core/java/android/bluetooth/BluetoothA2dpSink.java

/*
 * Copyright (C) 2014 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.annotation.UnsupportedAppUsage;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Binder;
import android.os.IBinder;
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 Sink
 * profile.
 *
 * <p>BluetoothA2dpSink is a proxy object for controlling the Bluetooth A2DP Sink
 * Service via IPC. Use {@link BluetoothAdapter#getProfileProxy} to get
 * the BluetoothA2dpSink proxy object.
 *
 * @hide
 */
public final class BluetoothA2dpSink implements BluetoothProfile {
    private static final String TAG = "BluetoothA2dpSink";
    private static final boolean DBG = true;
    private static final boolean VDBG = false;

    /**
     * Intent used to broadcast the change in connection state of the A2DP Sink
     * 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.
     */
    public static final String ACTION_CONNECTION_STATE_CHANGED =
            "android.bluetooth.a2dp-sink.profile.action.CONNECTION_STATE_CHANGED";

    /**
     * Intent used to broadcast the change in the Playing state of the A2DP Sink
     * 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.
     */
    public static final String ACTION_PLAYING_STATE_CHANGED =
            "android.bluetooth.a2dp-sink.profile.action.PLAYING_STATE_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;

    /**
     * Intent used to broadcast the change in the Playing state of the A2DP Sink
     * profile.
     *
     * <p>This intent will have 3 extras:
     * <ul>
     * <li> {@link #EXTRA_AUDIO_CONFIG} - The audio configuration for the remote device. </li>
     * <li> {@link BluetoothDevice#EXTRA_DEVICE} - The remote device. </li>
     * </ul>
     *
     * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission to
     * receive.
     */
    public static final String ACTION_AUDIO_CONFIG_CHANGED =
            "android.bluetooth.a2dp-sink.profile.action.AUDIO_CONFIG_CHANGED";

    /**
     * Extra for the {@link #ACTION_AUDIO_CONFIG_CHANGED} intent.
     *
     * This extra represents the current audio configuration of the A2DP source device.
     * {@see BluetoothAudioConfig}
     */
    public static final String EXTRA_AUDIO_CONFIG =
            "android.bluetooth.a2dp-sink.profile.extra.AUDIO_CONFIG";

    private Context mContext;
    private ServiceListener mServiceListener;
    private volatile IBluetoothA2dpSink mService;
    private BluetoothAdapter mAdapter;

    private final IBluetoothStateChangeCallback mBluetoothStateChangeCallback =
            new IBluetoothStateChangeCallback.Stub() {
                public void onBluetoothStateChange(boolean up) {
                    if (DBG) Log.d(TAG, "onBluetoothStateChange: up=" + up);
                    if (!up) {
                        if (VDBG) Log.d(TAG, "Unbinding service...");
                        synchronized (mConnection) {
                            try {
                                mService = null;
                                mContext.unbindService(mConnection);
                            } catch (Exception re) {
                                Log.e(TAG, "", re);
                            }
                        }
                    } else {
                        synchronized (mConnection) {
                            try {
                                if (mService == null) {
                                    if (VDBG) Log.d(TAG, "Binding service...");
                                    doBind();
                                }
                            } catch (Exception re) {
                                Log.e(TAG, "", re);
                            }
                        }
                    }
                }
            };

    /**
     * Create a BluetoothA2dp proxy object for interacting with the local
     * Bluetooth A2DP service.
     */
    /*package*/ BluetoothA2dpSink(Context context, ServiceListener l) {
        mContext = context;
        mServiceListener = l;
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        IBluetoothManager mgr = mAdapter.getBluetoothManager();
        if (mgr != null) {
            try {
                mgr.registerStateChangeCallback(mBluetoothStateChangeCallback);
            } catch (RemoteException e) {
                Log.e(TAG, "", e);
            }
        }

        doBind();
    }

    boolean doBind() {
        Intent intent = new Intent(IBluetoothA2dpSink.class.getName());
        ComponentName comp = intent.resolveSystemService(mContext.getPackageManager(), 0);
        intent.setComponent(comp);
        if (comp == null || !mContext.bindServiceAsUser(intent, mConnection, 0,
                mContext.getUser())) {
            Log.e(TAG, "Could not bind to Bluetooth A2DP Service with " + intent);
            return false;
        }
        return true;
    }

