fix bug on cupertino/segmented_control and fade_in_image

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

@@ -1,17 +1,5 @@
 using System.Collections.Generic;
 using Unity.UIWidgets.foundation;
-using Unity.UIWidgets.animation;
-using Unity.UIWidgets.rendering;
-using Unity.UIWidgets.ui;
-using Unity.UIWidgets.widgets;
-using Unity.UIWidgets.scheduler;
-using System;
-using Unity.UIWidgets.gestures;
-using Unity.UIWidgets.painting;
-using UnityEngine;
-using Color = Unity.UIWidgets.ui.Color;
-using Rect = Unity.UIWidgets.ui.Rect;
-using Transform = Unity.UIWidgets.widgets.Transform;
 
 namespace Unity.UIWidgets.animation {
     public class TweenSequence<T> : Animatable<T> {

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

@@ -11,16 +11,16 @@ using Unity.UIWidgets.rendering;
 using UnityEngine;
 using Color = Unity.UIWidgets.ui.Color;
 using Rect = Unity.UIWidgets.ui.Rect;
-using TextStyle = Unity.UIWidgets.painting.TextStyle;
 
 namespace Unity.UIWidgets.cupertino {
-    class CupertinoSegmentedControlsUtils {
+    static class CupertinoSegmentedControlsUtils {
         public static readonly EdgeInsetsGeometry _kHorizontalItemPadding = EdgeInsets.symmetric(horizontal: 16.0f);
         public const float _kMinSegmentedControlHeight = 28.0f;
         public static readonly TimeSpan _kFadeDuration = TimeSpan.FromMilliseconds(165);
     }
 
-    public class CupertinoSegmentedControl<T> : StatefulWidget {
+    public class CupertinoSegmentedControl<T> : StatefulWidget
+    {
         public CupertinoSegmentedControl(
             Key key = null,
             Dictionary<T, Widget> children = null,
@@ -31,8 +31,8 @@ namespace Unity.UIWidgets.cupertino {
             Color borderColor = null,
             Color pressedColor = null,
             EdgeInsetsGeometry padding = null
-        ) :base(key: key) 
+        ) : base(key: key) {
-        { D.assert(children != null);
+            D.assert(children != null);
             D.assert(children.Count >= 2);
             D.assert(onValueChanged != null);
             D.assert(
@@ -47,8 +47,8 @@ namespace Unity.UIWidgets.cupertino {
             this.borderColor = borderColor;
             this.pressedColor = pressedColor;
             this.padding = padding;
-
         }
+
         public readonly Dictionary<T, Widget> children;
         public readonly T groupValue;
         public readonly ValueChanged<T> onValueChanged;
@@ -62,11 +62,32 @@ namespace Unity.UIWidgets.cupertino {
             return new _SegmentedControlState<T>();
         }
     }
-    class _SegmentedControlState<T> : TickerProviderStateMixin<CupertinoSegmentedControl<T>> {
-      T _pressedKey;
 
-      public readonly List<AnimationController> _selectionControllers = new List<AnimationController>();
+    class _SegmentedControlState<T> : TickerProviderStateMixin<CupertinoSegmentedControl<T>> {
-      public readonly List<ColorTween> _childTweens = new List<ColorTween>();
+        
+        T __pressedKey = default;
+        bool __isNull = true;
+
+        void setPressedKey(T newkey) {
+            __pressedKey = newkey;
+            __isNull = false;
+        }
+
+        void setPressedKeyNull() {
+            __pressedKey = default;
+            __isNull = true;
+        }
+
+        bool isPressedKeyNull() {
+            return __isNull;
+        }
+
+        T getPressedKey() {
+            return __pressedKey;
+        }
+
+        readonly List<AnimationController> _selectionControllers = new List<AnimationController>();
+        readonly List<ColorTween> _childTweens = new List<ColorTween>();
 
