views: Dispatch key, touch, scroll and gesture events using the EventDispatch interface.

ui/views/widget/root_view.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_ROOT_VIEW_H_
 #define UI_VIEWS_WIDGET_ROOT_VIEW_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
+#include "ui/base/events/event_dispatcher.h"
 #include "ui/views/focus/focus_manager.h"
 #include "ui/views/focus/focus_search.h"
 #include "ui/views/view.h"
 
 namespace views {
 
 class Widget;
 
 // This is a views-internal API and should not be used externally.
 // Widget exposes this object as a View*.
 namespace internal {
 
 ////////////////////////////////////////////////////////////////////////////////
 // RootView class
 //
 //  The RootView is the root of a View hierarchy. A RootView is attached to a
 //  Widget. The Widget is responsible for receiving events from the host
 //  environment, converting them to views-compatible events and then forwarding
 //  them to the RootView for propagation into the View hierarchy.
 //
 //  A RootView can have only one child, called its "Contents View" which is
 //  sized to fill the bounds of the RootView (and hence the client area of the
 //  Widget). Call SetContentsView() after the associated Widget has been
 //  initialized to attach the contents view to the RootView.
 //  TODO(beng): Enforce no other callers to AddChildView/tree functions by
 //              overriding those methods as private here.
 //  TODO(beng): Clean up API further, make Widget a friend.
 //  TODO(sky): We don't really want to export this class.
 //
-class VIEWS_EXPORT RootView : public View, public FocusTraversable {
+class VIEWS_EXPORT RootView : public View,
+                              public FocusTraversable,
+                              public ui::EventDispatcherDelegate {
  public:
   static const char kViewClassName[];
 
   // Creation and lifetime -----------------------------------------------------
   explicit RootView(Widget* widget);
   virtual ~RootView();
 
   // Tree operations -----------------------------------------------------------
 
   // Sets the "contents view" of the RootView. This is the single child view
@@ skipping 75 matching lines @@
   // cursor during drag operations. The location of the mouse should be in the
   // current coordinate system (i.e. any necessary transformation should be
   // applied to the point prior to calling this).
   void UpdateCursor(const ui::MouseEvent& event);
 
   // Updates the last_mouse_* fields from e. The location of the mouse should be
   // in the current coordinate system (i.e. any necessary transformation should
   // be applied to the point prior to calling this).
   void SetMouseLocationAndFlags(const ui::MouseEvent& event);
 
+  void DispatchEventToTarget(View* target, ui::Event* event);
+
+  // Overridden from ui::EventDispatcherDelegate:
+  virtual bool CanDispatchToTarget(ui::EventTarget* target) OVERRIDE;
+
   //////////////////////////////////////////////////////////////////////////////
 
   // Tree operations -----------------------------------------------------------
 
   // The host Widget
   Widget* widget_;
 
   // Input ---------------------------------------------------------------------
 
   // The view currently handing down - drag - up
@@ skipping 34 matching lines @@
   // Whether this root view belongs to the current active window.
   // bool activated_;
 
   // The parent FocusTraversable, used for focus traversal.
   FocusTraversable* focus_traversable_parent_;
 
   // The View that contains this RootView. This is used when we have RootView
   // wrapped inside native components, and is used for the focus traversal.
   View* focus_traversable_parent_view_;
 
+  View* event_dispatch_target_;
+
   // Drag and drop -------------------------------------------------------------
 
   // Tracks drag state for a view.
   View::DragInfo drag_info_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(RootView);
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_ROOT_VIEW_H_