Merge pull request #781 from Hixie/box_decoration

Make BoxDecoration replaceable.

examples/widgets/drag_and_drop.dart

@@ -50,7 +50,7 @@ class Dot extends StatelessComponent {
       height: size,
       decoration: new BoxDecoration(
         backgroundColor: color,
-        shape: Shape.circle
+        shape: BoxShape.circle
       ),
       child: child
     );

examples/widgets/horizontal_scrolling.dart

@@ -14,7 +14,7 @@ class Circle extends StatelessComponent {
       width: 50.0,
       margin: margin + new EdgeDims.symmetric(horizontal: 2.0),
       decoration: new BoxDecoration(
-        shape: Shape.circle,
+        shape: BoxShape.circle,
         backgroundColor: const Color(0xFF00FF00)
       )
     );

packages/flutter/lib/painting.dart

@@ -15,6 +15,8 @@ library painting;
 export 'src/painting/basic_types.dart';
 export 'src/painting/box_painter.dart';
 export 'src/painting/colors.dart';
+export 'src/painting/decoration.dart';
+export 'src/painting/edge_dims.dart';
 export 'src/painting/shadows.dart';
 export 'src/painting/text_painter.dart';
 export 'src/painting/text_style.dart';

packages/flutter/lib/src/material/circle_avatar.dart

@@ -35,7 +35,7 @@ class CircleAvatar extends StatelessComponent {
       duration: kThemeChangeDuration,
       decoration: new BoxDecoration(
         backgroundColor: color,
-        shape: Shape.circle
+        shape: BoxShape.circle
       ),
       width: 40.0,
       height: 40.0,

packages/flutter/lib/src/material/date_picker.dart

@@ -226,7 +226,7 @@ class DayPicker extends StatelessComponent {
             selectedDate.day == day)
           decoration = new BoxDecoration(
             backgroundColor: theme.primarySwatch[100],
-            shape: Shape.circle
+            shape: BoxShape.circle
           );
 
         // Use a different font color for the current day
@@ -377,7 +377,7 @@ class _YearPickerState extends ScrollableWidgetListState<YearPicker> {
           height: config.itemExtent,
           decoration: year == config.selectedDate.year ? new BoxDecoration(
             backgroundColor: Theme.of(context).primarySwatch[100],
-            shape: Shape.circle
+            shape: BoxShape.circle
           ) : null,
           child: new Center(
             child: new Text(label, style: style)

packages/flutter/lib/src/material/dropdown.dart

@@ -37,11 +37,11 @@ class _DropDownMenuPainter extends CustomPainter {
   final RenderBox renderBox;
 
   void paint(Canvas canvas, Size size) {
-    final BoxPainter painter = new BoxPainter(new BoxDecoration(
+    final BoxPainter painter = new BoxDecoration(
       backgroundColor: color,
       borderRadius: 2.0,
       boxShadow: elevationToShadow[elevation]
-    ));
+    ).createBoxPainter();
 
     double top = renderBox.globalToLocal(new Point(0.0, menuTop)).y;
     double bottom = renderBox.globalToLocal(new Point(0.0, menuBottom)).y;

packages/flutter/lib/src/material/ink_well.dart

@@ -18,7 +18,7 @@ class InkResponse extends StatefulComponent {
     this.onLongPress,
     this.onHighlightChanged,
     this.containedInWell: false,
-    this.highlightShape: Shape.circle
+    this.highlightShape: BoxShape.circle
   }) : super(key: key);
 
   final Widget child;
@@ -27,7 +27,7 @@ class InkResponse extends StatefulComponent {
   final GestureLongPressCallback onLongPress;
   final ValueChanged<bool> onHighlightChanged;
   final bool containedInWell;
-  final Shape highlightShape;
+  final BoxShape highlightShape;
 
