[1.5.4] Upgrade most of material.

Runtime/material/dropdown.cs

 
         public override Widget buildPage(BuildContext context, Animation<float> animation,
             Animation<float> secondaryAnimation) {
+            return new LayoutBuilder(
+                builder: (ctx, constraints) => {
+                    return new _DropdownRoutePage<T>(
+                        route: this,
+                        constraints: constraints,
+                        items: this.items,
+                        padding: this.padding,
+                        buttonRect: this.buttonRect,
+                        selectedIndex: this.selectedIndex,
+                        elevation: this.elevation,
+                        theme: this.theme,
+                        style: this.style
+                    );
+                }
+            );
+        }
+
+        internal void _dismiss() {
+            this.navigator?.removeRoute(this);
+        }
+    }
+
+    class _DropdownRoutePage<T> : StatelessWidget where T : class {
+        public _DropdownRoutePage(
+            Key key = null,
+            _DropdownRoute<T> route = null,
+            BoxConstraints constraints = null,
+            List<DropdownMenuItem<T>> items = null,
+            EdgeInsets padding = null,
+            Rect buttonRect = null,
+            int? selectedIndex = null,
+            int elevation = 0,
+            ThemeData theme = null,
+            TextStyle style = null
+        ) : base(key: key) {
+            this.route = route;
+            this.constraints = constraints;
+            this.items = items;
+            this.padding = padding;
+            this.buttonRect = buttonRect;
+            this.selectedIndex = selectedIndex;
+            this.elevation = elevation;
+            this.theme = theme;
+            this.style = style;
+        }
+
+        public readonly _DropdownRoute<T> route;
+        public readonly BoxConstraints constraints;
+        public readonly List<DropdownMenuItem<T>> items;
+        public readonly EdgeInsets padding;
+        public readonly Rect buttonRect;
+        public readonly int? selectedIndex;
+        public readonly int elevation;
+        public readonly ThemeData theme;
+        public readonly TextStyle style;
+        
+        public override Widget build(BuildContext context) {
-            float screenHeight = MediaQuery.of(context).size.height;
-            float maxMenuHeight = screenHeight - 2.0f * DropdownConstants._kMenuItemHeight;
+            float availableHeight = this.constraints.maxHeight;
+            float maxMenuHeight = availableHeight - 2.0f * DropdownConstants._kMenuItemHeight;
-            float buttonBottom = this.buttonRect.bottom;
+            float buttonBottom = Mathf.Min(this.buttonRect.bottom, availableHeight);
-            float bottomLimit = Mathf.Max(screenHeight - DropdownConstants._kMenuItemHeight, buttonBottom);
+            float bottomLimit = Mathf.Max(availableHeight - DropdownConstants._kMenuItemHeight, buttonBottom);
 
             float? selectedItemOffset = this.selectedIndex * DropdownConstants._kMenuItemHeight +
                                         Constants.kMaterialListPadding.top;
                 menuTop = menuBottom - menuHeight;
             }
 
-            if (this.scrollController == null) {
+            if (this.route.scrollController == null) {
-                this.scrollController = new ScrollController(initialScrollOffset: scrollOffset);
+                this.route.scrollController = new ScrollController(initialScrollOffset: scrollOffset);
-                route: this,
+                route: this.route,
                 padding: this.padding
             );
 
                     }
                 )
             );
-        }
-
-        public void _dismiss() {
-            this.navigator?.removeRoute(this);
         }
     }
 
             ValueChanged<T> onChanged = null,
             int elevation = 8,
             TextStyle style = null,
+            Widget underline = null,
+            Widget icon = null,
+            Color iconDisabledColor = null,
+            Color iconEnabledColor = null,
             float iconSize = 24.0f,
             bool isDense = false,
             bool isExpanded = false
             this.onChanged = onChanged;
             this.elevation = elevation;
             this.style = style;
+            this.underline = underline;
+            this.icon = icon;
+            this.iconDisabledColor = iconDisabledColor;
+            this.iconEnabledColor = iconEnabledColor;
             this.iconSize = iconSize;
             this.isDense = isDense;
             this.isExpanded = isExpanded;
 
         public readonly TextStyle style;
 
+        public readonly Widget underline;
+            
+        public readonly Widget icon;
+                    
+        public readonly Color iconDisabledColor;
+                    
+        public readonly Color iconEnabledColor;
+
         public readonly float iconSize;
 
         public readonly bool isDense;
             }
         }
 
-        Color _downArrowColor {
+        Color _iconColor {
-                    if (Theme.of(this.context).brightness == Brightness.light) {
-                        return Colors.grey.shade700;
+                    if (this.widget.iconEnabledColor != null) {
+                        return this.widget.iconEnabledColor;
-                    else {
-                        return Colors.white70;
+
+                    switch (Theme.of(this.context).brightness) {
+                        case Brightness.light:
+                            return Colors.grey.shade700;
+                        case Brightness.dark:
+                            return Colors.white70;
-                    if (Theme.of(this.context).brightness == Brightness.light) {
-                        return Colors.grey.shade400;
+                    if (this.widget.iconDisabledColor != null) {
+                        return this.widget.iconDisabledColor;
-                    else {
-                        return Colors.white10;
+
+                    switch (Theme.of(this.context).brightness) {
+                        case Brightness.light:
+                            return Colors.grey.shade400;
+                        case Brightness.dark:
+                            return Colors.white10;
+                D.assert(false);
+                return null;
             }
         }
 
                 children: items
             );
 