         ColorTween _forwardBackgroundColorTween;
         ColorTween _reverseBackgroundColorTween;
@@ -84,7 +105,6 @@ namespace Unity.UIWidgets.cupertino {
             );
             controller.addListener(() => {
                 setState(() => {
-                        // State of background/text colors has changed
                 });
             });
             return controller;
@@ -92,23 +112,26 @@ namespace Unity.UIWidgets.cupertino {
 
         bool _updateColors() {
             D.assert(mounted, () => "This should only be called after didUpdateDependencies");
-        bool changed = false;
+            var changed = false;
-         Color selectedColor = widget.selectedColor ?? CupertinoTheme.of(context).primaryColor;
+            var selectedColor = widget.selectedColor ?? CupertinoTheme.of(context).primaryColor;
             if (_selectedColor != selectedColor) {
                 changed = true;
                 _selectedColor = selectedColor;
             }
-         Color unselectedColor = widget.unselectedColor ?? CupertinoTheme.of(context).primaryContrastingColor;
+
+            var unselectedColor = widget.unselectedColor ?? CupertinoTheme.of(context).primaryContrastingColor;
             if (_unselectedColor != unselectedColor) {
                 changed = true;
                 _unselectedColor = unselectedColor;
             }
-         Color borderColor = widget.borderColor ?? CupertinoTheme.of(context).primaryColor;
+
+            var borderColor = widget.borderColor ?? CupertinoTheme.of(context).primaryColor;
             if (_borderColor != borderColor) {
                 changed = true;
                 _borderColor = borderColor;
             }
-         Color pressedColor = widget.pressedColor ?? CupertinoTheme.of(context).primaryColor.withOpacity(0.2f);
+
+            var pressedColor = widget.pressedColor ?? CupertinoTheme.of(context).primaryColor.withOpacity(0.2f);
             if (_pressedColor != pressedColor) {
                 changed = true;
                 _pressedColor = pressedColor;
@@ -122,28 +145,33 @@ namespace Unity.UIWidgets.cupertino {
                 begin: _unselectedColor,
                 end: _selectedColor
             );
+            
             _textColorTween = new ColorTween(
                 begin: _selectedColor,
                 end: _unselectedColor
             );
+            
             return changed;
         }
 
         void _updateAnimationControllers() {
             D.assert(mounted, () => "This should only be called after didUpdateDependencies");
-        foreach ( AnimationController controller in _selectionControllers) {
+            foreach (var controller in _selectionControllers) {
                 controller.dispose();
             }
+
             _selectionControllers.Clear();
             _childTweens.Clear();
-        foreach ( T key in widget.children.Keys) {
+            foreach (var key in widget.children.Keys) {
-           AnimationController animationController = createAnimationController();
+                var animationController = createAnimationController();
                 if (widget.groupValue.Equals(key)) {
                     _childTweens.Add(_reverseBackgroundColorTween);
                     animationController.setValue(1.0f);
-          } else {
+                }
+                else {
                     _childTweens.Add(_forwardBackgroundColorTween);
                 }
+
                 _selectionControllers.Add(animationController);
             }
         }
@@ -157,57 +185,65 @@ namespace Unity.UIWidgets.cupertino {
         }
 
         public override void didUpdateWidget(StatefulWidget oldWidget) {
-          oldWidget = (CupertinoSegmentedControl<T>) oldWidget;
+            var _oldWidget = oldWidget as CupertinoSegmentedControl<T>;
             base.didUpdateWidget(oldWidget);
 
-        if (_updateColors() || ((CupertinoSegmentedControl<T>) oldWidget).children.Count != widget.children.Count) {
+            if (_updateColors() || _oldWidget.children.Count != widget.children.Count) {
                 _updateAnimationControllers();
             }
 
