Implement new audio handler which talks to the new audio dbus apis.

chromeos/audio/cras_audio_handler.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 CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
+#define CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
+
+#include "base/basictypes.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+#include "base/prefs/pref_change_registrar.h"
+#include "chromeos/dbus/audio_node.h"
+#include "chromeos/dbus/cras_audio_client.h"
+#include "chromeos/dbus/volume_state.h"
+
+class PrefRegistrySimple;
+class PrefService;
+
+namespace chromeos {
+
+class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer {
+ public:
+  class AudioObserver {
+   public:
+    // Called when output volume changed.
+    virtual void OnOutputVolumeChanged();
+
+    // Called when output mute state changed.
+    virtual void OnOutputMuteChanged();
+
+    // Called when input mute state changed.
+    virtual void OnInputMuteChanged();
+
+    // Called when audio nodes changed.
+    virtual void OnAudioNodesChanged();
+
+    // Called when active audio node changed.
+    virtual void OnActiveOutputNodeChanged();
+
+    // Called when active audio input node changed.
+    virtual void OnActiveInputNodeChanged();
+
+   protected:
+    AudioObserver();
+    virtual ~AudioObserver();
+    DISALLOW_COPY_AND_ASSIGN(AudioObserver);
+  };
+
+  // Sets the global instance. Must be called before any calls to Get().
+  static void Initialize(PrefService* local_state);
+
+  // Destroys the global instance.
+  static void Shutdown();
+
+  // Returns true if the global instance is initialized.
+  static bool IsInitialized();
+
+  // Gets the global instance. Initialize must be called first.
+  static CrasAudioHandler* Get();
+
+  // Registers audio preferences.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
+  // Adds an audio observer.
+  void AddAudioObserver(AudioObserver* observer);
+
+  // Removes an audio observer.
+  void RemoveAudioObserver(AudioObserver* observer);
+
+  // Returns true if audio output is muted.
+  bool IsOutputMuted();
+
+  // Returns true if audio input is muted.
+  bool IsInputMuted();
+
+  // Gets volume level in 0-100% range, 0 being pure silence.
+  int GetOutputVolumePercent();
+
+  // Returns node_id of the active output node.
+  uint64 GetActiveOutputNode() const;
+
+  // Returns the node_id of the active input node.
+  uint64 GetActiveInputNode() const;
+
+  // Sets volume level from 0-100%. If less than kMuteThresholdPercent, then
+  // mutes the sound. If it was muted, and |volume_percent| is larger than
+  // the threshold, then the sound is unmuted.
+  void SetOutputVolumePercent(int volume_percent);
+
+  // Adjusts volume up (positive percentage) or down (negative percentage).
+  void AdjustOutputVolumeByPercent(int adjust_by_percent);
+
+  // Mutes or unmutes audio output device.
+  void SetOutputMute(bool mute_on);
+
+  // Mutes or unmutes audio input device.
+  void SetInputMute(bool mute_on);
+
+  // Sets the active audio output node to the node with |node_id|.
+  void SetActiveOutputNode(uint64 node_id);
+
+  // Sets the active audio input node to the node with |node_id|.
+  void SetActiveInputNode(uint64 node_id);
+
+ private:
+  explicit CrasAudioHandler(PrefService* local_state);
+  virtual ~CrasAudioHandler();
+
+  // Overriden from CrasAuduiHandler::Observer.

[stevenjb, 2013/04/17 01:25:12]

s/Audui/Audio

[jennyz, 2013/04/18 01:21:19]

Done.

+  virtual void AudioClientRestarted() OVERRIDE;
+  virtual void OutputVolumeChanged(int volume) OVERRIDE;
+  virtual void OutputMuteChanged(bool mute_on) OVERRIDE;
+  virtual void InputMuteChanged(bool mute_on) OVERRIDE;
+  virtual void NodesChanged() OVERRIDE;
+  virtual void ActiveOutputNodeChanged(uint64 node_id) OVERRIDE;
+  virtual void ActiveInputNodeChanged(uint64 node_id) OVERRIDE;
+
+  // Initializes the observers for the policy prefs.
+  void InitializePrefObservers();
+
+  // Sets up the initial audio device state based on audio policy and
+  // audio settings saved in prefs.
+  void SetupInitialAudioState();
+
+  // Applies the audio muting policies whenever the user logs in or policy
+  // change notification is received.
+  void ApplyAudioPolicy();
+
+  // Sets output volume to specified value and notifies observers.
+  void SetOutputVolumeInternal(int volume);
+
+  // Calling dbus to get nodes data.
+  void GetNodes();
+
+  // Handles dbus callback for GetNodes.
+  void HandleGetNodes(const chromeos::AudioNodeList& node_list, bool success);
+
+  ObserverList<AudioObserver> observers_;
+
+  base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;

[stevenjb, 2013/04/17 01:25:12]

This should be after pref_change_registrar_ so that pref_change_registrar_ can't
make any callbacks to this from its destructor (which happens after this is
mostly destroyed).
Or inherit from SupportsWeakPtr.

[jennyz, 2013/04/18 01:21:19]

Done.

+  PrefService* local_state_;  // not owned
+  PrefChangeRegistrar pref_change_registrar_;
+
+  // Audio data and state.
+  AudioNodeList audio_nodes_;
+  VolumeState volume_state_;
+  bool output_mute_on_;
+  bool input_mute_on_;
+  int output_volume_;
+  uint64 active_output_node_id_;
+  uint64 active_input_node_id_;
+
+  bool output_mute_locked_;
+  bool input_mute_locked_;
+
+  DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_