Fix the wrong output device switching caused by an input device being plugged in.

BUG=286029

Review URL: https://chromiumcodereview.appspot.com/23819034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222133 0039d316-1c4b-4281-b951-d872f2087c98

chromeos/audio/cras_audio_handler.cc

@@ -513,9 +513,29 @@ void CrasAudioHandler::SwitchToDevice(const AudioDevice& device) {
   }
 }
 
+bool CrasAudioHandler::HasDeviceChange(const AudioNodeList& new_nodes,
+                                       bool is_input) {
+  size_t num_old_devices = 0;
+  size_t num_new_devices = 0;
+  for (AudioDeviceMap::const_iterator it = audio_devices_.begin();
+       it != audio_devices_.end(); ++it) {
+    if (is_input == it->second.is_input)
+      ++num_old_devices;
+  }
+
+  for (AudioNodeList::const_iterator it = new_nodes.begin();
+       it != new_nodes.end(); ++it) {
+    if (is_input == it->is_input)
+      ++num_new_devices;
+  }
+  return num_old_devices != num_new_devices;
+}
+
 void CrasAudioHandler::UpdateDevicesAndSwitchActive(
     const AudioNodeList& nodes) {
   size_t old_audio_devices_size = audio_devices_.size();
+  bool output_devices_changed = HasDeviceChange(nodes, false);
+  bool input_devices_changed = HasDeviceChange(nodes, true);
   audio_devices_.clear();
   has_alternative_input_ = false;
   has_alternative_output_ = false;
@@ -548,12 +568,14 @@ void CrasAudioHandler::UpdateDevicesAndSwitchActive(
   // If audio nodes change is caused by unplugging some non-active audio
   // devices, the previously set active audio device will stay active.
   // Otherwise, switch to a new active audio device according to their priority.
-  if (!NonActiveDeviceUnplugged(old_audio_devices_size,
+  if (input_devices_changed &&
+      !NonActiveDeviceUnplugged(old_audio_devices_size,
                                 audio_devices_.size(),
                                 active_input_node_id_) &&
       !input_devices_pq_.empty())
     SwitchToDevice(input_devices_pq_.top());
-  if (!NonActiveDeviceUnplugged(old_audio_devices_size,
+  if (output_devices_changed &&
+      !NonActiveDeviceUnplugged(old_audio_devices_size,
                                 audio_devices_.size(),
                                 active_output_node_id_) &&
       !output_devices_pq_.empty()) {

chromeos/audio/cras_audio_handler.h

@@ -219,6 +219,10 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
                                 size_t new_device_size,
                                 uint64 current_active_node);
 
+  // Returns true if there is any device change for for input or output,
+  // specified by |is_input|.
+  bool HasDeviceChange(const AudioNodeList& new_nodes, bool is_input);
+
   // Handles dbus callback for GetNodes.
   void HandleGetNodes(const chromeos::AudioNodeList& node_list, bool success);
 

chromeos/audio/cras_audio_handler_unittest.cc

@@ -948,7 +948,7 @@ TEST_F(CrasAudioHandlerTest, PlugUSBMic) {
   EXPECT_EQ(init_nodes_size, audio_devices.size());
   EXPECT_EQ(0, test_observer_->audio_nodes_changed_count());
 
-  // Verify the internal mic is selected as the active output.
+  // Verify the internal mic is selected as the active input.
   EXPECT_EQ(0, test_observer_->active_input_node_changed_count());
   EXPECT_EQ(kInternalMic.id, cras_audio_handler_->GetActiveInputNode());
   EXPECT_FALSE(cras_audio_handler_->has_alternative_input());
@@ -1006,6 +1006,65 @@ TEST_F(CrasAudioHandlerTest, UnplugUSBMic) {
   EXPECT_FALSE(cras_audio_handler_->has_alternative_input());
 }
 
+TEST_F(CrasAudioHandlerTest, PlugUSBMicNotAffectActiveOutput) {
+  // Set up initial audio devices.
+  AudioNodeList audio_nodes;
+  audio_nodes.push_back(kInternalSpeaker);
+  audio_nodes.push_back(kHeadphone);
+  audio_nodes.push_back(kInternalMic);
+  SetUpCrasAudioHandler(audio_nodes);
+  const size_t init_nodes_size = audio_nodes.size();
+
+  // Verify the audio devices size.
+  EXPECT_EQ(0, test_observer_->audio_nodes_changed_count());
+  AudioDeviceList audio_devices;
+  cras_audio_handler_->GetAudioDevices(&audio_devices);
+  EXPECT_EQ(init_nodes_size, audio_devices.size());
+
+  // Verify the internal mic is selected as the active input.
+  EXPECT_EQ(0, test_observer_->active_input_node_changed_count());
+  EXPECT_EQ(kInternalMicId, cras_audio_handler_->GetActiveInputNode());
+  EXPECT_FALSE(cras_audio_handler_->has_alternative_input());
+
+  // Verify the headphone is selected as the active output.
+  EXPECT_EQ(0, test_observer_->active_output_node_changed_count());
+  EXPECT_EQ(kHeadphoneId, cras_audio_handler_->GetActiveOutputNode());
+  EXPECT_TRUE(cras_audio_handler_->has_alternative_output());
+
+  // Switch the active output to internal speaker.
+  AudioDevice internal_speaker(kInternalSpeaker);
+  cras_audio_handler_->SwitchToDevice(internal_speaker);
+
+  // Verify the active output is switched to internal speaker, and the
+  // ActiveOutputNodeChanged event is fired.
+  EXPECT_EQ(1, test_observer_->active_output_node_changed_count());
+  AudioDevice active_output;
+  EXPECT_TRUE(cras_audio_handler_->GetActiveOutputDevice(&active_output));
+  EXPECT_EQ(kInternalSpeaker.id, active_output.id);
+  EXPECT_EQ(kInternalSpeaker.id, cras_audio_handler_->GetActiveOutputNode());
+
+  // Plug the USB Mic.
+  audio_nodes.push_back(kUSBMic);
+  ChangeAudioNodes(audio_nodes);
+
+  // Verify the AudioNodesChanged event is fired, one new device is added.
+  EXPECT_EQ(1, test_observer_->audio_nodes_changed_count());
+  cras_audio_handler_->GetAudioDevices(&audio_devices);
+  EXPECT_EQ(init_nodes_size + 1, audio_devices.size());
+
+  // Verify the active input device is switched to USB mic, and
+  // and ActiveInputChanged event is fired.
+  EXPECT_EQ(1, test_observer_->active_input_node_changed_count());
+  EXPECT_EQ(kUSBMic.id, cras_audio_handler_->GetActiveInputNode());
+  EXPECT_TRUE(cras_audio_handler_->has_alternative_input());
+
+  // Verify the active output device is not changed.
+  EXPECT_EQ(1, test_observer_->active_output_node_changed_count());
+  EXPECT_TRUE(cras_audio_handler_->GetActiveOutputDevice(&active_output));
+  EXPECT_EQ(kInternalSpeaker.id, active_output.id);
+  EXPECT_EQ(kInternalSpeaker.id, cras_audio_handler_->GetActiveOutputNode());
+}
+
 TEST_F(CrasAudioHandlerTest, SetOutputMute) {
   AudioNodeList audio_nodes;
   audio_nodes.push_back(kInternalSpeaker);