Add @override annotation to known overriden methods

sky/sdk/lib/rendering/box.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:math' as math;
 import 'dart:sky' as sky;
 
 import 'package:vector_math/vector_math.dart';
 
 import '../base/debug.dart';
@@ skipping 23 matching lines @@
                         this.left: 0.0 });
   const EdgeDims.symmetric({ double vertical: 0.0,
                              double horizontal: 0.0 })
     : top = vertical, left = horizontal, bottom = vertical, right = horizontal;
 
   final double top;
   final double right;
   final double bottom;
   final double left;
 
+  @override
   bool operator ==(other) {
     if (identical(this, other))
       return true;
     return other is EdgeDims
         && top == other.top
         && right == other.right
         && bottom == other.bottom
         && left == other.left;
   }
 
+  @override
   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;
   }
+
+  @override
   String toString() => "EdgeDims($top, $right, $bottom, $left)";
 }
 
 class BoxConstraints extends Constraints {
   const BoxConstraints({
     this.minWidth: 0.0,
     this.maxWidth: double.INFINITY,
     this.minHeight: 0.0,
     this.maxHeight: double.INFINITY
   });
@@ skipping 132 matching lines @@
       result = new _DebugSize(result, size._owner, size._canBeUsedByParent);
     return result;
   }
   Size get biggest => new Size(constrainWidth(), constrainHeight());
   Size get smallest => new Size(constrainWidth(0.0), constrainHeight(0.0));
 
   bool get isInfinite => maxWidth >= double.INFINITY && maxHeight >= double.INFINITY;
 
   bool get hasTightWidth => minWidth >= maxWidth;
   bool get hasTightHeight => minHeight >= maxHeight;
+
+  @override
   bool get isTight => hasTightWidth && hasTightHeight;
 
   bool contains(Size size) {
     return (minWidth <= size.width) && (size.width <= math.max(minWidth, maxWidth)) &&
            (minHeight <= size.height) && (size.height <= math.max(minHeight, maxHeight));
   }
 
+  @override
   bool operator ==(other) {
     if (identical(this, other))
       return true;
     return other is BoxConstraints &&
            minWidth == other.minWidth &&
            maxWidth == other.maxWidth &&
            minHeight == other.minHeight &&
            maxHeight == other.maxHeight;
   }
+
+  @override
   int get hashCode {
     int value = 373;
     value = 37 * value + minWidth.hashCode;
     value = 37 * value + maxWidth.hashCode;
     value = 37 * value + minHeight.hashCode;
     value = 37 * value + maxHeight.hashCode;
     return value;
   }
 
+  @override
   String toString() => "BoxConstraints($minWidth<=w<$maxWidth, $minHeight<=h<$maxHeight)";
 }
 
 class BoxHitTestEntry extends HitTestEntry {
   const BoxHitTestEntry(HitTestTarget target, this.localPosition) : super(target);
   final Point localPosition;
 }
 
 class BoxParentData extends ParentData {
   Point _position = Point.origin;
   Point get position => _position;
   void set position(Point value) {
     assert(RenderObject.debugDoingLayout);
     _position = value;
   }
+
+  @override
   String toString() => 'position=$position';
 }
 
 enum TextBaseline { alphabetic, ideographic }
 
 abstract class RenderBox extends RenderObject {
 
+  @override
   void setupParentData(RenderObject child) {
     if (child.parentData is! BoxParentData)
       child.parentData = new BoxParentData();
   }
 
   // getMinIntrinsicWidth() should return the minimum width that this box could
   // be without failing to render its contents within itself.
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     return constraints.constrainWidth(0.0);
   }
@@ skipping 72 matching lines @@
   // should not be called directly. Use getDistanceToBaseline() if you
   // need to know the baseline of a child from performLayout(). If you
   // need the baseline during paint, cache it during performLayout().
   // Use getDistanceToActualBaseline() if you are implementing
   // computeDistanceToActualBaseline() and need to defer to a child.
   double computeDistanceToActualBaseline(TextBaseline baseline) {
     assert(_debugDoingBaseline);
     return null;
   }
 
