Merge branch 'dev_1.17.5' into siyaoH/1.17/keyboard

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/cupertino/cupertino_navigation_demo.cs

         public readonly List<string> colorNameItems;
 
         public override Widget build(BuildContext context) {
+            
             return new WillPopScope(
                 //onWillPop: () => { return Promise<bool>.Resolved(true); },
                 //onWillPop: this.onWillPop,
                                     title: new Text("Profile")
                                 )
                             }
+                            
                         ),
                         tabBuilder: (BuildContext _context, int index) => {
                             D.assert(index >= 0 && index <= 2);
                                                         height: 44.0f,
                                                         decoration: new BoxDecoration(
                                                             image: new DecorationImage(
-                                                                image: new AssetImage(
-                                                                    "people/square/trevor"
+                                                                image: new FileImage(
+                                                                    file:""
                                                                 )
                                                             ),
                                                             shape: BoxShape.circle
                                                         height: 44.0f,
                                                         decoration: new BoxDecoration(
                                                             image: new DecorationImage(
-                                                                image: new AssetImage(
+                                                                image: new FileImage(
                                                                     "people/square/sandra"
                                                                 )
                                                             ),

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

 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Unity.UIWidgets.async2;
 using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.ui;
 
 
         public override void dispose() {
-            foreach (var key in _pointers.Keys) {
+            foreach (var key in _pointers.Keys.ToList()) {
                 _removeState(key);
             }
             D.assert(_pointers.isEmpty);

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

         public override Widget build(BuildContext context) {
             List<MergeableMaterialItem> items = new List<MergeableMaterialItem>();
 
-            for (int index = 0; index < widget.children.Count; index++) {
-                int expandIndex = index;
-                if (_isChildExpanded(index) && index != 0 && !_isChildExpanded(index - 1)) {
+            for (int i = 0; i < widget.children.Count; i++) {
+                int expandIndex = i;
+                if (_isChildExpanded(expandIndex) && expandIndex != 0 && !_isChildExpanded(expandIndex - 1)) {
-                        key: new _SaltedKey<BuildContext, int>(context, index * 2 - 1)));
+                        key: new _SaltedKey<BuildContext, int>(context, expandIndex * 2 - 1)));
-                ExpansionPanel child = widget.children[index];
+                ExpansionPanel child = widget.children[expandIndex];
-                    _isChildExpanded(index)
+                    _isChildExpanded(expandIndex)
-                    margin: (EdgeInsets) (EdgeInsetsGeometry) EdgeInsetsDirectional.only(end: 8.0f),
+                    //margin: (EdgeInsets) (EdgeInsetsGeometry) EdgeInsetsDirectional.only(end: 8.0f),
-                        isExpanded: _isChildExpanded(index),
+                        isExpanded: _isChildExpanded(expandIndex),
-                            ? (bool isExpanded) => _handlePressed(isExpanded, index)
+                            ? (bool isExpanded) => _handlePressed(isExpanded, expandIndex)
                             : (ValueChanged<bool>) null
                     )
                 );
                             child: new AnimatedContainer(
                                 duration: widget.animationDuration,
                                 curve: Curves.fastOutSlowIn,
-                                margin: _isChildExpanded(index) ? widget.expandedHeaderPadding : EdgeInsets.zero,
+                                margin: _isChildExpanded(expandIndex) ? widget.expandedHeaderPadding : EdgeInsets.zero,
                                 child: new ConstrainedBox(
                                     constraints: new BoxConstraints(
                                         minHeight: material_._kPanelHeaderCollapsedHeight),
                 );
                 if (child.canTapOnHeader) {
                     header = new InkWell(
-                        onTap: () => _handlePressed(_isChildExpanded(index), index),
+                        onTap: () => _handlePressed(_isChildExpanded(expandIndex), expandIndex),
-                        key: new _SaltedKey<BuildContext, int>(context, index * 2),
+                        key: new _SaltedKey<BuildContext, int>(context, expandIndex * 2),
                         child: new Column(
                             children: new List<Widget> {
                                 header,
                                     firstCurve: new Interval(0.0f, 0.6f, curve: Curves.fastOutSlowIn),
                                     secondCurve: new Interval(0.4f, 1.0f, curve: Curves.fastOutSlowIn),
                                     sizeCurve: Curves.fastOutSlowIn,
-                                    crossFadeState: _isChildExpanded(index)
+                                    crossFadeState: _isChildExpanded(expandIndex)
                                         ? CrossFadeState.showSecond
                                         : CrossFadeState.showFirst,
                                     duration: widget.animationDuration
                     )
                 );
 
-                if (_isChildExpanded(index) && index != widget.children.Count - 1) {
+                if (_isChildExpanded(expandIndex) && expandIndex != widget.children.Count - 1) {
-                        key: new _SaltedKey<BuildContext, int>(context, index * 2 + 1)));
+                        key: new _SaltedKey<BuildContext, int>(context, expandIndex * 2 + 1)));
                 }
             }
 

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

 
             return new RawMaterialButton(
                 onPressed: onPressed,
-                onLongPress: () => onLongPress(),
+                onLongPress: () => onLongPress?.Invoke(),
                 onHighlightChanged: onHighlightChanged,
                 fillColor: buttonTheme.getFillColor(this),
                 textStyle: theme.textTheme.button.copyWith(color: buttonTheme.getTextColor(this)),

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

 
             return new RawMaterialButton(
                 onPressed: onPressed,
-                onLongPress: () => onLongPress(),
+                onLongPress: () => onLongPress?.Invoke(),
                 onHighlightChanged: onHighlightChanged,
                 clipBehavior: clipBehavior.Value,
                 fillColor: buttonTheme.getFillColor(this),

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

         }
 
         public abstract Size getPreferredSize(
-            bool? isEnabled,
-            bool? isDiscrete,
+            bool isEnabled,
+            bool isDiscrete,
             TextPainter textPainter = null);
 
         public abstract void paint(
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
             SliderThemeData sliderTheme = null,
 
         public abstract Size getPreferredSize(
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null);
+            bool isEnabled = false);
 
         public abstract void paint(
             PaintingContext context,
             Animation<float> enableAnimation = null,
             Offset thumbCenter = null,
-            bool? isEnabled = null,
+            bool isEnabled = false,
             TextDirection? textDirection = null);
 
         public static readonly SliderTickMarkShape noTickMark = new _EmptySliderTickMarkShape();
             RenderBox parentBox = null,
             Offset offset = null,
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null,
-            bool? isDiscrete = null);
+            bool isEnabled = false,
+            bool isDiscrete = false);
 
         public abstract void paint(
             PaintingContext context,
             Animation<float> enableAnimation = null,
             Offset thumbCenter = null,
-            bool? isEnabled = null,
-            bool? isDiscrete = null,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextDirection? textDirection = null
         );
     }
         }
 
-        public abstract Size getPreferredSize(bool? isEnabled, bool? isDiscrete);
+        public abstract Size getPreferredSize(bool isEnabled, bool isDiscrete);
 
         public abstract void paint(
             PaintingContext context,
-            bool? isDiscrete = null,
-            bool? isEnabled = null,
+            bool isDiscrete = false,
+            bool isEnabled = false,
             bool? isOnTop = null,
             TextDirection? textDirection = null,
             SliderThemeData sliderTheme = null,
             Offset center,
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             bool? isOnTop = null,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
 
         public abstract Size getPreferredSize(
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null
+            bool isEnabled = false
         );
 
         public abstract void paint(
             Animation<float> enableAnimation = null,
             Offset startThumbCenter = null,
             Offset endThumbCenter = null,
-            bool? isEnabled = null,
+            bool isEnabled = false,
             TextDirection? textDirection = null
         );
     }
             RenderBox parentBox = null,
             Offset offset = null,
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null,
-            bool? isDiscrete = null
+            bool isEnabled = false,
+            bool isDiscrete = false
         );
 
         public abstract void paint(
             Animation<float> enableAnimation = null,
             Offset startThumbCenter = null,
             Offset endThumbCenter = null,
-            bool? isEnabled = null,
-            bool? isDiscrete = null,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextDirection? textDirection = null
         );
     }
             RenderBox parentBox = null,
             Offset offset = null,
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null,
-            bool? isDiscrete = null) {
+            bool isEnabled = false,
+            bool isDiscrete = false) {
-
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
+            
             D.assert(parentBox != null);
             D.assert(sliderTheme != null);
             float thumbWidth = sliderTheme.thumbShape.getPreferredSize(isEnabled, isDiscrete).width;
             SliderThemeData sliderTheme = null,
             Animation<float> enableAnimation = null,
             Offset thumbCenter = null,
-            bool? isEnabled = false,
-            bool? isDiscrete = false,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextDirection? textDirection = null) {
             D.assert(context != null);
             D.assert(offset != null);
             D.assert(enableAnimation != null);
             D.assert(textDirection != null);
             D.assert(thumbCenter != null);
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
 
             if (sliderTheme.trackHeight == 0) {
                 return;
             RenderBox parentBox = null,
             Offset offset = null,
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null,
-            bool? isDiscrete = null) {
+            bool isEnabled = false,
+            bool isDiscrete = false) {
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
             D.assert(parentBox != null);
             D.assert(sliderTheme != null);
             float thumbWidth = sliderTheme.thumbShape.getPreferredSize(isEnabled, isDiscrete).width;
             SliderThemeData sliderTheme = null,
             Animation<float> enableAnimation = null,
             Offset thumbCenter = null,
-            bool? isEnabled = false,
-            bool? isDiscrete = false,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextDirection? textDirection = null) {
             D.assert(context != null);
             D.assert(offset != null);
             RenderBox parentBox = null,
             Offset offset = null,
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = false,
-            bool? isDiscrete = false
+            bool isEnabled = false,
+            bool isDiscrete = false
         ) {
             offset = offset ?? Offset.zero;
 
