Persist the user's active audio device choice across chromeos session and reboots.

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 <stddef.h>
 #include <stdint.h>
 #include <queue>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/timer/timer.h"
 #include "chromeos/audio/audio_device.h"
+#include "chromeos/audio/audio_devices_pref_handler.h"
 #include "chromeos/audio/audio_pref_observer.h"
 #include "chromeos/dbus/audio_node.h"
 #include "chromeos/dbus/cras_audio_client.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "chromeos/dbus/volume_state.h"
 
 class PrefRegistrySimple;
 class PrefService;
 
 namespace chromeos {
@@ skipping 36 matching lines @@
 
     // Called when active audio input node changed.
     virtual void OnActiveInputNodeChanged();
 
    protected:
     AudioObserver();
     virtual ~AudioObserver();
     DISALLOW_COPY_AND_ASSIGN(AudioObserver);
   };
 
+  enum DeviceActivateType {
+    ACTIVATE_BY_PRIORITY = 0,
+    ACTIVATE_BY_USER,
+    ACTIVATE_BY_RESTORE_PREVIOUS_STATE,
+  };
+
   // Sets the global instance. Must be called before any calls to Get().
   static void Initialize(
       scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler);
 
   // Sets the global instance for testing.
   static void InitializeForTesting();
 
   // Destroys the global instance.
   static void Shutdown();
 
@@ skipping 76 matching lines @@
   // Adjusts all active output devices' volume to a minimum audible level if it
   // is too low.
   virtual void AdjustOutputVolumeToAudibleLevel();
 
   // Mutes or unmutes audio output device.
   virtual void SetOutputMute(bool mute_on);
 
   // Mutes or unmutes audio input device.
   virtual void SetInputMute(bool mute_on);
 
-  // Switches active audio device to |device|.
-  virtual void SwitchToDevice(const AudioDevice& device, bool notify);
+  // Switches active audio device to |device|. |activate_by| indicates why
+  // the device is switched to active: by user's manual choice, by priority,
+  // or by restoring to its previous active state.
+  virtual void SwitchToDevice(const AudioDevice& device,
+                              bool notify,
+                              DeviceActivateType activate_by);
 
   // Sets volume/gain level for a device.
   virtual void SetVolumeGainPercentForDevice(uint64_t device_id, int value);
 
   // Sets the mute for device.
   virtual void SetMuteForDevice(uint64_t device_id, bool mute_on);
 
   // Activates or deactivates keyboard mic if there's one.
   virtual void SetKeyboardMicActive(bool active);
 
@@ skipping 38 matching lines @@
   void NodesChanged() override;
   void ActiveOutputNodeChanged(uint64_t node_id) override;
   void ActiveInputNodeChanged(uint64_t node_id) override;
 
   // AudioPrefObserver overrides.
   void OnAudioPolicyPrefChanged() override;
 
   // SessionManagerClient::Observer overrides.
   void EmitLoginPromptVisibleCalled() override;
 
-  // Sets the active audio output/input node to the node with |node_id|.
+  // Sets the |active_device| to be active.
   // If |notify|, notifies Active*NodeChange.
-  void SetActiveOutputNode(uint64_t node_id, bool notify);
-  void SetActiveInputNode(uint64_t node_id, bool notify);
+  // Saves device active states in prefs. |activate_by| indicates how
+  // the device was activated.
+  void SetActiveDevice(const AudioDevice& active_device,
+                       bool notify,
+                       DeviceActivateType activate_by);
+
+  // Saves |device|'s state in pref. If |active| is true, |activate_by|
+  // indicates how |device| is activated.
+  void SaveDeviceState(const AudioDevice& device,
+                       bool active,
+                       DeviceActivateType activate_by);
 
   // Sets up the audio device state based on audio policy and audio settings
   // saved in prefs.
   void SetupAudioInputState();
   void SetupAudioOutputState();
 
   // Sets up the additional active audio node's state.
   void SetupAdditionalActiveAudioNodeState(uint64_t node_id);
 
   const AudioDevice* GetDeviceFromId(uint64_t device_id) const;
+  const AudioDevice* GetDeviceFromStableDeviceId(
+      uint64_t stable_device_id) const;
   const AudioDevice* GetKeyboardMic() const;
 
   // Initializes audio state, which should only be called when CrasAudioHandler
   // is created or cras audio client is restarted.
   void InitializeAudioState();
 
+  void InitializeAudioAfterCrasServiceAvailable(bool service_is_available);
+
   // Applies the audio muting policies whenever the user logs in or policy
   // change notification is received.
   void ApplyAudioPolicy();
 
   // Sets output volume of |node_id| to |volume|.
   void SetOutputNodeVolume(uint64_t node_id, int volume);
 
   void SetOutputNodeVolumePercent(uint64_t node_id, int volume_percent);
 
   // Sets output mute state to |mute_on| internally, returns true if output mute
   // is set.
   bool SetOutputMuteInternal(bool mute_on);
 
