core/java/android/bluetooth/BluetoothA2dp.java

/*
 * 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.annotation.SdkConstant;
import android.annotation.SdkConstant.SdkConstantType;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
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;

    /**
     * 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";

    /**
     * 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;

    private Context mContext;
    private ServiceListener mServiceListener;
    private IBluetoothA2dp mService;
    private BluetoothAdapter mAdapter;

    /**
     * Create a BluetoothA2dp proxy object for interacting with the local
     * Bluetooth A2DP service.
     *
     */
    /*package*/ BluetoothA2dp(Context context, ServiceListener l) {
        mContext = context;
        mServiceListener = l;
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        if (!context.bindService(new Intent(IBluetoothA2dp.class.getName()), mConnection, 0)) {
            Log.e(TAG, "Could not bind to Bluetooth A2DP Service");
        }
    }

    /*package*/ void close() {
        mServiceListener = null;
    }

    /**
     * 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 + ")");
        if (mService != null && isEnabled() &&
            isValidDevice(device)) {
            try {
                return mService.connect(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (mService == 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
     */
    public boolean disconnect(BluetoothDevice device) {
        if (DBG) log("disconnect(" + device + ")");
        if (mService != null && isEnabled() &&
            isValidDevice(device)) {
            try {
                return mService.disconnect(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (mService == null) Log.w(TAG, "Proxy not attached to service");
        return false;
    }

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

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

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

    /**
     * Set priority of the profile
     *
     * <p> The device should already be paired.
     *  Priority can be one of {@link #PRIORITY_ON} or
     * {@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 + ")");
        if (mService != null && isEnabled()
            && isValidDevice(device)) {
            if (priority != BluetoothProfile.PRIORITY_OFF &&
                priority != BluetoothProfile.PRIORITY_ON) {
              return false;
            }
            try {
                return mService.setPriority(device, priority);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (mService == 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 (DBG) log("getPriority(" + device + ")");
        if (mService != null && isEnabled()
            && isValidDevice(device)) {
            try {
                return mService.getPriority(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return BluetoothProfile.PRIORITY_OFF;
            }
        }
        if (mService == 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) {
        if (mService != null && isEnabled()
            && isValidDevice(device)) {
            try {
                return mService.isA2dpPlaying(device);
            } catch (RemoteException e) {
                Log.e(TAG, "Stack:" + Log.getStackTraceString(new Throwable()));
                return false;
            }
        }
        if (mService == null) Log.w(TAG, "Proxy not attached to service");
        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;
    }

    /**
     * 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 ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName className, IBinder service) {
            if (DBG) Log.d(TAG, "Proxy object connected");
            mService = IBluetoothA2dp.Stub.asInterface(service);

            if (mServiceListener != null) {
                mServiceListener.onServiceConnected(BluetoothProfile.A2DP, BluetoothA2dp.this);
            }
        }
        public void onServiceDisconnected(ComponentName className) {
            if (DBG) Log.d(TAG, "Proxy object disconnected");
            mService = null;
            if (mServiceListener != null) {
                mServiceListener.onServiceDisconnected(BluetoothProfile.A2DP);
            }
        }
    };

    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);
    }
}