device/bluetooth: Add BluetoothAudioSinkChromeOS.

device/bluetooth/bluetooth_audio_sink_chromeos.h

+// 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);
+
+  // Generates an unique path for initiating a Media Endpoint.
+  static dbus::ObjectPath GenerateEndpointPath();

[armansito, 2015/01/21 00:25:57]

nit: I'd make this private, since this will only be used internally.

+
+  // 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 MediaAdded(const dbus::ObjectPath& object_path) override;
+  void MediaRemoved(const dbus::ObjectPath& object_path) override;
+
+  // BluetoothMediaTransportClient::Observer overrides.
+  void MediaTransportAdded(const dbus::ObjectPath& object_path) override;
+  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_;
+
+  // A global sequence number used to generate unique paths for Media Endpoint
+  // objects.
+  static unsigned int sequence_number;

[armansito, 2015/01/21 00:25:57]

nit: Underscore at the end (i.e. |sequence_number_|) according to style guide:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Variable_Names

+
+  // 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_