1// Copyright 2014 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 CHROME_BROWSER_CHROMEOS_CAMERA_PRESENCE_NOTIFIER_H_
6#define CHROME_BROWSER_CHROMEOS_CAMERA_PRESENCE_NOTIFIER_H_
7
8#include "base/memory/singleton.h"
9#include "base/memory/weak_ptr.h"
10#include "base/observer_list.h"
11#include "base/timer/timer.h"
12
13namespace chromeos {
14
15// Camera presence status dispatcher.
16class CameraPresenceNotifier {
17 public:
18  class Observer {
19   public:
20    virtual void OnCameraPresenceCheckDone(bool is_camera_present) = 0;
21   protected:
22    virtual ~Observer() {}
23  };
24
25  static CameraPresenceNotifier* GetInstance();
26
27  void AddObserver(CameraPresenceNotifier::Observer* observer);
28  void RemoveObserver(CameraPresenceNotifier::Observer* observer);
29
30 private:
31  friend struct DefaultSingletonTraits<CameraPresenceNotifier>;
32  CameraPresenceNotifier();
33  ~CameraPresenceNotifier();
34
35  void CheckCameraPresence();
36
37  // Sends out a camera presence status notification.
38  void OnCameraPresenceCheckDone();
39
40  bool camera_present_on_last_check_;
41
42  // Timer for camera check cycle.
43  base::RepeatingTimer<CameraPresenceNotifier> camera_check_timer_;
44
45  ObserverList<Observer> observers_;
46
47  base::WeakPtrFactory<CameraPresenceNotifier> weak_factory_;
48
49  DISALLOW_COPY_AND_ASSIGN(CameraPresenceNotifier);
50};
51
52}  // namespace chromeos
53
54#endif  // CHROME_BROWSER_CHROMEOS_CAMERA_PRESENCE_NOTIFIER_H_
55
56