content: /*
   * Copyright (C) 2008 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.
   */
  
  package android.bluetooth;
  
  import android.Manifest;
  import android.annotation.Nullable;
  import android.annotation.RequiresPermission;
  import android.annotation.SdkConstant;
  import android.annotation.SdkConstant.SdkConstantType;
  import android.annotation.UnsupportedAppUsage;
  import android.content.Context;
  import android.os.Binder;
  import android.os.Build;
  import android.os.IBinder;
  import android.os.ParcelUuid;
  import android.os.RemoteException;
  import android.util.Log;
  
  import java.util.ArrayList;
  import java.util.List;
  
  
  /**
   * This class provides the public APIs to control the Bluetooth A2DP
   * profile.
   *
   * <p>BluetoothA2dp is a proxy object for controlling the Bluetooth A2DP
   * Service via IPC. Use {@link BluetoothAdapter#getProfileProxy} to get
   * the BluetoothA2dp proxy object.
   *
   * <p> Android only supports one connected Bluetooth A2dp device at a time.
   * Each method is protected with its appropriate permission.
   */
  public final class BluetoothA2dp implements BluetoothProfile {
      private static final String TAG = "BluetoothA2dp";
      private static final boolean DBG = true;
      private static final boolean VDBG = false;
  
      /**
       * Intent used to broadcast the change in connection state of the A2DP
       * profile.
       *
       * <p>This intent will have 3 extras:
       * <ul>
       * <li> {@link #EXTRA_STATE} - The current state of the profile. </li>
       * <li> {@link #EXTRA_PREVIOUS_STATE}- The previous state of the profile.</li>
       * <li> {@link BluetoothDevice#EXTRA_DEVICE} - The remote device. </li>
       * </ul>
       *
       * <p>{@link #EXTRA_STATE} or {@link #EXTRA_PREVIOUS_STATE} can be any of
       * {@link #STATE_DISCONNECTED}, {@link #STATE_CONNECTING},
       * {@link #STATE_CONNECTED}, {@link #STATE_DISCONNECTING}.
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission to
       * receive.
       */
      @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
      public static final String ACTION_CONNECTION_STATE_CHANGED =
              "android.bluetooth.a2dp.profile.action.CONNECTION_STATE_CHANGED";
  
      /**
       * Intent used to broadcast the change in the Playing state of the A2DP
       * profile.
       *
       * <p>This intent will have 3 extras:
       * <ul>
       * <li> {@link #EXTRA_STATE} - The current state of the profile. </li>
       * <li> {@link #EXTRA_PREVIOUS_STATE}- The previous state of the profile. </li>
       * <li> {@link BluetoothDevice#EXTRA_DEVICE} - The remote device. </li>
       * </ul>
       *
       * <p>{@link #EXTRA_STATE} or {@link #EXTRA_PREVIOUS_STATE} can be any of
       * {@link #STATE_PLAYING}, {@link #STATE_NOT_PLAYING},
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission to
       * receive.
       */
      @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
      public static final String ACTION_PLAYING_STATE_CHANGED =
              "android.bluetooth.a2dp.profile.action.PLAYING_STATE_CHANGED";
  
      /** @hide */
      @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
      public static final String ACTION_AVRCP_CONNECTION_STATE_CHANGED =
              "android.bluetooth.a2dp.profile.action.AVRCP_CONNECTION_STATE_CHANGED";
  
      /**
       * Intent used to broadcast the selection of a connected device as active.
       *
       * <p>This intent will have one extra:
       * <ul>
       * <li> {@link BluetoothDevice#EXTRA_DEVICE} - The remote device. It can
       * be null if no device is active. </li>
       * </ul>
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission to
       * receive.
       *
       * @hide
       */
      @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
      @UnsupportedAppUsage
      public static final String ACTION_ACTIVE_DEVICE_CHANGED =
              "android.bluetooth.a2dp.profile.action.ACTIVE_DEVICE_CHANGED";
  
      /**
       * Intent used to broadcast the change in the Audio Codec state of the
       * A2DP Source profile.
       *
       * <p>This intent will have 2 extras:
       * <ul>
       * <li> {@link BluetoothCodecStatus#EXTRA_CODEC_STATUS} - The codec status. </li>
       * <li> {@link BluetoothDevice#EXTRA_DEVICE} - The remote device if the device is currently
       * connected, otherwise it is not included.</li>
       * </ul>
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission to
       * receive.
       *
       * @hide
       */
      @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
      @UnsupportedAppUsage
      public static final String ACTION_CODEC_CONFIG_CHANGED =
              "android.bluetooth.a2dp.profile.action.CODEC_CONFIG_CHANGED";
  