+            Icon defaultIcon = new Icon(Icons.arrow_drop_down);
             Widget result = new DefaultTextStyle(
                 style: this._textStyle,
                 child: new Container(
                         mainAxisSize: MainAxisSize.min,
                         children: new List<Widget> {
                             this.widget.isExpanded ? new Expanded(child: innerItemsWidget) : (Widget) innerItemsWidget,
-                            new Icon(Icons.arrow_drop_down,
-                                size: this.widget.iconSize,
-                                color: this._downArrowColor
+                            new IconTheme(
+                                data: new IconThemeData(
+                                    color: this._iconColor,
+                                    size: this.widget.iconSize
+                                ),
+                                child: this.widget.icon ?? defaultIcon
                             )
                         }
                     )
                             left: 0.0f,
                             right: 0.0f,
                             bottom: bottom,
-                            child: new Container(
+                            child: this.widget.underline ?? new Container(
                                 height: 1.0f,
                                 decoration: new BoxDecoration(
                                     border: new Border(

Runtime/material/expansion_panel.cs

         public ExpansionPanel(
             ExpansionPanelHeaderBuilder headerBuilder = null,
             Widget body = null,
-            bool isExpanded = false) {
+            bool isExpanded = false,
+            bool canTapOnHeader = false) {
+            this.canTapOnHeader = false;
         }
 
         public readonly ExpansionPanelHeaderBuilder headerBuilder;
         public readonly bool isExpanded;
+
+        public readonly bool canTapOnHeader;
     }
 
 
             ExpansionPanelHeaderBuilder headerBuilder = null,
-            Widget body = null) : base(body: body, headerBuilder: headerBuilder) {
+            Widget body = null,
+            bool canTapOnHeader = false)
+            : base(body: body, headerBuilder: headerBuilder, canTapOnHeader: canTapOnHeader) {
             D.assert(headerBuilder != null);
             D.assert(body != null);
             D.assert(value != null);
                 }
 
                 ExpansionPanel child = this.widget.children[index];
+                Widget headerWidget = child.headerBuilder(
+                    context,
+                    this._isChildExpanded(index)
+                );
                 Row header = new Row(
                     children: new List<Widget> {
                         new Expanded(
                                 child: new ConstrainedBox(
                                     constraints: new BoxConstraints(
                                         minHeight: ExpansionPanelUtils._kPanelHeaderCollapsedHeight),
-                                    child: child.headerBuilder(
-                                        context,
-                                        this._isChildExpanded(index))
+                                    child: headerWidget
                                 )
                             )
                         ),
                                 isExpanded: this._isChildExpanded(index),
                                 padding: EdgeInsets.all(16.0f),
-                                onPressed: (bool isExpanded) => this._handlePressed(isExpanded, expandIndex)
+                                onPressed: !child.canTapOnHeader
+                                    ? (ValueChanged<bool>) ((bool isExpanded) => {
+                                        this._handlePressed(isExpanded, expandIndex);
+                                    })
+                                    : null
                             )
                         )
                     }
                         key: new _SaltedKey<BuildContext, int>(context, index * 2),
                         child: new Column(
                             children: new List<Widget> {
-                                header,
+                                child.canTapOnHeader
+                                    ? (Widget) new InkWell(
+                                        onTap: () =>
+                                            this._handlePressed(this._isChildExpanded(expandIndex), expandIndex),
+                                        child: header
+                                    )
+                                    : header,
                                 new AnimatedCrossFade(
                                     firstChild: new Container(height: 0.0f),
                                     secondChild: child.body,

Runtime/material/progress_indicator.cs

 
     class _CircularProgressIndicatorPainter : AbstractCustomPainter {
         public _CircularProgressIndicatorPainter(
+            Color backgroundColor = null,
             Color valueColor = null,
             float? value = null,
             float? headValue = null,
             float? strokeWidth = null
         ) {
+            this.backgroundColor = backgroundColor;
             this.valueColor = valueColor;
             this.value = value;
             this.headValue = headValue;
                 : Mathf.Max(headValue * 3 / 2 * Mathf.PI - tailValue * 3 / 2 * Mathf.PI ?? 0.0f, _epsilon);
         }
 