   _InkResponseState createState() => new _InkResponseState<InkResponse>();
 }
@@ -170,6 +170,6 @@ class InkWell extends InkResponse {
     onLongPress: onLongPress,
     onHighlightChanged: onHighlightChanged,
     containedInWell: true,
-    highlightShape: Shape.rectangle
+    highlightShape: BoxShape.rectangle
   );
 }

packages/flutter/lib/src/material/material.dart

@@ -65,7 +65,7 @@ abstract class MaterialInkController {
   InkSplash splashAt({ RenderBox referenceBox, Point position, Color color, bool containedInWell, VoidCallback onRemoved });
 
   /// Begin a highlight, coincident with the referenceBox.
-  InkHighlight highlightAt({ RenderBox referenceBox, Color color, Shape shape: Shape.rectangle, VoidCallback onRemoved });
+  InkHighlight highlightAt({ RenderBox referenceBox, Color color, BoxShape shape: BoxShape.rectangle, VoidCallback onRemoved });
 
   /// Add an arbitrary InkFeature to this InkController.
   void addInkFeature(InkFeature feature);
@@ -153,7 +153,7 @@ class _MaterialState extends State<Material> {
           backgroundColor: backgroundColor,
           borderRadius: kMaterialEdges[config.type],
           boxShadow: config.elevation == 0 ? null : elevationToShadow[config.elevation],
-          shape: config.type == MaterialType.circle ? Shape.circle : Shape.rectangle
+          shape: config.type == MaterialType.circle ? BoxShape.circle : BoxShape.rectangle
         ),
         child: contents
       );
@@ -217,7 +217,7 @@ class RenderInkFeatures extends RenderProxyBox implements MaterialInkController
   InkHighlight highlightAt({
     RenderBox referenceBox,
     Color color,
-    Shape shape: Shape.rectangle,
+    BoxShape shape: BoxShape.rectangle,
     VoidCallback onRemoved
   }) {
     _InkHighlight highlight = new _InkHighlight(
@@ -423,7 +423,7 @@ class _InkHighlight extends InkFeature implements InkHighlight {
     renderer.markNeedsPaint();
   }
 
-  final Shape shape;
+  final BoxShape shape;
 
   bool get active => _active;
   bool _active = true;
@@ -452,7 +452,7 @@ class _InkHighlight extends InkFeature implements InkHighlight {
   }
 
   void _paintHighlight(Canvas canvas, Rect rect, paint) {
-    if (shape == Shape.rectangle)
+    if (shape == BoxShape.rectangle)
       canvas.drawRect(rect, paint);
     else
       canvas.drawCircle(rect.center, _kDefaultSplashRadius, paint);

packages/flutter/lib/src/material/switch.dart

@@ -170,7 +170,8 @@ class _RenderSwitch extends RenderToggleable {
     super.handleEvent(event, entry);
   }
 
-  final BoxPainter _thumbPainter = new BoxPainter(const BoxDecoration());
+  Color _cachedThumbColor;
+  BoxPainter _thumbPainter;
 
   void paint(PaintingContext context, Offset offset) {
     final Canvas canvas = context.canvas;
@@ -200,11 +201,14 @@ class _RenderSwitch extends RenderToggleable {
 
     paintRadialReaction(canvas, thumbOffset);
 
-    _thumbPainter.decoration = new BoxDecoration(
-      backgroundColor: thumbColor,
-      shape: Shape.circle,
-      boxShadow: elevationToShadow[1]
-    );
+    if (_cachedThumbColor != thumbColor) {
+      _thumbPainter = new BoxDecoration(
+        backgroundColor: thumbColor,
+        shape: BoxShape.circle,
+        boxShadow: elevationToShadow[1]
+      ).createBoxPainter();
+      _cachedThumbColor = thumbColor;
+    }
 