      /**
       * A2DP sink device is streaming music. This state can be one of
       * {@link #EXTRA_STATE} or {@link #EXTRA_PREVIOUS_STATE} of
       * {@link #ACTION_PLAYING_STATE_CHANGED} intent.
       */
      public static final int STATE_PLAYING = 10;
  
      /**
       * A2DP sink device is NOT streaming music. This state can be one of
       * {@link #EXTRA_STATE} or {@link #EXTRA_PREVIOUS_STATE} of
       * {@link #ACTION_PLAYING_STATE_CHANGED} intent.
       */
      public static final int STATE_NOT_PLAYING = 11;
  
      /**
       * We don't have a stored preference for whether or not the given A2DP sink device supports
       * optional codecs.
       *
       * @hide
       */
      @UnsupportedAppUsage
      public static final int OPTIONAL_CODECS_SUPPORT_UNKNOWN = -1;
  
      /**
       * The given A2DP sink device does not support optional codecs.
       *
       * @hide
       */
      @UnsupportedAppUsage
      public static final int OPTIONAL_CODECS_NOT_SUPPORTED = 0;
  
      /**
       * The given A2DP sink device does support optional codecs.
       *
       * @hide
       */
      @UnsupportedAppUsage
      public static final int OPTIONAL_CODECS_SUPPORTED = 1;
  
      /**
       * We don't have a stored preference for whether optional codecs should be enabled or disabled
       * for the given A2DP device.
       *
       * @hide
       */
      @UnsupportedAppUsage
      public static final int OPTIONAL_CODECS_PREF_UNKNOWN = -1;
  
      /**
       * Optional codecs should be disabled for the given A2DP device.
       *
       * @hide
       */
      @UnsupportedAppUsage
      public static final int OPTIONAL_CODECS_PREF_DISABLED = 0;
  
      /**
       * Optional codecs should be enabled for the given A2DP device.
       *
       * @hide
       */
      @UnsupportedAppUsage
      public static final int OPTIONAL_CODECS_PREF_ENABLED = 1;
  
      private BluetoothAdapter mAdapter;
      private final BluetoothProfileConnector<IBluetoothA2dp> mProfileConnector =
              new BluetoothProfileConnector(this, BluetoothProfile.A2DP, "BluetoothA2dp",
                      IBluetoothA2dp.class.getName()) {
                  @Override
                  public IBluetoothA2dp getServiceInterface(IBinder service) {
                      return IBluetoothA2dp.Stub.asInterface(Binder.allowBlocking(service));
                  }
      };
  
      /**
       * Create a BluetoothA2dp proxy object for interacting with the local
       * Bluetooth A2DP service.
       */
      /*package*/ BluetoothA2dp(Context context, ServiceListener listener) {
          mAdapter = BluetoothAdapter.getDefaultAdapter();
          mProfileConnector.connect(context, listener);
      }
  
      @UnsupportedAppUsage
      /*package*/ void close() {
          mProfileConnector.disconnect();
      }
  
      private IBluetoothA2dp getService() {
          return mProfileConnector.getService();
      }
  
      @Override
      public void finalize() {
          // The empty finalize needs to be kept or the
          // cts signature tests would fail.
      }
  
      /**
       * Initiate connection to a profile of the remote Bluetooth device.
       *
       * <p> This API returns false in scenarios like the profile on the
       * device is already connected or Bluetooth is not turned on.
       * When this API returns true, it is guaranteed that
       * connection state intent for the profile will be broadcasted with
       * the state. Users can get the connection state of the profile
       * from this intent.
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}
       * permission.
       *
       * @param device Remote Bluetooth Device
       * @return false on immediate error, true otherwise
       * @hide
       */
      @UnsupportedAppUsage
      public boolean connect(BluetoothDevice device) {
          if (DBG) log("connect(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled() && isValidDevice(device)) {
                  return service.connect(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return false;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return false;
          }
      }
  
