Split layout2.dart into several files

sky/sdk/lib/framework/rendering/render_box.dart

Index: sky/sdk/lib/framework/rendering/render_box.dart
diff --git a/sky/sdk/lib/framework/rendering/render_box.dart b/sky/sdk/lib/framework/rendering/render_box.dart
new file mode 100644
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+++ b/sky/sdk/lib/framework/rendering/render_box.dart
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+// 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 'render_node.dart';
+import 'dart:sky' as sky;
+
+// GENERIC BOX RENDERING
+// Anything that has a concept of x, y, width, height is going to derive from this
+
+class EdgeDims {
+  // used for e.g. padding
+  const EdgeDims(this.top, this.right, this.bottom, this.left);
+  final double top;
+  final double right;
+  final double bottom;
+  final double left;
+  operator ==(EdgeDims other) => (top == other.top) ||
+                                 (right == other.right) ||
+                                 (bottom == other.bottom) ||
+                                 (left == other.left);
+}
+
+class BoxConstraints {
+  const BoxConstraints({
+    this.minWidth: 0.0,
+    this.maxWidth: double.INFINITY,
+    this.minHeight: 0.0,
+    this.maxHeight: double.INFINITY});
+
+  BoxConstraints.tight(sky.Size size)
+    : minWidth = size.width,
+      maxWidth = size.width,
+      minHeight = size.height,
+      maxHeight = size.height;
+
+  BoxConstraints deflate(EdgeDims edges) {
+    assert(edges != null);
+    return new BoxConstraints(
+      minWidth: minWidth,
+      maxWidth: maxWidth - (edges.left + edges.right),
+      minHeight: minHeight,
+      maxHeight: maxHeight - (edges.top + edges.bottom)
+    );
+  }
+
+  final double minWidth;
+  final double maxWidth;
+  final double minHeight;
+  final double maxHeight;
+
+  double constrainWidth(double width) {
+    return clamp(min: minWidth, max: maxWidth, value: width);
+  }
+
+  double constrainHeight(double height) {
+    return clamp(min: minHeight, max: maxHeight, value: height);
+  }
+
+  sky.Size constrain(sky.Size size) {
+    return new sky.Size(constrainWidth(size.width), constrainHeight(size.height));
+  }
+
+  bool get isInfinite => maxWidth >= double.INFINITY || maxHeight >= double.INFINITY;
+}
+
+class BoxParentData extends ParentData {
+  sky.Point position = new sky.Point(0.0, 0.0);
+}
+
+abstract class RenderBox extends RenderNode {
+
+  void setParentData(RenderNode child) {
+    if (child.parentData is! BoxParentData)
+      child.parentData = new BoxParentData();
+  }
+
+  // override this to report what dimensions you would have if you
+  // were laid out with the given constraints this can walk the tree
+  // if it must, but it should be as cheap as possible; just get the
+  // dimensions and nothing else (e.g. don't calculate hypothetical
+  // child positions if they're not needed to determine dimensions)
+  sky.Size getIntrinsicDimensions(BoxConstraints constraints) {
+    return constraints.constrain(new sky.Size(0.0, 0.0));
+  }
+
+  BoxConstraints get constraints => super.constraints as BoxConstraints;
+  void performResize() {
+    // default behaviour for subclasses that have sizedByParent = true
+    size = constraints.constrain(new sky.Size(0.0, 0.0));
+    assert(size.height < double.INFINITY);
+    assert(size.width < double.INFINITY);
+  }
+  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, { sky.Point position }) {
+    hitTestChildren(result, position: position);
+    result.add(this);
+    return true;
+  }
+  void hitTestChildren(HitTestResult result, { sky.Point position }) { }
+
+  sky.Size size = new sky.Size(0.0, 0.0);
+}
+
+abstract class RenderProxyBox extends RenderBox with RenderNodeWithChildMixin<RenderBox> {
+  RenderProxyBox(RenderBox child) {
+    this.child = child;
+  }
+