             D.assert(sliderTheme.overlayShape != null);
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
+
 
             float overlayWidth = sliderTheme.overlayShape.getPreferredSize(isEnabled, isDiscrete).width;
             float trackHeight = sliderTheme.trackHeight.Value;
             Animation<float> enableAnimation = null,
             Offset startThumbCenter = null,
             Offset endThumbCenter = null,
-            bool? isEnabled = false,
-            bool? isDiscrete = false,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextDirection? textDirection = null
         ) {
             D.assert(context != null);
             D.assert(enableAnimation != null);
             D.assert(startThumbCenter != null);
             D.assert(endThumbCenter != null);
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
             D.assert(textDirection != null);
 
             ColorTween activeTrackColorTween = new ColorTween(begin: sliderTheme.disabledActiveTrackColor,
             RenderBox parentBox = null,
             Offset offset = null,
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = false,
-            bool? isDiscrete = false
+            bool isEnabled = false,
+            bool isDiscrete = false
         ) {
             offset = offset ?? Offset.zero;
 
             D.assert(sliderTheme.overlayShape != null);
             D.assert(sliderTheme.trackHeight != null);
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
 
             float overlayWidth = sliderTheme.overlayShape.getPreferredSize(isEnabled, isDiscrete).width;
             float trackHeight = sliderTheme.trackHeight.Value;
             Animation<float> enableAnimation = null,
             Offset startThumbCenter = null,
             Offset endThumbCenter = null,
-            bool? isEnabled = false,
-            bool? isDiscrete = false,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextDirection? textDirection = null
         ) {
             D.assert(context != null);
             D.assert(enableAnimation != null);
             D.assert(startThumbCenter != null);
             D.assert(endThumbCenter != null);
-            D.assert(isEnabled != null);
-            D.assert(isDiscrete != null);
             D.assert(textDirection != null);
 
             ColorTween activeTrackColorTween = new ColorTween(begin: sliderTheme.disabledActiveTrackColor,
 
         public override Size getPreferredSize(
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null
+            bool isEnabled = false
-            D.assert(isEnabled != null);
             return Size.fromRadius(tickMarkRadius ?? sliderTheme.trackHeight.Value / 2f);
         }
 
             SliderThemeData sliderTheme = null,
             Animation<float> enableAnimation = null,
             Offset thumbCenter = null,
-            bool? isEnabled = null,
+            bool isEnabled = false,
             TextDirection? textDirection = null
         ) {
             D.assert(context != null);
             D.assert(enableAnimation != null);
             D.assert(textDirection != null);
             D.assert(thumbCenter != null);
-            D.assert(isEnabled != null);
 
             Color begin = null;
             Color end = null;
 
         public override Size getPreferredSize(
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = false
+            bool isEnabled = false
-            D.assert(isEnabled != null);
 
             return Size.fromRadius(tickMarkRadius ?? sliderTheme.trackHeight.Value / 2f);
         }
             Animation<float> enableAnimation = null,
             Offset startThumbCenter = null,
             Offset endThumbCenter = null,
-            bool? isEnabled = false,
+            bool isEnabled = false,
             TextDirection? textDirection = null
         ) {
             D.assert(context != null);
             D.assert(enableAnimation != null);
             D.assert(startThumbCenter != null);
             D.assert(endThumbCenter != null);
-            D.assert(isEnabled != null);
             D.assert(textDirection != null);
 
             bool isBetweenThumbs = false;
     class _EmptySliderTickMarkShape : SliderTickMarkShape {
         public override Size getPreferredSize(
             SliderThemeData sliderTheme = null,
-            bool? isEnabled = null) {
+            bool isEnabled = false) {
             return Size.zero;
         }
 
             SliderThemeData sliderTheme = null,
             Animation<float> enableAnimation = null,
             Offset thumbCenter = null,
-            bool? isEnabled = null,
+            bool isEnabled = false,
             TextDirection? textDirection = null) {
         }
     }
-            bool? isEnabled = null,
-            bool? isDiscrete = null,
+            bool isEnabled = false,
+            bool isDiscrete = false,
             TextPainter textPainter = null) {
             return Size.zero;
         }
             Offset center,
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
             SliderThemeData sliderTheme = null,
         }
 
 
-        public override Size getPreferredSize(bool? isEnabled, bool? isDiscrete, TextPainter textPainter = null) {
+        public override Size getPreferredSize(bool isEnabled, bool isDiscrete, TextPainter textPainter = null) {
             return Size.fromRadius(isEnabled == true ? enabledThumbRadius : _disabledThumbRadius);
         }
 
             Offset center,
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
             SliderThemeData sliderTheme = null,
             get { return disabledThumbRadius ?? enabledThumbRadius; }
         }
 
-        public override Size getPreferredSize(bool? isEnabled, bool? isDiscrete) {
+        public override Size getPreferredSize(bool isEnabled, bool isDiscrete) {
             return Size.fromRadius(isEnabled == true ? enabledThumbRadius : _disabledThumbRadius);
         }
 
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = false,
-            bool? isEnabled = false,
+            bool isDiscrete = false,
+            bool isEnabled = false,
             bool? isOnTop = null,
             TextDirection? textDirection = null,
             SliderThemeData sliderTheme = null,
                 bool showValueIndicator = false;
                 switch (sliderTheme.showValueIndicator) {
                     case ShowValueIndicator.onlyForDiscrete:
-                        showValueIndicator = isDiscrete.Value;
+                        showValueIndicator = isDiscrete;
-                        showValueIndicator = !isDiscrete.Value;
+                        showValueIndicator = !isDiscrete;
                         break;
                     case ShowValueIndicator.always:
                         showValueIndicator = true;
 
         public readonly float overlayRadius;
 
-        public override Size getPreferredSize(bool? isEnabled, bool? isDiscrete, TextPainter textPainter = null) {
+        public override Size getPreferredSize(bool isEnabled, bool isDiscrete, TextPainter textPainter = null) {
             return Size.fromRadius(overlayRadius);
         }
 
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
             SliderThemeData sliderTheme = null,
         static readonly _PaddleSliderTrackShapePathPainter _pathPainter = new _PaddleSliderTrackShapePathPainter();
 
         public override Size getPreferredSize(
-            bool? isEnabled,
-            bool? isDiscrete,
+            bool isEnabled,
+            bool isDiscrete,
             TextPainter labelPainter = null) {
             D.assert(labelPainter != null);
             return _pathPainter.getPreferredSize(isEnabled, isDiscrete, labelPainter);
             Offset center,
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
             SliderThemeData sliderTheme = null,
             Offset center,
             Animation<float> activationAnimation = null,
             Animation<float> enableAnimation = null,
-            bool? isDiscrete = null,
+            bool isDiscrete = false,
             bool? isOnTop = null,
             TextPainter labelPainter = null,
             RenderBox parentBox = null,
         const bool _debuggingLabelLocation = false;
 
         public Size getPreferredSize(
-            bool? isEnabled,
-            bool? isDiscrete,
+            bool isEnabled,
+            bool isDiscrete,
             TextPainter labelPainter
         ) {
             D.assert(labelPainter != null);

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

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

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

     public class AssetImage : AssetBundleImageProvider, IEquatable<AssetImage> {
         public AssetImage(string assetName,
             AssetBundle bundle = null) {
+            D.assert(false,() => "AssetImage is currently not supported, you can use FileImage instead");
             D.assert(assetName != null);
             this.assetName = assetName;
             this.bundle = bundle;

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

 using System;
 using System.Collections.Generic;
 using Unity.UIWidgets.animation;
+using Unity.UIWidgets.cupertino;
 using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.gestures;
 using Unity.UIWidgets.painting;
             RenderBox after = null
         ) {
             invokeLayoutCallback<BoxConstraints>((BoxConstraints constraints) => {
-                D.assert(this.constraints == this.constraints);
+                D.assert(constraints == this.constraints);
                 childManager.createChild(index, after: after);
             });
         }
-                D.assert(this.constraints == this.constraints);
+                D.assert(constraints == this.constraints);
                 childManager.removeChild(child);
             });
         }

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

                 constraints.remainingPaintExtent
                 ); 
             geometry = new SliverGeometry(
-                scrollExtent: mainAxisPadding ?? 0.0f+ childLayoutGeometry.scrollExtent, 
+                scrollExtent: (mainAxisPadding ?? 0.0f) + childLayoutGeometry.scrollExtent, 
                 paintExtent: paintExtent, 
                 layoutExtent: Mathf.Min(mainAxisPaddingPaintExtent + childLayoutGeometry.layoutExtent, paintExtent), 
                 cacheExtent: Mathf.Min(mainAxisPaddingCacheExtent + childLayoutGeometry.cacheExtent, constraints.remainingCacheExtent), 