      /**
       * Initiate disconnection from a profile
       *
       * <p> This API will return false in scenarios like the profile on the
       * Bluetooth device is not in connected state etc. When this API returns,
       * true, it is guaranteed that the connection state change
       * intent will be broadcasted with the state. Users can get the
       * disconnection state of the profile from this intent.
       *
       * <p> If the disconnection is initiated by a remote device, the state
       * will transition from {@link #STATE_CONNECTED} to
       * {@link #STATE_DISCONNECTED}. If the disconnect is initiated by the
       * host (local) device the state will transition from
       * {@link #STATE_CONNECTED} to state {@link #STATE_DISCONNECTING} to
       * state {@link #STATE_DISCONNECTED}. The transition to
       * {@link #STATE_DISCONNECTING} can be used to distinguish between the
       * two scenarios.
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}
       * permission.
       *
       * @param device Remote Bluetooth Device
       * @return false on immediate error, true otherwise
       * @hide
       */
      @UnsupportedAppUsage
      public boolean disconnect(BluetoothDevice device) {
          if (DBG) log("disconnect(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled() && isValidDevice(device)) {
                  return service.disconnect(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return false;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return false;
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public List<BluetoothDevice> getConnectedDevices() {
          if (VDBG) log("getConnectedDevices()");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  return service.getConnectedDevices();
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return new ArrayList<BluetoothDevice>();
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return new ArrayList<BluetoothDevice>();
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public List<BluetoothDevice> getDevicesMatchingConnectionStates(int[] states) {
          if (VDBG) log("getDevicesMatchingStates()");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  return service.getDevicesMatchingConnectionStates(states);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return new ArrayList<BluetoothDevice>();
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return new ArrayList<BluetoothDevice>();
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public @BtProfileState int getConnectionState(BluetoothDevice device) {
          if (VDBG) log("getState(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()
                      && isValidDevice(device)) {
                  return service.getConnectionState(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return BluetoothProfile.STATE_DISCONNECTED;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return BluetoothProfile.STATE_DISCONNECTED;
          }
      }
  
      /**
       * Select a connected device as active.
       *
       * The active device selection is per profile. An active device's
       * purpose is profile-specific. For example, A2DP audio streaming
       * is to the active A2DP Sink device. If a remote device is not
       * connected, it cannot be selected as active.
       *
       * <p> This API returns false in scenarios like the profile on the
       * device is not connected or Bluetooth is not turned on.
       * When this API returns true, it is guaranteed that the
       * {@link #ACTION_ACTIVE_DEVICE_CHANGED} intent will be broadcasted
       * with the active device.
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}
       * permission.
       *
       * @param device the remote Bluetooth device. Could be null to clear
       * the active device and stop streaming audio to a Bluetooth device.
       * @return false on immediate error, true otherwise
       * @hide
       */
      @UnsupportedAppUsage
      public boolean setActiveDevice(@Nullable BluetoothDevice device) {
          if (DBG) log("setActiveDevice(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()
                      && ((device == null) || isValidDevice(device))) {
                  return service.setActiveDevice(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return false;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return false;
          }
      }
  
      /**
       * Get the connected device that is active.
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH}
       * permission.
       *
       * @return the connected device that is active or null if no device
       * is active
       * @hide
       */
      @RequiresPermission(Manifest.permission.BLUETOOTH)
      @Nullable
      @UnsupportedAppUsage
      public BluetoothDevice getActiveDevice() {
          if (VDBG) log("getActiveDevice()");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  return service.getActiveDevice();
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return null;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return null;
          }
      }
  
      /**
       * Set priority of the profile
       *
       * <p> The device should already be paired.
       * Priority can be one of {@link #PRIORITY_ON} orgetBluetoothManager
       * {@link #PRIORITY_OFF},
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}
       * permission.
       *
       * @param device Paired bluetooth device
       * @param priority
       * @return true if priority is set, false on error
       * @hide
       */
      public boolean setPriority(BluetoothDevice device, int priority) {
          if (DBG) log("setPriority(" + device + ", " + priority + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()
                      && isValidDevice(device)) {
                  if (priority != BluetoothProfile.PRIORITY_OFF
                          && priority != BluetoothProfile.PRIORITY_ON) {
                      return false;
                  }
                  return service.setPriority(device, priority);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return false;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return false;
          }
      }
  
