Rationalise hit testing in the new RenderNode world

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/app.dart';
 import 'package:sky/framework/layout2.dart';
 
 class RenderSolidColor extends RenderDecoratedBox {
   final double desiredHeight;
   final double desiredWidth;
   final int backgroundColor;
 
   RenderSolidColor(int backgroundColor, { this.desiredHeight: double.INFINITY,
                                           this.desiredWidth: double.INFINITY })
       : backgroundColor = backgroundColor,
         super(new BoxDecoration(backgroundColor: backgroundColor));
 
   BoxDimensions getIntrinsicDimensions(BoxConstraints constraints) {
     return new BoxDimensions.withConstraints(constraints,
                                              height: desiredHeight,
                                              width: desiredWidth);
   }
 
   void layout(BoxConstraints constraints, { RenderNode relayoutSubtreeRoot }) {
     width = constraints.constrainWidth(desiredWidth);
     height = constraints.constrainHeight(desiredHeight);
     layoutDone();
   }
 
-  bool handlePointer(PointerEvent event, { double x: 0.0, double y: 0.0 }) {
-    if (event.type == 'pointerdown') {
+  void handlePointer(PointerEvent event) {
+    if (event.type == 'pointerdown')
       setBoxDecoration(new BoxDecoration(backgroundColor: 0xFFFF0000));
-      return true;
-    }
-
-    if (event.type == 'pointerup') {
+    else if (event.type == 'pointerup')
       setBoxDecoration(new BoxDecoration(backgroundColor: backgroundColor));
-      return true;
-    }
-
-    return false;
   }
 }
 
-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);
-}
+AppView app;
 
 void main() {
-  view.setEventCallback(handleEvent);
-  view.setBeginFrameCallback(beginFrame);
-
   var root = new RenderFlex(
       direction: FlexDirection.Vertical,
       decoration: new BoxDecoration(backgroundColor: 0xFF000000));
 
   void addFlexChild(RenderFlex parent, int backgroundColor, { int flex: 0 }) {
     RenderNode child = new RenderSolidColor(backgroundColor);
     parent.add(child);
     child.parentData.flex = flex;
   }
 
@@ skipping 17 matching lines @@
     direction: FlexDirection.Horizontal,
     decoration: new BoxDecoration(backgroundColor: 0xFF333333));
 
   // Purple and blue cells
   addFlexChild(row, 0x77FF00FF, flex: 1);
   addFlexChild(row, 0xFF0000FF, flex: 2);
 
   root.add(row);
   row.parentData.flex = 3;
 
-  renderView = new RenderView(root: root);
-  renderView.layout(newWidth: view.width, newHeight: view.height);
+  app = new AppView(root);
 
-  view.scheduleFrame();
 }