+  sky.Size getIntrinsicDimensions(BoxConstraints constraints) {
+    if (child != null)
+      return child.getIntrinsicDimensions(constraints);
+    return super.getIntrinsicDimensions(constraints);
+  }
+
+  void performLayout() {
+    if (child != null) {
+      child.layout(constraints, parentUsesSize: true);
+      size = child.size;
+    } else {
+      performResize();
+    }
+  }
+
+  void hitTestChildren(HitTestResult result, { sky.Point position }) {
+    if (child != null)
+      child.hitTest(result, position: position);
+    else
+      super.hitTestChildren(result, position: position);
+  }
+
+  void paint(RenderNodeDisplayList canvas) {
+    if (child != null)
+      child.paint(canvas);
+  }
+}
+
+class RenderSizedBox extends RenderProxyBox {
+  final sky.Size desiredSize;
+
+  RenderSizedBox({
+    RenderBox child, 
+    this.desiredSize: const sky.Size.infinite()
+  }) : super(child);
+
+  sky.Size getIntrinsicDimensions(BoxConstraints constraints) {
+    return constraints.constrain(desiredSize);
+  }
+
+  void performLayout() {
+    size = constraints.constrain(desiredSize);
+    child.layout(new BoxConstraints.tight(size));
+  }
+}
+
+class RenderPadding extends RenderBox with RenderNodeWithChildMixin<RenderBox> {
+
+  RenderPadding(EdgeDims padding, RenderBox child) {
+    assert(padding != null);
+    this.padding = padding;
+    this.child = child;
+  }
+
+  EdgeDims _padding;
+  EdgeDims get padding => _padding;
+  void set padding (EdgeDims value) {
+    assert(value != null);
+    if (_padding != value) {
+      _padding = value;
+      markNeedsLayout();
+    }
+  }
+
+  sky.Size getIntrinsicDimensions(BoxConstraints constraints) {
+    assert(padding != null);
+    constraints = constraints.deflate(padding);
+    if (child == null)
+      return super.getIntrinsicDimensions(constraints);
+    return child.getIntrinsicDimensions(constraints);
+  }
+
+  void performLayout() {
+    assert(padding != null);
+    BoxConstraints innerConstraints = constraints.deflate(padding);
+    if (child == null) {
+      size = innerConstraints.constrain(
+          new sky.Size(padding.left + padding.right, padding.top + padding.bottom));
+      return;
+    }
+    child.layout(innerConstraints, parentUsesSize: true);
+    assert(child.parentData is BoxParentData);
+    child.parentData.position = new sky.Point(padding.left, padding.top);
+    size = constraints.constrain(new sky.Size(padding.left + child.size.width + padding.right,
+                                              padding.top + child.size.height + padding.bottom));
+  }
+
+  void paint(RenderNodeDisplayList canvas) {
+    if (child != null)
+      canvas.paintChild(child, child.parentData.position);
+  }
+
+  void hitTestChildren(HitTestResult result, { sky.Point position }) {
+    if (child != null) {
+      assert(child.parentData is BoxParentData);
+      sky.Rect childBounds = new sky.Rect.fromPointAndSize(child.parentData.position, child.size);
+      if (childBounds.contains(position)) {
+        child.hitTest(result, position: new sky.Point(position.x - child.parentData.position.x,
+                                                      position.y - child.parentData.position.y));
+      }
+    }
+  }
+
+}
+
+// This must be immutable, because we won't notice when it changes
+class BoxDecoration {
+  const BoxDecoration({
+    this.backgroundColor
+  });
+
+  final int backgroundColor;
+}
+
+class RenderDecoratedBox extends RenderProxyBox {
+
+  RenderDecoratedBox({
+    BoxDecoration decoration,
+    RenderBox child
+  }) : _decoration = decoration, super(child);
+
+  BoxDecoration _decoration;
+  BoxDecoration get decoration => _decoration;
+  void set decoration (BoxDecoration value) {
+    if (value == _decoration)
+      return;
+    _decoration = value;
+    markNeedsPaint();
+  }
+