    /*package*/ void close() {
        mServiceListener = null;
        IBluetoothManager mgr = mAdapter.getBluetoothManager();
        if (mgr != null) {
            try {
                mgr.unregisterStateChangeCallback(mBluetoothStateChangeCallback);
            } catch (Exception e) {
                Log.e(TAG, "", e);
            }
        }

        synchronized (mConnection) {
            if (mService != null) {
                try {
                    mService = null;
                    mContext.unbindService(mConnection);
                } catch (Exception re) {
                    Log.e(TAG, "", re);
                }
            }
        }
    }

    @Override
    public void finalize() {
        close();
    }

    /**
     * Initiate connection to a profile of the remote bluetooth device.
     *
     * <p> Currently, the system supports only 1 connection to the
     * A2DP profile. The API will automatically disconnect connected
     * devices before connecting.
     *
     * <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
     */
    public boolean connect(BluetoothDevice device) {
        if (DBG) log("connect(" + device + ")");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            try {
                return service.connect(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        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 + ")");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            try {
                return service.disconnect(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public List<BluetoothDevice> getConnectedDevices() {
        if (VDBG) log("getConnectedDevices()");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled()) {
            try {
                return service.getConnectedDevices();
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return new ArrayList<BluetoothDevice>();
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        return new ArrayList<BluetoothDevice>();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public List<BluetoothDevice> getDevicesMatchingConnectionStates(int[] states) {
        if (VDBG) log("getDevicesMatchingStates()");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled()) {
            try {
                return service.getDevicesMatchingConnectionStates(states);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return new ArrayList<BluetoothDevice>();
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        return new ArrayList<BluetoothDevice>();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getConnectionState(BluetoothDevice device) {
        if (VDBG) log("getState(" + device + ")");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            try {
                return service.getConnectionState(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return BluetoothProfile.STATE_DISCONNECTED;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        return BluetoothProfile.STATE_DISCONNECTED;
    }

    /**
     * Get the current audio configuration for the A2DP source device,
     * or null if the device has no audio configuration
     *
     * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission.
     *
     * @param device Remote bluetooth device.
     * @return audio configuration for the device, or null
     *
     * {@see BluetoothAudioConfig}
     */
    public BluetoothAudioConfig getAudioConfig(BluetoothDevice device) {
        if (VDBG) log("getAudioConfig(" + device + ")");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            try {
                return service.getAudioConfig(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return null;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        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 + ")");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            if (priority != BluetoothProfile.PRIORITY_OFF
                    && priority != BluetoothProfile.PRIORITY_ON) {
                return false;
            }
            try {
                return service.setPriority(device, priority);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        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}
     *
     * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission.
     *
     * @param device Bluetooth device
     * @return priority of the device
     * @hide
     */
    public int getPriority(BluetoothDevice device) {
        if (VDBG) log("getPriority(" + device + ")");
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            try {
                return service.getPriority(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return BluetoothProfile.PRIORITY_OFF;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        return BluetoothProfile.PRIORITY_OFF;
    }

    /**
     * Check if A2DP profile is streaming music.
     *
     * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission.
     *
     * @param device BluetoothDevice device
     */
    public boolean isA2dpPlaying(BluetoothDevice device) {
        final IBluetoothA2dpSink service = mService;
        if (service != null && isEnabled() && isValidDevice(device)) {
            try {
                return service.isA2dpPlaying(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (service == null) Log.w(TAG, "Proxy not attached to service");
        return false;
    }

    /**
     * Helper for converting a state to a string.
     *
     * For debug use only - strings are not internationalized.
     *
     * @hide
     */
    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 final ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName className, IBinder service) {
            if (DBG) Log.d(TAG, "Proxy object connected");
            mService = IBluetoothA2dpSink.Stub.asInterface(Binder.allowBlocking(service));
            if (mServiceListener != null) {
                mServiceListener.onServiceConnected(BluetoothProfile.A2DP_SINK,
                        BluetoothA2dpSink.this);
            }
        }

        public void onServiceDisconnected(ComponentName className) {
            if (DBG) Log.d(TAG, "Proxy object disconnected");
            mService = null;
            if (mServiceListener != null) {
                mServiceListener.onServiceDisconnected(BluetoothProfile.A2DP_SINK);
            }
        }
    };

    private boolean isEnabled() {
        return mAdapter.getState() == BluetoothAdapter.STATE_ON;
    }

    private static boolean isValidDevice(BluetoothDevice device) {
        return device != null && BluetoothAdapter.checkBluetoothAddress(device.getAddress());
    }

    private static void log(String msg) {
        Log.d(TAG, msg);
    }
}