触发广播接收器时如何更改 ExoPlayer 的播放状态？
我有一个 BroadcastReceiver 在耳机断开连接时触发但是我不确定在调用 onReceive() 时处理音频暂停的正确方法。我需要在这里更改 Mediasession 的播放状态吗？
private static final int CORRECT_ANSWER_DELAY_MILLIS = 1000;
public static final String TAG = QuizActivity.class.getSimpleName();
private SimpleExoPlayer mExoPlayer;
private PlayerView mPlayerView;
private PlayerListener mPlayerListener;
private PlaybackStateCompat.Builder mPlaybackStateBuilder;
public static MediaSessionCompat mMediaSession;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz);
initializeMediaSession();
mPlayerListener = new PlayerListener();
// Initialize the player view.
mPlayerView = (PlayerView) findViewById(R.id.playerView);
// Initialize the player.
initializePlayer(Uri.parse(answerSample.getUri()));
}
/**
* Initialize ExoPlayer.
*
* @param mediaUri The URI of the sample to play.
*/
// done (2): Set the ExoPlayer.EventListener to this activity
private void initializePlayer(Uri mediaUri) {
// 1. Create a default TrackSelector
if (mExoPlayer == null) {
Handler mainHandler = new Handler();
BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
TrackSelection.Factory videoTrackSelectionFactory =
new AdaptiveTrackSelection.Factory(bandwidthMeter);
DefaultTrackSelector trackSelector =
new DefaultTrackSelector(videoTrackSelectionFactory);
// 2. Create the player
mExoPlayer =
ExoPlayerFactory.newSimpleInstance(this, trackSelector);
mExoPlayer.addListener(mPlayerListener);
mPlayerView.setPlayer(mExoPlayer);
DefaultBandwidthMeter defaultBandwidthMeter = new DefaultBandwidthMeter();
// Produces DataSource instances through which media data is loaded.
DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(this,
Util.getUserAgent(this, "yourApplicationName"), defaultBandwidthMeter);
// This is the MediaSource representing the media to be played.
MediaSource videoSource = new ExtractorMediaSource.Factory(dataSourceFactory)
.createMediaSource(mediaUri);
// Prepare the player with the source.
mExoPlayer.prepare(videoSource);
mExoPlayer.setPlayWhenReady(true);
}
}
/**
* Release ExoPlayer.
*/
private void releasePlayer() {
mExoPlayer.stop();
mExoPlayer.release();
mExoPlayer = null;
}
* toggles the UI to show the correct answer.
*
* @param v The button that was clicked.
*/
@Override
public void onClick(View v) {
// Wait some time so the user can see the correct answer, then go to the next question.
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
mExoPlayer.stop();
Intent nextQuestionIntent = new Intent(QuizActivity.this, QuizActivity.class);
nextQuestionIntent.putExtra(REMAINING_SONGS_KEY, mRemainingSampleIDs);
finish();
startActivity(nextQuestionIntent);
}
}, CORRECT_ANSWER_DELAY_MILLIS);
}
/**
* Release the player when the activity is destroyed.
*/
@Override
protected void onDestroy() {
super.onDestroy();
releasePlayer();
mMediaSession.setActive(false);
}
private void initializeMediaSession() {
mMediaSession = new MediaSessionCompat(this, TAG);
mMediaSession.setFlags(
MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS |
MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
// Do not let MediaButtons restart the player when the app is not visible.
mMediaSession.setMediaButtonReceiver(null);
mPlaybackStateBuilder = new PlaybackStateCompat.Builder()
// Set an initial PlaybackState with ACTION_PLAY, so media buttons can start the player.
.setActions(PlaybackStateCompat.ACTION_PLAY |
PlaybackStateCompat.ACTION_PAUSE |
PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS |
PlaybackStateCompat.ACTION_PLAY_PAUSE);
mMediaSession.setPlaybackState(mPlaybackStateBuilder.build());
mMediaSession.setCallback(new MediaSessionCompat.Callback() {
@Override
public void onPlay() {
mExoPlayer.setPlayWhenReady(true);
}
@Override
public void onPause() {
mExoPlayer.setPlayWhenReady(false);
}
});
// Start the Media Session since the activity is active.
mMediaSession.setActive(true);
}
public class PlayerListener extends Player.DefaultEventListener {
@Override
public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
//super.onPlayerStateChanged(playWhenReady, playbackState);
if (playbackState == Player.STATE_READY && playWhenReady) {
mPlaybackStateBuilder.setState(STATE_PLAYING, mExoPlayer.getCurrentPosition(), 1f);
} else if (playbackState == Player.STATE_READY) {
mPlaybackStateBuilder.setState(STATE_PAUSED, mExoPlayer.getCurrentPosition(), 1f);
}
mMediaSession.setPlaybackState(mPlaybackStateBuilder.build());
showMediaStyleNotification(mPlaybackStateBuilder.build());
}
}
public static class MediaReceiver extends BroadcastReceiver {
public MediaReceiver() { }
@Override
public void onReceive(final Context context, Intent intent) {
if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(intent.getAction())) {
Toast.makeText(context, "Headset unplugged", Toast.LENGTH_SHORT).show();
}
}
}