   // Sets input gain of |node_id| to |gain|.
   void SetInputNodeGain(uint64_t node_id, int gain);
 
   void SetInputNodeGainPercent(uint64_t node_id, int gain_percent);
 
   // Sets input mute state to |mute_on| internally.
   void SetInputMuteInternal(bool mute_on);
 
   // Calling dbus to get nodes data.
   void GetNodes();
 
   // Updates the current audio nodes list and switches the active device
   // if needed.
   void UpdateDevicesAndSwitchActive(const AudioNodeList& nodes);
 
-  // Returns true if *|current_active_node_id| device is changed to
+  // Returns true if the current active device is changed to
   // |new_active_device|.
-  bool ChangeActiveDevice(const AudioDevice& new_active_device,
-                          uint64_t* current_active_node_id);
+  bool ChangeActiveDevice(const AudioDevice& new_active_device);
 
-  // Returns true if the audio nodes change is caused by some non-active
-  // audio nodes unplugged.
-  bool NonActiveDeviceUnplugged(size_t old_devices_size,
-                                size_t new_device_size,
-                                uint64_t current_active_node);
-
-  // Returns true if there is any device change for for input or output,
-  // specified by |is_input|.
-  // The new discovered nodes are returned in |new_discovered|.
+  // Returns true if there are any device changes for input or output
+  // specified by |is_input|, by comparing |audio_devvices_| with |new_nodes|.

[hychao, 2016/03/02 15:34:05]

s/audio_devvices_/audio_devices_/

[jennyz, 2016/03/02 19:33:37]

Done.

+  // Passes the new nodes discovered in *|new_discovered|.
+  // *|device_removed| indicates if any devices have been removed.
+  // *|active_device_removed| indicates if the current active device has been
+  // removed.
   bool HasDeviceChange(const AudioNodeList& new_nodes,
                        bool is_input,
-                       AudioDevicePriorityQueue* new_discovered);
+                       AudioDevicePriorityQueue* new_discovered,
+                       bool* device_removed,
+                       bool* active_device_removed);
 
   // Handles dbus callback for GetNodes.
   void HandleGetNodes(const chromeos::AudioNodeList& node_list, bool success);
 
   // Handles the dbus error callback.
   void HandleGetNodesError(const std::string& error_name,
                            const std::string& error_msg);
 
   // Adds an active node.
   // If there is no active node, |node_id| will be switched to become the
@@ skipping 22 matching lines @@
     NEW_DEVICE,
     CHANGED_DEVICE,
   };
 
   // Checks if |device| is a newly discovered, changed, or existing device for
   // the nodes sent from NodesChanged signal.
   DeviceStatus CheckDeviceStatus(const AudioDevice& device);
 
   void NotifyActiveNodeChanged(bool is_input);
 
+  // Returns true if it retrieves an active audio device from user preference
+  // among the current |audio_devices_|.
+  bool GetActiveDeviceFromUserPref(bool is_input, AudioDevice* device);
+
+  // Handles either input or output device changes, specified by |is_input|.
+  void HandleAudioDeviceChange(bool is_input,
+                               const AudioDevicePriorityQueue& devices_pq,
+                               const AudioDevicePriorityQueue& hotplug_nodes,
+                               bool has_device_change,
+                               bool has_device_removed,
+                               bool active_device_removed);
+
+  // Handles non-hotplug nodes change cases.
+  void HandleNonHotplugNodesChange(
+      bool is_input,
+      const AudioDevicePriorityQueue& hotplug_nodes,
+      bool has_device_change,
+      bool has_device_removed,
+      bool active_device_removed);
+
+  // Handles the regular user hotplug case.
+  void HandleHotPlugDevice(
+      const AudioDevice& hotplug_device,
+      const AudioDevicePriorityQueue& device_priority_queue);
+
+  void SwitchToTopPriorityDevice(bool is_input);
+
+  // Switch to previous active device if it is found, otherwise, switch
+  // to the top priority device.
+  void SwitchToPreviousActiveDeviceIfAvailable(bool is_input);
+
   scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler_;
   base::ObserverList<AudioObserver> observers_;
 
   // Audio data and state.
   AudioDeviceMap audio_devices_;
 
   AudioDevicePriorityQueue input_devices_pq_;
   AudioDevicePriorityQueue output_devices_pq_;
 
   bool output_mute_on_;
   bool input_mute_on_;
   int output_volume_;
   int input_gain_;
   uint64_t active_output_node_id_;
   uint64_t active_input_node_id_;
   bool has_alternative_input_;
   bool has_alternative_output_;
 
   bool output_mute_locked_;
 
   // Failures are not logged at startup, since CRAS may not be running yet.
   bool log_errors_;
 
   // Timer for HDMI re-discovering grace period.
   base::OneShotTimer hdmi_rediscover_timer_;
   int hdmi_rediscover_grace_period_duration_in_ms_;
   bool hdmi_rediscovering_;
 
+  bool cras_service_available_ = false;
+
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_