NOSUBMIT: PointerWatcher observes all pointer events, with moves optional

ui/views/touch_event_watcher.h

-// Copyright 2016 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_TOUCH_EVENT_WATCHER_H_
-#define UI_VIEWS_TOUCH_EVENT_WATCHER_H_
-
-#include "base/macros.h"
-#include "ui/views/views_export.h"
-
-namespace gfx {
-class Point;
-}
-
-namespace ui {
-class LocatedEvent;
-}
-
-namespace views {
-class Widget;
-
-// An interface for read-only observation of touch events (in particular, the
-// events cannot be marked as handled). Only touch pointer kind are supported.
-// The |target| is the top-level widget that will receive the event, if any.
-// NOTE: On mus this allows observation of events outside of windows owned
-// by the current process, in which case the |target| will be null. On mus
-// event.target() is always null.
-class VIEWS_EXPORT TouchEventWatcher {
- public:
-  TouchEventWatcher() {}
-  virtual void OnTouchEventObserved(const ui::LocatedEvent& event,
-                                    Widget* target) = 0;
-
- protected:
-  virtual ~TouchEventWatcher() {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TouchEventWatcher);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_TOUCH_EVENT_WATCHER_H_