ash/system/audio/audio_observer.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 ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_
   6 #define ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_
   7
   8 namespace ash {
   9
  10 class AudioObserver {
  11  public:
  12   virtual ~AudioObserver() {}
  13
  14   // Called when output volume changed.
  15   virtual void OnOutputVolumeChanged() = 0;
  16
  17   // Called when output mute state changed.
  18   virtual void OnOutputMuteChanged() = 0;
  19
  20   // Called when audio nodes changed.
  21   virtual void OnAudioNodesChanged() = 0;
  22
  23   // Called when active audio output node changed.
  24   virtual void OnActiveOutputNodeChanged() = 0;
  25
  26   // Called when active audio input node changed.
  27   virtual void OnActiveInputNodeChanged() = 0;
  28 };
  29
  30 }  // namespace ash
  31
  32 #endif  // ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_