Added entry points to view/View to dispatch and process TouchEvents.

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* Get();
+
+  // 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_