chromeos/audio/audio_devices_pref_handler_impl.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_IMPL_H_
   6 #define CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
   7
   8 #include <string>
   9
  10 #include "base/observer_list.h"
  11 #include "base/prefs/pref_change_registrar.h"
  12 #include "base/values.h"
  13 #include "chromeos/audio/audio_devices_pref_handler.h"
  14 #include "chromeos/chromeos_export.h"
  15
  16 class PrefRegistrySimple;
  17 class PrefService;
  18
  19 namespace chromeos {
  20
  21 // Class which implements AudioDevicesPrefHandler interface and register audio
  22 // preferences as well.
  23 class CHROMEOS_EXPORT AudioDevicesPrefHandlerImpl
  24     : public AudioDevicesPrefHandler {
  25  public:
  26   // |local_state| is the device-wide preference service.
  27   explicit AudioDevicesPrefHandlerImpl(PrefService* local_state);
  28
  29   // Overridden from AudioDevicesPrefHandler.
  30   double GetOutputVolumeValue(const AudioDevice* device) override;
  31   double GetInputGainValue(const AudioDevice* device) override;
  32   void SetVolumeGainValue(const AudioDevice& device, double value) override;
  33
  34   bool GetMuteValue(const AudioDevice& device) override;
  35   void SetMuteValue(const AudioDevice& device, bool mute_on) override;
  36
  37   bool GetAudioOutputAllowedValue() override;
  38
  39   void AddAudioPrefObserver(AudioPrefObserver* observer) override;
  40   void RemoveAudioPrefObserver(AudioPrefObserver* observer) override;
  41
  42   // Registers volume and mute preferences.
  43   static void RegisterPrefs(PrefRegistrySimple* registry);
  44
  45  protected:
  46   ~AudioDevicesPrefHandlerImpl() override;
  47
  48  private:
  49   // Initializes the observers for the policy prefs.
  50   void InitializePrefObservers();
  51
  52   // Update and save methods for the mute preferences for all devices.
  53   void UpdateDevicesMutePref();
  54   void SaveDevicesMutePref();
  55
  56   // Update and save methods for the volume preferences for all devices.
  57   void UpdateDevicesVolumePref();
  58   void SaveDevicesVolumePref();
  59
  60   double GetVolumeGainPrefValue(const AudioDevice& device);
  61   double GetDeviceDefaultOutputVolume(const AudioDevice& device);
  62
  63   // Methods to migrate the mute and volume settings for a device from the
  64   // previous global pref value to the new per device pref value for the
  65   // current active device. If a previous global setting doesn't exist, we'll
  66   // use default values of mute = off and volume = 75%.
  67   void MigrateDeviceMuteSettings(std::string active_device);
  68   void MigrateDeviceVolumeSettings(std::string active_device);
  69
  70   // Notifies the AudioPrefObserver for audio policy pref changes.
  71   void NotifyAudioPolicyChange();
  72
  73   scoped_ptr<base::DictionaryValue> device_mute_settings_;
  74   scoped_ptr<base::DictionaryValue> device_volume_settings_;
  75
  76   PrefService* local_state_;  // not owned
  77
  78   PrefChangeRegistrar pref_change_registrar_;
  79   base::ObserverList<AudioPrefObserver> observers_;
  80
  81   DISALLOW_COPY_AND_ASSIGN(AudioDevicesPrefHandlerImpl);
  82 };
  83
  84 }  // namespace chromeos
  85
  86 #endif  // CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_