Host-side implementation of ARC audio bridge.

components/arc/audio/arc_audio_bridge.cc

Index: components/arc/audio/arc_audio_bridge.cc
diff --git a/components/arc/audio/arc_audio_bridge.cc b/components/arc/audio/arc_audio_bridge.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9f964d5cae3ecb36c85872730c0caeb84840987d
--- /dev/null
+++ b/components/arc/audio/arc_audio_bridge.cc
@@ -0,0 +1,75 @@
+// Copyright 2016 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 "components/arc/audio/arc_audio_bridge.h"
+
+#include "base/logging.h"
+#include "chromeos/audio/audio_device.h"
+
+namespace arc {
+
+ArcAudioBridge::ArcAudioBridge(ArcBridgeService* bridge_service)
+    : ArcService(bridge_service), binding_(this) {
+  arc_bridge_service()->AddObserver(this);
+  if (chromeos::CrasAudioHandler::IsInitialized()) {
+    cras_audio_handler_ = chromeos::CrasAudioHandler::Get();
+    cras_audio_handler_->AddAudioObserver(this);
+  }
+}
+
+ArcAudioBridge::~ArcAudioBridge() {
+  arc_bridge_service()->RemoveObserver(this);
+  if (cras_audio_handler_ && chromeos::CrasAudioHandler::IsInitialized()) {
+    cras_audio_handler_->RemoveAudioObserver(this);
+  }
+}
+
+void ArcAudioBridge::OnAudioInstanceReady() {
+  AudioInstance* audio_instance = arc_bridge_service()->audio_instance();
+  if (!audio_instance) {
+    LOG(ERROR) << "OnAudioInstanceReady called, but no audio instance found";
+    return;
+  }
+
+  audio_instance->Init(binding_.CreateInterfacePtrAndBind());
+}
+
+void ArcAudioBridge::OnAudioNodesChanged() {
+  chromeos::AudioDeviceList devices;
+  cras_audio_handler_->GetAudioDevices(&devices);
+  uint64_t output_id = cras_audio_handler_->GetPrimaryActiveOutputNode();
+  uint64_t input_id = cras_audio_handler_->GetPrimaryActiveInputNode();
+
+  bool headphone_inserted = false, microphone_inserted = false;
+  for (size_t i = 0; i < devices.size(); ++i) {
+    if (devices[i].id == output_id) {
+      headphone_inserted =
+          (devices[i].type == chromeos::AudioDeviceType::AUDIO_TYPE_HEADPHONE);
+    }
+    if (devices[i].id == input_id) {
+      microphone_inserted =
+          (devices[i].type == chromeos::AudioDeviceType::AUDIO_TYPE_MIC);
+    }
+  }

[jennyz, 2016/03/23 23:50:42]

GetDeviceFromId from CrasAudioHandler is more convenient here. It is private,
but you can change it to public.

[chinyue, 2016/03/25 09:50:31]

Done.

+
+  VLOG(1) << "HEADPHONE " << headphone_inserted
+          << " MICROPHONE " << microphone_inserted;
+  SendSwitchState(headphone_inserted, microphone_inserted);
+}
+
+void ArcAudioBridge::SendSwitchState(bool headphone_inserted,
+                                     bool microphone_inserted) {
+  int switch_state = 0;
+  if (headphone_inserted)
+    switch_state |= (1 << (int)AudioSwitch::SW_HEADPHONE_INSERT);
+  if (microphone_inserted)
+    switch_state |= (1 << (int)AudioSwitch::SW_MICROPHONE_INSERT);
+
+  VLOG(1) << "Send switch state " << switch_state;
+  AudioInstance* audio_instance = arc_bridge_service()->audio_instance();
+  if (audio_instance)
+    audio_instance->NotifySwitchState(switch_state);
+}
+
+}  // namespace arc