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

         bool _lastOverlapsContent = false;
         public OverScrollHeaderStretchConfiguration stretchConfiguration;
 
-        protected void updateChild(float shrinkOffset, bool overlapsContent) {
+        protected virtual void updateChild(float shrinkOffset, bool overlapsContent) {
         }
 
         public override void markNeedsLayout() {
             }
         }
 
-        FloatingHeaderSnapConfiguration _snapConfiguration;
+        public FloatingHeaderSnapConfiguration _snapConfiguration;
 
         protected virtual float updateGeometry() {
             float stretchOffset = 0.0f;

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

             AxisDirection axisDirection = AxisDirection.down,
             AxisDirection crossAxisDirection = AxisDirection.right,
             ViewportOffset offset = null,
-            float cacheExtent = RenderViewportUtils.defaultCacheExtent,
+            float? cacheExtent = null,
-            D.assert(cacheExtentStyle == CacheExtentStyle.pixel);
+            D.assert(cacheExtent != null || cacheExtentStyle == CacheExtentStyle.pixel);
-            _cacheExtent = cacheExtent;
+            _cacheExtent = cacheExtent ?? RenderViewportUtils.defaultCacheExtent;
             _cacheExtentStyle = cacheExtentStyle;
         }
 

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

             string text = "",
             TextSelection selection = null,
             TextRange composing = null) {
-            this.selection = this.selection ?? TextSelection.collapsed(offset: -1);
+            selection = selection ?? TextSelection.collapsed(offset: -1);
             
             D.assert(text != null);
             this.text = text;

com.unity.uiwidgets/Runtime/widgets/DiagnosticableTree.mixin.gen.cs

-using System;
-using Unity.UIWidgets.ui;
-using UnityEngine;
+
 namespace Unity.UIWidgets.foundation {
     public class DiagnosticableTreeMixinChangeNotifier : ChangeNotifier, DiagnosticableTreeMixin {
         protected DiagnosticableTreeMixinChangeNotifier() {
         }
 
         public virtual void debugFillProperties(DiagnosticPropertiesBuilder properties) { }
-
-
-        
     }
 
 }

com.unity.uiwidgets/Runtime/widgets/DiagnosticableTree.mixin.njk

+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
 namespace Unity.UIWidgets.foundation {
 {% macro DiagnosticableTreeMixin(with) %}
     {% set className = 'DiagnosticableTreeMixin' + with %}

com.unity.uiwidgets/Runtime/widgets/DirectionalFocusTraversalPolicy.mixin.gen.cs

-using System;
-using Unity.UIWidgets.widgets;
+
 namespace Unity.UIWidgets.widgets {
     public class DirectionalFocusTraversalPolicyMixinFocusTraversalPolicy : FocusTraversalPolicy, DirectionalFocusTraversalPolicyMixin {
         protected DirectionalFocusTraversalPolicyMixinFocusTraversalPolicy() {

com.unity.uiwidgets/Runtime/widgets/DirectionalFocusTraversalPolicy.mixin.njk

+using System.Collections.Generic;
+using System.Linq;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.ui;
+
 namespace Unity.UIWidgets.widgets {
 {% macro DirectionalFocusTraversalPolicyMixin(with) %}
     {% set className = 'DirectionalFocusTraversalPolicyMixin' + with %}

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

             TimeSpan? reverseDuration = null,
             TickerProvider vsync = null) : base(key: key, child: child) {
             D.assert(duration != null);
-            D.assert(reverseDuration != null);
             D.assert(vsync != null);
             this.alignment = alignment ?? Alignment.center;
             this.curve = curve ?? Curves.linear;

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

             D.assert(!_candidateAvatars.Contains(avatar));
             D.assert(!_rejectedAvatars.Contains(avatar));
 
-            if (avatar.data is _DragAvatar<T> && (widget.onWillAccept == null || widget.onWillAccept(avatar.data))) {
+            if (avatar is _DragAvatar<T> && (widget.onWillAccept == null || widget.onWillAccept(avatar.data))) {
                 setState(() => { _candidateAvatars.Add(avatar); });
                 return true;
             }

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

                     hasSameSuperclass = oldElementClass == newWidgetClass;
                     return true;
                 });
-                if (hasSameSuperclass && child.widget == newWidget) {
+                if (hasSameSuperclass && Equals(child.widget,newWidget)) {
                     if (!Equals(child.slot, newSlot)) {
                         updateSlotForChild(child, newSlot);
                     }
                     }
 
                     child.update(newWidget);
-                    D.assert(child.widget == newWidget);
+                    D.assert(Equals(child.widget, newWidget));
                     D.assert(() => {
                         child.owner._debugElementWasRebuilt(child);
                         return true;

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

         public static Future<T> pushNamed<T>(BuildContext context, string routeName, object arguments = null) {
             return of(context).pushNamed<T>(routeName, arguments: arguments);
         }
+        
+        public static Future pushNamed(BuildContext context, string routeName, object arguments = null) {
+            return of(context).pushNamed(routeName, arguments: arguments);
+        }
 
         public static Future<T> pushReplacementNamed<T,TO>(BuildContext context, string routeName,
             TO result = default , object arguments = null) {
                 name: name,
                 arguments: arguments
             );
-            Route<T> route = widget.onGenerateRoute(settings) as Route<T>;
+
+            var routeee = widget.onGenerateRoute(settings);
+            Route<T> route = routeee as Route<T>;
             if (route == null && !allowNull) {
                 D.assert(() => {
                     if (widget.onUnknownRoute == null) {
             object arguments = null
         ) {
             return push<T>(_routeNamed<T>(routeName, arguments: arguments));
+        }
+        
+        public Future pushNamed(
+            string routeName,
+            object arguments = null
+        ) {
+            return push(_routeNamed(routeName, arguments: arguments));
         }
 
         public Future<T> pushReplacementNamed<T, TO>(

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

         }
 
         public override bool applyViewportDimension(float viewportDimension) {
-            float oldViewportDimensions = this.viewportDimension;
+            float oldViewportDimensions = 0.0f;
+            if (haveDimensions) {
+                oldViewportDimensions = this.viewportDimension;
+            }
+            
             bool result = base.applyViewportDimension(viewportDimension);
             float? oldPixels = null;
             if (havePixels) {

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

 using Unity.UIWidgets.rendering;
 
 namespace Unity.UIWidgets.widgets {
+    
+    static class sliver_persistent_header_utils {
+       public static _SliverPersistentHeaderElement _element { get; set; }
+    }
+    
     public abstract class SliverPersistentHeaderDelegate {
         public SliverPersistentHeaderDelegate() {
         }
         }
     }
 
-    class _SliverPersistentHeaderElement : RenderObjectElement {
+    public class _SliverPersistentHeaderElement : RenderObjectElement {
         public _SliverPersistentHeaderElement(_SliverPersistentHeaderRenderObjectWidget widget) : base(widget) {
         }
 
 
         public override void mount(Element parent, object newSlot) {
             base.mount(parent, newSlot);
-            (renderObject as _RenderSliverPersistentHeaderForWidgetsMixin)._element = this;
+            sliver_persistent_header_utils._element = this;
-            (renderObject as _RenderSliverPersistentHeaderForWidgetsMixin)._element = null;
+            sliver_persistent_header_utils._element = null;
         }
 
         public override void update(Widget _newWidget) {
         }
     }
 
-    abstract class _SliverPersistentHeaderRenderObjectWidget : RenderObjectWidget {
+    public abstract class _SliverPersistentHeaderRenderObjectWidget : RenderObjectWidget {
         public _SliverPersistentHeaderRenderObjectWidget(
             Key key = null,
             SliverPersistentHeaderDelegate layoutDelegate = null
         }
     }
 
-    interface _RenderSliverPersistentHeaderForWidgetsMixin {
-        // on RenderSliverPersistentHeader  ???? todo 
-        _SliverPersistentHeaderElement _element { get; set; }
+    public interface _RenderSliverPersistentHeaderForWidgetsMixin {
-        float? minExtent {
-            get;
-        }
-
-        float? maxExtent {
-            get;
-        }
-
-        void updateChild(float shrinkOffset, bool overlapsContent);
         void triggerRebuild();
     }
 
     abstract class _RenderSliverScrollingPersistentHeader : RenderSliverScrollingPersistentHeader {
     }
 
-    class _RenderSliverScrollingPersistentHeaderForWidgets : RenderSliverScrollingPersistentHeader, _RenderSliverPersistentHeaderForWidgetsMixin {
-
+    class _RenderSliverScrollingPersistentHeaderForWidgets : _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverScrollingPersistentHeader {
+        
         public _RenderSliverScrollingPersistentHeaderForWidgets(
             RenderBox child = null,
             OverScrollHeaderStretchConfiguration stretchConfiguration = null
     abstract class _RenderSliverPinnedPersistentHeader : RenderSliverPinnedPersistentHeader {
     }
 
-    class _RenderSliverPinnedPersistentHeaderForWidgets : RenderSliverPinnedPersistentHeader,
-        _RenderSliverPersistentHeaderForWidgetsMixin {
+    class _RenderSliverPinnedPersistentHeaderForWidgets : _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverPinnedPersistentHeader {
 
         public _RenderSliverPinnedPersistentHeaderForWidgets(
             RenderBox child = null,
         }
 
         public _SliverPersistentHeaderElement _element {
-            get { return _ele; }
-            set { _ele = value; }
+            get { return sliver_persistent_header_utils._element; }
+            set { sliver_persistent_header_utils._element = value; }
         }
 
