Initial views touchui GestureRecognizer support

views/touchui/gesture_manager.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 VIEWS_TOUCHUI_GESTURE_MANAGER_H_
 #define VIEWS_TOUCHUI_GESTURE_MANAGER_H_
 #pragma once
 
 #include "base/memory/singleton.h"
+#include "views/touchui/gesture_recognizer.h"
 #include "views/view.h"
 
 namespace ui {
 enum TouchStatus;
 }
 
 namespace views {
 class TouchEvent;
 
 // A GestureManager singleton detects gestures occurring in the
@@ skipping 21 matching lines @@
 
   // TODO(rjkroege): Write the remainder of this class.
   // It will appear in a subsequent CL.
 
  protected:
   GestureManager();
 
  private:
   friend struct DefaultSingletonTraits<GestureManager>;
 
+  // Source view's RootView, This instance is not owned by GestureManager.
+  // See ProcessTouchEventForGesture() for source definition.
+  // Note: Simultaneous Gestures happening across two different RootViews are
+  // Not Recognized. Exception to this is TYPE_CHILD widget which still could
+  // be NativeWidgetGtk.
+  RootView* root_view_;

[rjkroege, 2011/10/24 17:41:09]

Why do we need this pointer when the view of interest is passed in to PTEFG?
This seems like a bad idea.

[Gajen, 2011/10/25 14:32:29]

GestureManager being singleton, can be in all possible RootViews, So, I guess,
[source] view passed in PTEFG may be different in multitouch case.

+
+  // GestureRecognizer instance.
+  GestureRecognizer gesture_recognizer;

[rjkroege, 2011/10/24 17:41:09]

members need a trailing _

More general observation: why not make GestureRecognizer a subclass of
GestureManager and override PTEFG when appropriate? (BTW: because GR makes
different events than GM, you will need to make the flip-on of GR be optional as
touchui currently depends on the synthetic mouse events.

[Gajen, 2011/10/25 14:32:29]

Done
Agreed, Do we need a GYP_DEFINE(say enable_gesture)??, this condition would
instantiate GR in RootView's ctor.
I have a doubt, as per Singleton template guidelines, class should be trivial
and leaf only, so would it be right to inherit GR from GM.

+
   DISALLOW_COPY_AND_ASSIGN(GestureManager);
 };
 
 
 }  // namespace views
 
 #endif  // VIEWS_TOUCHUI_GESTURE_MANAGER_H_