1// Copyright 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 MEDIA_BASE_KEYBOARD_EVENT_COUNTER_H_
6#define MEDIA_BASE_KEYBOARD_EVENT_COUNTER_H_
7
8#include <set>
9
10#include "base/synchronization/lock.h"
11#include "media/base/media_export.h"
12#include "ui/events/event_constants.h"
13#include "ui/events/keycodes/keyboard_codes.h"
14
15namespace media {
16
17// This class tracks the total number of keypresses based on the OnKeyboardEvent
18// calls it receives from the client.
19// Multiple key down events for the same key are counted as one keypress until
20// the same key is released.
21class MEDIA_EXPORT KeyboardEventCounter {
22 public:
23  KeyboardEventCounter();
24  ~KeyboardEventCounter();
25
26  // Resets the count to 0. Must be called on the same thread as
27  // OnKeyboardEvent.
28  void Reset();
29
30  // Returns the total number of keypresses since its creation or last Reset()
31  // call. Can be called on any thread.
32  size_t GetKeyPressCount() const;
33
34  // The client should call this method on key down or key up events.
35  // Must be called on a single thread.
36  void OnKeyboardEvent(ui::EventType event, ui::KeyboardCode key_code);
37
38 private:
39  // The set of keys currently held down.
40  std::set<ui::KeyboardCode> pressed_keys_;
41
42  size_t total_key_presses_;
43
44  DISALLOW_COPY_AND_ASSIGN(KeyboardEventCounter);
45};
46
47}  // namespace media
48
49#endif  // MEDIA_BASE_KEYBOARD_EVENT_COUNTER_H_
50