Audio focus

src/org/kreed/vanilla/CompatFroyo.java

@@ -30,19 +30,58 @@ import android.media.AudioManager;
 /**
  * Framework methods only in Froyo or above go here.
  */
-public class CompatFroyo {
+public class CompatFroyo implements AudioManager.OnAudioFocusChangeListener {
+	/**
+	 * Instance of the audio focus listener created by {@link #createAudioFocus()}.
+	 */
+	private static CompatFroyo sAudioFocus;
+
+	/**
+	 * Calls {@link AudioManager#registerMediaButtonEventReceiver(ComponentName)}.
+	 */
 	public static void registerMediaButtonEventReceiver(AudioManager manager, ComponentName receiver)
 	{
 		manager.registerMediaButtonEventReceiver(receiver);
 	}
 
+	/**
+	 * Calls {@link AudioManager#unregisterMediaButtonEventReceiver(ComponentName)}.
+	 */
 	public static void unregisterMediaButtonEventReceiver(AudioManager manager, ComponentName receiver)
 	{
 		manager.unregisterMediaButtonEventReceiver(receiver);
 	}
 
+	/**
+	 * Calls {@link BackupManager#dataChanged()}.
+	 */
 	public static void dataChanged(Context context)
 	{
 		new BackupManager(context).dataChanged();
 	}
+
+	/**
+	 * Creates an audio focus listener that calls back to {@link PlaybackService#onAudioFocusChange(int)}.
+	 */
+	public static void createAudioFocus()
+	{
+		sAudioFocus = new CompatFroyo();
+	}
+
+	/**
+	 * Calls {@link AudioManager#requestAudioFocus(AudioManager.OnAudioFocusChangeListener, int, int)}
+	 */
+	public static void requestAudioFocus(AudioManager manager)
+	{
+		manager.requestAudioFocus(sAudioFocus, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
+	}
+
+	@Override
+	public void onAudioFocusChange(int type)
+	{
+		PlaybackService service = PlaybackService.sInstance;
+		if (service != null) {
+			service.onAudioFocusChange(type);
+		}
+	}
 }

src/org/kreed/vanilla/PlaybackService.java

@@ -216,8 +216,11 @@ public final class PlaybackService extends Service
 	 */
 	private static final long IDLE_GRACE_PERIOD = 60000;
 
-	private static final Object sWait = new Object();
+	private static final Object sWait = new Object[0];
-	private static PlaybackService sInstance;
+	/**
+	 * The appplication-wide instance of the PlaybackService.
+	 */
+	public static PlaybackService sInstance;
 	private static final ArrayList<PlaybackActivity> sActivities = new ArrayList<PlaybackActivity>(5);
 	/**
 	 * Cached app-wide SharedPreferences instance.
@@ -300,6 +303,10 @@ public final class PlaybackService extends Service
 	 * indicates that no timeout has occurred.
 	 */
 	private long mIdleStart = -1;
+	/**
+	 * True if the last audio focus loss can be ducked.
+	 */
+	private boolean mDuckedLoss;
 
 	@Override
 	public void onCreate()
@@ -319,6 +326,10 @@ public final class PlaybackService extends Service
 		mNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
 		mAudioManager = (AudioManager)getSystemService(AUDIO_SERVICE);
 
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
+			CompatFroyo.createAudioFocus();
+		}
+
 		SharedPreferences settings = getSettings(this);
 		settings.registerOnSharedPreferenceChangeListener(this);
 		mNotificationMode = Integer.parseInt(settings.getString("notification_mode", "1"));
@@ -335,13 +346,26 @@ public final class PlaybackService extends Service
 		mHeadsetPlay = settings.getBoolean("headset_play", false);
 		mInvertNotification = settings.getBoolean("notification_inverted_color", false);
 		mNotificationAction = createNotificationAction(settings);
+		mHeadsetPause = getSettings(this).getBoolean("headset_pause", true);
 
 		PowerManager powerManager = (PowerManager)getSystemService(POWER_SERVICE);
 		mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "VanillaMusicLock");
 
+		mCallListener = new InCallListener();
+		TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
+		telephonyManager.listen(mCallListener, PhoneStateListener.LISTEN_CALL_STATE);
+
+		mReceiver = new Receiver();
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(AudioManager.ACTION_AUDIO_BECOMING_NOISY);
+		filter.addAction(Intent.ACTION_HEADSET_PLUG);
+		filter.addAction(Intent.ACTION_SCREEN_ON);
+		registerReceiver(mReceiver, filter);
+
+		getContentResolver().registerContentObserver(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, true, mObserver);
+
 		mLooper = thread.getLooper();
 		mHandler = new Handler(mLooper, this);
-		mHandler.sendEmptyMessage(POST_CREATE);
 
 		initWidgets();
 
@@ -556,6 +580,9 @@ public final class PlaybackService extends Service
 				if (mNotificationMode != NEVER)
 					startForeground(NOTIFICATION_ID, createNotification(mCurrentSong, mState));
 
+				if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
+					CompatFroyo.requestAudioFocus(mAudioManager);
+				}
 				if (mWakeLock != null)
 					mWakeLock.acquire();
 			} else {
@@ -968,18 +995,6 @@ public final class PlaybackService extends Service
 		loadPreference(key);
 	}
 
-	private void setupReceiver()
-	{
-		if (mReceiver == null)
-			mReceiver = new Receiver();
-		IntentFilter filter = new IntentFilter();
-		filter.addAction(AudioManager.ACTION_AUDIO_BECOMING_NOISY);
-		filter.addAction(Intent.ACTION_HEADSET_PLUG);
-		filter.addAction(Intent.ACTION_SCREEN_ON);
-		registerReceiver(mReceiver, filter);
-	}
-
-	private static final int POST_CREATE = 1;
 	/**
 	 * Run the given query and add the results to the timeline.
 	 *
@@ -1030,16 +1045,6 @@ public final class PlaybackService extends Service
 		case QUERY:
 			runQuery(message.arg1, (QueryTask)message.obj, message.arg2);
 			break;
-		case POST_CREATE:
-			mHeadsetPause = getSettings(this).getBoolean("headset_pause", true);
-			setupReceiver();
-
-			mCallListener = new InCallListener();
-			TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
-			telephonyManager.listen(mCallListener, PhoneStateListener.LISTEN_CALL_STATE);
-
-			getContentResolver().registerContentObserver(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, true, mObserver);
-			break;
 		case IDLE_TIMEOUT:
 			if ((mState & FLAG_PLAYING) != 0)
 				mHandler.sendMessage(mHandler.obtainMessage(FADE_OUT, 100, 0));
@@ -1511,4 +1516,26 @@ public final class PlaybackService extends Service
 		notification.contentIntent = mNotificationAction;
 		return notification;
 	}
+
+	public void onAudioFocusChange(int type)
+	{
+		Log.d("VanillaMusic", "audio focus change: " + type);
+		switch (type) {
+		case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
+			mDuckedLoss = (mState & FLAG_PLAYING) != 0;
+			unsetFlag(FLAG_PLAYING);
+			break;
+		case AudioManager.AUDIOFOCUS_LOSS:
+		case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
+			mDuckedLoss = false;
+			unsetFlag(FLAG_PLAYING);
+			break;
+		case AudioManager.AUDIOFOCUS_GAIN:
+			if (mDuckedLoss) {
+				mDuckedLoss = false;
+				setFlag(FLAG_PLAYING);
+			}
+			break;
+		}
+	}
 }