chromeos/audio/audio_devices_pref_handler.h

   1 // Copyright (c) 2013 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 CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_H_
   6 #define CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "chromeos/audio/audio_pref_observer.h"
  11 #include "chromeos/chromeos_export.h"
  12
  13 class PrefService;
  14
  15 namespace chromeos {
  16
  17 struct AudioDevice;
  18
  19 // Interface that handles audio preference related work, reads and writes
  20 // audio preferences, and notifies AudioPrefObserver for audio preference
  21 // changes.
  22 class CHROMEOS_EXPORT AudioDevicesPrefHandler
  23     : public base::RefCountedThreadSafe<AudioDevicesPrefHandler> {
  24  public:
  25   // Gets the audio output volume value from prefs for a device. Since we can
  26   // only have either a gain or a volume for a device (depending on whether it
  27   // is input or output), we don't really care which value it is.
  28   virtual double GetOutputVolumeValue(const AudioDevice* device) = 0;
  29   virtual double GetInputGainValue(const AudioDevice* device) = 0;
  30   // Sets the audio volume or gain value to prefs for a device.
  31   virtual void SetVolumeGainValue(const AudioDevice& device, double value) = 0;
  32
  33   // Reads the audio mute value from prefs for a device.
  34   virtual bool GetMuteValue(const AudioDevice& device) = 0;
  35   // Sets the audio mute value to prefs for a device.
  36   virtual void SetMuteValue(const AudioDevice& device, bool mute_on) = 0;
  37
  38   // Reads the audio capture allowed value from prefs.
  39   virtual bool GetAudioCaptureAllowedValue() = 0;
  40   // Reads the audio output allowed value from prefs.
  41   virtual bool GetAudioOutputAllowedValue() = 0;
  42
  43   // Adds an audio preference observer.
  44   virtual void AddAudioPrefObserver(AudioPrefObserver* observer) = 0;
  45   // Removes an audio preference observer.
  46   virtual void RemoveAudioPrefObserver(AudioPrefObserver* observer) = 0;
  47
  48   // Creates the instance.
  49   static AudioDevicesPrefHandler* Create(PrefService* local_state);
  50
  51  protected:
  52   virtual ~AudioDevicesPrefHandler() {}
  53
  54  private:
  55   friend class base::RefCountedThreadSafe<AudioDevicesPrefHandler>;
  56 };
  57
  58 }  // namespace chromeos
  59
  60 #endif  // CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_H_