Manifest permission
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BROADCAST_STICKY" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
Create an inner class BluetoothHelper extends BluetoothHeadSetUtils in your Activity or Service. Declare a class member mBluetoothHelper and instantiate it in onCreate()
BluetoothHelper mBluetoothHelper;
@Override
public void onCreate()
{
mBluetoothHelper = new BluetoothHelper(this);
}
@Override
onResume()
{
mBluetoothHelper.start();
}
@Override
onPause()
{
mBluetoothHelper.stop();
}
// inner class
// BluetoothHeadsetUtils is an abstract class that has
// 4 abstracts methods that need to be implemented.
private class BluetoothHelper extends BluetoothHeadSetUtils
{
public BluetoothHelper(Context context)
{
super(context);
}
@Override
public void onScoAudioDisconnected()
{
// Cancel speech recognizer if desired
}
@Override
public void onScoAudioConnected()
{
// Should start speech recognition here if not already started
}
@Override
public void onHeadsetDisconnected()
{
}
@Override
public void onHeadsetConnected()
{
}
}
To use bluetooth headset with Text To Speech you need to set the AudioManager to STREAM_VOICE_CALL before calling speak. Or use the code below
protected void speak(String text)
{
HashMap<String, String> myHashRender = new HashMap<String, String>();
if (mBluetoothHelper.isOnHeadsetSco())
{
myHashRender.put(TextToSpeech.Engine.KEY_PARAM_STREAM,
String.valueOf(AudioManager.STREAM_VOICE_CALL));
}
mTts.speak(text, TextToSpeech.QUEUE_FLUSH, myHashRender);
}
Copy the BluetoothHeadsetUtils class to your project.
import java.util.List;
import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothClass;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothHeadset;
import android.bluetooth.BluetoothProfile;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.AudioManager;
import android.os.Build;
import android.os.CountDownTimer;
import android.util.Log;
/**
* This is a utility to detect bluetooth headset connection and establish audio connection
* for android API >= 8. This includes a work around for API < 11 to detect already connected headset
* before the application starts. This work around would only fails if Sco audio
* connection is accepted but the connected device is not a headset.
*
* @author Hoan Nguyen
*
*/
public abstract class BluetoothHeadsetUtils
{
private Context mContext;
private BluetoothAdapter mBluetoothAdapter;
private BluetoothHeadset mBluetoothHeadset;
private BluetoothDevice mConnectedHeadset;
private AudioManager mAudioManager;
private boolean mIsCountDownOn;
private boolean mIsStarting;
private boolean mIsOnHeadsetSco;
private boolean mIsStarted;
private static final String TAG = "BluetoothHeadsetUtils"; //$NON-NLS-1$
/**
* Constructor
* @param context
*/
public BluetoothHeadsetUtils(Context context)
{
mContext = context;
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mAudioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
}
/**
* Call this to start BluetoothHeadsetUtils functionalities.
* @return The return value of startBluetooth() or startBluetooth11()
*/
public boolean start()
{
if (!mIsStarted)
{
mIsStarted = true;
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB)
{
mIsStarted = startBluetooth();
}
else
{
mIsStarted = startBluetooth11();
}
}
return mIsStarted;
}
/**
* Should call this on onResume or onDestroy.
* Unregister broadcast receivers and stop Sco audio connection
* and cancel count down.
*/
public void stop()
{
if (mIsStarted)
{
mIsStarted = false;
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB)
{
stopBluetooth();
}
else
{
stopBluetooth11();
}
}
}
/**
*
* @return true if audio is connected through headset.
*/
public boolean isOnHeadsetSco()
{
return mIsOnHeadsetSco;
}
public abstract void onHeadsetDisconnected();
public abstract void onHeadsetConnected();
public abstract void onScoAudioDisconnected();
public abstract void onScoAudioConnected();
/**
* Register for bluetooth headset connection states and Sco audio states.
* Try to connect to bluetooth headset audio by calling startBluetoothSco().
* This is a work around for API < 11 to detect if a headset is connected before
* the application starts.
*
* The official documentation for startBluetoothSco() states
*
* "This method can be used by applications wanting to send and received audio to/from
* a bluetooth SCO headset while the phone is not in call."
*
* Does this mean that startBluetoothSco() would fail if the connected bluetooth device
* is not a headset?
