With multiple apps potentially playing audio it's important to think about how they should interact. To avoid every music app playing at the same time, Android uses audio focus to moderate audio playback—only apps that hold the audio focus should play audio.
-Before your app starts playing audio it should request—and receive—the audio focus. +
Before your app starts playing audio it should request—and receive—the audio focus. Likewise, it should know how to listen for a loss of audio focus and respond appropriately when that happens.
- -Before your app starts playing any audio, it should hold the audio focus for the stream it will be using. This is done with a call to {@link android.media.AudioManager#requestAudioFocus requestAudioFocus()} which returns @@ -55,7 +55,7 @@ plan to play audio for the foreseeable future (for example, when playing music).
The following snippet requests permanent audio focus on the music audio stream. You should request the audio focus immediately before you begin playback, such as when the user presses play or the background music for the next game level begins.
- +
AudioManager am = mContext.getSystemService(Context.AUDIO_SERVICE);
...
@@ -66,7 +66,7 @@ int result = am.requestAudioFocus(afChangeListener,
AudioManager.STREAM_MUSIC,
// Request permanent focus.
AudioManager.AUDIOFOCUS_GAIN);
-
+
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
am.registerMediaButtonEventReceiver(RemoteControlReceiver);
// Start playback.
@@ -80,7 +80,7 @@ android.media.AudioManager.OnAudioFocusChangeListener}. In the case of abandonin
this allows any interupted app to continue playback.
-// Abandon audio focus when playback complete
+// Abandon audio focus when playback complete
am.abandonAudioFocus(afChangeListener);
@@ -97,7 +97,7 @@ int result = am.requestAudioFocus(afChangeListener,
AudioManager.STREAM_MUSIC,
// Request permanent focus.
AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK);
-
+
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
// Start playback.
}
@@ -111,7 +111,7 @@ transient (with or without support for ducking) audio focus is received by the l
registered when requesting focus.
-Handle the Loss of Audio Focus
+Handle the Loss of Audio Focus
If your app can request audio focus, it follows that it will in turn lose that focus when another
app requests it. How your app responds to a loss of audio focus depends on the manner of that
@@ -139,26 +139,27 @@ loss is transient and resume it when we have regained the focus. If the loss is
unregisters our media button event receiver and stops monitoring audio focus changes.
-OnAudioFocusChangeListener afChangeListener = new OnAudioFocusChangeListener() {
- public void onAudioFocusChange(int focusChange) {
- if (focusChange == AUDIOFOCUS_LOSS_TRANSIENT
- // Pause playback
- } else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
- // Resume playback
- } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
- am.unregisterMediaButtonEventReceiver(RemoteControlReceiver);
- am.abandonAudioFocus(afChangeListener);
- // Stop playback
+AudioManager.OnAudioFocusChangeListener afChangeListener =
+ new AudioManager.OnAudioFocusChangeListener() {
+ public void onAudioFocusChange(int focusChange) {
+ if (focusChange == AUDIOFOCUS_LOSS_TRANSIENT) {
+ // Pause playback
+ } else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
+ // Resume playback
+ } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
+ am.unregisterMediaButtonEventReceiver(RemoteControlReceiver);
+ am.abandonAudioFocus(afChangeListener);
+ // Stop playback
+ }
}
- }
-};
+ };
-
+
In the case of a transient loss of audio focus where ducking is permitted, rather than pausing
playback, you can "duck" instead.
-Duck!
+Duck!
Ducking is the process of lowering your audio stream output volume to make transient audio from
another app easier to hear without totally disrupting the audio from your own application.