Audio extension API.

chrome/browser/extensions/api/audio/audio_service_chromeos.cc

+// 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.
+
+#include "chrome/browser/extensions/api/audio/audio_service.h"
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "chromeos/dbus/audio_node.h"
+#include "chromeos/dbus/cras_audio_client.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace extensions {
+
+using api::audio::OutputDeviceInfo;
+using api::audio::InputDeviceInfo;
+
+class AudioServiceImpl : public AudioService,
+                         public chromeos::CrasAudioClient::Observer {
+ public:
+  AudioServiceImpl();
+  virtual ~AudioServiceImpl();
+
+  // Called by listeners to this service to add/remove themselves as observers.
+  virtual void AddObserver(AudioService::Observer* observer);
+  virtual void RemoveObserver(AudioService::Observer* observer);
+
+  // Start to query audio device information.
+  virtual void StartGetInfo(const GetInfoCallback& callback);
+
+ protected:
+  // chromeos::CrasAudioClient::Observer overrides.
+  virtual void OutputVolumeChanged(int volume) OVERRIDE;
+  virtual void OutputMuteChanged(bool mute_on) OVERRIDE;
+  virtual void InputGainChanged(int gain) 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;
+
+ private:
+  void NotifyDeviceChanged();
+
+  // Callback for CrasAudioClient::GetNodes().
+  void OnGetNodes(const GetInfoCallback& callback,
+                  const chromeos::AudioNodeList& audio_nodes,
+                  bool success);
+
+  // List of observers.
+  ObserverList<AudioService::Observer> observer_list_;
+
+  chromeos::CrasAudioClient* cras_audio_client_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate the weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<AudioServiceImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioServiceImpl);
+};
+
+AudioServiceImpl::AudioServiceImpl()
+    : ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
+  if (chromeos::DBusThreadManager::Get()) {
+    cras_audio_client_ =
+        chromeos::DBusThreadManager::Get()->GetCrasAudioClient();
+    DCHECK(cras_audio_client_);
+
+    if (cras_audio_client_)
+      cras_audio_client_->AddObserver(this);
+  }
+}
+
+AudioServiceImpl::~AudioServiceImpl() {
+  if (cras_audio_client_)
+    cras_audio_client_->RemoveObserver(this);
+}
+
+void AudioServiceImpl::AddObserver(AudioService::Observer* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void AudioServiceImpl::RemoveObserver(AudioService::Observer* observer) {
+  observer_list_.RemoveObserver(observer);
+}
+
+void AudioServiceImpl::StartGetInfo(const GetInfoCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(cras_audio_client_);
+  if (cras_audio_client_)
+    cras_audio_client_->GetNodes(base::Bind(&AudioServiceImpl::OnGetNodes,
+                                            weak_ptr_factory_.GetWeakPtr(),
+                                            callback));
+}
+
+void AudioServiceImpl::OnGetNodes(const GetInfoCallback& callback,
+                                  const chromeos::AudioNodeList& audio_nodes,
+                                  bool success) {
+  OutputInfo output_info;
+  InputInfo input_info;
+  if (success) {
+    for (chromeos::AudioNodeList::const_iterator iter = audio_nodes.begin();
+        iter != audio_nodes.end(); ++iter) {
+      if (!iter->is_input) {
+        linked_ptr<OutputDeviceInfo> info(new OutputDeviceInfo());
+        info->id = iter->id;
+        info->name = iter->name;
+        info->is_active = iter->active;
+        output_info.push_back(info);
+      } else {
+        linked_ptr<InputDeviceInfo> info(new InputDeviceInfo());
+        info->id = iter->id;
+        info->name = iter->name;
+        info->is_active = iter->active;
+        input_info.push_back(info);
+      }
+    }
+  }
+
+  DCHECK(!callback.is_null());
+  if (!callback.is_null())
+    callback.Run(output_info, input_info, success);
+}
+
+void AudioServiceImpl::OutputVolumeChanged(int volume) {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::OutputMuteChanged(bool mute_on) {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::InputGainChanged(int gain) {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::InputMuteChanged(bool mute_on) {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::NodesChanged() {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::ActiveOutputNodeChanged(uint64 node_id) {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::ActiveInputNodeChanged(uint64 node_id) {
+  NotifyDeviceChanged();
+}
+
+void AudioServiceImpl::NotifyDeviceChanged() {
+  FOR_EACH_OBSERVER(AudioService::Observer, observer_list_, OnDeviceChanged());
+}
+
+AudioService* AudioService::CreateInstance() {
+  return new AudioServiceImpl;
+}
+
+}  // namespace extensions