-        if (!((CupertinoSegmentedControl<T>)oldWidget).groupValue.Equals(widget.groupValue)) {
+            if (!_oldWidget.groupValue.Equals(widget.groupValue)) {
-          int index = 0;
+                var index = 0;
-          foreach ( T key in widget.children.Keys) {
+                foreach (var key in widget.children.Keys) {
                     if (widget.groupValue.Equals(key)) {
                         _childTweens[index] = _forwardBackgroundColorTween;
                         _selectionControllers[index].forward();
-            } else {
+                    }
+                    else {
                         _childTweens[index] = _reverseBackgroundColorTween;
                         _selectionControllers[index].reverse();
                     }
+
                     index += 1;
                 }
             }
         }
 
         public override void dispose() {
-          foreach( AnimationController animationController in _selectionControllers) {
+            foreach (var animationController in _selectionControllers) {
                 animationController.dispose();
             }
+
             base.dispose();
         }
 
 
         void _onTapDown(T currentKey) {
-        if (_pressedKey == null && !currentKey.Equals(widget.groupValue)) {
+            if (isPressedKeyNull() && !currentKey.Equals(widget.groupValue)) {
                 setState(() => {
-            _pressedKey = currentKey;
+                    setPressedKey(currentKey);
                 });
             }
         }
 
         void _onTapCancel() {
-        setState(()=> {
+            setState(setPressedKeyNull);
-          _pressedKey = default(T);
+        }
-        });
+
+        bool isPressKeyEquals(T currentKey) {
+            return isPressedKeyNull() && currentKey == null ||
+                   !isPressedKeyNull() && currentKey.Equals(getPressedKey());
         }
 
         void _onTap(T currentKey) {
-        if (!currentKey.Equals( _pressedKey))
+            if (!isPressKeyEquals(currentKey))
                 return;
+            
             if (!currentKey.Equals(widget.groupValue)) {
                 widget.onValueChanged(currentKey);
             }
-        _pressedKey = default;
+
+            setPressedKeyNull();
         }
 
         Color getTextColor(int index, T currentKey) {
@@ -223,7 +259,7 @@ namespace Unity.UIWidgets.cupertino {
                 return _childTweens[index].evaluate(_selectionControllers[index]);
             if (widget.groupValue.Equals(currentKey))
                 return _selectedColor;
-        if (_pressedKey.Equals(currentKey))
+            if (isPressKeyEquals(currentKey))
                 return _pressedColor;
             return _unselectedColor;
         }
@@ -232,29 +268,30 @@ namespace Unity.UIWidgets.cupertino {
             List<Widget> _gestureChildren = new List<Widget>();
             List<Color> _backgroundColors = new List<Color>();
             int index = 0;
-        int selectedIndex = 0;
+            int? selectedIndex = null;
-        int pressedIndex = 0;
+            int? pressedIndex = null;
-        foreach ( T currentKey in widget.children.Keys) {
+            foreach (var currentKey in widget.children.Keys) {
-          selectedIndex = (widget.groupValue.Equals(currentKey)) ? index : selectedIndex;
+                var currentKey2 = currentKey;
-          pressedIndex = (_pressedKey.Equals(currentKey)) ? index : pressedIndex;
+                selectedIndex = (widget.groupValue.Equals(currentKey2)) ? index : selectedIndex;
-          TextStyle textStyle = DefaultTextStyle.of(context).style.copyWith(
+                pressedIndex = (isPressKeyEquals(currentKey2)) ? index : pressedIndex;
-            color: getTextColor(index, currentKey)
+                var textStyle = DefaultTextStyle.of(context).style.copyWith(
+                    color: getTextColor(index, currentKey2)
                 );
-           IconThemeData iconTheme = new IconThemeData(
+                var iconTheme = new IconThemeData(
-            color: getTextColor(index, currentKey)
+                    color: getTextColor(index, currentKey2)
                 );
 