*
* Thus if a call to startBluetoothSco() is successful, i.e mBroadcastReceiver will receive
* an ACTION_SCO_AUDIO_STATE_CHANGED with intent extra SCO_AUDIO_STATE_CONNECTED, then
* we assume that a headset is connected.
*
* @return false if device does not support bluetooth or current platform does not supports
* use of SCO for off call.
*/
@SuppressWarnings("deprecation")
private boolean startBluetooth()
{
Log.d(TAG, "startBluetooth"); //$NON-NLS-1$
// Device support bluetooth
if (mBluetoothAdapter != null)
{
if (mAudioManager.isBluetoothScoAvailableOffCall())
{
mContext.registerReceiver(mBroadcastReceiver,
new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));
mContext.registerReceiver(mBroadcastReceiver,
new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED));
mContext.registerReceiver(mBroadcastReceiver,
new IntentFilter(AudioManager.ACTION_SCO_AUDIO_STATE_CHANGED));
// Need to set audio mode to MODE_IN_CALL for call to startBluetoothSco() to succeed.
mAudioManager.setMode(AudioManager.MODE_IN_CALL);
mIsCountDownOn = true;
// mCountDown repeatedly tries to start bluetooth Sco audio connection.
mCountDown.start();
// need for audio sco, see mBroadcastReceiver
mIsStarting = true;
return true;
}
}
return false;
}
/**
* Register a headset profile listener
* @return false if device does not support bluetooth or current platform does not supports
* use of SCO for off call or error in getting profile proxy.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
private boolean startBluetooth11()
{
Log.d(TAG, "startBluetooth11"); //$NON-NLS-1$
// Device support bluetooth
if (mBluetoothAdapter != null)
{
if (mAudioManager.isBluetoothScoAvailableOffCall())
{
// All the detection and audio connection are done in mHeadsetProfileListener
if (mBluetoothAdapter.getProfileProxy(mContext,
mHeadsetProfileListener,
BluetoothProfile.HEADSET))
{
return true;
}
}
}
return false;
}
/**
* API < 11
* Unregister broadcast receivers and stop Sco audio connection
* and cancel count down.
*/
private void stopBluetooth()
{
Log.d(TAG, "stopBluetooth"); //$NON-NLS-1$
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mCountDown.cancel();
}
// Need to stop Sco audio connection here when the app
// change orientation or close with headset still turns on.
mContext.unregisterReceiver(mBroadcastReceiver);
mAudioManager.stopBluetoothSco();
mAudioManager.setMode(AudioManager.MODE_NORMAL);
}
/**
* API >= 11
* Unregister broadcast receivers and stop Sco audio connection
* and cancel count down.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
protected void stopBluetooth11()
{
Log.d(TAG, "stopBluetooth11"); //$NON-NLS-1$
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mCountDown11.cancel();
}
if (mBluetoothHeadset != null)
{
// Need to call stopVoiceRecognition here when the app
// change orientation or close with headset still turns on.
mBluetoothHeadset.stopVoiceRecognition(mConnectedHeadset);
mContext.unregisterReceiver(mHeadsetBroadcastReceiver);
mBluetoothAdapter.closeProfileProxy(BluetoothProfile.HEADSET, mBluetoothHeadset);
mBluetoothHeadset = null;
}
}
/**
* Broadcast receiver for API < 11
* Handle headset and Sco audio connection states.
*/
private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver()
{
@SuppressWarnings({"deprecation", "synthetic-access"})
@Override
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
if (action.equals(BluetoothDevice.ACTION_ACL_CONNECTED))
{
mConnectedHeadset = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
BluetoothClass bluetoothClass = mConnectedHeadset.getBluetoothClass();
if (bluetoothClass != null)
{
// Check if device is a headset. Besides the 2 below, are there other
// device classes also qualified as headset?
int deviceClass = bluetoothClass.getDeviceClass();
if (deviceClass == BluetoothClass.Device.AUDIO_VIDEO_HANDSFREE
|| deviceClass == BluetoothClass.Device.AUDIO_VIDEO_WEARABLE_HEADSET)
{
// start bluetooth Sco audio connection.
