// Copyright 2014 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_ #define ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_ namespace ash { class AudioObserver { public: virtual ~AudioObserver() {} // Called when output volume changed. virtual void OnOutputVolumeChanged() = 0; // Called when output mute state changed. virtual void OnOutputMuteChanged() = 0; // Called when audio nodes changed. virtual void OnAudioNodesChanged() = 0; // Called when active audio output node changed. virtual void OnActiveOutputNodeChanged() = 0; // Called when active audio input node changed. virtual void OnActiveInputNodeChanged() = 0; }; } // namespace ash #endif // ASH_SYSTEM_AUDIO_AUDIO_OBSERVER_H_