                 Widget child = new Center(
-            child: widget.children[currentKey]
+                    child: widget.children[currentKey2]
                 );
 
                 child = new GestureDetector(
                     onTapDown: (TapDownDetails _event) => {
-              _onTapDown(currentKey);
+                        _onTapDown(currentKey2);
                     },
                     onTapCancel: _onTapCancel,
                     onTap: () => {
-              _onTap(currentKey);
+                        _onTap(currentKey2);
                     },
                     child: new IconTheme(
                         data: iconTheme,
@@ -265,7 +302,7 @@ namespace Unity.UIWidgets.cupertino {
                     )
                 );
 
-          _backgroundColors.Add(getBackgroundColor(index, currentKey));
+                _backgroundColors.Add(getBackgroundColor(index, currentKey2));
                 _gestureChildren.Add(child);
                 index += 1;
             }
@@ -287,6 +324,7 @@ namespace Unity.UIWidgets.cupertino {
             );
         }
     }
+
     public class _SegmentedControlRenderWidget<T> : MultiChildRenderObjectWidget {
         public _SegmentedControlRenderWidget(
             Key key = null,
@@ -309,6 +347,7 @@ namespace Unity.UIWidgets.cupertino {
         public readonly int? pressedIndex;
         public readonly List<Color> backgroundColors;
         public readonly Color borderColor;
+
         public override RenderObject createRenderObject(BuildContext context) {
             return new _RenderSegmentedControl<T>(
                 textDirection: Directionality.of(context),
@@ -318,6 +357,7 @@ namespace Unity.UIWidgets.cupertino {
                 borderColor: borderColor
             );
         }
+
         public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
             renderObject = (_RenderSegmentedControl<T>) renderObject;
             ((_RenderSegmentedControl<T>) renderObject).textDirection = Directionality.of(context);
@@ -325,7 +365,6 @@ namespace Unity.UIWidgets.cupertino {
             ((_RenderSegmentedControl<T>) renderObject).pressedIndex = pressedIndex;
             ((_RenderSegmentedControl<T>) renderObject).backgroundColors = backgroundColors;
             ((_RenderSegmentedControl<T>) renderObject).borderColor = borderColor;
-              
         }
     }
 
@@ -358,71 +397,70 @@ namespace Unity.UIWidgets.cupertino {
                 if (_selectedIndex == value) {
                     return;
                 }
+
                 _selectedIndex = value;
                 markNeedsPaint();
             }
         }
+
         int? _selectedIndex;
 
         public int? pressedIndex {
-               get {
+            get { return _pressedIndex; }
-                   return _pressedIndex;
-               }
             set {
                 if (_pressedIndex == value) {
                     return;
                 }
+
                 _pressedIndex = value;
                 markNeedsPaint();
             }
         }
+
         int? _pressedIndex;
 
         public TextDirection? textDirection {
-               get {
+            get { return _textDirection; }
-                   return _textDirection;
-               }
             set {
                 if (_textDirection == value) {
                     return;
                 }
+
                 _textDirection = value;
                 markNeedsLayout();
             }
         }
+
         TextDirection? _textDirection;
 
 
         public List<Color> backgroundColors {
-               get {
+            get { return _backgroundColors; }
-                   return _backgroundColors;
-               }
             set {
                 if (_backgroundColors == value) {
                     return;
                 }
+
                 _backgroundColors = value;
                 markNeedsPaint();
             }
         }
+
         List<Color> _backgroundColors;
 
 
         public Color borderColor {
-               get {
+            get { return _borderColor; }
-                   return _borderColor;
-                   
-               }
             set {
                 if (_borderColor == value) {
                     return;
                 }
+
                 _borderColor = value;
                 markNeedsPaint();
-               
+            }
         }
 
-           }
         Color _borderColor;
 
 
@@ -430,11 +468,13 @@ namespace Unity.UIWidgets.cupertino {
             RenderBox child = firstChild;
             float minWidth = 0.0f;
             while (child != null) {
-                   _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+                _SegmentedControlContainerBoxParentData childParentData =
+                    child.parentData as _SegmentedControlContainerBoxParentData;
                 float childWidth = child.getMinIntrinsicWidth(height);
                 minWidth = Mathf.Max(minWidth, childWidth);
                 child = childParentData.nextSibling;
             }
+
             return minWidth * childCount;
         }
 
