Switch Audio Preferences to per device.

chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h

+// Copyright (c) 2013 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 CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
+#define CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
+
+#include "base/observer_list.h"
+#include "base/prefs/pref_change_registrar.h"
+#include "base/values.h"
+#include "chromeos/audio/audio_devices_pref_handler.h"
+
+class PrefRegistrySimple;
+class PrefService;
+
+namespace chromeos {
+
+// Class which implements AudioDevicesPrefHandler interface and register audio
+// preferences as well.
+class AudioDevicesPrefHandlerImpl : public AudioDevicesPrefHandler {
+ public:
+  explicit AudioDevicesPrefHandlerImpl(PrefService* local_state);
+
+  // Overridden from AudioDevicesPrefHandler.
+  virtual double GetOutputVolumeValue() OVERRIDE;
+  virtual bool GetOutputMuteValue() OVERRIDE;
+  virtual void SetOutputVolumeValue(double volume_percent) OVERRIDE;
+  virtual void SetOutputMuteValue(bool mute_on) OVERRIDE;
+  virtual bool GetAudioCaptureAllowedValue() OVERRIDE;
+  virtual bool GetAudioOutputAllowedValue() OVERRIDE;
+  virtual void AddAudioPrefObserver(AudioPrefObserver* observer) OVERRIDE;
+  virtual void RemoveAudioPrefObserver(AudioPrefObserver* observer) OVERRIDE;
+
+  // Registers volume and mute preferences.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
+ protected:
+  virtual ~AudioDevicesPrefHandlerImpl();
+
+ private:
+  // Initializes the observers for the policy prefs.
+  void InitializePrefObservers();
+
+  // Update and save methods for the mute preferences for all devices.
+  void UpdateDevicesMutePref();
+  void SaveDevicesMutePref();
+
+  // Update and save methods for the volume preferences for all devices.
+  void UpdateDevicesVolumePref();
+  void SaveDevicesVolumePref();
+
+  // Methods to migrate the mute and volume settings for a device from the
+  // previous global pref value to the new per device pref value for the
+  // current active device. If a previous global setting doesn't exist, we'll
+  // use default values of mute=off and volume=75%.
+  void MigrateDeviceMuteSettings(std::string active_device);
+  void MigrateDeviceVolumeSettings(std::string active_device);
+
+  // Notifies the AudioPrefObserver for audio policy pref changes.
+  void NotifyAudioPolicyChange();
+
+  scoped_ptr<base::DictionaryValue> device_mute_settings_;
+  scoped_ptr<base::DictionaryValue> device_volume_settings_;
+
+  PrefService* local_state_;  // not owned
+  PrefChangeRegistrar pref_change_registrar_;
+  ObserverList<AudioPrefObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioDevicesPrefHandlerImpl);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_