+  @override
   BoxConstraints get constraints => super.constraints;
+
+  @override
   bool debugDoesMeetConstraints() {
     assert(constraints != null);
     assert(_size != null);
     assert(!_size.isInfinite);
     bool result = constraints.contains(_size);
     if (!result)
       print("${this.runtimeType} does not meet its constraints. Constraints: $constraints, size: $_size");
     return result;
   }
 
+  @override
   void markNeedsLayout() {
     if (_cachedBaselines != null && _cachedBaselines.isNotEmpty) {
       // if we have cached data, then someone must have used our data
       assert(_ancestorUsesBaseline);
       final parent = this.parent; // TODO(ianh): Remove this once the analyzer is cleverer
       assert(parent is RenderObject);
       parent.markNeedsLayout();
       assert(parent == this.parent); // TODO(ianh): Remove this once the analyzer is cleverer
       // Now that they're dirty, we can forget that they used the
       // baseline. If they use it again, then we'll set the bit
       // again, and if we get dirty again, we'll notify them again.
       _ancestorUsesBaseline = false;
       _cachedBaselines.clear();
     } else {
       // if we've never cached any data, then nobody can have used it
       assert(!_ancestorUsesBaseline);
     }
     super.markNeedsLayout();
   }
+
+  @override
   void performResize() {
     // default behaviour for subclasses that have sizedByParent = true
     size = constraints.constrain(Size.zero);
     assert(!size.isInfinite);
   }
+
+  @override
   void performLayout() {
     // descendants have to either override performLayout() to set both
     // width and height and lay out children, or, set sizedByParent to
     // true so that performResize()'s logic above does its thing.
     assert(sizedByParent);
   }
 
   bool hitTest(HitTestResult result, { Point position }) {
     hitTestChildren(result, position: position);
     result.add(new BoxHitTestEntry(this, position));
@@ skipping 24 matching lines @@
   void set size(Size value) {
     assert((sizedByParent && debugDoingThisResize) ||
            (!sizedByParent && debugDoingThisLayout));
     if (value is _DebugSize) {
       assert(value._canBeUsedByParent);
       assert(value._owner.parent == this);
     }
     _size = inDebugBuild ? new _DebugSize(value, this, debugCanParentUseSize) : value;
   }
 
+  @override
   Rect get paintBounds => Point.origin & size;
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}size: ${size}\n';
 }
 
 class RenderProxyBox extends RenderBox with RenderObjectWithChildMixin<RenderBox> {
 
   // ProxyBox assumes the child will be at 0,0 and will have the same size
 
   RenderProxyBox([RenderBox child = null]) {
     this.child = child;
   }
 
+  @override
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
       return child.getMinIntrinsicWidth(constraints);
     return super.getMinIntrinsicWidth(constraints);
   }
 
+  @override
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
       return child.getMaxIntrinsicWidth(constraints);
     return super.getMaxIntrinsicWidth(constraints);
   }
 
+  @override
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     if (child != null)
       return child.getMinIntrinsicHeight(constraints);
     return super.getMinIntrinsicHeight(constraints);
   }
 
+  @override
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     if (child != null)
       return child.getMaxIntrinsicHeight(constraints);
     return super.getMaxIntrinsicHeight(constraints);
   }
 
+  @override
   double computeDistanceToActualBaseline(TextBaseline baseline) {
     if (child != null)
       return child.getDistanceToActualBaseline(baseline);
     return super.computeDistanceToActualBaseline(baseline);
   }
 
+  @override
   void performLayout() {
     if (child != null) {
       child.layout(constraints, parentUsesSize: true);
       size = child.size;
     } else {
       performResize();
     }
   }
 
+  @override
   void hitTestChildren(HitTestResult result, { Point position }) {
     if (child != null)
       child.hitTest(result, position: position);
     else
       super.hitTestChildren(result, position: position);
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null)
       canvas.paintChild(child, offset.toPoint());
   }
 
 }
 
 class RenderConstrainedBox extends RenderProxyBox {
   RenderConstrainedBox({
     RenderBox child,
     BoxConstraints additionalConstraints
   }) : super(child), _additionalConstraints = additionalConstraints {
     assert(additionalConstraints != null);
   }
 