@@ -442,11 +482,13 @@ namespace Unity.UIWidgets.cupertino {
             RenderBox child = firstChild;
             float maxWidth = 0.0f;
             while (child != null) {
-                   _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+                _SegmentedControlContainerBoxParentData childParentData =
+                    child.parentData as _SegmentedControlContainerBoxParentData;
                 float childWidth = child.getMaxIntrinsicWidth(height);
                 maxWidth = Mathf.Max(maxWidth, childWidth);
                 child = childParentData.nextSibling;
             }
+
             return maxWidth * childCount;
         }
 
@@ -454,22 +496,27 @@ namespace Unity.UIWidgets.cupertino {
             RenderBox child = firstChild;
             float minHeight = 0.0f;
             while (child != null) {
-                   _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+                _SegmentedControlContainerBoxParentData childParentData =
+                    child.parentData as _SegmentedControlContainerBoxParentData;
                 float childHeight = child.getMinIntrinsicHeight(width);
                 minHeight = Mathf.Max(minHeight, childHeight);
                 child = childParentData.nextSibling;
             }
+
             return minHeight;
         }
+
         protected internal override float computeMaxIntrinsicHeight(float width) {
             RenderBox child = firstChild;
             float maxHeight = 0.0f;
             while (child != null) {
-                   _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+                _SegmentedControlContainerBoxParentData childParentData =
+                    child.parentData as _SegmentedControlContainerBoxParentData;
                 float childHeight = child.getMaxIntrinsicHeight(width);
                 maxHeight = Mathf.Max(maxHeight, childHeight);
                 child = childParentData.nextSibling;
             }
+
             return maxHeight;
         }
 
@@ -488,7 +535,8 @@ namespace Unity.UIWidgets.cupertino {
             RenderBox child = leftChild;
             float start = 0.0f;
             while (child != null) {
-               _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+                _SegmentedControlContainerBoxParentData childParentData =
+                    child.parentData as _SegmentedControlContainerBoxParentData;
                 Offset childOffset = new Offset(start, 0.0f);
                 childParentData.offset = childOffset;
                 Rect childRect = Rect.fromLTWH(start, 0.0f, child.size.width, child.size.height);
@@ -496,17 +544,21 @@ namespace Unity.UIWidgets.cupertino {
                 if (child == leftChild) {
                     rChildRect = RRect.fromRectAndCorners(childRect, topLeft: Radius.circular(3.0f),
                         bottomLeft: Radius.circular(3.0f));
-              } else if (child == rightChild) {
+                }
+                else if (child == rightChild) {
                     rChildRect = RRect.fromRectAndCorners(childRect, topRight: Radius.circular(3.0f),
                         bottomRight: Radius.circular(3.0f));
-              } else {
+                }
+                else {
                     rChildRect = RRect.fromRectAndCorners(childRect, topRight: Radius.zero);
                 }
+
                 childParentData.surroundingRect = rChildRect;
                 start += child.size.width;
                 child = nextChild(child);
             }
         }
+
         protected override void performLayout() {
             BoxConstraints constraints = this.constraints;
             float maxHeight = CupertinoSegmentedControlsUtils._kMinSegmentedControlHeight;
@@ -515,6 +567,7 @@ namespace Unity.UIWidgets.cupertino {
             foreach (RenderBox child in getChildrenAsList()) {
                 childWidth = Mathf.Max(childWidth, child.getMaxIntrinsicWidth(float.PositiveInfinity));
             }
+
             childWidth = Mathf.Min(childWidth, constraints.maxWidth / childCount);
 