         _SliverPersistentHeaderElement _ele;
     abstract class _RenderSliverFloatingPinnedPersistentHeader : RenderSliverFloatingPinnedPersistentHeader {
     }
 
-    class _RenderSliverFloatingPinnedPersistentHeaderForWidgets : RenderSliverFloatingPinnedPersistentHeader,
-        _RenderSliverPersistentHeaderForWidgetsMixin {
+    class _RenderSliverFloatingPinnedPersistentHeaderForWidgets : _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPinnedPersistentHeader {
         public _RenderSliverFloatingPinnedPersistentHeaderForWidgets(
             RenderBox child = null,
             FloatingHeaderSnapConfiguration snapConfiguration = null,
     abstract class _RenderSliverFloatingPersistentHeader : RenderSliverFloatingPersistentHeader {
     }
 
-    class _RenderSliverFloatingPersistentHeaderForWidgets : RenderSliverFloatingPersistentHeader,
-        _RenderSliverPersistentHeaderForWidgetsMixin {
+    class _RenderSliverFloatingPersistentHeaderForWidgets : _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPersistentHeader {
 
         public _RenderSliverFloatingPersistentHeaderForWidgets(
             RenderBox child = null,

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample.meta

+fileFormatVersion: 2
+guid: c0f377c78881e9243879a01b93524d63
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialInkWellSample.cs

+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using Color = Unity.UIWidgets.ui.Color;
+using Material = Unity.UIWidgets.material.Material;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    
+    public class MaterialInkWellSample : UIWidgetsPanel {
+
+        protected override void main() {
+            ui_.runApp(new MaterialApp(
+                showPerformanceOverlay: false,
+                home: new MaterialInkWellWidget()));
+        }
+
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+    
+    public class MaterialInkWellWidget : StatefulWidget {
+        public MaterialInkWellWidget(Key key = null) : base(key) {
+        }
+
+        public override State createState() {
+            return new MaterialInkWidgetState();
+        }
+    }
+
+    public class MaterialInkWidgetState : State<MaterialInkWellWidget> {
+        public override Widget build(BuildContext context) {
+            return new Material(
+                //color: Colors.blue,
+                child: new Center(
+                    child: new Container(
+                        width: 200,
+                        height: 200,
+                        child: new InkWell(
+                            borderRadius: BorderRadius.circular(2.0f),
+                            highlightColor: new Color(0xAAFF0000),
+                            splashColor: new Color(0xAA0000FF),
+                            onTap: () => { Debug.Log("on tap"); }
+                        )
+                    )
+                )
+            );
+        }
+    }
+
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialInkWellSample.cs.meta

+fileFormatVersion: 2
+guid: b9e88c33e9f304d40bab9c27f1276033
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialNavigationBarSample.cs

+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    
+    public class MaterialNavigationBarSample : UIWidgetsPanel {
+
+        protected override void main() {
+            ui_.runApp(new MaterialApp(
+                showPerformanceOverlay: false,
+                home: new MaterialNavigationBarWidget()));
+        }
+
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+    
+    class MaterialNavigationBarWidget : StatefulWidget {
+        public MaterialNavigationBarWidget(Key key = null) : base(key) {
+        }
+
+        public override State createState() {
+            return new MaterialNavigationBarWidgetState();
+        }
+    }
+
+    class MaterialNavigationBarWidgetState : SingleTickerProviderStateMixin<MaterialNavigationBarWidget> {
+        int _currentIndex = 0;
+
+        public MaterialNavigationBarWidgetState() {
+        }
+
+        public override Widget build(BuildContext context) {
+            return new Scaffold(
+                bottomNavigationBar: new Container(
+                    height: 100,
+                    color: Colors.blue,
+                    child: new Center(
+                        child: new BottomNavigationBar(
+                            type: BottomNavigationBarType.shifting,
+                            // type: BottomNavigationBarType.fix,
+                            items: new List<BottomNavigationBarItem> {
+                                new BottomNavigationBarItem(
+                                    icon: new Icon(icon: Unity.UIWidgets.material.Icons.work, size: 30),
+                                    title: new Text("Work"),
+                                    activeIcon: new Icon(icon: Unity.UIWidgets.material.Icons.work, size: 50),
+                                    backgroundColor: Colors.blue
+                                ),
+                                new BottomNavigationBarItem(
+                                    icon: new Icon(icon: Unity.UIWidgets.material.Icons.home, size: 30),
+                                    title: new Text("Home"),
+                                    activeIcon: new Icon(icon: Unity.UIWidgets.material.Icons.home, size: 50),
+                                    backgroundColor: Colors.blue
+                                ),
+                                new BottomNavigationBarItem(
+                                    icon: new Icon(icon: Unity.UIWidgets.material.Icons.shop, size: 30),
+                                    title: new Text("Shop"),
+                                    activeIcon: new Icon(icon: Unity.UIWidgets.material.Icons.shop, size: 50),
+                                    backgroundColor: Colors.blue
+                                ),
+                                new BottomNavigationBarItem(
+                                    icon: new Icon(icon: Unity.UIWidgets.material.Icons.school, size: 30),
+                                    title: new Text("School"),
+                                    activeIcon: new Icon(icon: Unity.UIWidgets.material.Icons.school, size: 50),
+                                    backgroundColor: Colors.blue
+                                ),
+                            },
+                            currentIndex: this._currentIndex,
+                            onTap: (value) => { this.setState(() => { this._currentIndex = value; }); }
+                        )
+                    )
+                )
+            );
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialNavigationBarSample.cs.meta

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+guid: cc34344049d222b468f2487b97076448
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialSliderSample.cs

+using System.Collections.Generic;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    
+    public class MaterialSliderSample : UIWidgetsPanel {
+
+        protected override void main() {
+            ui_.runApp(new MaterialApp(
+                showPerformanceOverlay: false,
+                home: new MaterialSliderWidget()));
+        }
+
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+    
+    public class MaterialSliderWidget : StatefulWidget {
+        public override State createState() {
+            return new MaterialSliderState();
+        }
+    }
+
+    public class MaterialSliderState : State<MaterialSliderWidget> {
+
+        float _value = 0.8f;
+
+        void onChanged(float value) {
+            this.setState(() => { this._value = value; });
+        }
+
+        public override Widget build(BuildContext context) {
+            return new Scaffold(
+                appBar: new AppBar(
+                    title: new Text("Slider and Indicators")),
+                body: new Column(
+                    children: new List<Widget> {
+                        new Padding(
+                            padding: EdgeInsets.only(top: 100.0f),
+                            child: new Container(
+                            child: new Slider(
+                                divisions: 10,
+                                min: 0.4f,
+                                label: "Here",
+                                value: this._value,
+                                onChanged: this.onChanged))
+                            )
+                    }
+                )
+            );
+        }
+    }
+
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialSliderSample.cs.meta

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+  serializedVersion: 2
+  defaultReferences: []
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialTabBarSample.cs

+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    
+    public class MaterialTabBarSample : UIWidgetsPanel {
+
+        protected override void main() {
+            ui_.runApp(new MaterialApp(
+                showPerformanceOverlay: false,
+                home: new TabBarDemo()));
+        }
+
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+
+    public class TabBarDemo : StatelessWidget
+    {
+        public override Widget build(BuildContext context)
+        {
+
+            return new MaterialTabBarWidget();
+            /*
+            return new DefaultTabController(
+                    length: 3,
+                    child: new Scaffold(
+                        appBar: new AppBar(
+                            bottom: new TabBar(
+                                tabs: new List<Widget> {
+                                new Tab(icon: new Icon(Icons.directions_car)),
+                                new Tab(icon: new Icon(Icons.directions_transit)),
+                                new Tab(icon: new Icon(Icons.directions_bike)),
+                            }
+                        ),
+                        title: new Text("Tabs Demo")
+                    ),
+                    body: new TabBarView(
+                        children: new List<Widget> {
+                            new Icon(Icons.directions_car),
+                            new Icon(Icons.directions_transit),
+                            new Icon(Icons.directions_bike),
+                    }
+                    )
+                )
+                );*/
+        }
+    }
+    
+    public class MaterialTabBarWidget : StatefulWidget {
+        public MaterialTabBarWidget(Key key = null) : base(key) {
+        }
+
+        public override State createState() {
+            return new MaterialTabBarWidgetState();
+        }
+    }
+    
+    public class MaterialTabBarWidgetState : SingleTickerProviderStateMixin<MaterialTabBarWidget> {
+        TabController _tabController;
+
+        public override void initState() {
+            base.initState();
+            this._tabController = new TabController(vsync: this, length: Choice.choices.Count);
+        }
+
+        public override void dispose() {
+            this._tabController.dispose();
+            base.dispose();
+        }
+
+        void _nextPage(int delta) {
+            int newIndex = this._tabController.index + delta;
+            if (newIndex < 0 || newIndex >= this._tabController.length) {
+                return;
+            }
+
+            this._tabController.animateTo(newIndex);
+        }
+
+        public override Widget build(BuildContext context) {
+            List<Widget> tapChildren = new List<Widget>();
+            foreach (Choice choice in Choice.choices) {
+                tapChildren.Add(
+                    new Padding(
+                        padding: EdgeInsets.all(16.0f),
+                        child: new ChoiceCard(choice: choice)));
+            }
+
+            return new Scaffold(
+                appBar: new AppBar(
+                    title: new Center(
+                        child: new Text("AppBar Bottom Widget")
+                    ),
+                    leading: new IconButton(
+                        tooltip: "Previous choice",
+                        icon: new Icon(Unity.UIWidgets.material.Icons.arrow_back),
+                        onPressed: () => { this._nextPage(-1); }
+                    ),
+                    actions: new List<Widget> {
+                        new IconButton(
+                            icon: new Icon(Unity.UIWidgets.material.Icons.arrow_forward),
+                            tooltip: "Next choice",
+                            onPressed: () => { this._nextPage(1); })
+                    },
+                    bottom: new PreferredSize(
+                        preferredSize: Size.fromHeight(48.0f),
+                        child: new Theme(
+                            data: Theme.of(context).copyWith(accentColor: Colors.white),
+                            child: new Container(
+                                height: 48.0f,
+                                alignment: Alignment.center,
+                                child: new TabPageSelector(
+                                    controller: this._tabController))))
+                ),
+                body: new TabBarView(
+                    controller: this._tabController,
+                    children: tapChildren
+                ));
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialTabBarSample.cs.meta