     // The thumb contracts slightly during the animation
     double inset = 2.0 - (position.value - 0.5).abs() * 2.0;

packages/flutter/lib/src/painting/decoration.dart

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:ui' as ui;
+
+import 'edge_dims.dart';
+
+export 'edge_dims.dart' show EdgeDims;
+
+// This group of classes is intended for painting in cartesian coordinates.
+
+abstract class Decoration {
+  const Decoration();
+  bool debugAssertValid() => true;
+  EdgeDims get padding => null;
+  Decoration lerpFrom(Decoration a, double t) => this;
+  Decoration lerpTo(Decoration b, double t) => b;
+  bool hitTest(ui.Size size, ui.Point position) => true;
+  bool get needsListeners => false;
+  void addChangeListener(ui.VoidCallback listener) { assert(false); }
+  void removeChangeListener(ui.VoidCallback listener) { assert(false); }
+  BoxPainter createBoxPainter();
+  String toString([String prefix = '']) => '$prefix$runtimeType';
+}
+
+abstract class BoxPainter {
+  void paint(ui.Canvas canvas, ui.Rect rect);
+}

packages/flutter/lib/src/painting/edge_dims.dart

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:ui' as ui;
+
+/// An immutable set of offsets in each of the four cardinal directions.
+///
+/// Typically used for an offset from each of the four sides of a box. For
+/// example, the padding inside a box can be represented using this class.
+class EdgeDims {
+  /// Constructs an EdgeDims from offsets from the top, right, bottom and left.
+  const EdgeDims.TRBL(this.top, this.right, this.bottom, this.left);
+
+  /// Constructs an EdgeDims where all the offsets are value.
+  const EdgeDims.all(double value)
+      : top = value, right = value, bottom = value, left = value;
+
+  /// Constructs an EdgeDims with only the given values non-zero.
+  const EdgeDims.only({ this.top: 0.0,
+                        this.right: 0.0,
+                        this.bottom: 0.0,
+                        this.left: 0.0 });
+
+  /// Constructs an EdgeDims with symmetrical vertical and horizontal offsets.
+  const EdgeDims.symmetric({ double vertical: 0.0,
+                             double horizontal: 0.0 })
+    : top = vertical, left = horizontal, bottom = vertical, right = horizontal;
+
+  /// The offset from the top.
+  final double top;
+
+  /// The offset from the right.
+  final double right;
+
+  /// The offset from the bottom.
+  final double bottom;
+
+  /// The offset from the left.
+  final double left;
+
+  /// Whether every dimension is non-negative.
+  bool get isNonNegative => top >= 0.0 && right >= 0.0 && bottom >= 0.0 && left >= 0.0;
+
+  /// The size that this edge dims would occupy with an empty interior.
+  ui.Size get collapsedSize => new ui.Size(left + right, top + bottom);
+
+  ui.Rect inflateRect(ui.Rect rect) {
+    return new ui.Rect.fromLTRB(rect.left - left, rect.top - top, rect.right + right, rect.bottom + bottom);
+  }
+
+  EdgeDims operator -(EdgeDims other) {
+    return new EdgeDims.TRBL(
+      top - other.top,
+      right - other.right,
+      bottom - other.bottom,
+      left - other.left
+    );
+  }
+
+  EdgeDims operator +(EdgeDims other) {
+    return new EdgeDims.TRBL(
+      top + other.top,
+      right + other.right,
+      bottom + other.bottom,
+      left + other.left
+    );
+  }
+
+  EdgeDims operator *(double other) {
+    return new EdgeDims.TRBL(
+      top * other,
+      right * other,
+      bottom * other,
+      left * other
+    );
+  }
+
+  EdgeDims operator /(double other) {
+    return new EdgeDims.TRBL(
+      top / other,
+      right / other,
+      bottom / other,
+      left / other
+    );
+  }
+
+  EdgeDims operator ~/(double other) {
+    return new EdgeDims.TRBL(
+      (top ~/ other).toDouble(),
+      (right ~/ other).toDouble(),
+      (bottom ~/ other).toDouble(),
+      (left ~/ other).toDouble()
+    );
+  }
+
+  EdgeDims operator %(double other) {
+    return new EdgeDims.TRBL(
+      top % other,
+      right % other,
+      bottom % other,
+      left % other
+    );
+  }
+
+  /// Linearly interpolate between two EdgeDims.
+  ///
+  /// If either is null, this function interpolates from [EdgeDims.zero].
+  static EdgeDims lerp(EdgeDims a, EdgeDims b, double t) {
+    if (a == null && b == null)
+      return null;
+    if (a == null)
+      return b * t;
+    if (b == null)
+      return a * (1.0 - t);
+    return new EdgeDims.TRBL(
+      ui.lerpDouble(a.top, b.top, t),
+      ui.lerpDouble(a.right, b.right, t),
+      ui.lerpDouble(a.bottom, b.bottom, t),
+      ui.lerpDouble(a.left, b.left, t)
+    );
+  }
+
+  /// An EdgeDims with zero offsets in each direction.
+  static const EdgeDims zero = const EdgeDims.TRBL(0.0, 0.0, 0.0, 0.0);
+
+  bool operator ==(dynamic other) {
+    if (identical(this, other))
+      return true;
+    if (other is! EdgeDims)
+      return false;
+    final EdgeDims typedOther = other;
+    return top == typedOther.top &&
+           right == typedOther.right &&
+           bottom == typedOther.bottom &&
+           left == typedOther.left;
+  }
+
+  int get hashCode {
+    int value = 373;
+    value = 37 * value + top.hashCode;
+    value = 37 * value + left.hashCode;
+    value = 37 * value + bottom.hashCode;
+    value = 37 * value + right.hashCode;
+    return value;
+  }
+
+  String toString() => "EdgeDims($top, $right, $bottom, $left)";
+}