+        public readonly Color backgroundColor;
         public readonly Color valueColor;
         public readonly float? value;
         public readonly float? headValue;
             paint.strokeWidth = this.strokeWidth ?? 0.0f;
             paint.style = PaintingStyle.stroke;
 
+            if (this.backgroundColor != null) {
+                Paint backgroundPaint = new Paint() {
+                    color = this.backgroundColor,
+                    strokeWidth = this.strokeWidth ?? 0.0f,
+                    style = PaintingStyle.stroke
+                };
+                canvas.drawArc(Offset.zero & size, 0, _sweep, false, backgroundPaint);
+            }
+
             if (this.value == null)
             {
                 paint.strokeCap = StrokeCap.square;
         public override bool shouldRepaint(CustomPainter oldPainter) {
             D.assert(oldPainter is _CircularProgressIndicatorPainter);
             _CircularProgressIndicatorPainter painter = oldPainter as _CircularProgressIndicatorPainter;
-            return painter.valueColor != this.valueColor
+            return painter.backgroundColor != this.backgroundColor
+                   || painter.valueColor != this.valueColor
                    || painter.value != this.value
                    || painter.headValue != this.headValue
                    || painter.tailValue != this.tailValue
                 ),
                 child: new CustomPaint(
                     painter: new _CircularProgressIndicatorPainter(
+                        backgroundColor: this.widget.backgroundColor,
                         valueColor: this.widget._getValueColor(context),
                         value: this.widget.value,
                         headValue: headValue,

Runtime/material/scaffold.cs

         }
     }
 
+    class _BodyBoxConstraints : BoxConstraints {
+        public _BodyBoxConstraints(
+            float minWidth = 0.0f,
+            float maxWidth = float.PositiveInfinity,
+            float minHeight = 0.0f,
+            float maxHeight = float.PositiveInfinity,
+            float? bottomWidgetsHeight = null
+        ) : base(minWidth: minWidth, maxWidth: maxWidth, minHeight: minHeight, maxHeight: maxHeight) {
+            D.assert(bottomWidgetsHeight != null);
+            D.assert(bottomWidgetsHeight >= 0);
+            this.bottomWidgetsHeight = bottomWidgetsHeight.Value;
+        }
+
+        public readonly float bottomWidgetsHeight;
+        
+        public bool Equals(_BodyBoxConstraints other) {
+            if (ReferenceEquals(null, other)) {
+                return false;
+            }
+
+            if (ReferenceEquals(this, other)) {
+                return true;
+            }
+
+            return this.bottomWidgetsHeight.Equals(other.bottomWidgetsHeight)
+                   && base.Equals(other);
+        }
+
+        public override bool Equals(object obj) {
+            if (ReferenceEquals(null, obj)) {
+                return false;
+            }
+
+            if (ReferenceEquals(this, obj)) {
+                return true;
+            }
+
+            if (obj.GetType() != this.GetType()) {
+                return false;
+            }
+
+            return this.Equals((_BodyBoxConstraints) obj);
+        }
+
+        public override int GetHashCode() {
+            unchecked {
+                var hashCode = base.GetHashCode();
+                hashCode = (hashCode * 397) ^ this.bottomWidgetsHeight.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        public static bool operator ==(_BodyBoxConstraints left, _BodyBoxConstraints right) {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(_BodyBoxConstraints left, _BodyBoxConstraints right) {
+            return !Equals(left, right);
+        }
+    }
+
+    class _BodyBuilder : StatelessWidget {
+        public _BodyBuilder(Key key = null, Widget body = null) : base(key: key) {
+            this.body = body;
+        }
+
+        public readonly Widget body;
+
+        public override Widget build(BuildContext context) {
+            return new LayoutBuilder(
+                builder: (ctx, constraints) => {
+                    _BodyBoxConstraints bodyConstraints = (_BodyBoxConstraints) constraints;
+                    MediaQueryData metrics = MediaQuery.of(context);
+                    return new MediaQuery(
+                        data: metrics.copyWith(
+                            padding: metrics.padding.copyWith(
+                                bottom: Mathf.Max(metrics.padding.bottom, bodyConstraints.bottomWidgetsHeight)
+                            )
+                        )
+                    );
+                }
+            );
+        }
+    }
+
     class _ScaffoldLayout : MultiChildLayoutDelegate {
         public _ScaffoldLayout(
             EdgeInsets minInsets,
             float floatingActionButtonMoveAnimationProgress,
-            FloatingActionButtonAnimator floatingActionButtonMotionAnimator
+            FloatingActionButtonAnimator floatingActionButtonMotionAnimator,
+            bool extendBody
         ) {
             D.assert(minInsets != null);
             D.assert(geometryNotifier != null);
             this.currentFloatingActionButtonLocation = currentFloatingActionButtonLocation;
             this.floatingActionButtonMoveAnimationProgress = floatingActionButtonMoveAnimationProgress;
             this.floatingActionButtonMotionAnimator = floatingActionButtonMotionAnimator;
+            this.extendBody = extendBody;
+        public readonly bool extendBody;
+        
         public readonly EdgeInsets minInsets;
 
