device/bluetooth: Add BluetoothAudioSinkChromeOS.

This CL implements Bluetooth Audio Sink API for ChromeOS platform,
where user applications can register/unregister a BT audio sink
via BlueAdapter interface. This API acts as a middle layer hiding
the components of BlueZ/D-Bus.

BUG=441581

Review URL: https://codereview.chromium.org/787743002

Cr-Commit-Position: refs/heads/master@{#312562}

device/bluetooth/BUILD.gn

@@ -29,6 +29,8 @@ component("bluetooth") {
     "bluetooth_adapter_win.h",
     "bluetooth_audio_sink.cc",
     "bluetooth_audio_sink.h",
+    "bluetooth_audio_sink_chromeos.cc",
+    "bluetooth_audio_sink_chromeos.h",
     "bluetooth_channel_mac.mm",
     "bluetooth_channel_mac.h",
     "bluetooth_device.cc",

device/bluetooth/bluetooth.gyp

@@ -34,6 +34,8 @@
         'bluetooth_adapter_win.h',
         'bluetooth_audio_sink.cc',
         'bluetooth_audio_sink.h',
+        'bluetooth_audio_sink_chromeos.cc',
+        'bluetooth_audio_sink_chromeos.h',
         'bluetooth_channel_mac.mm',
         'bluetooth_channel_mac.h',
         'bluetooth_device.cc',