             RenderBox child1 = firstChild;
@@ -556,6 +609,7 @@ namespace Unity.UIWidgets.cupertino {
 
             size = constraints.constrain(new Size(childWidth * childCount, maxHeight));
         }
+
         public override void paint(PaintingContext context, Offset offset) {
             RenderBox child = firstChild;
             int index = 0;
@@ -569,20 +623,23 @@ namespace Unity.UIWidgets.cupertino {
         void _paintChild(PaintingContext context, Offset offset, RenderBox child, int childIndex) {
             D.assert(child != null);
 
-             _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+            _SegmentedControlContainerBoxParentData childParentData =
+                child.parentData as _SegmentedControlContainerBoxParentData;
 
             context.canvas.drawRRect(
                 childParentData.surroundingRect.shift(offset),
                 new Paint() {
                     color = backgroundColors[childIndex],
-                style = PaintingStyle.fill}
+                    style = PaintingStyle.fill
+                }
             );
             context.canvas.drawRRect(
                 childParentData.surroundingRect.shift(offset),
                 new Paint() {
                     color = borderColor,
                     strokeWidth = 1.0f,
-                style = PaintingStyle.stroke}
+                    style = PaintingStyle.stroke
+                }
             );
 
             context.paintChild(child, childParentData.offset + offset);
@@ -592,7 +649,8 @@ namespace Unity.UIWidgets.cupertino {
             D.assert(position != null);
             RenderBox child = lastChild;
             while (child != null) {
-               _SegmentedControlContainerBoxParentData childParentData = child.parentData as _SegmentedControlContainerBoxParentData;
+                _SegmentedControlContainerBoxParentData childParentData =
+                    child.parentData as _SegmentedControlContainerBoxParentData;
                 if (childParentData.surroundingRect.contains(position)) {
                     Offset center = (Offset.zero & child.size).center;
                     return result.addWithRawTransform(
@@ -604,15 +662,11 @@ namespace Unity.UIWidgets.cupertino {
                         }
                     );
                 }
+
                 child = childParentData.previousSibling;
             }
+
             return false;
         }
     }
-
-    
-    
-
-
-
 }

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

@@ -1,15 +1,11 @@
 using System;
 using System.Collections.Generic;
-using System.Runtime.CompilerServices;
 using Unity.UIWidgets.animation;
 using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.painting;
 using Unity.UIWidgets.rendering;
 using Unity.UIWidgets.ui;
 using UnityEngine;
-using Color = Unity.UIWidgets.ui.Color;
-using Debug = System.Diagnostics.Debug;
-using Object = System.Object;
 
