Hearing Aid BTA interface

/******************************************************************************

 *

 *  Copyright 2018 The Android Open Source Project

 *

 *  Licensed under the Apache License, Version 2.0 (the "License");

 *  you may not use this file except in compliance with the License.

 *  You may obtain a copy of the License at:

 *

 *  http://www.apache.org/licenses/LICENSE-2.0

 *

 *  Unless required by applicable law or agreed to in writing, software

 *  distributed under the License is distributed on an "AS IS" BASIS,

 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *  See the License for the specific language governing permissions and

 *  limitations under the License.

 *

 ******************************************************************************/

#pragma once

#include <base/callback_forward.h>

#include <hardware/bt_hearing_aid.h>

using bluetooth::Uuid;

/** Implementations of HearingAid will also implement this interface */

class HearingAidAudioReceiver {

 public:

  virtual ~HearingAidAudioReceiver() = default;

  virtual void OnAudioDataReady(const std::vector<uint8_t>& data) = 0;

  virtual void OnAudioSuspend();

  virtual void OnAudioResume();

};

class HearingAid {

 public:

  virtual ~HearingAid() = default;

  static void Initialize(bluetooth::hearing_aid::HearingAidCallbacks* callbacks,

                         base::Closure initCb);

  static void CleanUp();

  static bool IsInitialized();

  static HearingAid* Get();

  static void AddFromStorage(const RawAddress& address, uint16_t psm,

                             uint8_t capabilities, uint8_t codec,

                             uint16_t audioControlPointHandle,

                             uint16_t volumeHandle, uint64_t hiSyncId);

  virtual void Connect(const RawAddress& address) = 0;

  virtual void Disconnect(const RawAddress& address) = 0;

  virtual void SetVolume(int8_t volume) = 0;

};

/* Represents configuration of audio codec, as exchanged between hearing aid and

 * phone.

 * It can also be passed to the audio source to configure its parameters.

 */

struct CodecConfiguration {

  /** sampling rate that the codec expects to receive from audio framework */

  uint32_t sample_rate;

  /** bitrate that codec expects to receive from audio framework in bits per

   * channel */

  uint32_t bit_rate;

  /** Data interval determines how often we send samples to the remote. This

   * should match how often we grab data from audio source, optionally we can

   * grab data every 2 or 3 intervals, but this would increase latency.

   *

   * Value is provided in ms, must be divisable by 1.25 to make sure the

   * connection interval is integer.

   */

  uint16_t data_interval_ms;

};

/** Represents source of audio for hearing aids */

class HearingAidAudioSource {

 public:

  static void Start(const CodecConfiguration& codecConfiguration,

                    HearingAidAudioReceiver* audioReceiver);

  static void Stop();

  static void Initialize();

  static void CleanUp();

};