device/bluetooth/bluetooth_audio_sink_chromeos.cc

@@ -0,0 +1,164 @@
+// Copyright 2015 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 "device/bluetooth/bluetooth_audio_sink_chromeos.h"
+
+#include <sstream>
+
+#include "base/logging.h"
+
+namespace chromeos {
+
+BluetoothAudioSinkChromeOS::BluetoothAudioSinkChromeOS(
+    BluetoothAdapterChromeOS* adapter)
+    : state_(device::BluetoothAudioSink::STATE_INVALID),
+      present_(false),
+      powered_(false),
+      volume_(0),
+      read_mtu_(0),
+      write_mtu_(0),
+      adapter_(adapter),
+      weak_ptr_factory_(this) {
+  DCHECK(adapter_);
+
+  present_ = adapter_->IsPresent();
+  powered_ = adapter_->IsPowered();
+  if (present_ && powered_)
+    state_ = device::BluetoothAudioSink::STATE_DISCONNECTED;
+  adapter_->AddObserver(this);
+}
+
+BluetoothAudioSinkChromeOS::~BluetoothAudioSinkChromeOS() {
+  DCHECK(adapter_);
+  adapter_->RemoveObserver(this);
+}
+
+void BluetoothAudioSinkChromeOS::AddObserver(
+    device::BluetoothAudioSink::Observer* observer) {
+  DCHECK(observer);
+  observers_.AddObserver(observer);
+}
+
+void BluetoothAudioSinkChromeOS::RemoveObserver(
+    device::BluetoothAudioSink::Observer* observer) {
+  DCHECK(observer);
+  observers_.RemoveObserver(observer);
+}
+
+device::BluetoothAudioSink::State BluetoothAudioSinkChromeOS::GetState() const {
+  return state_;
+}
+
+uint16_t BluetoothAudioSinkChromeOS::GetVolume() const {
+  return volume_;
+}
+
+void BluetoothAudioSinkChromeOS::AdapterPresentChanged(
+    device::BluetoothAdapter* adapter,
+    bool present) {
+  // TODO(mcchou): BUG=441581
+  // If |persent| is true, change state to |STATE_DISCONNECTED| and call
+  // StateChanged(). Otherwise, change state to |STATE_INVALID| and call
+  // StateChanged.
+}
+
+void BluetoothAudioSinkChromeOS::AdapterPoweredChanged(
+    device::BluetoothAdapter* adapter,
+    bool powered) {
+  // TODO(mcchou): BUG=441581
+  // If |powered| is true, change state to |STATE_DISCONNECTED| and call
+  // StateChanged(). Otherwise, change state to |STATE_INVALID| and call
+  // StateChanged.
+}
+
+void BluetoothAudioSinkChromeOS::MediaRemoved(
+    const dbus::ObjectPath& object_path) {
+  // TODO(mcchou): BUG=441581
+  // Check if |object_path| equals to |media_path_|. If true, change the state
+  // of the audio sink, call StateChanged and reset the audio sink.
+}
+
+void BluetoothAudioSinkChromeOS::MediaTransportRemoved(
+    const dbus::ObjectPath& object_path) {
+  // TODO(mcchou): BUG=441581
+  // Check if |object_path| equals to |transport_path_|. If true, change the
+  // state of the audio sink, call StateChanged and reset the audio sink.
+}
+
+void BluetoothAudioSinkChromeOS::MediaTransportPropertyChanged(
+    const dbus::ObjectPath& object_path,
+    const std::string& property_name) {
+  // TODO(mcchou): BUG=441581
+  // Call StateChanged and VolumeChanged accordingly if there is any change on
+  // state/volume.
+}
+
+void BluetoothAudioSinkChromeOS::SetConfiguration(
+    const dbus::ObjectPath& transport_path,
+    const dbus::MessageReader& properties) {
+  // TODO(mcchou): BUG=441581
+  // Update |transport_path_| and store properties if needed.
+}
+
+void BluetoothAudioSinkChromeOS::SelectConfiguration(
+    const std::vector<uint8_t>& capabilities,
+    const SelectConfigurationCallback& callback) {
+  // TODO(mcchou): BUG=441581
+  // Use SelectConfigurationCallback to return the agreed capabilities.
+}
+
+void BluetoothAudioSinkChromeOS::ClearConfiguration(
+    const dbus::ObjectPath& transport_path) {
+  // TODO(mcchou): BUG=441581
+  // Reset the configuration to the default one and close IOBuffer.
+}
+
+void BluetoothAudioSinkChromeOS::Release() {
+  // TODO(mcchou): BUG=441581
+  // Let the audio sink does the clean-up and do nothing here.
+}
+
+void BluetoothAudioSinkChromeOS::Register(
+    const device::BluetoothAudioSink::Options& options,
+    const base::Closure& callback,
+    const device::BluetoothAudioSink::ErrorCallback& error_callback) {
+  // TODO(mcchou): BUG=441581
+  // Get Media object, initiate an Media Endpoint with options, and return the
+  // audio sink via callback. Add the audio sink as observer of both Media and
+  // Media Transport.
+}
+
+void BluetoothAudioSinkChromeOS::Unregister(
+    const base::Closure& callback,
+    const device::BluetoothAudioSink::ErrorCallback& error_callback) {
+  // TODO(mcchou): BUG=441581
+  // Clean |observers_| and |transport_path_| and reset |state_| and |volume_|.
+}
+
+void BluetoothAudioSinkChromeOS::StateChanged(
+    device::BluetoothAudioSink::State state) {
+  DCHECK_NE(state, state_);
+  VLOG(1) << "Bluetooth audio sink state changed: " << state;
+  state_ = state;
+  FOR_EACH_OBSERVER(device::BluetoothAudioSink::Observer, observers_,
+                    BluetoothAudioSinkStateChanged(this, state_));
+}
+
+void BluetoothAudioSinkChromeOS::VolumeChanged(uint16_t volume) {
+  DCHECK_NE(volume, volume_);
+  VLOG(1) << "Bluetooth audio sink volume changed: " << volume;
+  volume_ = volume;
+  FOR_EACH_OBSERVER(device::BluetoothAudioSink::Observer, observers_,
+                    BluetoothAudioSinkVolumeChanged(this, volume_));
+}
+
+void BluetoothAudioSinkChromeOS::ReadFromFD() {
+  DCHECK_GE(fd_.value(), 0);
+
+  // TODO(mcchou): BUG=441581
+  // Read from file descriptor using watcher and create a buffer to contain the
+  // data. Notify |Observers_| while there is audio data available.
+}
+
+}  // namespace chromeos

