aura: Gesture event plumbing (skeleton).

ui/aura/event_filter.h

 // Copyright (c) 2011 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_AURA_EVENT_FILTER_H_
 #define UI_AURA_EVENT_FILTER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "ui/aura/aura_export.h"
 #include "ui/base/events.h"
 
 namespace aura {
 
+class GestureEvent;
 class KeyEvent;
 class MouseEvent;
 class TouchEvent;
 class Window;
 
 // An object that filters events sent to an owner window. The filter can stop
 // further processing of events.
 //
 // When the Desktop receives an event, it determines the "target window" for
 // the event, this is typically the visible window whose bounds most tightly
@@ skipping 21 matching lines @@
   // that further processing can occur.
 
   virtual bool PreHandleKeyEvent(Window* target, KeyEvent* event) = 0;
   virtual bool PreHandleMouseEvent(Window* target, MouseEvent* event) = 0;
 
   // Returns a value other than ui::TOUCH_STATUS_UNKNOWN if the event is
   // consumed.
   virtual ui::TouchStatus PreHandleTouchEvent(Window* target,
                                               TouchEvent* event) = 0;
 
+  // Returns a value other than ui::GESTURE_STATUS_UNKNOWN if the gesture is
+  // consumed.
+  virtual ui::GestureStatus PreHandleGestureEvent(Window* target,
+                                                  GestureEvent* event) = 0;
+
  protected:
   Window* owner() { return owner_; }
 
  private:
   Window* owner_;
 
   DISALLOW_COPY_AND_ASSIGN(EventFilter);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_EVENT_FILTER_H_