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+guid: fecd06f805d0b0f4ead134b1ad6a9a49
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialThemeSample.cs

+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.animation;
+using Unity.UIWidgets.engine;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.service;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using Image = Unity.UIWidgets.widgets.Image;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class MaterialThemeSample: UIWidgetsPanel {
+        
+        protected override void main()  {
+            ui_.runApp(new MaterialApp(
+                home: new MaterialThemeSampleWidget(),
+                darkTheme: new ThemeData(primaryColor: Colors.black26)
+            ));
+        }
+        
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+
+    public class MaterialThemeSampleWidget: StatefulWidget {
+        public override State createState() {
+            return new _MaterialThemeSampleWidgetState();
+        }
+    }
+
+    class _MaterialThemeSampleWidgetState : State<MaterialThemeSampleWidget> {
+        public override Widget build(BuildContext context) {
+            return new Theme(
+                data: new ThemeData(
+                    appBarTheme: new AppBarTheme(
+                        color: Colors.purple
+                    ),
+                    bottomAppBarTheme: new BottomAppBarTheme(
+                        color: Colors.blue
+                    ),
+                    cardTheme: new CardTheme(
+                        color: Colors.red,
+                        elevation: 2.0f
+                    )
+                ),
+                child: new Scaffold(
+                    appBar: new AppBar(title: new Text("Test App Bar Theme")),
+                    body: new Center(
+                        child: new Card(
+                            shape: new RoundedRectangleBorder(
+                                borderRadius: BorderRadius.all(5.0f)
+                            ),
+                            child: new Container(
+                                height: 250,
+                                child: new Column(
+                                    children: new List<Widget> {
+                                        new Text("Card Theme")
+                                    }
+                                )
+                            )
+                        )
+                    ),
+                    bottomNavigationBar: new BottomAppBar(
+                        child: new Row(
+                        mainAxisSize: MainAxisSize.max,
+                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                        children: new List<Widget> {
+                            new IconButton(icon: new Icon(Unity.UIWidgets.material.Icons.menu), onPressed: () => { }),
+                            new IconButton(icon: new Icon(Unity.UIWidgets.material.Icons.account_balance), onPressed: () => { })
+                        })
+                    )
+                )
+            );
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/MaterialThemeSample.cs.meta

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+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/ReorderableListSample.cs

+using System.Collections.Generic;
+using System.Linq;
+using uiwidgets;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using Color = Unity.UIWidgets.ui.Color;
+using Material = Unity.UIWidgets.material.Material;
+using TextStyle = Unity.UIWidgets.painting.TextStyle;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class ReorderableListSample : UIWidgetsPanel {
+        protected override void main() {
+            ui_.runApp(new MaterialApp(
+                showPerformanceOverlay: false,
+                home: new MaterialReorderableListViewWidget()));
+        }
+
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+
+    class MaterialReorderableListViewWidget : StatefulWidget {
+        public MaterialReorderableListViewWidget(Key key = null) : base(key) {
+        }
+
+        public override State createState() {
+            return new MaterialReorderableListViewWidgetState();
+        }
+    }
+
+    class MaterialReorderableListViewWidgetState : State<MaterialReorderableListViewWidget> {
+        List<string> _list = new List<string> {"Apple", "Ball", "Cat", "Dog", "Elephant"};
+
+        public override Widget build(BuildContext context) {
+            return new Scaffold(
+                body: new ReorderableListView(
+                    children: this._list.Select<string, Widget>((item) =>
+                    {
+                        return new ListTile(
+                            Key.key(item),
+                            title: new Text(item),
+                            trailing: new Icon(Icons.menu));
+                    }).ToList(),
+                    onReorder: (int start, int current) =>
+                    {
+                        if (start < current) {
+                            int end = current - 1;
+                            string startItem = _list[start];
+                            int i = 0;
+                            int local = start;
+                            do {
+                                _list[local] = _list[++local];
+                                i++;
+                            } while (i < end - start);
+                            _list[end] = startItem;
+                        }
+                        // dragging from bottom to top
+                        else if (start > current) {
+                            string startItem = _list[start];
+                            for (int i = start; i > current; i--) {
+                                _list[i] = _list[i - 1];
+                            }
+                            _list[current] = startItem;
+                        }
+                        setState(() => {});
+                    }
+                    )
+            );
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/ReorderableListSample.cs.meta

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+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/TableSample.cs

+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using Color = Unity.UIWidgets.ui.Color;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    
+    public class TableSample : UIWidgetsPanel {
+
+        protected override void main() {
+            ui_.runApp(new MaterialApp(
+                showPerformanceOverlay: false,
+                home: new TableWidget()));
+        }
+
+        protected new void OnEnable() {
+            base.OnEnable();
+        }
+    }
+    
+    public class TableWidget : StatelessWidget {
+        public TableWidget(Key key = null) : base(key) {
+        }
+
+        public override Widget build(BuildContext context) {
+            return new Scaffold(
+                body: new Table(
+                    children: new List<TableRow> {
+                        new TableRow(
+                            decoration: new BoxDecoration(color: Colors.blue),
+                            children: new List<Widget> {
+                                new Text("item 1"),
+                                new Text("item 2")
+                            }
+                        ),
+                        new TableRow(children: new List<Widget> {
+                                new Text("item 3"),
+                                new Text("item 4")
+                            }
+                        )
+                    },
+                    defaultVerticalAlignment: TableCellVerticalAlignment.middle));
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/TableSample.cs.meta

+fileFormatVersion: 2
+guid: 1cba65c03fbf50f4cac974273a7c9445
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
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+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample.meta

+fileFormatVersion: 2
+guid: 00ea9ee5829c47a687a61fb521f91107
+timeCreated: 1612237197

com.unity.uiwidgets/Runtime/widgets/sliver_persistent_header.mixin.gen.cs

+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.rendering;
+
+namespace Unity.UIWidgets.widgets {
+
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPersistentHeader : RenderSliverFloatingPersistentHeader, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPersistentHeader(
+            RenderBox child = null,
+            FloatingHeaderSnapConfiguration snapConfiguration = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(
+            child: child,
+            stretchConfiguration: stretchConfiguration) {
+            _snapConfiguration = snapConfiguration;
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+
+
+
+
+
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPinnedPersistentHeader : RenderSliverFloatingPinnedPersistentHeader, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPinnedPersistentHeader(
+            RenderBox child = null,
+            FloatingHeaderSnapConfiguration snapConfiguration = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(child: child,
+            snapConfiguration: snapConfiguration,
+            stretchConfiguration: stretchConfiguration) {
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+
+
+
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverPinnedPersistentHeader : RenderSliverPinnedPersistentHeader, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverPinnedPersistentHeader(
+            RenderBox child = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(child: child,
+            stretchConfiguration: stretchConfiguration) {
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+
+
+
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverScrollingPersistentHeader : RenderSliverScrollingPersistentHeader, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverScrollingPersistentHeader(
+            RenderBox child = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(child: child,
+            stretchConfiguration: stretchConfiguration) {
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+
+
+}