packages/flutter/lib/src/rendering/box.dart

@@ -13,7 +13,7 @@ import 'package:vector_math/vector_math_64.dart';
 import 'debug.dart';
 import 'object.dart';
 
-export 'package:flutter/painting.dart' show FractionalOffset, TextBaseline;
+export 'package:flutter/painting.dart' show EdgeDims, FractionalOffset, TextBaseline;
 
 // This class should only be used in debug builds
 class _DebugSize extends Size {

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:math' as math;
 import 'dart:ui' as ui;
 
 import 'package:flutter/painting.dart';
@@ -13,13 +12,13 @@ import 'box.dart';
 import 'debug.dart';
 import 'object.dart';
 
-export 'package:flutter/src/painting/box_painter.dart';
 export 'package:flutter/gestures.dart' show
   PointerEvent,
   PointerDownEvent,
   PointerMoveEvent,
   PointerUpEvent,
   PointerCancelEvent;
+export 'package:flutter/painting.dart' show Decoration, BoxDecoration;
 
 /// A base class for render objects that resemble their children.
 ///
@@ -704,9 +703,11 @@ class RenderClipOval extends _RenderCustomClip<Rect> {
   bool hitTest(HitTestResult result, { Point position }) {
     Rect clipBounds = _clip;
     Point center = clipBounds.center;
+    // convert the position to an offset from the center of the unit circle
     Offset offset = new Offset((position.x - center.x) / clipBounds.width,
                                (position.y - center.y) / clipBounds.height);
-    if (offset.distance > 0.5)
+    // check if the point is outside the unit circle
+    if (offset.distanceSquared > 0.25) // x^2 + y^2 > r^2
       return false;
     return super.hitTest(result, position: position);
   }
@@ -720,7 +721,7 @@ class RenderClipOval extends _RenderCustomClip<Rect> {
 }
 
 /// Where to paint a box decoration.
-enum BoxDecorationPosition {
+enum DecorationPosition {
   /// Paint the box decoration behind the children.
   background,
 