 namespace Unity.UIWidgets.widgets {
     public class FadeInImage : StatelessWidget {
@@ -30,7 +26,6 @@ namespace Unity.UIWidgets.widgets {
             Key key = null,
             bool matchTextDirection = false
         ) : base(key) {
-           
             D.assert(image != null);
             D.assert(fadeOutDuration != null);
             D.assert(fadeOutCurve != null);
@@ -128,7 +123,6 @@ namespace Unity.UIWidgets.widgets {
             int? imageCacheWidth = null,
             int? imageCacheHeight = null
         ) {
-           
             fadeOutDuration = fadeOutDuration ?? new TimeSpan(0, 0, 0, 0, 300);
             fadeOutCurve = fadeOutCurve ?? Curves.easeOut;
             fadeInDuration = fadeInDuration ?? new TimeSpan(0, 0, 0, 0, 700);
@@ -143,7 +137,61 @@ namespace Unity.UIWidgets.widgets {
             return new FadeInImage(
                 placeholder: _placeholder,
                 placeholderErrorBuilder: placeholderErrorBuilder,
-                image: ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight, new NetworkImage(image, scale: imageScale)),
+                image: ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight,
+                    new NetworkImage(image, scale: imageScale)),
+                imageErrorBuilder: imageErrorBuilder,
+                fadeOutDuration: fadeOutDuration,
+                fadeOutCurve: fadeOutCurve,
+                fadeInDuration: fadeInDuration,
+                fadeInCurve: fadeInCurve,
+                width: width, height: height,
+                fit: fit,
+                alignment: alignment,
+                repeat: repeat,
+                matchTextDirection: matchTextDirection,
+                key: key
+            );
+        }
+        
+        public static FadeInImage fileNetwork(
+            string placeholder,
+            string image,
+            ImageErrorWidgetBuilder placeholderErrorBuilder = null,
+            ImageErrorWidgetBuilder imageErrorBuilder = null,
+            float? placeholderScale = null,
+            float imageScale = 1.0f,
+            TimeSpan? fadeOutDuration = null,
+            Curve fadeOutCurve = null,
+            TimeSpan? fadeInDuration = null,
+            Curve fadeInCurve = null,
+            float? width = null,
+            float? height = null,
+            BoxFit? fit = null,
+            AlignmentGeometry alignment = null,
+            ImageRepeat repeat = ImageRepeat.noRepeat,
+            bool matchTextDirection = false,
+            Key key = null,
+            int? placeholderCacheWidth = null,
+            int? placeholderCacheHeight = null,
+            int? imageCacheWidth = null,
+            int? imageCacheHeight = null
+        ) {
+            fadeOutDuration = fadeOutDuration ?? new TimeSpan(0, 0, 0, 0, 300);
+            fadeOutCurve = fadeOutCurve ?? Curves.easeOut;
+            fadeInDuration = fadeInDuration ?? new TimeSpan(0, 0, 0, 0, 700);
+            fadeInCurve = Curves.easeIn;
+            alignment = alignment ?? Alignment.center;
+            var holder = placeholderScale ?? 1.0f;
+            var _placeholder = placeholderScale != null
+                ? ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight,
+                    new FileImage(placeholder, scale: holder))
+                : ResizeImage.resizeIfNeeded(placeholderCacheWidth, placeholderCacheHeight,
+                    new FileImage(placeholder));
+            return new FadeInImage(
+                placeholder: _placeholder,
+                placeholderErrorBuilder: placeholderErrorBuilder,
+                image: ResizeImage.resizeIfNeeded(imageCacheWidth, imageCacheHeight,
+                    new NetworkImage(image, scale: imageScale)),
                 imageErrorBuilder: imageErrorBuilder,
                 fadeOutDuration: fadeOutDuration,
                 fadeOutCurve: fadeOutCurve,
@@ -190,7 +238,6 @@ namespace Unity.UIWidgets.widgets {
                 repeat: repeat,
                 matchTextDirection: matchTextDirection,
                 gaplessPlayback: true
-                
             );
         }
 
@@ -227,7 +274,6 @@ namespace Unity.UIWidgets.widgets {
             Curve fadeInCurve,
             Key key = null
         ) : base(key: key, duration: fadeInDuration + fadeOutDuration) {
-            
             this.target = target;
             this.placeholder = placeholder;
             this.isTargetLoaded = isTargetLoaded;
@@ -260,30 +306,30 @@ namespace Unity.UIWidgets.widgets {
                     state: this,
                     tween: _targetOpacity,
                     targetValue: widget.isTargetLoaded ? 1.0f : 0.0f,
-                    constructor: (float value) => new FloatTween(begin: value, 0));
+                    constructor: (float value) => new FloatTween(begin: 1 - value, 0));  //TODO: in flutter it is "new FloatTween(begin: value, 0)", which doesn't work out in UIWidgets
 
                 _placeholderOpacity = (FloatTween) visitor.visit(
                     state: this,
                     tween: _placeholderOpacity,
                     targetValue: widget.isTargetLoaded ? 0.0f : 1.0f,
-                    constructor: (float value) => new FloatTween(begin: value, 0));
+                    constructor: (float value) => new FloatTween(begin: 1 - value, 0)); //TODO: in flutter it is "new FloatTween(begin: value, 0)", which doesn't work out in UIWidgets
             }
 
             protected override void didUpdateTweens() {
                 List<TweenSequenceItem<float>> list = new List<TweenSequenceItem<float>>();
 