   BoxConstraints _additionalConstraints;
   BoxConstraints get additionalConstraints => _additionalConstraints;
   void set additionalConstraints (BoxConstraints value) {
     assert(value != null);
     if (_additionalConstraints == value)
       return;
     _additionalConstraints = value;
     markNeedsLayout();
   }
 
+  @override
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
       return child.getMinIntrinsicWidth(_additionalConstraints.apply(constraints));
     return constraints.constrainWidth(0.0);
   }
 
+  @override
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
       return child.getMaxIntrinsicWidth(_additionalConstraints.apply(constraints));
     return constraints.constrainWidth(0.0);
   }
 
+  @override
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     if (child != null)
       return child.getMinIntrinsicHeight(_additionalConstraints.apply(constraints));
     return constraints.constrainHeight(0.0);
   }
 
+  @override
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     if (child != null)
       return child.getMaxIntrinsicHeight(_additionalConstraints.apply(constraints));
     return constraints.constrainHeight(0.0);
   }
 
+  @override
   void performLayout() {
     if (child != null) {
       child.layout(_additionalConstraints.apply(constraints), parentUsesSize: true);
       size = child.size;
     } else {
       size = _additionalConstraints.apply(constraints).constrain(Size.zero);
     }
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}additionalConstraints: ${additionalConstraints}\n';
 }
 
 class RenderShrinkWrapWidth extends RenderProxyBox {
 
   // This class will attempt to size its child to the child's maximum
   // intrinsic width, snapped to a multiple of the stepWidth, if one
   // is provided, and given the provided constraints; and will then
   // adopt the child's resulting dimensions.
 
@@ skipping 31 matching lines @@
   }
 
   BoxConstraints _getInnerConstraints(BoxConstraints constraints) {
     if (constraints.hasTightWidth)
       return constraints;
     double width = child.getMaxIntrinsicWidth(constraints);
     assert(width == constraints.constrainWidth(width));
     return constraints.applyWidth(applyStep(width, _stepWidth));
   }
 
+  @override
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     return getMaxIntrinsicWidth(constraints);
   }
 
+  @override
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     if (child == null)
       return constraints.constrainWidth(0.0);
     double childResult = child.getMaxIntrinsicWidth(constraints);
     return constraints.constrainWidth(applyStep(childResult, _stepWidth));
   }
 
+  @override
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     if (child == null)
       return constraints.constrainWidth(0.0);
     double childResult = child.getMinIntrinsicHeight(_getInnerConstraints(constraints));
     return constraints.constrainHeight(applyStep(childResult, _stepHeight));
   }
 
+  @override
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     if (child == null)
       return constraints.constrainWidth(0.0);
     double childResult = child.getMaxIntrinsicHeight(_getInnerConstraints(constraints));
     return constraints.constrainHeight(applyStep(childResult, _stepHeight));
   }
 
+  @override
   void performLayout() {
     if (child != null) {
       BoxConstraints childConstraints = _getInnerConstraints(constraints);
       if (_stepHeight != null)
         childConstraints.applyHeight(getMaxIntrinsicHeight(childConstraints));
       child.layout(childConstraints, parentUsesSize: true);
       size = child.size;
     } else {
       performResize();
     }
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}stepWidth: ${stepWidth}\n${prefix}stepHeight: ${stepHeight}\n';
 
 }
 
 class RenderOpacity extends RenderProxyBox {
   RenderOpacity({ RenderBox child, double opacity })
     : this._opacity = opacity, super(child) {
     assert(opacity >= 0.0 && opacity <= 1.0);
   }
 
   double _opacity;
   double get opacity => _opacity;
   void set opacity (double value) {
     assert(value != null);
     assert(value >= 0.0 && value <= 1.0);
     if (_opacity == value)
       return;
     _opacity = value;
     markNeedsPaint();
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null) {
       int a = (_opacity * 255).round();
 
       if (a == 0)
         return;
 
