Jak dodać odtwarzacz audio?

1. Dodaj do pliku build.gradle -> dependencies
   compile 'com.google.android.exoplayer:exoplayer:r2.2.0'
2. Dodaj do swojej aktywności
   implements View.OnClickListener, ExoPlayer.EventListener
3. Dodaj do swojej aktywności obsługującej audio zmienne ExoPlayer
   private SimpleExoPlayer mExoPlayer;
   private SimpleExoPlayerView mPlayerView;
   private static MediaSessionCompat mMediaSession;
   private PlaybackStateCompat.Builder mStateBuilder;
   private NotificationManager mNotificationManager;
4. Zainicjalizuj wstępnie zmienne
   mPlayerView = (SimpleExoPlayerView) findViewById(R.id.playerView);
   mPlayerView.setPlayer(mExoPlayer);
   initializeMediaSession();
   initializePlayer(Uri.parse(audioPath));
   
5. Zaimplementuj inicjalizację MediaSession
    mMediaSession = new MediaSessionCompat(this, this.getClass().getSimpleName());
   mMediaSession.setFlags(
           MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS |
                   MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
   mMediaSession.setMediaButtonReceiver(null);
   mStateBuilder = new PlaybackStateCompat.Builder()
           .setActions(
                   PlaybackStateCompat.ACTION_PLAY |
                   PlaybackStateCompat.ACTION_PAUSE |
                   PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS |
                   PlaybackStateCompat.ACTION_PLAY_PAUSE);
   mMediaSession.setPlaybackState(mStateBuilder.build());
   mMediaSession.setCallback(new MySessionCallback());
   mMediaSession.setActive(true);
6. Zaimplementuj podklasę MySessionCallback
           @Override
           public void onPlay() {
               mExoPlayer.setPlayWhenReady(true);
           }
   
           @Override
           public void onPause() {
               mExoPlayer.setPlayWhenReady(false);
           }
   
           @Override
           public void onSkipToPrevious() {
               mExoPlayer.seekTo(0);
           }
7. Zaimplementuj inicjalizację playera
   if (mExoPlayer == null) {
       // Create an instance of the ExoPlayer.
       TrackSelector trackSelector = new DefaultTrackSelector();
       LoadControl loadControl = new DefaultLoadControl();
       mExoPlayer = ExoPlayerFactory.newSimpleInstance(this, trackSelector, loadControl);
       mPlayerView.setPlayer(mExoPlayer);
   
       // Set the ExoPlayer.EventListener to this activity.
       mExoPlayer.addListener(this);
      
       // Prepare the MediaSource.
       String userAgent = Util.getUserAgent(this, "ClassicalMusicQuiz");
       MediaSource mediaSource = new ExtractorMediaSource(mediaUri, new DefaultDataSourceFactory(
               this, userAgent), new DefaultExtractorsFactory(), null, null);
       mExoPlayer.prepare(mediaSource);
       mExoPlayer.setPlayWhenReady(true);
   }
8. Zaimplementuj funkcję zamykania playera
   mNotificationManager.cancelAll();
   mExoPlayer.stop();
   mExoPlayer.release();
   mExoPlayer = null;
9. Dodaj funkcję zamykania playera do odDestroy()
       super.onDestroy();
       releasePlayer();
       mMediaSession.setActive(false);
10. Zaimplementuj funkcję onPlayerStateChanged()
    if((playbackState == ExoPlayer.STATE_READY) && playWhenReady){
        mStateBuilder.setState(PlaybackStateCompat.STATE_PLAYING,
                mExoPlayer.getCurrentPosition(), 1f);
    } else if((playbackState == ExoPlayer.STATE_READY)){
        mStateBuilder.setState(PlaybackStateCompat.STATE_PAUSED,
                mExoPlayer.getCurrentPosition(), 1f);
    }
    mMediaSession.setPlaybackState(mStateBuilder.build());
    showNotification(mStateBuilder.build());
11. Zaimplementuj MediaReceiver
    public static class MediaReceiver extends BroadcastReceiver {
        public MediaReceiver() {
        }
    
        @Override
        public void onReceive(Context context, Intent intent) {
            MediaButtonReceiver.handleIntent(mMediaSession, intent);
        }
    }
12. Dodaj do manifestu aktywność obsługującą odtwarzacz
    <activity android:name=".QuizActivity"
        android:launchMode="singleTop"/>
    <receiver android:name=".QuizActivity$MediaReceiver">
        <intent-filter>
            <action android:name="android.intent.action.MEDIA_BUTTON" />
        </intent-filter>
    </receiver>
13. Przygotuj layout uwzględniający SimpleExoPlayerView
     <com.google.android.exoplayer2.ui.SimpleExoPlayerView
            android:id="@+id/playerView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="0dp"
            android:layout_marginRight="0dp"
            android:layout_marginBottom="0dp"
            android:layout_marginLeft="0dp"/>