-                Debug.Assert(widget.fadeOutDuration?.Milliseconds != null,
+                Debug.Assert(widget.fadeOutDuration?.TotalMilliseconds != null,
                     "widget.fadeOutDuration?.Milliseconds != null");
                 list.Add(new TweenSequenceItem<float>(
                     tween: _placeholderOpacity.chain(new CurveTween(curve: widget.fadeOutCurve)),
-                    weight: (float) widget.fadeOutDuration?.Milliseconds
+                    weight: (float) widget.fadeOutDuration?.TotalMilliseconds
                 ));
 
-                Debug.Assert(widget.fadeInDuration?.Milliseconds != null,
+                Debug.Assert(widget.fadeInDuration?.TotalMilliseconds != null,
                     "widget.fadeInDuration?.Milliseconds != null");
                 list.Add(new TweenSequenceItem<float>(
                     tween: new ConstantTween<float>(0),
-                    weight: (float) widget.fadeInDuration?.Milliseconds
+                    weight: (float) widget.fadeInDuration?.TotalMilliseconds
                 ));
 
 
@@ -297,11 +343,11 @@ namespace Unity.UIWidgets.widgets {
                 List<TweenSequenceItem<float>> list2 = new List<TweenSequenceItem<float>>();
                 list2.Add(new TweenSequenceItem<float>(
                     tween: new ConstantTween<float>(0),
-                    weight: (float) widget.fadeOutDuration?.Milliseconds
+                    weight: (float) widget.fadeOutDuration?.TotalMilliseconds
                 ));
                 list2.Add(new TweenSequenceItem<float>(
                     tween: _targetOpacity.chain(new CurveTween(curve: widget.fadeInCurve)),
-                    weight: (float) widget.fadeInDuration?.Milliseconds
+                    weight: (float) widget.fadeInDuration?.TotalMilliseconds
                 ));
                 _targetOpacityAnimation = animation.drive(new TweenSequence<float>(list2));
                 if (!widget.isTargetLoaded && _isValid(_placeholderOpacity) && _isValid(_targetOpacity)) {
@@ -313,7 +359,6 @@ namespace Unity.UIWidgets.widgets {
                 return tween?.begin != null && tween?.end != null;
             }
 
-
             public override Widget build(BuildContext context) {
                 Widget target = new FadeTransition(
                     opacity: _targetOpacityAnimation,
@@ -345,6 +390,5 @@ namespace Unity.UIWidgets.widgets {
                     new DiagnosticsProperty<Animation<float>>("placeholderOpacity", _placeholderOpacityAnimation));
             }
         }
-        
     }
 }

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

@@ -339,7 +339,7 @@ namespace Unity.UIWidgets.widgets {
     }
 
     public class _ImageState : State<Image>, WidgetsBindingObserver {
-        int _frameNumber;
+        int? _frameNumber = null;
 
         ImageInfo _imageInfo;
         ImageStream _imageStream;
@@ -584,7 +584,7 @@ namespace Unity.UIWidgets.widgets {
             description.add(new DiagnosticsProperty<ImageStream>("stream", value: _imageStream));
             description.add(new DiagnosticsProperty<ImageInfo>("pixels", value: _imageInfo));
             description.add(new DiagnosticsProperty<ImageChunkEvent>("loadingProgress", value: _loadingProgress));
-            description.add(new DiagnosticsProperty<int>("frameNumber", value: _frameNumber));
+            description.add(new DiagnosticsProperty<int?>("frameNumber", value: _frameNumber));
             description.add(new DiagnosticsProperty<bool>("wasSynchronouslyLoaded", value: _wasSynchronouslyLoaded));
         }
     }