opaque;
             this.pageBuilder = pageBuilder;
             this.transitionsBuilder = transitionsBuilder ?? PagesUtils._defaultTransitionsBuilder;

com.unity.uiwidgets/Runtime/widgets/performance_overlay.cs

     public class PerformanceOverlay : LeafRenderObjectWidget {
         public PerformanceOverlay(
             Key key = null,
-            int optionsMask = 0
+            int optionsMask = 0,
+            int rasterizerThreshold = 0,
+            bool checkerboardRasterCacheImages = false,
+            bool checkerboardOffscreenLayers = false
+            
+            this.rasterizerThreshold = rasterizerThreshold;
+            this.checkerboardOffscreenLayers = checkerboardOffscreenLayers;
+            this.checkerboardRasterCacheImages = checkerboardRasterCacheImages;
+        public readonly int rasterizerThreshold;
+        public readonly bool checkerboardRasterCacheImages;
+        public readonly bool checkerboardOffscreenLayers;
+        
+        
-            Key key = null
+            Key key = null,
+            int rasterizerThreshold = 0,
+            bool checkerboardRasterCacheImages = false,
+            bool checkerboardOffscreenLayers = false
+            
-                optionsMask: (1 << (int) PerformanceOverlayOption.drawFPS) |
-                             (1 << (int) PerformanceOverlayOption.drawFrameCost)
+                optionsMask :
+                    1 <<  (int) PerformanceOverlayOption.displayRasterizerStatistics |
+                    1 <<  (int) PerformanceOverlayOption.visualizeRasterizerStatistics |
+                    1 <<  (int) PerformanceOverlayOption.displayEngineStatistics |
+                    1 <<  (int) PerformanceOverlayOption.visualizeEngineStatistics
-                optionsMask: optionsMask);
+                optionsMask: optionsMask,
+                rasterizerThreshold: rasterizerThreshold,
+                checkerboardRasterCacheImages: checkerboardRasterCacheImages,
+                checkerboardOffscreenLayers: checkerboardOffscreenLayers
+                );
+             _renderObject.rasterizerThreshold = rasterizerThreshold;
         }
     }
 }

com.unity.uiwidgets/Runtime/widgets/placeholder.cs

 namespace Unity.UIWidgets.widgets {
     class _Placeholderpainter : AbstractCustomPainter {
         public _Placeholderpainter(
-            Color color,
+            Color color = null,
             float strokeWidth = 0f
         ) {
             this.color = color;

com.unity.uiwidgets/Runtime/widgets/preferred_size.cs

         Size preferredSize { get; }
     }
 
-    public abstract class PreferredSizeWidget : StatefulWidget{//Widget{ //StatefulWidget, SizePreferred {
+    public abstract class PreferredSizeWidget : StatefulWidget{
         protected PreferredSizeWidget(Key key = null) : base(key: key) {
         }
 
 
-    public class PreferredSize : StatelessWidget{//PreferredSizeWidget {
+    public class PreferredSize : StatelessWidget{
         public PreferredSize(
             Key key = null,
             Widget child = null,
         public readonly Widget child;
 
         //public override Size preferredSize { get; }
-        public  Size preferredSize { get; }
+        public Size preferredSize { get; }
         
         /*public override State createState() {
             return new _PreferredSizeState();

com.unity.uiwidgets/Runtime/widgets/primary_scroll_controller.cs

             this.controller = controller;
         }
 
-        PrimaryScrollController(
+        public PrimaryScrollController(
             Key key = null,
             Widget child = null
         ) : base(key: key, child: child) {

com.unity.uiwidgets/Runtime/widgets/routes.cs

 
 namespace Unity.UIWidgets.widgets {
     public abstract class OverlayRoute : Route {
-        public readonly List<OverlayEntry> _overlayEntries = new List<OverlayEntry>();
+       
 
         public OverlayRoute(
             RouteSettings settings = null
             get { return _overlayEntries; }
         }
+        public readonly List<OverlayEntry> _overlayEntries = new List<OverlayEntry>();
 
         protected virtual bool finishedWhenPopped {
             get { return true; }