AudioPlayerService.java

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.android.exoplayer.audiodemo;

import static com.google.android.exoplayer.audiodemo.C.MEDIA_SESSION_TAG;
import static com.google.android.exoplayer.audiodemo.C.PLAYBACK_CHANNEL_ID;
import static com.google.android.exoplayer.audiodemo.C.PLAYBACK_NOTIFICATION_ID;
import static com.google.android.exoplayer.audiodemo.Samples.SAMPLES;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Debug;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.support.v4.app.NotificationManagerCompat;
import android.support.v4.media.MediaDescriptionCompat;
import android.support.v4.media.session.MediaSessionCompat;
import com.google.android.exoplayer2.ExoPlayerFactory;
import com.google.android.exoplayer2.Player;
import com.google.android.exoplayer2.SimpleExoPlayer;
import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector;
import com.google.android.exoplayer2.ext.mediasession.TimelineQueueNavigator;
import com.google.android.exoplayer2.source.ConcatenatingMediaSource;
import com.google.android.exoplayer2.source.ExtractorMediaSource;
import com.google.android.exoplayer2.source.MediaSource;
import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
import com.google.android.exoplayer2.ui.PlayerNotificationManager;
import com.google.android.exoplayer2.ui.PlayerNotificationManager.BitmapCallback;
import com.google.android.exoplayer2.ui.PlayerNotificationManager.MediaDescriptionAdapter;
import com.google.android.exoplayer2.ui.PlayerNotificationManager.NotificationListener;
import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
import com.google.android.exoplayer2.upstream.cache.CacheDataSourceFactory;
import com.google.android.exoplayer2.util.Log;
import com.google.android.exoplayer2.util.NotificationUtil;
import com.google.android.exoplayer2.util.Util;

public class AudioPlayerService extends Service {

  private SimpleExoPlayer player;
  private PlayerNotificationManager playerNotificationManager;
  private MediaSessionCompat mediaSession;
  private MediaSessionConnector mediaSessionConnector;

  @Override
  public void onCreate() {
    super.onCreate();
    final Context context = this;

    player = ExoPlayerFactory.newSimpleInstance(context, new DefaultTrackSelector());
    DefaultDataSourceFactory dataSourceFactory = new DefaultDataSourceFactory(
        context, Util.getUserAgent(context, getString(R.string.application_name)));
    ConcatenatingMediaSource concatenatingMediaSource = new ConcatenatingMediaSource();
    for (Samples.Sample sample : SAMPLES) {
      MediaSource mediaSource = new ExtractorMediaSource.Factory(dataSourceFactory)
          .createMediaSource(sample.uri);
      concatenatingMediaSource.addMediaSource(mediaSource);
    }
    player.prepare(concatenatingMediaSource);
    player.setPlayWhenReady(true);

    NotificationUtil.createNotificationChannel(
      context,
      PLAYBACK_CHANNEL_ID,
      R.string.playback_channel_name,
      NotificationUtil.IMPORTANCE_LOW
    );

    MediaDescriptionAdapter descriptionAdapter = new MediaDescriptionAdapter() {
      @Override
      public String getCurrentContentTitle(Player player) {
        return SAMPLES[player.getCurrentWindowIndex()].title;
      }

      @Nullable
      @Override
      public PendingIntent createCurrentContentIntent(Player player) {
        return null;
      }

      @Nullable
      @Override
      public String getCurrentContentText(Player player) {
        return SAMPLES[player.getCurrentWindowIndex()].description;
      }

      @Nullable
      @Override
      public Bitmap getCurrentLargeIcon(Player player, BitmapCallback callback) {
        return Samples.getBitmap(
                context, SAMPLES[player.getCurrentWindowIndex()].bitmapResource);
      }
    };

    PlayerNotificationManager.NotificationDispatcher notificationDispatcher = new PlayerNotificationManager.NotificationDispatcher() {
      boolean foregrounded = false;
      final NotificationManagerCompat notificationManager = NotificationManagerCompat.from(AudioPlayerService.this);

      @Override
      public void notify(int notificationId, Notification notification) {
        if (player.getPlayWhenReady() && !foregrounded) {
          Util.startForegroundService(
            AudioPlayerService.this,
            new Intent(context, AudioPlayerService.class)
          );

          startForeground(notificationId, notification);
          foregrounded = true;
        } else {
          notificationManager.notify(notificationId, notification);
        }

        if (!player.getPlayWhenReady() && foregrounded) {
          stopForeground(false);
          foregrounded = false;
        }
      }

      @Override
      public void cancel(int notificationId) {
        notificationManager.cancel(notificationId);
        stopForeground(true);
        stopSelf();
        foregrounded = false;
      }
    };

    playerNotificationManager = new PlayerNotificationManager(
      context,
      PLAYBACK_CHANNEL_ID,
      PLAYBACK_NOTIFICATION_ID,
      descriptionAdapter,
      null,
      null,
       notificationDispatcher
    );
    playerNotificationManager.setOngoing(false);

    playerNotificationManager.setPlayer(player);

    mediaSession = new MediaSessionCompat(context, MEDIA_SESSION_TAG);
    mediaSession.setActive(true);
    playerNotificationManager.setMediaSessionToken(mediaSession.getSessionToken());

    mediaSessionConnector = new MediaSessionConnector(mediaSession);
    mediaSessionConnector.setQueueNavigator(new TimelineQueueNavigator(mediaSession) {
      @Override
      public MediaDescriptionCompat getMediaDescription(Player player, int windowIndex) {
        return Samples.getMediaDescription(context, SAMPLES[windowIndex]);
      }
    });
    mediaSessionConnector.setPlayer(player, null);
  }

  @Override
  public void onDestroy() {
    mediaSession.release();
    mediaSessionConnector.setPlayer(null, null);
    playerNotificationManager.setPlayer(null);
    player.release();
    player = null;

    super.onDestroy();
  }

  @Nullable
  @Override
  public IBinder onBind(Intent intent) {
    return null;
  }

  @Override
  public int onStartCommand(Intent intent, int flags, int startId) {
    return START_STICKY;
  }

}

@ciaranodc Yeah, I don't remember what state I left it in exactly: https://github.com/forte-music/android

Where is the playerView and when to attach it to the play in case of MainActivity as a Service ? because I instantiated it either in onCreate MainActivity or the AudioPlayerService and all the mainActivity UI doesnt' show at all !