Make hit testing work in layout2.dart

sky/sdk/lib/framework/layout2.dart

Index: sky/sdk/lib/framework/layout2.dart
diff --git a/sky/sdk/lib/framework/layout2.dart b/sky/sdk/lib/framework/layout2.dart
index c3ae7d70c05360f0dc2d9861de50665e881b549d..75ff4e6878d10d540d89d2818ffe75f371bddfc8 100644
--- a/sky/sdk/lib/framework/layout2.dart
+++ b/sky/sdk/lib/framework/layout2.dart
@@ -218,7 +218,7 @@ abstract class RenderNode extends AbstractNode {
 
   // HIT TESTING  
 
-  void handlePointer(sky.PointerEvent event) {
+  bool handlePointer(sky.PointerEvent event, { double x: 0.0, double y: 0.0 }) {

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

Remove the x/y arguments here.

     // override this if you have children, to hand it to the appropriate child
     // override this if you want to do anything with the pointer event
   }

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

Add the following (or something like it):

// The parent will call this if the pointer is within the bounds of the child.
For
// RenderBox, the bounds are defined by the height and width; other RenderNode
// subclasses may define this differently.
// If the child does not cover its entire bounds, for example if it has a hole
in
// the middle, then it can decide that the pointer in fact did not hit it, and
// should be propagated to any siblings that are below it in the stack.
// handlePointer() should return true if the pointer hit the child, and false if
// it missed (because the child doesn't cover its entire bounds).
// Note that the return value is _not_ whether the pointer was handled!

Also, add "return true" here. (Or false. I don't know what the right default is.
Probably true.)

@@ -229,6 +229,10 @@ abstract class RenderNode extends AbstractNode {
   static bool _debugDoingPaint = false;
   void markNeedsPaint() {
     assert(!_debugDoingPaint);
+    // TODO(abarth): It's very redunant to call this for every node in the
+    // render tree during layout. We should instead compute a summary bit and
+    // call it once at the end of layout.
+    sky.view.scheduleFrame();
   }
   void paint(RenderNodeDisplayList canvas) { }
 
@@ -468,19 +472,26 @@ class BoxDecoration {
 }
 
 class RenderDecoratedBox extends RenderBox {
-  BoxDecoration decoration;
+  BoxDecoration _decoration;
 
-  RenderDecoratedBox(this.decoration);
+  RenderDecoratedBox(BoxDecoration decoration) : _decoration = decoration;
+
+  void setBoxDecoration(BoxDecoration decoration) {
+    if (_decoration == decoration)
+      return;
+    _decoration = decoration;
+    markNeedsPaint();
+  }
 
   void paint(RenderNodeDisplayList canvas) {
     assert(width != null);
     assert(height != null);
 
-    if (decoration == null)
+    if (_decoration == null)
       return;
 
-    if (decoration.backgroundColor != null) {
-      sky.Paint paint = new sky.Paint()..color = decoration.backgroundColor;
+    if (_decoration.backgroundColor != null) {
+      sky.Paint paint = new sky.Paint()..color = _decoration.backgroundColor;
       canvas.drawRect(new sky.Rect()..setLTRB(0.0, 0.0, width, height), paint);
     }
   }
@@ -547,6 +558,12 @@ class RenderView extends RenderNode {
     assert(false); // nobody tells the screen to rotate, the whole rotate() dance is started from our layout()
   }
 
+  bool handlePointer(sky.PointerEvent event, { double x: 0.0, double y: 0.0 }) {
+    if (x < 0.0 || x >= root.width || y < 0.0 || y >= root.height)
+      return false;
+    return root.handlePointer(event, x: x, y: y);
+  }
+
   void paint(RenderNodeDisplayList canvas) {
     canvas.paintChild(root, 0.0, 0.0);
   }
@@ -556,7 +573,6 @@ class RenderView extends RenderNode {
     var canvas = new RenderNodeDisplayList(sky.view.width, sky.view.height);
     paint(canvas);
     sky.view.picture = canvas.endRecording();
-    sky.view.schedulePaint();
     RenderNode._debugDoingPaint = false;
   }
 
@@ -669,19 +685,20 @@ class RenderBlock extends RenderDecoratedBox with ContainerRenderNodeMixin<Rende
     layoutDone();
   }
 
-  void handlePointer(sky.PointerEvent event, { double x: 0.0, double y: 0.0 }) {
+  bool handlePointer(sky.PointerEvent event, { double x: 0.0, double y: 0.0 }) {
     // the x, y parameters have the top left of the node's box as the origin
     RenderBox child = _lastChild;
     while (child != null) {
       assert(child.parentData is BlockParentData);
       if ((x >= child.parentData.x) && (x < child.parentData.x + child.width) &&
           (y >= child.parentData.y) && (y < child.parentData.y + child.height)) {
-        child.handlePointer(event, x: x-child.parentData.x, y: y-child.parentData.y);
+        if (child.handlePointer(event, x: x-child.parentData.x, y: y-child.parentData.y))
+          return true;
         break;
       }
       child = child.parentData.previousSibling;
     }
-    super.handlePointer(event);
+    return super.handlePointer(event, x: x, y: y);

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

Render block should always return true, by definition it always covers its
entire bounds.

   }
 
   void paint(RenderNodeDisplayList canvas) {
@@ -756,17 +773,21 @@ class ScaffoldBox extends RenderBox {
     layoutDone();
   }
 
-  void handlePointer(sky.PointerEvent event, { double x: 0.0, double y: 0.0 }) {
+  bool handlePointer(sky.PointerEvent event, { double x: 0.0, double y: 0.0 }) {
     if ((drawer != null) && (x < drawer.width)) {
-      drawer.handlePointer(event, x: x, y: y);
+      if (drawer.handlePointer(event, x: x, y: y))
+        return true;
     } else if ((toolbar != null) && (y < toolbar.height)) {
-      toolbar.handlePointer(event, x: x, y: y);
+      if (toolbar.handlePointer(event, x: x, y: y))
+        return true;
     } else if ((statusbar != null) && (y > (statusbar.parentData as BoxParentData).y)) {
-      statusbar.handlePointer(event, x: x, y: y-(statusbar.parentData as BoxParentData).y);
+      if (statusbar.handlePointer(event, x: x, y: y-(statusbar.parentData as BoxParentData).y))
+        return true;
     } else {
-      body.handlePointer(event, x: x, y: y-(body.parentData as BoxParentData).y);
+      if (body.handlePointer(event, x: x, y: y-(body.parentData as BoxParentData).y))
+        return true;
     }
-    super.handlePointer(event, x: x, y: y);
+    return super.handlePointer(event, x: x, y: y);

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

I think ScaffoldBox.handlePointer should always return true (it's always
rectangular with no holes) and should always call super.handlePointer().

ScaffoldBox knows that its children never overlap, so it can just ignore the
return value.

   }
 
   void paint(RenderNodeDisplayList canvas) {