       if (a == 255) {
         canvas.paintChild(child, offset.toPoint());
         return;
@@ skipping 27 matching lines @@
   sky.TransferMode _transferMode;
   sky.TransferMode get transferMode => _transferMode;
   void set transferMode (sky.TransferMode value) {
     assert(value != null);
     if (_transferMode == value)
       return;
     _transferMode = value;
     markNeedsPaint();
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null) {
       Paint paint = new Paint()
         ..setColorFilter(new sky.ColorFilter.mode(_color, _transferMode));
       canvas.saveLayer(null, paint);
       canvas.paintChild(child, offset.toPoint());
       canvas.restore();
     }
   }
 }
 
 class RenderClipRect extends RenderProxyBox {
   RenderClipRect({ RenderBox child }) : super(child);
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null) {
       canvas.save();
       canvas.clipRect(offset & size);
       canvas.paintChild(child, offset.toPoint());
       canvas.restore();
     }
   }
 }
 
@@ skipping 17 matching lines @@
   double _yRadius;
   double get yRadius => _yRadius;
   void set yRadius (double value) {
     assert(value != null);
     if (_yRadius == value)
       return;
     _yRadius = value;
     markNeedsPaint();
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null) {
       Rect rect = offset & size;
       canvas.saveLayer(rect, new Paint());
       sky.RRect rrect = new sky.RRect()..setRectXY(rect, xRadius, yRadius);
       canvas.clipRRect(rrect);
       canvas.paintChild(child, offset.toPoint());
       canvas.restore();
     }
   }
 }
 
 class RenderClipOval extends RenderProxyBox {
   RenderClipOval({ RenderBox child }) : super(child);
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null) {
       Rect rect = offset & size;
       canvas.saveLayer(rect, new Paint());
       Path path = new Path();
       path.addOval(rect);
       canvas.clipPath(path);
       canvas.paintChild(child, offset.toPoint());
       canvas.restore();
     }
   }
 }
 
 abstract class RenderShiftedBox extends RenderBox with RenderObjectWithChildMixin<RenderBox> {
 
   // Abstract class for one-child-layout render boxes
 
   RenderShiftedBox(RenderBox child) {
     this.child = child;
   }
 
+  @override
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
       return child.getMinIntrinsicWidth(constraints);
     return super.getMinIntrinsicWidth(constraints);
   }
 
+  @override
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
       return child.getMaxIntrinsicWidth(constraints);
     return super.getMaxIntrinsicWidth(constraints);
   }
 
+  @override
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     if (child != null)
       return child.getMinIntrinsicHeight(constraints);
     return super.getMinIntrinsicHeight(constraints);
   }
 
+  @override
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     if (child != null)
       return child.getMaxIntrinsicHeight(constraints);
     return super.getMaxIntrinsicHeight(constraints);
   }
 
+  @override
   double computeDistanceToActualBaseline(TextBaseline baseline) {
     double result;
     if (child != null) {
       assert(!needsLayout);
       result = child.getDistanceToActualBaseline(baseline);
       assert(child.parentData is BoxParentData);
       if (result != null)
         result += child.parentData.position.y;
     } else {
       result = super.computeDistanceToActualBaseline(baseline);
     }
     return result;
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null)
       canvas.paintChild(child, child.parentData.position + offset);
   }
 
+  @override
   void hitTestChildren(HitTestResult result, { Point position }) {
     if (child != null) {
       assert(child.parentData is BoxParentData);
       Rect childBounds = child.parentData.position & child.size;
       if (childBounds.contains(position)) {
         child.hitTest(result, position: new Point(position.x - child.parentData.position.x,
                                                       position.y - child.parentData.position.y));
       }
     }
   }
@@ skipping 10 matching lines @@
   EdgeDims _padding;
   EdgeDims get padding => _padding;
   void set padding (EdgeDims value) {
     assert(value != null);
     if (_padding == value)
       return;
     _padding = value;
     markNeedsLayout();
   }
 
+  @override
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     double totalPadding = padding.left + padding.right;
     if (child != null)
       return child.getMinIntrinsicWidth(constraints.deflate(padding)) + totalPadding;
     return constraints.constrainWidth(totalPadding);
   }
 