      /**
       * Get the priority of the profile.
       *
       * <p> The priority can be any of:
       * {@link #PRIORITY_AUTO_CONNECT}, {@link #PRIORITY_OFF},
       * {@link #PRIORITY_ON}, {@link #PRIORITY_UNDEFINED}
       *
       * @param device Bluetooth device
       * @return priority of the device
       * @hide
       */
      @RequiresPermission(Manifest.permission.BLUETOOTH)
      @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
      public int getPriority(BluetoothDevice device) {
          if (VDBG) log("getPriority(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()
                      && isValidDevice(device)) {
                  return service.getPriority(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return BluetoothProfile.PRIORITY_OFF;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return BluetoothProfile.PRIORITY_OFF;
          }
      }
  
      /**
       * Checks if Avrcp device supports the absolute volume feature.
       *
       * @return true if device supports absolute volume
       * @hide
       */
      public boolean isAvrcpAbsoluteVolumeSupported() {
          if (DBG) Log.d(TAG, "isAvrcpAbsoluteVolumeSupported");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  return service.isAvrcpAbsoluteVolumeSupported();
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return false;
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in isAvrcpAbsoluteVolumeSupported()", e);
              return false;
          }
      }
  
      /**
       * Tells remote device to set an absolute volume. Only if absolute volume is supported
       *
       * @param volume Absolute volume to be set on AVRCP side
       * @hide
       */
      public void setAvrcpAbsoluteVolume(int volume) {
          if (DBG) Log.d(TAG, "setAvrcpAbsoluteVolume");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  service.setAvrcpAbsoluteVolume(volume);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in setAvrcpAbsoluteVolume()", e);
          }
      }
  
      /**
       * Check if A2DP profile is streaming music.
       *
       * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission.
       *
       * @param device BluetoothDevice device
       */
      public boolean isA2dpPlaying(BluetoothDevice device) {
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()
                      && isValidDevice(device)) {
                  return service.isA2dpPlaying(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return false;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return false;
          }
      }
  
      /**
       * This function checks if the remote device is an AVCRP
       * target and thus whether we should send volume keys
       * changes or not.
       *
       * @hide
       */
      public boolean shouldSendVolumeKeys(BluetoothDevice device) {
          if (isEnabled() && isValidDevice(device)) {
              ParcelUuid[] uuids = device.getUuids();
              if (uuids == null) return false;
  
              for (ParcelUuid uuid : uuids) {
                  if (BluetoothUuid.isAvrcpTarget(uuid)) {
                      return true;
                  }
              }
          }
          return false;
      }
  
      /**
       * Gets the current codec status (configuration and capability).
       *
       * @param device the remote Bluetooth device. If null, use the current
       * active A2DP Bluetooth device.
       * @return the current codec status
       * @hide
       */
      @UnsupportedAppUsage
      public @Nullable BluetoothCodecStatus getCodecStatus(BluetoothDevice device) {
          if (DBG) Log.d(TAG, "getCodecStatus(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  return service.getCodecStatus(device);
              }
              if (service == null) {
                  Log.w(TAG, "Proxy not attached to service");
              }
              return null;
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in getCodecStatus()", e);
              return null;
          }
      }
  
      /**
       * Sets the codec configuration preference.
       *
       * @param device the remote Bluetooth device. If null, use the current
       * active A2DP Bluetooth device.
       * @param codecConfig the codec configuration preference
       * @hide
       */
      @UnsupportedAppUsage
      public void setCodecConfigPreference(BluetoothDevice device,
                                           BluetoothCodecConfig codecConfig) {
          if (DBG) Log.d(TAG, "setCodecConfigPreference(" + device + ")");
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  service.setCodecConfigPreference(device, codecConfig);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return;
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in setCodecConfigPreference()", e);
              return;
          }
      }
  
      /**
       * Enables the optional codecs.
       *
       * @param device the remote Bluetooth device. If null, use the currect
       * active A2DP Bluetooth device.
       * @hide
       */
      @UnsupportedAppUsage
      public void enableOptionalCodecs(BluetoothDevice device) {
          if (DBG) Log.d(TAG, "enableOptionalCodecs(" + device + ")");
          enableDisableOptionalCodecs(device, true);
      }
  
      /**
       * Disables the optional codecs.
       *
       * @param device the remote Bluetooth device. If null, use the currect
       * active A2DP Bluetooth device.
       * @hide
       */
      @UnsupportedAppUsage
      public void disableOptionalCodecs(BluetoothDevice device) {
          if (DBG) Log.d(TAG, "disableOptionalCodecs(" + device + ")");
          enableDisableOptionalCodecs(device, false);
      }
  
