chrome/browser/chromeos/camera_presence_notifier.h

   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
  13 namespace chromeos {
  14
  15 // Camera presence status dispatcher.
  16 class 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