com.unity.uiwidgets/Runtime/widgets/sliver_persistent_header.mixin.njk

+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.rendering;
+
+namespace Unity.UIWidgets.widgets {
+{% macro _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader(with) %}
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader{{with}} : {{with}}, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPersistentHeader(
+            RenderBox child = null,
+            FloatingHeaderSnapConfiguration snapConfiguration = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(
+            child: child,
+            stretchConfiguration: stretchConfiguration) {
+            _snapConfiguration = snapConfiguration;
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+{% endmacro %}
+
+{{ _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader('RenderSliverFloatingPersistentHeader') }}
+
+{% macro _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader(with) %}
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader{{with}} : {{with}}, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverFloatingPinnedPersistentHeader(
+            RenderBox child = null,
+            FloatingHeaderSnapConfiguration snapConfiguration = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(child: child,
+            snapConfiguration: snapConfiguration,
+            stretchConfiguration: stretchConfiguration) {
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+{% endmacro %}
+
+
+
+{{ _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader('RenderSliverFloatingPinnedPersistentHeader') }}
+
+{% macro _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader(with) %}
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader{{with}} : {{with}}, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverPinnedPersistentHeader(
+            RenderBox child = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(child: child,
+            stretchConfiguration: stretchConfiguration) {
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+{% endmacro %}
+
+{{ _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader('RenderSliverPinnedPersistentHeader') }}
+
+{% macro _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader(with) %}
+    public abstract class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader{{with}} : {{with}}, _RenderSliverPersistentHeaderForWidgetsMixin {
+         
+        public _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeaderRenderSliverScrollingPersistentHeader(
+            RenderBox child = null,
+            OverScrollHeaderStretchConfiguration stretchConfiguration = null
+        ) : base(child: child,
+            stretchConfiguration: stretchConfiguration) {
+        }
+
+         public _SliverPersistentHeaderElement _element {
+             get {
+                 return sliver_persistent_header_utils._element;
+             }
+             set {
+                 if (value == sliver_persistent_header_utils._element) {
+                     return;
+                 }
+ 
+                 sliver_persistent_header_utils._element = value;
+             }
+             
+         }
+         
+         public override float? minExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         public override float? maxExtent {
+             get {
+                 return _element.widget.layoutDelegate.minExtent;
+             }
+         }
+ 
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
+             D.assert(_element != null);
+             _element._build(shrinkOffset, overlapsContent);
+         }
+ 
+        void _RenderSliverPersistentHeaderForWidgetsMixin.triggerRebuild() {
+            triggerRebuild();
+        }
+        
+        void triggerRebuild() {
+            markNeedsLayout();
+        }
+        
+        protected override void performLayout() {
+            base.performLayout();
+        }
+    }
+{% endmacro %}
+
+{{ _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader('RenderSliverScrollingPersistentHeader') }}
+
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/DragDropSample.cs

+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class DragDropSample : UIWidgetsPanel {
+        protected override void main() {
+            ui_.runApp(new MyApp());
+        }
+        
+        class MyApp : StatelessWidget
+        {
+            public override Widget build(BuildContext context)
+            {
+                return new WidgetsApp(
+                    home: new DragDropApp(),
+                    pageRouteBuilder: (settings, builder) =>
+                        new PageRouteBuilder(
+                            settings: settings,
+                            pageBuilder: (Buildcontext, animation, secondaryAnimation) => builder(context)
+                        )
+                );
+            }
+        }
+
+        class DragDropApp : StatefulWidget {
+            public DragDropApp(Key key = null) : base(key) {
+            }
+
+            public override State createState() {
+                return new DragDropState();
+            }
+        }
+
+        class DragTargetWidget : StatefulWidget {
+            public DragTargetWidget(Key key = null) : base(key) {
+            }
+
+            public override State createState() {
+                return new DragTargetWidgetState();
+            }
+        }
+
+        class DragTargetWidgetState : State<DragTargetWidget> {
+            int value;
+
+            public override Widget build(BuildContext context)
+            {
+                return new Positioned(
+                    left: 40.0f,
+                    bottom: 40.0f,
+                    child: new DragTarget<int>(
+                        onWillAccept: (o) => true,
+                        onAccept: obj => {
+                            Debug.Log("ON ACCEPTED ..." + obj);
+                            this.setState(() => { this.value += obj; });
+                        },
+                        builder: (inner_context2, accepted, rejected) => {
+                            return new Container(
+                                width: 40.0f,
+                                height: 40.0f,
+                                constraints: BoxConstraints.tight(new Size(40, 40)),
+                                color: Colors.red,
+                                child: new Center(child: new Text("" + this.value))
+                            );
+                        }
+                    )
+                );
+            }
+        }
+
+        class DragDropState : State<DragDropApp> {
+            public override Widget build(BuildContext context) {
+                var entries = new List<OverlayEntry>();
+
+                var entry_bg = new OverlayEntry(
+                    inner_context => new Container(
+                        color: Colors.white
+                    ));
+
+                var entry = new OverlayEntry(
+                    inner_context => new Positioned(
+                        left: 0.0f,
+                        bottom: 0.0f,
+                        child: new GestureDetector(
+                            onTap: () => { },
+                            child: new Draggable<int>(
+                                data: 5,
+                                child: new Container(
+                                    color: Colors.blue,
+                                    width: 30.0f,
+                                    height: 30.0f,
+                                    constraints: BoxConstraints.tight(new Size(30, 30)),
+                                    child: new Center(child: new Text("5"))
+                                ),
+                                feedback: new Container(
+                                    color: Colors.green,
+                                    width: 30.0f,
+                                    height: 30.0f),
+                                //maxSimultaneousDrags: 1,
+                                childWhenDragging: new Container(
+                                    color: Colors.black,
+                                    width: 30.0f,
+                                    height: 30.0f,
+                                    constraints: BoxConstraints.tight(new Size(30, 30))
+                                )
+                            )
+                        )
+                    )
+                );
+
+                var entry3 = new OverlayEntry(
+                    inner_context => new Positioned(
+                        left: 0.0f,
+                        bottom: 40.0f,
+                        child: new GestureDetector(
+                            onTap: () => { },
+                            child:
+                            new Draggable<int>(
+                                data: 8,
+                                child: new Container(
+                                    color: Colors.grey,
+                                    width: 30.0f,
+                                    height: 30.0f,
+                                    constraints: BoxConstraints.tight(new Size(30, 30)),
+                                    child: new Center(child: new Text("8")))
+                                ,
+                                feedback: new Container(
+                                    color: Colors.green,
+                                    width: 30.0f,
+                                    height: 30.0f),
+                                maxSimultaneousDrags: 1,
+                                childWhenDragging: new Container(
+                                    color: Colors.black,
+                                    width: 30.0f,
+                                    height: 30.0f,
+                                    constraints: BoxConstraints.tight(new Size(30, 30))
+                                )
+                            )
+                        )
+                    )
+                );
+
+                var entry2 = new OverlayEntry(
+                    inner_context => new DragTargetWidget()
+                );
+
+                entries.Add(entry_bg);
+                entries.Add(entry);
+                entries.Add(entry2);
+                entries.Add(entry3);
+
+                return new Container(
+                    color: Colors.white,
+                    child: new Overlay(
+                        initialEntries: entries
+                    )
+                );
+            }
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/DragDropSample.cs.meta

+fileFormatVersion: 2
+guid: f6b796615f43b734d8c9507513773ff3
+MonoImporter:
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+  serializedVersion: 2
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+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/LongPressSample.cs

+using uiwidgets;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+
+namespace UIWidgetsSample {
+    public class LongPressSample : UIWidgetsPanel {
+        protected override void main() {
+            ui_.runApp(new MyApp());
+        }
+    }
+    
+    class MyApp : StatelessWidget
+    {
+        public override Widget build(BuildContext context)
+        {
+            return new WidgetsApp(
+                home: new LongPressSampleWidget(),
+                pageRouteBuilder: (settings, builder) =>
+                    new PageRouteBuilder(
+                        settings: settings,
+                        pageBuilder: (Buildcontext, animation, secondaryAnimation) => builder(context)
+                    )
+            );
+        }
+    }
+
+    public class LongPressSampleWidget : StatefulWidget {
+        public override State createState() {
+            return new _LongPressSampleWidgetState();
+        }
+    }
+
+    class _LongPressSampleWidgetState : State<LongPressSampleWidget> {
+        public override Widget build(BuildContext context) {
+            return new GestureDetector(
+                onLongPressStart: (value) => { Debug.Log($"Long Press Drag Start: {value}"); },
+                onLongPressMoveUpdate: (value) => { Debug.Log($"Long Press Drag Update: {value}"); },
+                onLongPressEnd: (value) => { Debug.Log($"Long Press Drag Up: {value}"); },
+                onLongPressUp: () => { Debug.Log($"Long Press Up"); },
+                onLongPress: () => { Debug.Log($"Long Press"); },
+                child: new Center(
+                    child: new Container(
+                        width: 200,
+                        height: 200,
+                        color: Colors.blue
+                    )
+                )
+            );
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/LongPressSample.cs.meta

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+guid: b77689aad2545fb4bb66d5d41126fab2
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+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/NavigationSample.cs