         public readonly _ScaffoldGeometryNotifier geometryNotifier;
             float contentBottom = Mathf.Max(0.0f, bottom - Mathf.Max(this.minInsets.bottom, bottomWidgetsHeight));
 
             if (this.hasChild(_ScaffoldSlot.body)) {
-                BoxConstraints bodyConstraints = new BoxConstraints(
+                float bodyMaxHeight = Mathf.Max(0.0f, contentBottom - contentTop);
+                if (this.extendBody) {
+                    bodyMaxHeight += bottomWidgetsHeight;
+                    D.assert(bodyMaxHeight <= Mathf.Max(0.0f, looseConstraints.maxHeight - contentTop));
+                }
+                BoxConstraints bodyConstraints = new _BodyBoxConstraints(
-                    maxHeight: Mathf.Max(0.0f, contentBottom - contentTop)
+                    maxHeight: bodyMaxHeight,
+                    bottomWidgetsHeight: this.extendBody ? bottomWidgetsHeight : 0.0f
                 );
                 this.layoutChild(_ScaffoldSlot.body, bodyConstraints);
                 this.positionChild(_ScaffoldSlot.body, new Offset(0.0f, contentTop));
             bool? resizeToAvoidBottomPadding = null,
             bool? resizeToAvoidBottomInset = null,
             bool primary = true,
-            DragStartBehavior drawerDragStartBehavior = DragStartBehavior.down
+            DragStartBehavior drawerDragStartBehavior = DragStartBehavior.start,
+            bool extendBody = false
         ) : base(key: key) {
             this.appBar = appBar;
             this.body = body;
             this.resizeToAvoidBottomInset = resizeToAvoidBottomInset;
             this.primary = primary;
             this.drawerDragStartBehavior = drawerDragStartBehavior;
+            this.extendBody = extendBody;
+
+        public readonly bool extendBody;
 
         public readonly PreferredSizeWidget appBar;
 
 
             this._addIfNonNull(
                 children: children,
-                child: this.widget.body,
+                child: this.widget.body != null && this.widget.extendBody
+                    ? new _BodyBuilder(body: this.widget.body) : this.widget.body,
                 childId: _ScaffoldSlot.body,
                 removeLeftPadding: false,
                 removeTopPadding: this.widget.appBar != null,
                 bottom: this._resizeToAvoidBottomInset ? mediaQuery.viewInsets.bottom : 0.0f
             );
 
+            bool _extendBody = !(minInsets.bottom > 0) && this.widget.extendBody;
+            
             return new _ScaffoldScope(
                 hasDrawer: this.hasDrawer,
                 geometryNotifier: this._geometryNotifier,
                                 return new CustomMultiChildLayout(
                                     children: new List<Widget>(children),
                                     layoutDelegate: new _ScaffoldLayout(
+                                        extendBody: _extendBody,
                                         minInsets: minInsets,
                                         currentFloatingActionButtonLocation: this._floatingActionButtonLocation,
                                         floatingActionButtonMoveAnimationProgress: this

Runtime/material/floating_action_button.cs.meta

 fileFormatVersion: 2
-guid: 274f3c1005cd046a28b169d8048c0292
+guid: 44d53f5996891c54780cbc0073567bfd
 MonoImporter:
   externalObjects: {}
   serializedVersion: 2

Runtime/material/floating_action_button_location.cs.meta

 fileFormatVersion: 2
-guid: cfa1c894caa2a46b19d419f6f53ae91f
+guid: 6c8b71fe76d6bdb4ca66ecad56f25d3f
 MonoImporter:
   externalObjects: {}
   serializedVersion: 2

