event_transformation_handler.h revision d0247b1b59f9c528cb6df88b4f2b9afaf80d181e 
1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_
6#define ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_
7
8#include "ash/ash_export.h"
9#include "base/compiler_specific.h"
10#include "ui/events/event_handler.h"
11
12namespace ash {
13
14namespace internal {
15
16// An event filter that transforms input event properties in extended desktop
17// environment.
18class ASH_EXPORT EventTransformationHandler : public ui::EventHandler {
19 public:
20  enum TransformationMode {
21    TRANSFORM_AUTO,   // Transform events by the default amount.
22                      // 1. Linear scaling w.r.t. the device scale factor.
23                      // 2. Add 20% more for non-integrated displays.
24    TRANSFORM_NONE,   // No transformation.
25  };
26
27  EventTransformationHandler();
28  virtual ~EventTransformationHandler();
29
30  void set_transformation_mode(TransformationMode transformation_mode) {
31    transformation_mode_ = transformation_mode;
32  }
33
34  // Overridden from ui::EventHandler.
35  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
36#if defined(OS_CHROMEOS)
37  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
38#endif  // defined(OS_CHROMEOS)
39
40 private:
41  TransformationMode transformation_mode_;
42
43  DISALLOW_COPY_AND_ASSIGN(EventTransformationHandler);
44};
45
46}  // namespace internal
47}  // namespace ash
48
49#endif  // ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_
50