+using System;
+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.animation;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.gestures;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using DialogUtils = Unity.UIWidgets.widgets.DialogUtils;
+using TextStyle = Unity.UIWidgets.painting.TextStyle;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class NavigationSample : UIWidgetsPanel {
+
+        protected override void main()
+        {
+            ui_.runApp(new MyApp());
+        }
+        
+        
+        
+            
+        class MyApp : StatelessWidget
+        {
+            public override Widget build(BuildContext context)
+            {
+                return new WidgetsApp(
+                    initialRoute: "/",
+                    textStyle: new TextStyle(fontSize: 24),
+                    pageRouteBuilder: (settings, builder) =>
+                        new PageRouteBuilder(
+                            settings: settings,
+                            pageBuilder: (BuildContext subContext, Animation<float> animation,
+                                Animation<float> secondaryAnimation) => builder(subContext),
+                            transitionsBuilder: (BuildContext subContext, Animation<float>
+                                    animation, Animation<float> secondaryAnimation, Widget child) =>
+                                new _FadeUpwardsPageTransition(
+                                    routeAnimation: animation,
+                                    child: child
+                                )
+                        ),
+                    routes: new Dictionary<string, WidgetBuilder> {
+                        {"/", (subContext) => new HomeScreen()},
+                        {"/detail", (subContext) => new DetailScreen()}
+                    }
+                );
+            }
+        }
+    }
+    
+    public class CustomButton : StatelessWidget {
+        public CustomButton(
+            Key key = null,
+            GestureTapCallback onPressed = null,
+            EdgeInsets padding = null,
+            Color backgroundColor = null,
+            Widget child = null
+        ) : base(key: key) {
+            this.onPressed = onPressed;
+            this.padding = padding ?? EdgeInsets.all(8.0f);
+            this.backgroundColor = backgroundColor ?? Colors.white;
+            this.child = child;
+        }
+
+        public readonly GestureTapCallback onPressed;
+        public readonly EdgeInsets padding;
+        public readonly Widget child;
+        public readonly Color backgroundColor;
+
+        public override Widget build(BuildContext context) {
+            return new GestureDetector(
+                onTap: this.onPressed,
+                child: new Container(
+                    padding: this.padding,
+                    color: this.backgroundColor,
+                    child: this.child
+                )
+            );
+        }
+    }
+
+
+    class HomeScreen : StatelessWidget {
+        public override Widget build(BuildContext context) {
+            return new NavigationPage(
+                body: new Container(
+                    color: new Color(0xFF888888),
+                    child: new Center(
+                        child: new CustomButton(onPressed: () => { Navigator.pushNamed(context, "/detail"); },
+                            child: new Text("Go to Detail"))
+                    )),
+                title: "Home"
+            );
+        }
+    }
+
+    class DetailScreen : StatelessWidget {
+        public override Widget build(BuildContext context) {
+            return new NavigationPage(
+                body: new Container(
+                    color: new Color(0xFF1389FD),
+                    child: new Center(
+                        child: new Column(
+                            children: new List<Widget>() {
+                                new CustomButton(onPressed: () => { Navigator.pop<object>(context); }, child: new Text("Back")),
+                                new CustomButton(
+                                    onPressed: () => {
+                                        _Dialog.showDialog(context, builder: (BuildContext c) => new Dialog());
+                                    }, child: new Text("Show Dialog"))
+                            }
+                        )
+                    )),
+                title: "Detail");
+        }
+    }
+
+    class Dialog : StatelessWidget {
+        public override Widget build(BuildContext context) {
+            return new Center(child: new Container(
+                color: new Color(0xFFFF0000),
+                width: 100,
+                height: 80,
+                child: new Center(
+                    child: new Text("Hello Dialog")
+                )));
+        }
+    }
+
+    class _FadeUpwardsPageTransition : StatelessWidget {
+        internal _FadeUpwardsPageTransition(
+            Key key = null,
+            Animation<float> routeAnimation = null, // The route's linear 0.0 - 1.0 animation.
+            Widget child = null
+        ) : base(key: key) {
+            this._positionAnimation = _bottomUpTween.chain(_fastOutSlowInTween).animate(routeAnimation);
+            this._opacityAnimation = _easeInTween.animate(routeAnimation);
+            this.child = child;
+        }
+
+        static Tween<Offset> _bottomUpTween = new OffsetTween(
+            begin: new Offset(0.0f, 0.25f),
+            end: Offset.zero
+        );
+
+        static Animatable<float> _fastOutSlowInTween = new CurveTween(curve: Curves.fastOutSlowIn);
+        static Animatable<float> _easeInTween = new CurveTween(curve: Curves.easeIn);
+
+        readonly Animation<Offset> _positionAnimation;
+        readonly Animation<float> _opacityAnimation;
+        public readonly Widget child;
+
+        public override Widget build(BuildContext context) {
+            return new SlideTransition(
+                position: this._positionAnimation,
+                child: new FadeTransition(
+                    opacity: this._opacityAnimation,
+                    child: this.child
+                )
+            );
+        }
+    }
+
+    class NavigationPage : StatelessWidget {
+        public readonly Widget body;
+        public readonly string title;
+
+        public NavigationPage(Widget body = null, string title = null) {
+            this.title = title;
+            this.body = body;
+        }
+
+        public override Widget build(BuildContext context) {
+            Widget back = null;
+            if (Navigator.of(context).canPop()) {
+                back = new CustomButton(onPressed: () => { Navigator.pop<object>(context); },
+                    child: new Text("Go Back"));
+                back = new Column(mainAxisAlignment: MainAxisAlignment.center, children: new List<Widget>() {back});
+            }
+
+
+            return new Container(
+                child: new Column(
+                    children: new List<Widget>() {
+                        new ConstrainedBox(constraints: new BoxConstraints(maxHeight: 80),
+                            child: new DecoratedBox(
+                                decoration: new BoxDecoration(color: new Color(0XFFE1ECF4)),
+                                child: new NavigationToolbar(leading: back,
+                                    middle: new Text(this.title, textAlign: TextAlign.center)))),
+                        new Flexible(child: this.body)
+                    }
+                )
+            );
+        }
+    }
+
+    static class _Dialog {
+        public static void showDialog(BuildContext context,
+            bool barrierDismissible = true, WidgetBuilder builder = null) {
+            DialogUtils.showGeneralDialog<object>(
+                context: context,
+                pageBuilder: (BuildContext buildContext, Animation<float> animation,
+                    Animation<float> secondaryAnimation) => {
+                    return builder(buildContext);
+                },
+                barrierDismissible: barrierDismissible,
+                barrierColor: new Color(0x8A000000),
+                transitionDuration: TimeSpan.FromMilliseconds(150),
+                transitionBuilder: _buildMaterialDialogTransitions
+            );
+        }
+
+        static Widget _buildMaterialDialogTransitions(BuildContext context,
+            Animation<float> animation, Animation<float> secondaryAnimation, Widget child) {
+            return new FadeTransition(
+                opacity: new CurvedAnimation(
+                    parent: animation,
+                    curve: Curves.easeOut
+                ),
+                child: child
+            );
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/NavigationSample.cs.meta

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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/PageViewSample.cs

+using System.Collections.Generic;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class PageViewSample : UIWidgetsPanel {
+            
+        protected override void main()
+        {
+            ui_.runApp(new MyApp());
+        }
+        
+        class MyApp : StatelessWidget
+        {
+            public override Widget build(BuildContext context)
+            {
+                return new WidgetsApp(
+                    home: new Container(
+                        width: 200,
+                        height: 400,
+                        child: new PageView(
+                            children: new List<Widget>() {
+                                new Container(
+                                    color: new Color(0xFFE91E63)
+                                ),
+                                new Container(
+                                    color: new Color(0xFF00BCD4)
+                                ),
+                                new Container(
+                                    color: new Color(0xFF673AB7)
+                                )
+                            }
+                        )),
+                    pageRouteBuilder: (settings, builder) =>
+                        new PageRouteBuilder(
+                            settings: settings,
+                            pageBuilder: (Buildcontext, animation, secondaryAnimation) => builder(context)
+                        )
+                );
+            }
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/PageViewSample.cs.meta

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+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/ScrollbarSample.cs

+using System.Collections.Generic;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class ScrollbarSample : UIWidgetsPanel {
+        protected override void main()
+        {
+            ui_.runApp(new MyApp());
+        }
+        
+        class MyApp : StatelessWidget
+        {
+            public override Widget build(BuildContext context)
+            {
+                return new WidgetsApp(
+                    home: new Container(
+                        decoration: new BoxDecoration(
+                            border: Border.all(color: new Color(0xFFFFFF00))
+                        ),
+                        child: new Scrollbar(
+                            child: new ListView(
+                                children: new List<Widget> {
+                                    new Container(height: 40.0f, child: new Text("0")),
+                                    new Container(height: 40.0f, child: new Text("1")),
+                                    new Container(height: 40.0f, child: new Text("2")),
+                                    new Container(height: 40.0f, child: new Text("3")),
+                                    new Container(height: 40.0f, child: new Text("4")),
+                                    new Container(height: 40.0f, child: new Text("5")),
+                                    new Container(height: 40.0f, child: new Text("6")),
+                                    new Container(height: 40.0f, child: new Text("7")),
+                                    new Container(height: 40.0f, child: new Text("8")),
+                                    new Container(height: 40.0f, child: new Text("9")),
+                                    new Container(height: 40.0f, child: new Text("10")),
+                                    new Container(height: 40.0f, child: new Text("11")),
+                                    new Container(height: 40.0f, child: new Text("12")),
+                                    new Container(height: 40.0f, child: new Text("13")),
+                                    new Container(height: 40.0f, child: new Text("14")),
+                                    new Container(height: 40.0f, child: new Text("15")),
+                                    new Container(height: 40.0f, child: new Text("16")),
+                                    new Container(height: 40.0f, child: new Text("17")),
+                                }
+                            )
+                        )
+                    ),
+                    pageRouteBuilder: (settings, builder) =>
+                        new PageRouteBuilder(
+                            settings: settings,
+                            pageBuilder: (Buildcontext, animation, secondaryAnimation) => builder(context)
+                        )
+                );
+            }
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/ScrollbarSample.cs.meta

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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/CustomPaintSample.cs