Runtime/material/floating_action_button.cs

+using System.Collections.Generic;
+using Unity.UIWidgets.foundation;
+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 TextStyle = Unity.UIWidgets.painting.TextStyle;
+
+namespace Unity.UIWidgets.material {
+    static class FloatActionButtonUtils {
+        public static readonly BoxConstraints _kSizeConstraints = BoxConstraints.tightFor(width: 56.0f, height: 56.0f);
+
+        public static readonly BoxConstraints _kMiniSizeConstraints =
+            BoxConstraints.tightFor(width: 40.0f, height: 40.0f);
+
+        public static readonly BoxConstraints _kExtendedSizeConstraints =
+            new BoxConstraints(minHeight: 48.0f, maxHeight: 48.0f);
+    }
+
+
+    class _DefaultHeroTag {
+        public _DefaultHeroTag() {
+        }
+
+        public override string ToString() {
+            return "<default FloatingActionButton tag>";
+        }
+    }
+
+    public class FloatingActionButton : StatelessWidget {
+        FloatingActionButton(
+            Key key = null,
+            Widget child = null,
+            string tooltip = null,
+            Color foregroundColor = null,
+            Color backgroundColor = null,
+            object heroTag = null,
+            float? elevation = null,
+            float? highlightElevation = null,
+            float? disabledElevation = null,
+            VoidCallback onPressed = null,
+            bool mini = false,
+            ShapeBorder shape = null,
+            Clip clipBehavior = Clip.none,
+            MaterialTapTargetSize? materialTapTargetSize = null,
+            bool isExtended = false,
+            BoxConstraints _sizeConstraints = null
+        ) : base(key: key) {
+            D.assert(elevation == null || elevation >= 0.0f);
+            D.assert(highlightElevation == null || highlightElevation >= 0.0f);
+            D.assert(disabledElevation == null || disabledElevation >= 0.0f);
+            heroTag = heroTag ?? new _DefaultHeroTag();
+            this.child = child;
+            this.tooltip = tooltip;
+            this.foregroundColor = foregroundColor;
+            this.backgroundColor = backgroundColor;
+            this.heroTag = heroTag;
+            this.elevation = elevation;
+            this.highlightElevation = highlightElevation;
+            this.onPressed = onPressed;
+            this.mini = mini;
+            this.shape = shape;
+            this.clipBehavior = clipBehavior;
+            this.materialTapTargetSize = materialTapTargetSize;
+            this.isExtended = isExtended;
+            this.disabledElevation = disabledElevation;
+            this._sizeConstraints = _sizeConstraints ?? (mini
+                                        ? FloatActionButtonUtils._kMiniSizeConstraints
+                                        : FloatActionButtonUtils._kSizeConstraints);
+        }
+
+        public FloatingActionButton(
+            Key key = null,
+            Widget child = null,
+            string tooltip = null,
+            Color foregroundColor = null,
+            Color backgroundColor = null,
+            object heroTag = null,
+            float elevation = 6.0f,
+            float highlightElevation = 12.0f,
+            VoidCallback onPressed = null,
+            bool mini = false,
+            ShapeBorder shape = null,
+            Clip clipBehavior = Clip.none,
+            MaterialTapTargetSize? materialTapTargetSize = null,
+            bool isExtended = false
+        ) : this(key: key,
+            child: child,
+            tooltip: tooltip,
+            foregroundColor: foregroundColor,
+            backgroundColor: backgroundColor,
+            heroTag: heroTag,
+            elevation: elevation,
+            highlightElevation: highlightElevation,
+            onPressed: onPressed,
+            mini: mini,
+            shape: shape,
+            clipBehavior: clipBehavior,
+            materialTapTargetSize: materialTapTargetSize,
+            isExtended: isExtended,
+            _sizeConstraints: null) {
+        }
+
+        public static FloatingActionButton extended(
+            Key key = null,
+            string tooltip = null,
+            Color foregroundColor = null,
+            Color backgroundColor = null,
+            object heroTag = null,
+            float? elevation = null,
+            float? highlightElevation = null,
+            float? disabledElevation = null,
+            VoidCallback onPressed = null,
+            ShapeBorder shape = null,
+            bool isExtended = true,
+            MaterialTapTargetSize? materialTapTargetSize = null,
+            Clip clipBehavior = Clip.none,
+            Widget icon = null,
+            Widget label = null
+        ) {
+            D.assert(elevation == null || elevation >= 0.0f);
+            D.assert(highlightElevation == null || highlightElevation >= 0.0f);
+            D.assert(disabledElevation == null || disabledElevation >= 0.0f);
+            D.assert(label != null);
+            heroTag = heroTag ?? new _DefaultHeroTag();
+
+            BoxConstraints _sizeConstraints = FloatActionButtonUtils._kExtendedSizeConstraints;
+            bool mini = false;
+            Widget child = new _ChildOverflowBox(
+                child: new Row(
+                    mainAxisSize: MainAxisSize.min,
+                    children: icon == null
+                        ? new List<Widget> {
+                            new SizedBox(width: 20.0f),
+                            label,
+                            new SizedBox(width: 20.0f),
+                        }
+                        : new List<Widget> {
+                            new SizedBox(width: 16.0f),
+                            icon,
+                            new SizedBox(width: 8.0f),
+                            label,
+                            new SizedBox(width: 20.0f)
+                        }));
+
+            return new FloatingActionButton(
+                key: key,
+                child: child,
+                tooltip: tooltip,
+                foregroundColor: foregroundColor,
+                backgroundColor: backgroundColor,