@@ -728,97 +729,90 @@ enum BoxDecorationPosition {
   foreground,
 }
 
-/// Paints a [BoxDecoration] either before or after its child paints.
+/// Paints a [Decoration] either before or after its child paints.
 class RenderDecoratedBox extends RenderProxyBox {
 
   RenderDecoratedBox({
-    BoxDecoration decoration,
-    RenderBox child,
-    BoxDecorationPosition position: BoxDecorationPosition.background
-  }) : _painter = new BoxPainter(decoration),
+    Decoration decoration,
+    DecorationPosition position: DecorationPosition.background,
+    RenderBox child
+  }) : _decoration = decoration,
        _position = position,
        super(child) {
     assert(decoration != null);
     assert(position != null);
   }
 
-  /// Where to paint the box decoration.
-  BoxDecorationPosition get position => _position;
-  BoxDecorationPosition _position;
-  void set position (BoxDecorationPosition newPosition) {
-    assert(newPosition != null);
-    if (newPosition == _position)
-      return;
-    markNeedsPaint();
-  }
+  BoxPainter _painter;
 
   /// What decoration to paint.
-  BoxDecoration get decoration => _painter.decoration;
-  void set decoration (BoxDecoration newDecoration) {
+  Decoration get decoration => _decoration;
+  Decoration _decoration;
+  void set decoration (Decoration newDecoration) {
     assert(newDecoration != null);
-    if (newDecoration == _painter.decoration)
+    if (newDecoration == _decoration)
       return;
-    _removeBackgroundImageListenerIfNeeded();
-    _painter.decoration = newDecoration;
-    _addBackgroundImageListenerIfNeeded();
+    _removeListenerIfNeeded();
+    _painter = null;
+    _decoration = newDecoration;
+    _addListenerIfNeeded();
     markNeedsPaint();
   }
 
-  final BoxPainter _painter;
+  /// Where to paint the box decoration.
+  DecorationPosition get position => _position;
+  DecorationPosition _position;
+  void set position (DecorationPosition newPosition) {
+    assert(newPosition != null);
+    if (newPosition == _position)
+      return;
+    _position = newPosition;
+    markNeedsPaint();
+  }
 
-  bool get _needsBackgroundImageListener {
-    return attached &&
-        _painter.decoration != null &&
-        _painter.decoration.backgroundImage != null;
+  bool get _needsListeners {
+    return attached && _decoration.needsListeners;
   }
 
-  void _addBackgroundImageListenerIfNeeded() {
-    if (_needsBackgroundImageListener)
-      _painter.decoration.backgroundImage.addChangeListener(markNeedsPaint);
+  void _addListenerIfNeeded() {
+    if (_needsListeners)
+      _decoration.addChangeListener(markNeedsPaint);
   }
 
-  void _removeBackgroundImageListenerIfNeeded() {
-    if (_needsBackgroundImageListener)
-      _painter.decoration.backgroundImage.removeChangeListener(markNeedsPaint);
+  void _removeListenerIfNeeded() {
+    if (_needsListeners)
+      _decoration.removeChangeListener(markNeedsPaint);
   }
 
   void attach() {
     super.attach();
-    _addBackgroundImageListenerIfNeeded();
+    _addListenerIfNeeded();
   }
 
   void detach() {
-    _removeBackgroundImageListenerIfNeeded();
+    _removeListenerIfNeeded();
     super.detach();
   }
 
   bool hitTestSelf(Point position) {
-    switch (_painter.decoration.shape) {
-      case Shape.rectangle:
-        // TODO(abarth): We should check the border radius.
-        return true;
-      case Shape.circle:
-        // Circles are inscribed into our smallest dimension.
-        Point center = size.center(Point.origin);
-        double distance = (position - center).distance;
-        return distance <= math.min(size.width, size.height) / 2.0;
-    }
+    return _decoration.hitTest(size, position);
   }
 