+  @override
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     double totalPadding = padding.left + padding.right;
     if (child != null)
       return child.getMaxIntrinsicWidth(constraints.deflate(padding)) + totalPadding;
     return constraints.constrainWidth(totalPadding);
   }
 
+  @override
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     double totalPadding = padding.top + padding.bottom;
     if (child != null)
       return child.getMinIntrinsicHeight(constraints.deflate(padding)) + totalPadding;
     return constraints.constrainHeight(totalPadding);
   }
 
+  @override
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     double totalPadding = padding.top + padding.bottom;
     if (child != null)
       return child.getMaxIntrinsicHeight(constraints.deflate(padding)) + totalPadding;
     return constraints.constrainHeight(totalPadding);
   }
 
+  @override
   void performLayout() {
     assert(padding != null);
     if (child == null) {
       size = constraints.constrain(new Size(
         padding.left + padding.right,
         padding.top + padding.bottom
       ));
       return;
     }
     BoxConstraints innerConstraints = constraints.deflate(padding);
     child.layout(innerConstraints, parentUsesSize: true);
     assert(child.parentData is BoxParentData);
     child.parentData.position = new Point(padding.left, padding.top);
     size = constraints.constrain(new Size(
       padding.left + child.size.width + padding.right,
       padding.top + child.size.height + padding.bottom
     ));
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}padding: ${padding}\n';
 }
 
 class RenderPositionedBox extends RenderShiftedBox {
 
   // This box aligns a child box within itself. It's only useful for
   // children that don't always size to fit their parent. For example,
   // to align a box at the bottom right, you would pass this box a
   // tight constraint that is bigger than the child's natural size,
   // with horizontal and vertical set to 1.0.
@@ skipping 22 matching lines @@
   double _vertical;
   double get vertical => _vertical;
   void set vertical (double value) {
     assert(value != null);
     if (_vertical == value)
       return;
     _vertical = value;
     markNeedsLayout();
   }
 
+  @override
   void performLayout() {
     if (child != null) {
       child.layout(constraints.loosen(), parentUsesSize: true);
       size = constraints.constrain(child.size);
       assert(child.parentData is BoxParentData);
       Offset delta = size - child.size;
       child.parentData.position = (delta.scale(horizontal, vertical)).toPoint();
     } else {
       performResize();
     }
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}horizontal: ${horizontal}\n${prefix}vertical: ${vertical}\n';
 }
 
 class RenderBaseline extends RenderShiftedBox {
 
   RenderBaseline({
     RenderBox child,
     double baseline,
     TextBaseline baselineType
   }) : _baseline = baseline,
@@ skipping 16 matching lines @@
   TextBaseline _baselineType;
   TextBaseline get baselineType => _baselineType;
   void set baselineType (TextBaseline value) {
     assert(value != null);
     if (_baselineType == value)
       return;
     _baselineType = value;
     markNeedsLayout();
   }
 
+  @override
   void performLayout() {
     if (child != null) {
       child.layout(constraints.loosen(), parentUsesSize: true);
       size = constraints.constrain(child.size);
       assert(child.parentData is BoxParentData);
       double delta = baseline - child.getDistanceToBaseline(baselineType);
       child.parentData.position = new Point(0.0, delta);
     } else {
       performResize();
     }
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}baseline: ${baseline}\nbaselineType: ${baselineType}';
 }
 
 class RenderImage extends RenderBox {
 
   RenderImage(sky.Image image, Size requestedSize)
     : _image = image, _requestedSize = requestedSize;
 
   sky.Image _image;
   sky.Image get image => _image;
@@ skipping 50 matching lines @@
       }
       if (requestedSize.height == null) {
         // determine height from width
         double height = requestedSize.width * _image.height / _image.width;
         return constraints.constrain(new Size(requestedSize.width, height));
       }
     }
     return constraints.constrain(requestedSize);
   }
 
+  @override
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     if (requestedSize.width == null && requestedSize.height == null)
       return constraints.constrainWidth(0.0);
     return _sizeForConstraints(constraints).width;
   }
 
