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 #include <stdint.h>
   9
  10 namespace ash {
  11
  12 class AudioObserver {
  13  public:
  14   virtual ~AudioObserver() {}
  15
  16   // Called when an active output device's volume changed.
  17   // |node_id|: id of the active node.
  18   // |volume|: volume as a percentage, 0.0 -- 100.0.
  19   virtual void OnOutputNodeVolumeChanged(uint64_t node_id, double volume) = 0;
  20
  21   // Called when output mute state changed.
  22   // |mute_on|: True if output is muted.
  23   // |system_adjust|: True if the mute state is adjusted by the system
  24   // automatically, UI should be consistent with the system's mute state,
  25   // but it should not be too loud, e.g., the volume pop up window should not
  26   // be triggered.
  27   virtual void OnOutputMuteChanged(bool mute_on, bool system_adjust) = 0;
  28
  29   // Called when audio nodes changed.
  30   virtual void OnAudioNodesChanged() = 0;
  31
  32   // Called when active audio output node changed.
  33   virtual void OnActiveOutputNodeChanged() = 0;
  34
  35   // Called when active audio input node changed.
  36   virtual void OnActiveInputNodeChanged() = 0;
  37 };
  38
  39 }  // namespace ash
  40
  41 #endif  // ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_