Introduce View::CanProcessEventsWithinSubtree()

ui/views/view.cc

 // Copyright (c) 2012 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.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 831 matching lines @@
   View* rect_view = NULL;
   int rect_view_distance = INT_MAX;
 
   // |point_view| represents the view that would have been returned
   // from this function call if point-based targeting were used.
   View* point_view = NULL;
 
   for (int i = child_count() - 1; i >= 0; --i) {
     View* child = child_at(i);
 
+    if (!child->CanProcessEventsWithinSubtree())
+      continue;
+
     // Ignore any children which are invisible or do not intersect |rect|.
     if (!child->visible())
       continue;
     gfx::RectF rect_in_child_coords_f(rect);
     ConvertRectToTarget(this, child, &rect_in_child_coords_f);
     gfx::Rect rect_in_child_coords = gfx::ToEnclosingRect(
         rect_in_child_coords_f);
     if (!child->HitTestRect(rect_in_child_coords))
       continue;
 
@@ skipping 35 matching lines @@
     gfx::Point touch_center(rect.CenterPoint());
     int cur_dist = views::DistanceSquaredFromCenterToPoint(touch_center,
                                                            local_bounds);
     if (!rect_view || cur_dist < rect_view_distance)
       rect_view = this;
   }
 
   return rect_view ? rect_view : point_view;
 }
 
+bool View::CanProcessEventsWithinSubtree() const {
+  return true;
+}
+
 View* View::GetTooltipHandlerForPoint(const gfx::Point& point) {
   if (!HitTestPoint(point))
     return NULL;
 
   // Walk the child Views recursively looking for the View that most
   // tightly encloses the specified point.
   for (int i = child_count() - 1; i >= 0; --i) {
     View* child = child_at(i);
     if (!child->visible())
       continue;
 
+    if (!child->CanProcessEventsWithinSubtree())
+      continue;
+
     gfx::Point point_in_child_coords(point);
     ConvertPointToTarget(this, child, &point_in_child_coords);
     View* handler = child->GetTooltipHandlerForPoint(point_in_child_coords);
     if (handler)
       return handler;
   }
   return this;
 }
 
 gfx::NativeCursor View::GetCursor(const ui::MouseEvent& event) {
@@ skipping 1562 matching lines @@
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views