Proper MouseEvent targeting. Adds a Window method that locates a Window for a given point.

aura/window.cc

Index: aura/window.cc
===================================================================
--- aura/window.cc	(revision 98852)
+++ aura/window.cc	(working copy)
@@ -24,6 +24,10 @@
 }
 
 Window::~Window() {
+  if (delegate_)
+    delegate_->OnWindowDestroyed();
+  if (parent_)
+    parent_->RemoveChild(this);
 }
 
 void Window::Init() {
@@ -70,7 +74,6 @@
   UpdateLayerCanvas();
   Draw();
 
-  // First pass updates the layer bitmaps.
   for (Windows::iterator i = children_.begin(); i != children_.end(); ++i)
     (*i)->DrawTree();
 }
@@ -91,10 +94,37 @@
   children_.erase(i);
 }
 
+// static
+void Window::ConvertPointToWindow(Window* source,
+                                  Window* target,
+                                  gfx::Point* point) {
+  ui::Layer::ConvertPointToLayer(source->layer(), target->layer(), point);
+}
+
 bool Window::OnMouseEvent(const MouseEvent& event) {
   return true;
 }
 
+bool Window::HitTest(const gfx::Point& point) {
+  gfx::Rect local_bounds(gfx::Point(), bounds().size());
+  // TODO(beng): hittest masks.
+  return local_bounds.Contains(point);
+}
+
+Window* Window::GetEventHandlerForPoint(const gfx::Point& point) {
+  Windows::const_reverse_iterator i = children_.rbegin();
+  for (; i != children_.rend(); ++i) {
+    Window* child = *i;
+    if (child->visibility() == Window::VISIBILITY_HIDDEN)
+      continue;
+    gfx::Point point_in_child_coords(point);
+    Window::ConvertPointToWindow(this, child, &point_in_child_coords);
+    if (child->HitTest(point_in_child_coords))
+      return child->GetEventHandlerForPoint(point_in_child_coords);
+  }
+  return this;
+}
+
 void Window::UpdateLayerCanvas() {
   if (needs_paint_all_) {
     needs_paint_all_ = false;