+  @override
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     return _sizeForConstraints(constraints).width;
   }
 
+  @override
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     if (requestedSize.width == null && requestedSize.height == null)
       return constraints.constrainHeight(0.0);
     return _sizeForConstraints(constraints).height;
   }
 
+  @override
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     return _sizeForConstraints(constraints).height;
   }
 
+  @override
   void performLayout() {
     size = _sizeForConstraints(constraints);
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (_image == null)
       return;
     bool needsScale = size.width != _image.width || size.height != _image.height;
     if (needsScale) {
       double widthScale = size.width / _image.width;
       double heightScale = size.height / _image.height;
       canvas.save();
       canvas.translate(offset.dx, offset.dy);
       canvas.scale(widthScale, heightScale);
       offset = Offset.zero;
     }
     Paint paint = new Paint();
     canvas.drawImage(_image, offset.toPoint(), paint);
     if (needsScale)
       canvas.restore();
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}dimensions: ${requestedSize}\n';
 }
 
 class RenderDecoratedBox extends RenderProxyBox {
 
   RenderDecoratedBox({
     BoxDecoration decoration,
     RenderBox child
   }) : _painter = new BoxPainter(decoration), super(child);
 
   BoxPainter _painter;
   BoxDecoration get decoration => _painter.decoration;
   void set decoration (BoxDecoration value) {
     assert(value != null);
     if (_painter.decoration.backgroundImage != null)
       _painter.decoration.backgroundImage.removeChangeListener(markNeedsPaint);
     if (value.backgroundImage != null)
       value.backgroundImage.addChangeListener(markNeedsPaint);
     if (value == _painter.decoration)
       return;
     _painter.decoration = value;
     markNeedsPaint();
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     assert(size.width != null);
     assert(size.height != null);
     _painter.paint(canvas, offset & size);
     super.paint(canvas, offset);
   }
 
+  @override
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}decoration:\n${_painter.decoration.toString(prefix + "  ")}\n';
 }
 
 class RenderTransform extends RenderProxyBox {
+  @override
   bool get createNewDisplayList => true;
 
   RenderTransform({
     Matrix4 transform,
     RenderBox child
   }) : super(child) {
     assert(transform != null);
     this.transform = transform;
   }
 
@@ skipping 30 matching lines @@
   void translate(x, [double y = 0.0, double z = 0.0]) {
     _transform.translate(x, y, z);
     markNeedsPaint();
   }
 
   void scale(x, [double y, double z]) {
     _transform.scale(x, y, z);
     markNeedsPaint();
   }
 
+  @override
   void hitTestChildren(HitTestResult result, { Point position }) {
     Matrix4 inverse = new Matrix4.zero();
     /* double det = */ inverse.copyInverse(_transform);
     // TODO(abarth): Check the determinant for degeneracy.
 
     Vector3 position3 = new Vector3(position.x, position.y, 0.0);
     Vector3 transformed3 = inverse.transform3(position3);
     Point transformed = new Point(transformed3.x, transformed3.y);
     super.hitTestChildren(result, position: transformed);
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     canvas.save();
     canvas.translate(offset.dx, offset.dy);
     canvas.concat(_transform.storage);
     super.paint(canvas, Offset.zero);
     canvas.restore();
   }
 
+  @override
   String debugDescribeSettings(String prefix) {
     List<String> result = _transform.toString().split('\n').map((s) => '$prefix  $s\n').toList();
     result.removeLast();
     return '${super.debugDescribeSettings(prefix)}${prefix}transform matrix:\n${result.join()}';
   }
 }
 
 typedef void SizeChangedCallback(Size newSize);
 
 class RenderSizeObserver extends RenderProxyBox {
   RenderSizeObserver({
     this.callback,
     RenderBox child
   }) : super(child) {
     assert(callback != null);
   }
 
   SizeChangedCallback callback;
 