   void paint(PaintingContext context, Offset offset) {
     assert(size.width != null);
     assert(size.height != null);
-    if (position == BoxDecorationPosition.background)
+    _painter ??= _decoration.createBoxPainter();
+    if (position == DecorationPosition.background)
       _painter.paint(context.canvas, offset & size);
     super.paint(context, offset);
-    if (position == BoxDecorationPosition.foreground)
+    if (position == DecorationPosition.foreground)
       _painter.paint(context.canvas, offset & size);
   }
 
   void debugDescribeSettings(List<String> settings) {
     super.debugDescribeSettings(settings);
     settings.add('decoration:');
-    settings.addAll(_painter.decoration.toString("  ").split('\n'));
+    settings.addAll(_decoration.toString("  ").split('\n'));
   }
 }
 

packages/flutter/lib/src/widgets/animated_container.dart

@@ -16,11 +16,17 @@ class AnimatedBoxConstraintsValue extends AnimatedValue<BoxConstraints> {
   BoxConstraints lerp(double t) => BoxConstraints.lerp(begin, end, t);
 }
 
-class AnimatedBoxDecorationValue extends AnimatedValue<BoxDecoration> {
-  AnimatedBoxDecorationValue(BoxDecoration begin, { BoxDecoration end, Curve curve, Curve reverseCurve })
+class AnimatedDecorationValue extends AnimatedValue<Decoration> {
+  AnimatedDecorationValue(Decoration begin, { Decoration end, Curve curve, Curve reverseCurve })
     : super(begin, end: end, curve: curve, reverseCurve: reverseCurve);
 
-  BoxDecoration lerp(double t) => BoxDecoration.lerp(begin, end, t);
+  Decoration lerp(double t) {
+    if (begin == null && end == null)
+      return null;
+    if (end == null)
+      return begin.lerpTo(end, t);
+    return end.lerpFrom(begin, t);
+  }
 }
 
 class AnimatedEdgeDimsValue extends AnimatedValue<EdgeDims> {
@@ -62,14 +68,14 @@ class AnimatedContainer extends StatefulComponent {
     assert(margin == null || margin.isNonNegative);
     assert(padding == null || padding.isNonNegative);
     assert(curve != null);
-    assert(duration != null);
+    assert(duration != null || decoration.debugAssertValid());
   }
 
   final Widget child;
 
   final BoxConstraints constraints;
-  final BoxDecoration decoration;
-  final BoxDecoration foregroundDecoration;
+  final Decoration decoration;
+  final Decoration foregroundDecoration;
   final EdgeDims margin;
   final EdgeDims padding;
   final Matrix4 transform;
@@ -84,8 +90,8 @@ class AnimatedContainer extends StatefulComponent {
 
 class _AnimatedContainerState extends State<AnimatedContainer> {
   AnimatedBoxConstraintsValue _constraints;
-  AnimatedBoxDecorationValue _decoration;
-  AnimatedBoxDecorationValue _foregroundDecoration;
+  AnimatedDecorationValue _decoration;
+  AnimatedDecorationValue _foregroundDecoration;
   AnimatedEdgeDimsValue _margin;
   AnimatedEdgeDimsValue _padding;
   AnimatedMatrix4Value _transform;
@@ -167,7 +173,7 @@ class _AnimatedContainerState extends State<AnimatedContainer> {
     }
 
     if (config.decoration != null) {
-      _decoration ??= new AnimatedBoxDecorationValue(config.decoration);
+      _decoration ??= new AnimatedDecorationValue(config.decoration);
       if (_configVariable(_decoration, config.decoration))
         needsAnimation = true;
     } else {
@@ -175,7 +181,7 @@ class _AnimatedContainerState extends State<AnimatedContainer> {
     }
 
     if (config.foregroundDecoration != null) {
-      _foregroundDecoration ??= new AnimatedBoxDecorationValue(config.foregroundDecoration);
+      _foregroundDecoration ??= new AnimatedDecorationValue(config.foregroundDecoration);
       if (_configVariable(_foregroundDecoration, config.foregroundDecoration))
         needsAnimation = true;
     } else {

