touch: Return an enum from OnTouchEvent.

views/touchui/gesture_manager.h

 // Copyright (c) 2010 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 VIEWS_TOUCHUI_GESTURE_MANAGER_H_
 #define VIEWS_TOUCHUI_GESTURE_MANAGER_H_
 #pragma once
 
 #include "base/singleton.h"
 
 namespace views {
 class View;
 class TouchEvent;
 
 
 // A GestureManager singleton detects gestures occurring in the
 // incoming feed of touch events across all of the RootViews in
 // the system. In response to a given touch event, the GestureManager
 // updates its internal state and optionally dispatches synthetic
 // events to the invoking view.
 //
 class GestureManager {
  public:
   virtual ~GestureManager();
 
   static GestureManager* GetInstance();
 
+  // TODO(sad): Use TouchStatus instead of bool for previouslyHandled.
   // Invoked for each touch event that could contribute to the current gesture.
   // Takes the event and the View that originated it and which will also
   // be the target of any generated synthetic event. Finally, handled
   // specifies if the event was actually handled explicitly by a view so that
   // GestureManager state can correctly reflect events that are handled
   // already.
   // Returns true if the event resulted in firing a synthetic event.
   virtual bool ProcessTouchEventForGesture(const TouchEvent& event,
                                            View* source,
                                            bool previouslyHandled);
 
   // TODO(rjkroege): Write the remainder of this class.
   // It will appear in a subsequent CL.
 
  protected:
   GestureManager();
 
  private:
   friend struct DefaultSingletonTraits<GestureManager>;
 
   DISALLOW_COPY_AND_ASSIGN(GestureManager);
 };
 
 
 }  // namespace views
 
 #endif  // VIEWS_TOUCHUI_GESTURE_MANAGER_H_