      /**
       * Enables or disables the optional codecs.
       *
       * @param device the remote Bluetooth device. If null, use the currect
       * active A2DP Bluetooth device.
       * @param enable if true, enable the optional codecs, other disable them
       */
      private void enableDisableOptionalCodecs(BluetoothDevice device, boolean enable) {
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()) {
                  if (enable) {
                      service.enableOptionalCodecs(device);
                  } else {
                      service.disableOptionalCodecs(device);
                  }
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return;
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in enableDisableOptionalCodecs()", e);
              return;
          }
      }
  
      /**
       * Returns whether this device supports optional codecs.
       *
       * @param device The device to check
       * @return one of OPTIONAL_CODECS_SUPPORT_UNKNOWN, OPTIONAL_CODECS_NOT_SUPPORTED, or
       * OPTIONAL_CODECS_SUPPORTED.
       * @hide
       */
      @UnsupportedAppUsage
      public int supportsOptionalCodecs(BluetoothDevice device) {
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled() && isValidDevice(device)) {
                  return service.supportsOptionalCodecs(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return OPTIONAL_CODECS_SUPPORT_UNKNOWN;
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in getSupportsOptionalCodecs()", e);
              return OPTIONAL_CODECS_SUPPORT_UNKNOWN;
          }
      }
  
      /**
       * Returns whether this device should have optional codecs enabled.
       *
       * @param device The device in question.
       * @return one of OPTIONAL_CODECS_PREF_UNKNOWN, OPTIONAL_CODECS_PREF_ENABLED, or
       * OPTIONAL_CODECS_PREF_DISABLED.
       * @hide
       */
      @UnsupportedAppUsage
      public int getOptionalCodecsEnabled(BluetoothDevice device) {
          try {
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled() && isValidDevice(device)) {
                  return service.getOptionalCodecsEnabled(device);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return OPTIONAL_CODECS_PREF_UNKNOWN;
          } catch (RemoteException e) {
              Log.e(TAG, "Error talking to BT service in getSupportsOptionalCodecs()", e);
              return OPTIONAL_CODECS_PREF_UNKNOWN;
          }
      }
  
      /**
       * Sets a persistent preference for whether a given device should have optional codecs enabled.
       *
       * @param device The device to set this preference for.
       * @param value Whether the optional codecs should be enabled for this device.  This should be
       * one of OPTIONAL_CODECS_PREF_UNKNOWN, OPTIONAL_CODECS_PREF_ENABLED, or
       * OPTIONAL_CODECS_PREF_DISABLED.
       * @hide
       */
      @UnsupportedAppUsage
      public void setOptionalCodecsEnabled(BluetoothDevice device, int value) {
          try {
              if (value != BluetoothA2dp.OPTIONAL_CODECS_PREF_UNKNOWN
                      && value != BluetoothA2dp.OPTIONAL_CODECS_PREF_DISABLED
                      && value != BluetoothA2dp.OPTIONAL_CODECS_PREF_ENABLED) {
                  Log.e(TAG, "Invalid value passed to setOptionalCodecsEnabled: " + value);
                  return;
              }
              final IBluetoothA2dp service = getService();
              if (service != null && isEnabled()
                      && isValidDevice(device)) {
                  service.setOptionalCodecsEnabled(device, value);
              }
              if (service == null) Log.w(TAG, "Proxy not attached to service");
              return;
          } catch (RemoteException e) {
              Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
              return;
          }
      }
  
      /**
       * Helper for converting a state to a string.
       *
       * For debug use only - strings are not internationalized.
       *
       * @hide
       */
      @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
      public static String stateToString(int state) {
          switch (state) {
              case STATE_DISCONNECTED:
                  return "disconnected";
              case STATE_CONNECTING:
                  return "connecting";
              case STATE_CONNECTED:
                  return "connected";
              case STATE_DISCONNECTING:
                  return "disconnecting";
              case STATE_PLAYING:
                  return "playing";
              case STATE_NOT_PLAYING:
                  return "not playing";
              default:
                  return "<unknown state " + state + ">";
          }
      }
  
      private boolean isEnabled() {
          if (mAdapter.getState() == BluetoothAdapter.STATE_ON) return true;
          return false;
      }
  
      private boolean isValidDevice(BluetoothDevice device) {
          if (device == null) return false;
  
          if (BluetoothAdapter.checkBluetoothAddress(device.getAddress())) return true;
          return false;
      }
  
      private static void log(String msg) {
          Log.d(TAG, msg);
      }
  }
  