packages/flutter/lib/src/widgets/basic.dart

@@ -16,13 +16,15 @@ export 'package:flutter/rendering.dart' show
     BorderSide,
     BoxConstraints,
     BoxDecoration,
-    BoxDecorationPosition,
     BoxShadow,
+    BoxShape,
     Canvas,
     Color,
     ColorFilter,
     CustomClipper,
     CustomPainter,
+    Decoration,
+    DecorationPosition,
     EdgeDims,
     FlexAlignItems,
     FlexDirection,
@@ -51,7 +53,6 @@ export 'package:flutter/rendering.dart' show
     RadialGradient,
     Rect,
     ScrollDirection,
-    Shape,
     Size,
     StyledTextSpan,
     TextAlign,
@@ -135,7 +136,7 @@ class DecoratedBox extends OneChildRenderObjectWidget {
   DecoratedBox({
     Key key,
     this.decoration,
-    this.position: BoxDecorationPosition.background,
+    this.position: DecorationPosition.background,
     Widget child
   }) : super(key: key, child: child) {
     assert(decoration != null);
@@ -143,10 +144,10 @@ class DecoratedBox extends OneChildRenderObjectWidget {
   }
 
   /// What decoration to paint.
-  final BoxDecoration decoration;
+  final Decoration decoration;
 
   /// Where to paint the box decoration.
-  final BoxDecorationPosition position;
+  final DecorationPosition position;
 
   RenderDecoratedBox createRenderObject() => new RenderDecoratedBox(decoration: decoration, position: position);
 
@@ -782,26 +783,26 @@ class Container extends StatelessComponent {
   }) : super(key: key) {
     assert(margin == null || margin.isNonNegative);
     assert(padding == null || padding.isNonNegative);
-    assert(decoration == null || decoration.shape != Shape.circle || decoration.borderRadius == null); // can't have a border radius if you're a circle
+    assert(decoration == null || decoration.debugAssertValid());
   }
 
   final Widget child;
   final BoxConstraints constraints;
-  final BoxDecoration decoration;
-  final BoxDecoration foregroundDecoration;
+  final Decoration decoration;
+  final Decoration foregroundDecoration;
   final EdgeDims margin;
   final EdgeDims padding;
   final Matrix4 transform;
   final double width;
   final double height;
 
-  EdgeDims get _paddingIncludingBorder {
-    if (decoration == null || decoration.border == null)
+  EdgeDims get _paddingIncludingDecoration {
+    if (decoration == null || decoration.padding == null)
       return padding;
-    EdgeDims borderPadding = decoration.border.dimensions;
+    EdgeDims decorationPadding = decoration.padding;
     if (padding == null)
-      return borderPadding;
-    return padding + borderPadding;
+      return decorationPadding;
+    return padding + decorationPadding;
   }
 
   Widget build(BuildContext context) {
@@ -810,7 +811,7 @@ class Container extends StatelessComponent {
     if (child == null && (width == null || height == null))
       current = new ConstrainedBox(constraints: const BoxConstraints.expand());
 
-    EdgeDims effectivePadding = _paddingIncludingBorder;
+    EdgeDims effectivePadding = _paddingIncludingDecoration;
     if (effectivePadding != null)
       current = new Padding(padding: effectivePadding, child: current);
 
@@ -820,7 +821,7 @@ class Container extends StatelessComponent {
     if (foregroundDecoration != null) {
       current = new DecoratedBox(
         decoration: foregroundDecoration,
-        position: BoxDecorationPosition.foreground,
+        position: DecorationPosition.foreground,
         child: current
       );
     }

packages/unit/test/widget/animated_container_test.dart

@@ -21,6 +21,8 @@ void main() {
         backgroundColor: new Color(0xFF0000FF)
       );
 