// Calling startBluetoothSco() always returns faIL here,
// that why a count down timer is implemented to call
// startBluetoothSco() in the onTick.
mAudioManager.setMode(AudioManager.MODE_IN_CALL);
mIsCountDownOn = true;
mCountDown.start();
// override this if you want to do other thing when the device is connected.
onHeadsetConnected();
}
}
Log.d(TAG, mConnectedHeadset.getName() + " connected"); //$NON-NLS-1$
}
else if (action.equals(BluetoothDevice.ACTION_ACL_DISCONNECTED))
{
Log.d(TAG, "Headset disconnected"); //$NON-NLS-1$
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mCountDown.cancel();
}
mAudioManager.setMode(AudioManager.MODE_NORMAL);
// override this if you want to do other thing when the device is disconnected.
onHeadsetDisconnected();
}
else if (action.equals(AudioManager.ACTION_SCO_AUDIO_STATE_CHANGED))
{
int state = intent.getIntExtra(AudioManager.EXTRA_SCO_AUDIO_STATE,
AudioManager.SCO_AUDIO_STATE_ERROR);
if (state == AudioManager.SCO_AUDIO_STATE_CONNECTED)
{
mIsOnHeadsetSco = true;
if (mIsStarting)
{
// When the device is connected before the application starts,
// ACTION_ACL_CONNECTED will not be received, so call onHeadsetConnected here
mIsStarting = false;
onHeadsetConnected();
}
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mCountDown.cancel();
}
// override this if you want to do other thing when Sco audio is connected.
onScoAudioConnected();
Log.d(TAG, "Sco connected"); //$NON-NLS-1$
}
else if (state == AudioManager.SCO_AUDIO_STATE_DISCONNECTED)
{
Log.d(TAG, "Sco disconnected"); //$NON-NLS-1$
// Always receive SCO_AUDIO_STATE_DISCONNECTED on call to startBluetooth()
// which at that stage we do not want to do anything. Thus the if condition.
if (!mIsStarting)
{
mIsOnHeadsetSco = false;
// Need to call stopBluetoothSco(), otherwise startBluetoothSco()
// will not be successful.
mAudioManager.stopBluetoothSco();
// override this if you want to do other thing when Sco audio is disconnected.
onScoAudioDisconnected();
}
}
}
}
};
/**
* API < 11
* Try to connect to audio headset in onTick.
*/
private CountDownTimer mCountDown = new CountDownTimer(10000, 1000)
{
@SuppressWarnings("synthetic-access")
@Override
public void onTick(long millisUntilFinished)
{
// When this call is successful, this count down timer will be canceled.
mAudioManager.startBluetoothSco();
Log.d(TAG, "\nonTick start bluetooth Sco"); //$NON-NLS-1$
}
@SuppressWarnings("synthetic-access")
@Override
public void onFinish()
{
// Calls to startBluetoothSco() in onStick are not successful.
// Should implement something to inform user of this failure
mIsCountDownOn = false;
mAudioManager.setMode(AudioManager.MODE_NORMAL);
Log.d(TAG, "\nonFinish fail to connect to headset audio"); //$NON-NLS-1$
}
};
/**
* API >= 11
* Check for already connected headset and if so start audio connection.
* Register for broadcast of headset and Sco audio connection states.
*/
private BluetoothProfile.ServiceListener mHeadsetProfileListener = new BluetoothProfile.ServiceListener()
{
/**
* This method is never called, even when we closeProfileProxy on onPause.
* When or will it ever be called???
*/
@Override
public void onServiceDisconnected(int profile)
{
Log.d(TAG, "Profile listener onServiceDisconnected"); //$NON-NLS-1$
stopBluetooth11();
}
@SuppressWarnings("synthetic-access")
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
public void onServiceConnected(int profile, BluetoothProfile proxy)
{
Log.d(TAG, "Profile listener onServiceConnected"); //$NON-NLS-1$
// mBluetoothHeadset is just a headset profile,
// it does not represent a headset device.
mBluetoothHeadset = (BluetoothHeadset) proxy;
// If a headset is connected before this application starts,
// ACTION_CONNECTION_STATE_CHANGED will not be broadcast.
// So we need to check for already connected headset.
List<BluetoothDevice> devices = mBluetoothHeadset.getConnectedDevices();
if (devices.size() > 0)
{
// Only one headset can be connected at a time,
// so the connected headset is at index 0.
mConnectedHeadset = devices.get(0);
onHeadsetConnected();
// Should not need count down timer, but just in case.