+  void paint(RenderNodeDisplayList canvas) {
+    assert(size.width != null);
+    assert(size.height != null);
+
+    if (_decoration == null)
+      return;
+
+    if (_decoration.backgroundColor != null) {
+      sky.Paint paint = new sky.Paint()..color = _decoration.backgroundColor;
+      canvas.drawRect(new sky.Rect.fromLTRB(0.0, 0.0, size.width, size.height), paint);
+    }
+    super.paint(canvas);
+  }
+
+}
+
+
+// RENDER VIEW LAYOUT MANAGER
+
+class ViewConstraints {
+
+  const ViewConstraints({
+    this.width: 0.0, this.height: 0.0, this.orientation: null
+  });
+
+  final double width;
+  final double height;
+  final int orientation;
+
+}
+
+class RenderView extends RenderNode with RenderNodeWithChildMixin<RenderBox> {
+
+  RenderView({
+    RenderBox child,
+    this.timeForRotation: const Duration(microseconds: 83333)
+  }) {
+    this.child = child;
+  }
+
+  sky.Size _size = new sky.Size(0.0, 0.0);
+  double get width => _size.width;
+  double get height => _size.height;
+
+  int _orientation; // 0..3
+  int get orientation => _orientation;
+  Duration timeForRotation;
+
+  ViewConstraints get constraints => super.constraints as ViewConstraints;
+  bool get sizedByParent => true;
+  void performResize() {
+    if (constraints.orientation != _orientation) {
+      if (_orientation != null && child != null)
+        child.rotate(oldAngle: _orientation, newAngle: constraints.orientation, time: timeForRotation);
+      _orientation = constraints.orientation;
+    }
+    _size = new sky.Size(constraints.width, constraints.height);
+    assert(_size.height < double.INFINITY);
+    assert(_size.width < double.INFINITY);
+  }
+  void performLayout() {
+    if (child != null) {
+      child.layout(new BoxConstraints.tight(_size));
+      assert(child.size.width == width);
+      assert(child.size.height == height);
+    }
+  }
+
+  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, { sky.Point position }) {
+    if (child != null) {
+      sky.Rect childBounds = new sky.Rect.fromSize(child.size);
+      if (childBounds.contains(position))
+        child.hitTest(result, position: position);
+    }
+    result.add(this);
+    return true;
+  }
+
+  void paint(RenderNodeDisplayList canvas) {
+    if (child != null)
+      canvas.paintChild(child, new sky.Point(0.0, 0.0));
+  }
+
+  void paintFrame() {
+    RenderNode.debugDoingPaint = true;
+    var canvas = new RenderNodeDisplayList(sky.view.width, sky.view.height);
+    paint(canvas);
+    sky.view.picture = canvas.endRecording();
+    RenderNode.debugDoingPaint = false;
+  }
+
+}
+
+// DEFAULT BEHAVIORS FOR RENDERBOX CONTAINERS
+abstract class RenderBoxContainerDefaultsMixin<ChildType extends RenderBox, ParentDataType extends ContainerParentDataMixin<ChildType>> implements ContainerRenderNodeMixin<ChildType, ParentDataType> {
+
+  void defaultHitTestChildren(HitTestResult result, { sky.Point position }) {
+    // the x, y parameters have the top left of the node's box as the origin
+    ChildType child = lastChild;
+    while (child != null) {
+      assert(child.parentData is ParentDataType);
+      sky.Rect childBounds = new sky.Rect.fromPointAndSize(child.parentData.position, child.size);
+      if (childBounds.contains(position)) {
+        if (child.hitTest(result, position: new sky.Point(position.x - child.parentData.position.x,
+                                                          position.y - child.parentData.position.y)))
+          break;
+      }
+      child = child.parentData.previousSibling;
+    }
+  }
+
+  void defaultPaint(RenderNodeDisplayList canvas) {
+    RenderBox child = firstChild;
+    while (child != null) {
+      assert(child.parentData is ParentDataType);
+      canvas.paintChild(child, child.parentData.position);
+      child = child.parentData.nextSibling;
+    }
+  }
+}