+                heroTag: heroTag,
+                elevation: elevation,
+                highlightElevation: highlightElevation,
+                disabledElevation: disabledElevation,
+                onPressed: onPressed,
+                mini: mini,
+                shape: shape,
+                clipBehavior: clipBehavior,
+                materialTapTargetSize: materialTapTargetSize,
+                isExtended: isExtended,
+                _sizeConstraints: _sizeConstraints
+            );
+        }
+
+        public readonly Widget child;
+
+        public readonly string tooltip;
+
+        public readonly Color foregroundColor;
+
+        public readonly Color backgroundColor;
+
+        public readonly object heroTag;
+
+        public readonly VoidCallback onPressed;
+
+        public readonly float? elevation;
+
+        public readonly float? highlightElevation;
+
+        public readonly float? disabledElevation;
+
+        public readonly bool mini;
+
+        public readonly ShapeBorder shape;
+
+        public readonly Clip clipBehavior;
+
+        public readonly bool isExtended;
+
+        public readonly MaterialTapTargetSize? materialTapTargetSize;
+
+        readonly BoxConstraints _sizeConstraints;
+
+        const float _defaultElevation = 6;
+        const float _defaultHighlightElevation = 12;
+        readonly ShapeBorder _defaultShape = new CircleBorder();
+        readonly ShapeBorder _defaultExtendedShape = new StadiumBorder();
+
+        public override Widget build(BuildContext context) {
+            ThemeData theme = Theme.of(context);
+            FloatingActionButtonThemeData floatingActionButtonTheme = theme.floatingActionButtonTheme;
+            Color backgroundColor = this.backgroundColor
+                                    ?? floatingActionButtonTheme.backgroundColor
+                                    ?? theme.colorScheme.secondary;
+            Color foregroundColor = this.foregroundColor
+                                    ?? floatingActionButtonTheme.foregroundColor
+                                    ?? theme.accentIconTheme.color
+                                    ?? theme.colorScheme.onSecondary;
+
+            float elevation = this.elevation
+                              ?? floatingActionButtonTheme.elevation
+                              ?? _defaultElevation;
+            float disabledElevation = this.disabledElevation
+                                      ?? floatingActionButtonTheme.disabledElevation
+                                      ?? elevation;
+            float highlightElevation = this.highlightElevation
+                                       ?? floatingActionButtonTheme.highlightElevation
+                                       ?? _defaultHighlightElevation;
+            MaterialTapTargetSize materialTapTargetSize = this.materialTapTargetSize
+                                                          ?? theme.materialTapTargetSize;
+            TextStyle textStyle = theme.accentTextTheme.button.copyWith(
+                color: foregroundColor,
+                letterSpacing: 1.2f
+            );
+            ShapeBorder shape = this.shape
+                                ?? floatingActionButtonTheme.shape
+                                ?? (this.isExtended ? this._defaultExtendedShape : this._defaultShape);
+
+            Widget result = null;
+
+            if (this.child != null) {
+                result = IconTheme.merge(
+                    data: new IconThemeData(
+                        color: foregroundColor),
+                    child: this.child
+                );
+            }
+
+            result = new RawMaterialButton(
+                onPressed: this.onPressed,
+                elevation: elevation,
+                highlightElevation: highlightElevation,
+                disabledElevation: disabledElevation,
+                constraints: this._sizeConstraints,
+                materialTapTargetSize: materialTapTargetSize,
+                fillColor: backgroundColor,
+                textStyle: textStyle,
+                shape: shape,
+                clipBehavior: this.clipBehavior,
+                child: result);
+
+            if (this.tooltip != null) {
+                result = new Tooltip(
+                    message: this.tooltip,
+                    child: result);
+            }
+
+            if (this.heroTag != null) {
+                result = new Hero(
+                    tag: this.heroTag,
+                    child: result);
+            }
+
+            return result;
+        }
+    }
+
+    class _ChildOverflowBox : SingleChildRenderObjectWidget {
+        public _ChildOverflowBox(
+            Key key = null,
+            Widget child = null) : base(key: key, child: child) {
+        }
+
+        public override RenderObject createRenderObject(BuildContext context) {
+            return new _RenderChildOverflowBox();
+        }
+
+        public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
+        }
+    }
+
+
+    class _RenderChildOverflowBox : RenderAligningShiftedBox {
+        public _RenderChildOverflowBox(
+            RenderBox child = null) : base(child: child, alignment: Alignment.center) {
+        }
+
+        protected override float computeMinIntrinsicWidth(float height) {
+            return 0.0f;
+        }
+
+        protected override float computeMinIntrinsicHeight(float width) {
+            return 0.0f;
+        }
+
+        protected override void performLayout() {
+            if (this.child != null) {
+                this.child.layout(new BoxConstraints(), parentUsesSize: true);
+                this.size = new Size(
+                    Mathf.Max(this.constraints.minWidth, Mathf.Min(this.constraints.maxWidth, this.child.size.width)),
+                    Mathf.Max(this.constraints.minHeight, Mathf.Min(this.constraints.maxHeight, this.child.size.height))
+                );
+                this.alignChild();
+            }
+            else {
+                this.size = this.constraints.biggest;
+            }
+        }
+    }
+}