+      BoxDecoration actualDecoration;
+
       tester.pumpWidget(
         new AnimatedContainer(
           key: key,
@@ -30,7 +32,8 @@ void main() {
       );
 
       RenderDecoratedBox box = key.currentState.context.findRenderObject();
-      expect(box.decoration.backgroundColor, equals(decorationA.backgroundColor));
+      actualDecoration = box.decoration;
+      expect(actualDecoration.backgroundColor, equals(decorationA.backgroundColor));
 
       tester.pumpWidget(
         new AnimatedContainer(
@@ -41,11 +44,13 @@ void main() {
       );
 
       expect(key.currentState.context.findRenderObject(), equals(box));
-      expect(box.decoration.backgroundColor, equals(decorationA.backgroundColor));
+      actualDecoration = box.decoration;
+      expect(actualDecoration.backgroundColor, equals(decorationA.backgroundColor));
 
       tester.pump(const Duration(seconds: 1));
 
-      expect(box.decoration.backgroundColor, equals(decorationB.backgroundColor));
+      actualDecoration = box.decoration;
+      expect(actualDecoration.backgroundColor, equals(decorationB.backgroundColor));
 
     });
   });

packages/unit/test/widget/box_decoration_test.dart

@@ -14,7 +14,7 @@ void main() {
         new Container(
           padding: new EdgeDims.all(50.0),
           decoration: new BoxDecoration(
-            shape: Shape.circle,
+            shape: BoxShape.circle,
             border: new Border.all(width: 10.0, color: const Color(0x80FF00FF)),
             backgroundColor: Colors.teal[600]
           )

packages/unit/test/widget/render_object_widget_test.dart

@@ -27,7 +27,7 @@ void main() {
       expect(element.renderObject is RenderDecoratedBox, isTrue);
       RenderDecoratedBox renderObject = element.renderObject;
       expect(renderObject.decoration, equals(kBoxDecorationA));
-      expect(renderObject.position, equals(BoxDecorationPosition.background));
+      expect(renderObject.position, equals(DecorationPosition.background));
 
       tester.pumpWidget(new DecoratedBox(decoration: kBoxDecorationB));
       element = tester.findElement((Element element) => element is OneChildRenderObjectElement);
@@ -35,7 +35,7 @@ void main() {
       expect(element.renderObject is RenderDecoratedBox, isTrue);
       renderObject = element.renderObject;
       expect(renderObject.decoration, equals(kBoxDecorationB));
-      expect(renderObject.position, equals(BoxDecorationPosition.background));
+      expect(renderObject.position, equals(DecorationPosition.background));
     });
   });
 
@@ -49,12 +49,12 @@ void main() {
         expect(element.renderObject is RenderDecoratedBox, isTrue);
         RenderDecoratedBox renderObject = element.renderObject;
         expect(renderObject.decoration, equals(kBoxDecorationA));
-        expect(renderObject.position, equals(BoxDecorationPosition.background));
+        expect(renderObject.position, equals(DecorationPosition.background));
         expect(renderObject.child, isNotNull);
         expect(renderObject.child is RenderDecoratedBox, isTrue);
         RenderDecoratedBox child = renderObject.child;
         expect(child.decoration, equals(kBoxDecorationB));
-        expect(child.position, equals(BoxDecorationPosition.background));
+        expect(child.position, equals(DecorationPosition.background));
         expect(child.child, isNull);
       }
 
@@ -65,7 +65,7 @@ void main() {
         expect(element.renderObject is RenderDecoratedBox, isTrue);
         RenderDecoratedBox renderObject = element.renderObject;
         expect(renderObject.decoration, equals(kBoxDecorationA));
-        expect(renderObject.position, equals(BoxDecorationPosition.background));
+        expect(renderObject.position, equals(DecorationPosition.background));
         expect(renderObject.child, isNull);
       }