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
14// An event filter that transforms input event properties in extended desktop
15// environment.
16class ASH_EXPORT EventTransformationHandler : public ui::EventHandler {
17 public:
18  enum TransformationMode {
19    TRANSFORM_AUTO,   // Transform events by the default amount.
20                      // 1. Linear scaling w.r.t. the device scale factor.
21                      // 2. Add 20% more for non-integrated displays.
22    TRANSFORM_NONE,   // No transformation.
23  };
24
25  EventTransformationHandler();
26  virtual ~EventTransformationHandler();
27
28  void set_transformation_mode(TransformationMode transformation_mode) {
29    transformation_mode_ = transformation_mode;
30  }
31
32  // Overridden from ui::EventHandler.
33  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
34
35 private:
36  TransformationMode transformation_mode_;
37
38  DISALLOW_COPY_AND_ASSIGN(EventTransformationHandler);
39};
40
41}  // namespace ash
42
43#endif  // ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_
44