Runtime/material/float_action_button.cs

-using System.Collections.Generic;
-using Unity.UIWidgets.foundation;
-using Unity.UIWidgets.painting;
-using Unity.UIWidgets.rendering;
-using Unity.UIWidgets.ui;
-using Unity.UIWidgets.widgets;
-using UnityEngine;
-using Color = Unity.UIWidgets.ui.Color;
-
-namespace Unity.UIWidgets.material {
-    static class FloatActionButtonUtils {
-        public static readonly BoxConstraints _kSizeConstraints = BoxConstraints.tightFor(width: 56.0f, height: 56.0f);
-
-        public static readonly BoxConstraints _kMiniSizeConstraints =
-            BoxConstraints.tightFor(width: 40.0f, height: 40.0f);
-
-        public static readonly BoxConstraints _kExtendedSizeConstraints =
-            new BoxConstraints(minHeight: 48.0f, maxHeight: 48.0f);
-    }
-
-
-    class _DefaultHeroTag {
-        public _DefaultHeroTag() {
-        }
-
-        public override string ToString() {
-            return "<default FloatingActionButton tag>";
-        }
-    }
-
-    public class FloatingActionButton : StatelessWidget {
-        FloatingActionButton(
-            Key key = null,
-            Widget child = null,
-            string tooltip = null,
-            Color foregroundColor = null,
-            Color backgroundColor = null,
-            object heroTag = null,
-            float elevation = 6.0f,
-            float highlightElevation = 12.0f,
-            float? disabledElevation = null,
-            VoidCallback onPressed = null,
-            bool mini = false,
-            ShapeBorder shape = null,
-            Clip clipBehavior = Clip.none,
-            MaterialTapTargetSize? materialTapTargetSize = null,
-            bool isExtended = false,
-            BoxConstraints _sizeConstraints = null
-        ) : base(key: key) {
-            D.assert(elevation >= 0.0f);
-            D.assert(highlightElevation >= 0.0f);
-            D.assert(disabledElevation == null || disabledElevation >= 0.0f);
-            heroTag = heroTag ?? new _DefaultHeroTag();
-            shape = shape ?? new CircleBorder();
-            this.child = child;
-            this.tooltip = tooltip;
-            this.foregroundColor = foregroundColor;
-            this.backgroundColor = backgroundColor;
-            this.heroTag = heroTag;
-            this.elevation = elevation;
-            this.highlightElevation = highlightElevation;
-            this.onPressed = onPressed;
-            this.mini = mini;
-            this.shape = shape;
-            this.clipBehavior = clipBehavior;
-            this.materialTapTargetSize = materialTapTargetSize;
-            this.isExtended = isExtended;
-            this.disabledElevation = disabledElevation;
-            this._sizeConstraints = _sizeConstraints ?? (mini
-                                        ? FloatActionButtonUtils._kMiniSizeConstraints
-                                        : FloatActionButtonUtils._kSizeConstraints);
-        }
-
-        public FloatingActionButton(
-            Key key = null,
-            Widget child = null,
-            string tooltip = null,
-            Color foregroundColor = null,
-            Color backgroundColor = null,
-            object heroTag = null,
-            float elevation = 6.0f,
-            float highlightElevation = 12.0f,
-            VoidCallback onPressed = null,
-            bool mini = false,
-            ShapeBorder shape = null,
-            Clip clipBehavior = Clip.none,
-            MaterialTapTargetSize? materialTapTargetSize = null,
-            bool isExtended = false
-        ) : this(key: key,
-            child: child,
-            tooltip: tooltip,
-            foregroundColor: foregroundColor,
-            backgroundColor: backgroundColor,
-            heroTag: heroTag,
-            elevation: elevation,
-            highlightElevation: highlightElevation,
-            onPressed: onPressed,
-            mini: mini,
-            shape: shape,
-            clipBehavior: clipBehavior,
-            materialTapTargetSize: materialTapTargetSize,
-            isExtended: isExtended,
-            _sizeConstraints: null) {
-        }
-
-        public static FloatingActionButton extended(
-            Key key = null,
-            string tooltip = null,
-            Color foregroundColor = null,
-            Color backgroundColor = null,
-            object heroTag = null,
-            float elevation = 6.0f,
-            float highlightElevation = 12.0f,
-            float? disabledElevation = null,
-            VoidCallback onPressed = null,
-            ShapeBorder shape = null,
-            bool isExtended = true,
-            MaterialTapTargetSize? materialTapTargetSize = null,
-            Clip clipBehavior = Clip.none,
-            Widget icon = null,
-            Widget label = null
-        ) {
-            D.assert(elevation >= 0.0f);
-            D.assert(highlightElevation >= 0.0f);
-            D.assert(disabledElevation == null || disabledElevation >= 0.0f);
-            D.assert(icon != null);
-            D.assert(label != null);
-            heroTag = heroTag ?? new _DefaultHeroTag();
-            shape = shape ?? new StadiumBorder();
-
