Make hit testing work in layout2.dart

sky/examples/raw/simple_render_tree.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';
 import 'dart:sky';
 import 'package:sky/framework/layout2.dart';
 
 class SimpleBlock extends RenderDecoratedBox {
+  final int backgroundColor;
+
   SimpleBlock(int backgroundColor)
-      : super(new BoxDecoration(backgroundColor: backgroundColor));
+      : super(new BoxDecoration(backgroundColor: backgroundColor)),
+        backgroundColor = backgroundColor;
 
   BoxDimensions getIntrinsicDimensions(BoxConstraints constraints) {
     return new BoxDimensions.withConstraints(constraints, height: 200.0);
   }
 
   void layout(BoxConstraints constraints, { RenderNode relayoutSubtreeRoot }) {
     setWidth(constraints, constraints.maxWidth);
     setHeight(constraints, 200.0);
     layoutDone();
   }
+
+  bool handlePointer(PointerEvent event, { double x: 0.0, double y: 0.0 }) {
+    if (event.type == 'pointerdown') {
+      setBoxDecoration(new BoxDecoration(backgroundColor: 0xFFFF0000));
+      return true;
+    }
+
+    if (event.type == 'pointerup') {
+      setBoxDecoration(new BoxDecoration(backgroundColor: backgroundColor));
+      return true;
+    }
+
+    return false;

[Hixie, 2015/05/21 19:31:42]

This is a rectangle with no holes, so it should always return true.

+  }
+}
+
+RenderView renderView;
+
+void beginFrame(double timeStamp) {
+  RenderNode.flushLayout();
+
+  renderView.paintFrame();
+}
+
+bool handleEvent(Event event) {
+  if (event is! PointerEvent)
+    return false;
+  return renderView.handlePointer(event, x: event.x, y: event.y);
 }
 
 void main() {
+  view.setEventCallback(handleEvent);
+  view.setBeginFrameCallback(beginFrame);
+
   var root = new RenderBlock(
       decoration: new BoxDecoration(backgroundColor: 0xFF00FFFF));
-
   root.add(new SimpleBlock(0xFF00FF00));
   root.add(new SimpleBlock(0xFF0000FF));
 
-  RenderView renderView = new RenderView(root: root);
+  renderView = new RenderView(root: root);
   renderView.layout(newWidth: view.width, newHeight: view.height);
-  renderView.paintFrame();
+
+  view.scheduleFrame();
 }