+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class CustomPaintSample : UIWidgetsPanel {
+        protected override void main()
+        {
+            ui_.runApp(new MyApp());
+        }
+        
+        class MyApp : StatelessWidget
+        {
+            public override Widget build(BuildContext context)
+            {
+                return new WidgetsApp(
+                    home: new Unity.UIWidgets.widgets.CustomPaint(
+                        child: new Container(width: 300, height: 300, color: new Color(0XFFFFFFFF)),
+                        foregroundPainter: new GridPainter(null)
+                    ),
+                    pageRouteBuilder: (settings, builder) =>
+                        new PageRouteBuilder(
+                            settings: settings,
+                            pageBuilder: (Buildcontext, animation, secondaryAnimation) => builder(context)
+                        )
+                );
+            }
+        }
+
+    }
+    
+    
+    public class GridPainter : AbstractCustomPainter {
+        public GridPainter(Listenable repaint) : base(repaint) {
+        }
+
+        public override void paint(Canvas canvas, Size size) {
+            int numGrid = 4;
+            var paint = new Paint();
+            paint.color = new Color(0xFFFF0000);
+            paint.strokeWidth = 2;
+            paint.style = PaintingStyle.stroke;
+            for (int i = 1; i < numGrid; i++) {
+                float offsetY = size.height * i / numGrid;
+                canvas.drawLine(new Offset(0, offsetY), new Offset(size.width, offsetY),
+                    paint);
+            }
+
+            for (int i = 1; i < numGrid; i++) {
+                float offsetx = size.width * i / numGrid;
+                canvas.drawLine(new Offset(offsetx, 0), new Offset(offsetx, size.height),
+                    paint);
+            }
+
+
+            // draw a arrow line
+            canvas.save();
+            canvas.rotate(0.4f);
+            canvas.scale(2, 2);
+            canvas.translate(50, 50);
+            canvas.drawLine(new Offset(0, 0), new Offset(100, 0),
+                new Paint() {
+                    color = new Color(0xFFFF0000),
+                    strokeWidth = 2,
+                    style = PaintingStyle.stroke
+                });
+            var path = new Path();
+            var arrowPaint = new Paint() {
+                color = new Color(0xFFFF0000),
+                style = PaintingStyle.fill
+            };
+            path.moveTo(100, 0);
+            path.lineTo(100, 5);
+            path.lineTo(120, 0);
+            path.lineTo(100, -5);
+            path.close();
+            canvas.drawPath(path, arrowPaint);
+            canvas.restore();
+        }
+
+        public override bool shouldRepaint(CustomPainter oldDelegate) {
+            return false;
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/CustomPaintSample.cs.meta

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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/ExpansionPanelSample.cs

+using System.Collections.Generic;
+using uiwidgets;
+using Unity.UIWidgets.engine;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using Material = Unity.UIWidgets.material.Material;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+namespace UIWidgetsSample {
+    public class ExpansionPanelSample : UIWidgetsPanel {
+        
+        protected override void main()  {
+            ui_.runApp(new MyApp());
+        }
+        
+        class MyApp : StatelessWidget
+        {
+            int testCaseId = 1;
+
+            readonly List<Widget> testCases = new List<Widget> {
+                new SingleChildScrollWidget(),
+                new ExpansionPanelWidget()
+            };
+
+            public override Widget build(BuildContext context)
+            {
+                return new MaterialApp(
+                    home: this.testCases[this.testCaseId]
+                );
+            }
+        }
+    }
+    
+    
+
+
+    class SingleChildScrollWidget : StatefulWidget {
+        public SingleChildScrollWidget(Key key = null) : base(key) {
+        }
+
+        public override State createState() {
+            return new SingleChildScrollWidgetState();
+        }
+    }
+
+    class SingleChildScrollWidgetState : State<SingleChildScrollWidget> {
+        public override Widget build(BuildContext context) {
+            return new Material(
+                child: new SingleChildScrollView(
+                    child: new Container(
+                        width: 40.0f,
+                        height: 40.0f,
+                        constraints: BoxConstraints.tight(new Size(40, 600)),
+                        color:Colors.red,
+                        child: new Center(child: new Text("Beijing"))
+                    )
+                )
+            );
+        }
+    }
+
+
+    class ExpansionPanelWidget : StatefulWidget {
+        public ExpansionPanelWidget(Key key = null) : base(key) {
+        }
+
+        public override State createState() {
+            return new ExpansionPanelWidgetState();
+        }
+    }
+
+    class ExpansionPanelWidgetState : State<ExpansionPanelWidget> {
+        readonly List<bool> isExpand = new List<bool> {false, false};
+
+        public override Widget build(BuildContext context) {
+            return new Material(
+                child: new SingleChildScrollView(
+                    child: new ExpansionPanelList(
+                        expansionCallback: (int _index, bool _isExpanded) => {
+                            Debug.Log("<tile " + _index + "> from [" + (_isExpanded ? "Open" : "Close") + "]" +
+                                      " to [" + (_isExpanded ? "Close" : "Open") + "]");
+
+                            this.isExpand[_index] = !_isExpanded;
+                            this.setState(() => { });
+                        },
+                        children: new List<ExpansionPanel> {
+                            new ExpansionPanel(
+                                headerBuilder: (BuildContext subContext, bool isExpanded) => {
+                                    return new Container(
+                                        color: Colors.black45,
+                                        child: new Center(
+                                            child: new Text("Beijing")
+                                        )
+                                    );
+                                },
+                                body: new Container(
+                                    child: new Column(
+                                        children: new List<Widget> {
+                                            new Card(
+                                                child: new Container(
+                                                    color: Colors.black38,
+                                                    height: 36,
+                                                    width: 300,
+                                                    child: new Center(
+                                                        child: new Text("Beijing")
+                                                    )
+                                                )
+                                            )
+                                        }
+                                    )
+                                ),
+                                isExpanded: this.isExpand[0]
+                            ),
+                            new ExpansionPanel(
+                                headerBuilder: (BuildContext subContext, bool isExpanded) => {
+                                    return new Container(
+                                        color: Colors.black45,
+                                        child: new Center(
+                                            child: new Text("Hebei")
+                                        )
+                                    );
+                                },
+                                body: new Container(
+                                    child: new Column(
+                                        children: new List<Widget> {
+                                            new Card(
+                                                child: new Container(
+                                                    color: Colors.black38,
+                                                    height: 36,
+                                                    width: 300,
+                                                    child: new Center(
+                                                        child: new Text("Tianjin")
+                                                    )
+                                                )
+                                            ),
+                                            new Card(
+                                                child: new Container(
+                                                    color: Colors.black38,
+                                                    height: 36,
+                                                    width: 300,
+                                                    child: new Center(
+                                                        child: new Text("Shijiazhuang")
+                                                    )
+                                                )
+                                            ),
+                                            new Card(
+                                                child: new Container(
+                                                    color: Colors.black38,
+                                                    height: 36,
+                                                    width: 300,
+                                                    child: new Center(
+                                                        child: new Text("Zhumadian")
+                                                    )
+                                                )
+                                            )
+                                        }
+                                    )
+                                ),
+                                isExpanded: this.isExpand[1]
+                            ),
+                        }
+                    )
+                )
+            );
+        }
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/ExpansionPanelSample.cs.meta

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+  assetBundleName: 
+  assetBundleVariant: 

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/HttpRequestSample.cs

+using System;
+using System.Collections.Generic;
+using Unity.UIWidgets.engine;
+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.material;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using UnityEngine.Networking;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+
+public class HttpRequestSample : UIWidgetsPanel
+{
+    protected override void main() {
+        ui_.runApp(new MaterialApp(
+            title: "Http Request Sample",
+            home: new Scaffold(
+                body:new AsyncRequestWidget(this.gameObject)
+                )
+        ));
+    }
+}
+
+public class AsyncRequestWidget : StatefulWidget {
+    
+    public readonly GameObject gameObjOfUIWidgetsPanel;
+
+    public AsyncRequestWidget(GameObject gameObjOfUiWidgetsPanel, Key key = null) : base(key) {
+        this.gameObjOfUIWidgetsPanel = gameObjOfUiWidgetsPanel;
+    }
+
+    public override State createState() {
+        return new _AsyncRequestWidgetState();
+    }
+}
+
+[Serializable]
+public class TimeData {
+    public long currentFileTime;
+}
+
+class _AsyncRequestWidgetState : State<AsyncRequestWidget> {
+    
+    long _fileTime;
+    
+    public override Widget build(BuildContext context) {
+        var isolate = Isolate.current;
+        
+        return new Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: new List<Widget>() {
+                new FlatButton(child: new Text("Click To Get Time"), onPressed: () => {
+                    UnityWebRequest www = UnityWebRequest.Get("http://worldclockapi.com/api/json/est/now");
+                    var asyncOperation  = www.SendWebRequest();
+                    asyncOperation.completed += operation => {
+                        var timeData = JsonUtility.FromJson<TimeData>(www.downloadHandler.text);
+                        using(Isolate.getScope(isolate))
+                        {
+                            this.setState(() => { this._fileTime = timeData.currentFileTime; });
+                        }
+                       
+                    };
+                }),
+                new Text($"current file time: {this._fileTime}")
+            });
+    }
+}

Samples/UIWidgetsSamples_2019_4/Assets/WidgetsSample/HttpRequestSample.cs.meta

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