+  @override
   void performLayout() {
     Size oldSize = size;
 
     super.performLayout();
 
     if (oldSize != size)
       callback(size);
   }
 }
 
@@ skipping 11 matching lines @@
 
   CustomPaintCallback _callback;
   void set callback (CustomPaintCallback value) {
     assert(value != null || !attached);
     if (_callback == value)
       return;
     _callback = value;
     markNeedsPaint();
   }
 
+  @override
   void attach() {
     assert(_callback != null);
     super.attach();
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     assert(_callback != null);
     canvas.translate(offset.dx, offset.dy);
     _callback(canvas, size);
     super.paint(canvas, Offset.zero);
     canvas.translate(-offset.dx, -offset.dy);
   }
 }
 
 // RENDER VIEW LAYOUT MANAGER
 
 class ViewConstraints {
   const ViewConstraints({
     this.size: Size.zero,
     this.orientation
   });
   final Size size;
   final int orientation;
 }
 
 class RenderView extends RenderObject with RenderObjectWithChildMixin<RenderBox> {
+  @override
   bool get createNewDisplayList => true;
 
   RenderView({
     RenderBox child,
     this.timeForRotation: const Duration(microseconds: 83333)
   }) {
     this.child = child;
   }
 
   Size _size = Size.zero;
   Size get size => _size;
 
   int _orientation; // 0..3
   int get orientation => _orientation;
   Duration timeForRotation;
 
   ViewConstraints _rootConstraints;
   ViewConstraints get rootConstraints => _rootConstraints;
   void set rootConstraints(ViewConstraints value) {
     if (_rootConstraints == value)
       return;
     _rootConstraints = value;
     markNeedsLayout();
   }
 
   // We never call layout() on this class, so this should never get
   // checked. (This class is laid out using scheduleInitialLayout().)
+  @override
   bool debugDoesMeetConstraints() { assert(false); return false; }
 
+  @override
   void performResize() {
     assert(false);
   }
 
+  @override
   void performLayout() {
     if (_rootConstraints.orientation != _orientation) {
       if (_orientation != null && child != null)
         child.rotate(oldAngle: _orientation, newAngle: _rootConstraints.orientation, time: timeForRotation);
       _orientation = _rootConstraints.orientation;
     }
     _size = _rootConstraints.size;
     assert(!_size.isInfinite);
 
     if (child != null)
       child.layout(new BoxConstraints.tight(_size));
   }
 
+  @override
   void rotate({ int oldAngle, int newAngle, Duration time }) {
     assert(false); // nobody tells the screen to rotate, the whole rotate() dance is started from our performResize()
   }
 
   bool hitTest(HitTestResult result, { Point position }) {
     if (child != null) {
       Rect childBounds = Point.origin & child.size;
       if (childBounds.contains(position))
         child.hitTest(result, position: position);
     }
     result.add(new HitTestEntry(this));
     return true;
   }
 
+  @override
   void paint(PaintingCanvas canvas, Offset offset) {
     if (child != null)
       canvas.paintChild(child, offset.toPoint());
   }
 
   void paintFrame() {
     sky.tracing.begin('RenderView.paintFrame');
     try {
       sky.PictureRecorder recorder = new sky.PictureRecorder();
       PaintingCanvas canvas = new PaintingCanvas(recorder, paintBounds);
       canvas.drawPaintingNode(paintingNode, Point.origin);
       sky.view.picture = recorder.endRecording();
     } finally {
       sky.tracing.end('RenderView.paintFrame');
     }
   }
 
+  @override
   Rect get paintBounds => Point.origin & size;
 }
 
 // HELPER METHODS FOR RENDERBOX CONTAINERS
 abstract class RenderBoxContainerDefaultsMixin<ChildType extends RenderBox, ParentDataType extends ContainerParentDataMixin<ChildType>> implements ContainerRenderObjectMixin<ChildType, ParentDataType> {
 
   // This class, by convention, doesn't override any members of the superclass.
   // It only provides helper functions that subclasses can call.
 
   double defaultComputeDistanceToFirstActualBaseline(TextBaseline baseline) {
@@ skipping 45 matching lines @@
 
   void defaultPaint(PaintingCanvas canvas, Offset offset) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position + offset);
       child = child.parentData.nextSibling;
     }
   }
 }