device/bluetooth/bluetooth_audio_sink_chromeos.h

@@ -0,0 +1,150 @@
+// Copyright 2015 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 DEVICE_BLUETOOTH_BLUETOOTH_AUDIO_SINK_CHROMEOS_H_
+#define DEVICE_BLUETOOTH_BLUETOOTH_AUDIO_SINK_CHROMEOS_H_
+
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+#include "chromeos/dbus/bluetooth_media_client.h"
+#include "chromeos/dbus/bluetooth_media_endpoint_service_provider.h"
+#include "chromeos/dbus/bluetooth_media_transport_client.h"
+#include "dbus/file_descriptor.h"
+#include "dbus/object_path.h"
+#include "device/bluetooth/bluetooth_adapter.h"
+#include "device/bluetooth/bluetooth_adapter_chromeos.h"
+#include "device/bluetooth/bluetooth_audio_sink.h"
+#include "device/bluetooth/bluetooth_export.h"
+
+namespace chromeos {
+
+class DEVICE_BLUETOOTH_EXPORT BluetoothAudioSinkChromeOS
+    : public device::BluetoothAudioSink,
+      public device::BluetoothAdapter::Observer,
+      public BluetoothMediaClient::Observer,
+      public BluetoothMediaTransportClient::Observer,
+      public BluetoothMediaEndpointServiceProvider::Delegate {
+ public:
+  explicit BluetoothAudioSinkChromeOS(BluetoothAdapterChromeOS* adapter);
+
+  // device::BluetoothAudioSink overrides.
+  void AddObserver(BluetoothAudioSink::Observer* observer) override;
+  void RemoveObserver(BluetoothAudioSink::Observer* observer) override;
+  device::BluetoothAudioSink::State GetState() const override;
+  uint16_t GetVolume() const override;
+
+  // device::BluetoothAdapter::Observer overrides.
+  void AdapterPresentChanged(device::BluetoothAdapter* adapter,
+                             bool present) override;
+  void AdapterPoweredChanged(device::BluetoothAdapter* adapter,
+                             bool powered) override;
+
+  // BluetoothMediaClient::Observer overrides.
+  void MediaRemoved(const dbus::ObjectPath& object_path) override;
+
+  // BluetoothMediaTransportClient::Observer overrides.
+  void MediaTransportRemoved(const dbus::ObjectPath& object_path) override;
+  void MediaTransportPropertyChanged(const dbus::ObjectPath& object_path,
+                                     const std::string& property_name) override;
+
+  // BluetoothMediaEndpointServiceProvider::Delegate overrides.
+  void SetConfiguration(const dbus::ObjectPath& transport_path,
+                        const dbus::MessageReader& properties) override;
+  void SelectConfiguration(
+      const std::vector<uint8_t>& capabilities,
+      const SelectConfigurationCallback& callback) override;
+  void ClearConfiguration(const dbus::ObjectPath& transport_path) override;
+  void Release() override;
+
+  // Registers a BluetoothAudioSink. User applications can use |options| to
+  // configure the audio sink. |callback| will be executed if the audio sink is
+  // successfully registered, otherwise |error_callback| will be called. Called
+  // from BluetoothAdapterChromeOS.
+  void Register(
+      const device::BluetoothAudioSink::Options& options,
+      const base::Closure& callback,
+      const device::BluetoothAudioSink::ErrorCallback& error_callback);
+
+  // Unregisters a BluetoothAudioSink. |callback| should handle
+  // the clean-up after the audio sink is deleted successfully, otherwise
+  // |error_callback| will be called.
+  void Unregister(
+      const base::Closure& callback,
+      const device::BluetoothAudioSink::ErrorCallback& error_callback) override;
+
+ private:
+  ~BluetoothAudioSinkChromeOS() override;
+
+  // Called when the state property of BluetoothMediaTransport has been updated.
+  void StateChanged(device::BluetoothAudioSink::State state);
+
+  // Called when the volume property of BluetoothMediaTransport has been
+  // updated.
+  void VolumeChanged(uint16_t volume);
+
+  // Reads from the file descriptor acquired via Media Transport object and
+  // notify |observer_| while the audio data is available.
+  void ReadFromFD();
+
+  // The connection state between the BluetoothAudioSinkChromeOS and the remote
+  // device.
+  device::BluetoothAudioSink::State state_;
+
+  // Indicates whether the adapter is present.
+  bool present_;
+
+  // Indicates whether the adapter is powered.
+  bool powered_;
+
+  // The volume control by the remote device during the streaming.
+  uint16_t volume_;
+
+  // Read MTU of the file descriptor acquired via Media Transport object.
+  uint16_t read_mtu_;
+
+  // Write MTU of the file descriptor acquired via Media Transport object.
+  uint16_t write_mtu_;
+
+  // File descriptor acquired via Media Transport object.
+  dbus::FileDescriptor fd_;
+
+  // Object path of the media object being used.
+  dbus::ObjectPath media_path_;
+
+  // Object path of the transport object being used.
+  dbus::ObjectPath transport_path_;
+
+  // Object path of the media endpoint object being used.
+  dbus::ObjectPath endpoint_path_;
+
+  // BT adapter which the audio sink binds to. |adapter_| should outlive
+  // a BluetoothAudioSinkChromeOS object.
+  BluetoothAdapterChromeOS* adapter_;
+
+  // Options used to initiate Media Endpoint and select configuration for the
+  // transport.
+  device::BluetoothAudioSink::Options options_;
+
+  // Media Endpoint object owned by the audio sink object.
+  scoped_ptr<BluetoothMediaEndpointServiceProvider> media_endpoint_;
+
+  // List of observers interested in event notifications from us. Objects in
+  // |observers_| are expected to outlive a BluetoothAudioSinkChromeOS object.
+  ObserverList<BluetoothAudioSink::Observer> observers_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate its weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<BluetoothAudioSinkChromeOS> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(BluetoothAudioSinkChromeOS);
+};
+
+}  // namespace chromeos
+
+#endif  // DEVICE_BLUETOOTH_BLUETOOTH_AUDIO_SINK_CHROMEOS_H_