// See comment below in mHeadsetBroadcastReceiver onReceive()
mIsCountDownOn = true;
mCountDown11.start();
Log.d(TAG, "Start count down"); //$NON-NLS-1$
}
// During the active life time of the app, a user may turn on and off the headset.
// So register for broadcast of connection states.
mContext.registerReceiver(mHeadsetBroadcastReceiver,
new IntentFilter(BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED));
// Calling startVoiceRecognition does not result in immediate audio connection.
// So register for broadcast of audio connection states. This broadcast will
// only be sent if startVoiceRecognition returns true.
mContext.registerReceiver(mHeadsetBroadcastReceiver,
new IntentFilter(BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED));
}
};
/**
* API >= 11
* Handle headset and Sco audio connection states.
*/
private BroadcastReceiver mHeadsetBroadcastReceiver = new BroadcastReceiver()
{
@SuppressWarnings("synthetic-access")
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
int state;
if (action.equals(BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED))
{
state = intent.getIntExtra(BluetoothHeadset.EXTRA_STATE,
BluetoothHeadset.STATE_DISCONNECTED);
Log.d(TAG, "\nAction = " + action + "\nState = " + state); //$NON-NLS-1$ //$NON-NLS-2$
if (state == BluetoothHeadset.STATE_CONNECTED)
{
mConnectedHeadset = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// Calling startVoiceRecognition always returns false here,
// that why a count down timer is implemented to call
// startVoiceRecognition in the onTick.
mIsCountDownOn = true;
mCountDown11.start();
// override this if you want to do other thing when the device is connected.
onHeadsetConnected();
Log.d(TAG, "Start count down"); //$NON-NLS-1$
}
else if (state == BluetoothHeadset.STATE_DISCONNECTED)
{
// Calling stopVoiceRecognition always returns false here
// as it should since the headset is no longer connected.
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mCountDown11.cancel();
}
mConnectedHeadset = null;
// override this if you want to do other thing when the device is disconnected.
onHeadsetDisconnected();
Log.d(TAG, "Headset disconnected"); //$NON-NLS-1$
}
}
else // audio
{
state = intent.getIntExtra(BluetoothHeadset.EXTRA_STATE, BluetoothHeadset.STATE_AUDIO_DISCONNECTED);
Log.d(TAG, "\nAction = " + action + "\nState = " + state); //$NON-NLS-1$ //$NON-NLS-2$
if (state == BluetoothHeadset.STATE_AUDIO_CONNECTED)
{
Log.d(TAG, "\nHeadset audio connected"); //$NON-NLS-1$
mIsOnHeadsetSco = true;
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mCountDown11.cancel();
}
// override this if you want to do other thing when headset audio is connected.
onScoAudioConnected();
}
else if (state == BluetoothHeadset.STATE_AUDIO_DISCONNECTED)
{
mIsOnHeadsetSco = false;
// The headset audio is disconnected, but calling
// stopVoiceRecognition always returns true here.
mBluetoothHeadset.stopVoiceRecognition(mConnectedHeadset);
// override this if you want to do other thing when headset audio is disconnected.
onScoAudioDisconnected();
Log.d(TAG, "Headset audio disconnected"); //$NON-NLS-1$
}
}
}
};
/**
* API >= 11
* Try to connect to audio headset in onTick.
*/
private CountDownTimer mCountDown11 = new CountDownTimer(10000, 1000)
{
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@SuppressWarnings("synthetic-access")
@Override
public void onTick(long millisUntilFinished)
{
// First stick calls always returns false. The second stick
// always returns true if the countDownInterval is set to 1000.
// It is somewhere in between 500 to a 1000.
mBluetoothHeadset.startVoiceRecognition(mConnectedHeadset);
Log.d(TAG, "onTick startVoiceRecognition"); //$NON-NLS-1$
}
@SuppressWarnings("synthetic-access")
@Override
public void onFinish()
{
// Calls to startVoiceRecognition in onStick are not successful.
// Should implement something to inform user of this failure
mIsCountDownOn = false;
Log.d(TAG, "\nonFinish fail to connect to headset audio"); //$NON-NLS-1$
}
};
}
(April 30 2013) Edit to change to @TargetApi(Build.VERSION_CODES.HONEYCOMB) when necessary. If you have problem with java.lang.NoClassDefFoundError for API 8 or 9, just remove all the API >= 11 codes. The startBluetoothSco() works for all API versions.