-            BoxConstraints _sizeConstraints = FloatActionButtonUtils._kExtendedSizeConstraints;
-            bool mini = false;
-            Widget child = new _ChildOverflowBox(
-                child: new Row(
-                    mainAxisSize: MainAxisSize.min,
-                    children: new List<Widget> {
-                        new SizedBox(width: 16.0f),
-                        icon,
-                        new SizedBox(width: 8.0f),
-                        label,
-                        new SizedBox(width: 20.0f)
-                    }));
-
-            return new FloatingActionButton(
-                key: key,
-                child: child,
-                tooltip: tooltip,
-                foregroundColor: foregroundColor,
-                backgroundColor: backgroundColor,
-                heroTag: heroTag,
-                elevation: elevation,
-                highlightElevation: highlightElevation,
-                disabledElevation: disabledElevation ?? elevation,
-                onPressed: onPressed,
-                mini: mini,
-                shape: shape,
-                clipBehavior: clipBehavior,
-                materialTapTargetSize: materialTapTargetSize,
-                isExtended: isExtended,
-                _sizeConstraints: _sizeConstraints
-            );
-        }
-
-        public readonly Widget child;
-
-        public readonly string tooltip;
-
-        public readonly Color foregroundColor;
-
-        public readonly Color backgroundColor;
-
-        public readonly object heroTag;
-
-        public readonly VoidCallback onPressed;
-
-        public readonly float elevation;
-
-        public readonly float highlightElevation;
-
-        public readonly float? disabledElevation;
-
-        public readonly bool mini;
-
-        public readonly ShapeBorder shape;
-
-        public readonly Clip clipBehavior;
-
-        public readonly bool isExtended;
-
-        public readonly MaterialTapTargetSize? materialTapTargetSize;
-
-        public readonly BoxConstraints _sizeConstraints;
-
-        public override Widget build(BuildContext context) {
-            ThemeData theme = Theme.of(context);
-            Color foregroundColor = this.foregroundColor ?? theme.accentIconTheme.color;
-            Widget result = null;
-
-            if (this.child != null) {
-                result = IconTheme.merge(
-                    data: new IconThemeData(
-                        color: foregroundColor),
-                    child: this.child
-                );
-            }
-
-            result = new RawMaterialButton(
-                onPressed: this.onPressed,
-                elevation: this.elevation,
-                highlightElevation: this.highlightElevation,
-                disabledElevation: this.disabledElevation ?? this.elevation,
-                constraints: this._sizeConstraints,
-                materialTapTargetSize: this.materialTapTargetSize ?? theme.materialTapTargetSize,
-                fillColor: this.backgroundColor ?? theme.accentColor,
-                textStyle: theme.accentTextTheme.button.copyWith(
-                    color: foregroundColor,
-                    letterSpacing: 1.2f),
-                shape: this.shape,
-                clipBehavior: this.clipBehavior,
-                child: result);
-
-            if (this.tooltip != null) {
-                result = new Tooltip(
-                    message: this.tooltip,
-                    child: result);
-            }
-
-            if (this.heroTag != null) {
-                result = new Hero(
-                    tag: this.heroTag,
-                    child: result);
-            }
-
-            return result;
-        }
-    }
-
-    class _ChildOverflowBox : SingleChildRenderObjectWidget {
-        public _ChildOverflowBox(
-            Key key = null,
-            Widget child = null) : base(key: key, child: child) {
-        }
-
-        public override RenderObject createRenderObject(BuildContext context) {
-            return new _RenderChildOverflowBox();
-        }
-
-        public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
-        }
-    }
-
-
-    class _RenderChildOverflowBox : RenderAligningShiftedBox {
-        public _RenderChildOverflowBox(
-            RenderBox child = null) : base(child: child, alignment: Alignment.center) {
-        }
-
-        protected override float computeMinIntrinsicWidth(float height) {
-            return 0.0f;
-        }
-
-        protected override float computeMinIntrinsicHeight(float width) {
-            return 0.0f;
-        }
-
-        protected override void performLayout() {
-            if (this.child != null) {
-                this.child.layout(new BoxConstraints(), parentUsesSize: true);
-                this.size = new Size(
-                    Mathf.Max(this.constraints.minWidth, Mathf.Min(this.constraints.maxWidth, this.child.size.width)),
-                    Mathf.Max(this.constraints.minHeight, Mathf.Min(this.constraints.maxHeight, this.child.size.height))
-                );
-                this.alignChild();
-            }
-            else {
-                this.size = this.constraints.biggest;
-            }
-        }
-    }
-}