Java tutorial
/** Copyright 2016 Allan Pichardo 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.mylovemhz.simplay; import android.app.PendingIntent; import android.app.Service; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.graphics.Bitmap; import android.graphics.drawable.Drawable; import android.media.AudioManager; import android.media.MediaPlayer; import android.net.wifi.WifiManager; import android.os.Binder; import android.os.IBinder; import android.os.PowerManager; import android.support.annotation.Nullable; import android.support.v4.app.NotificationManagerCompat; import android.support.v4.content.ContextCompat; import android.support.v4.media.MediaMetadataCompat; import android.support.v4.media.session.MediaSessionCompat; import android.support.v4.media.session.PlaybackStateCompat; import android.support.v7.app.NotificationCompat; import android.util.Log; import com.squareup.picasso.Picasso; import com.squareup.picasso.Target; import java.io.IOException; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; public class MusicService extends Service implements MediaPlayer.OnCompletionListener, MediaPlayer.OnErrorListener, MediaPlayer.OnPreparedListener, AudioManager.OnAudioFocusChangeListener { public static final String TAG_MUSIC_SERVICE = "Music Service"; public static final int ID_NOTIFICATION = 1; public static final int TIME_FFWD_RWD = 10 * 1000; public static final String RATIONALE_WAKE_LOCK = "The music player needs to keep your phone from going into sleep mode " + "to prevent interrupting the music."; public static final int REQUEST_PERMISSION_INTERNET = 0; public static final int REQUEST_PERMISSION_WAKE_LOCK = 1; public static final int REQUEST_PERMISSION_READ_EXTERNAL_STORAGE = 2; public static final String ACTION_PLAY = "action_play"; public static final String ACTION_PAUSE = "action_pause"; public static final String ACTION_REWIND = "action_rewind"; public static final String ACTION_FAST_FORWARD = "action_fast_foward"; public static final String ACTION_NEXT = "action_next"; public static final String ACTION_PREVIOUS = "action_previous"; public static final String ACTION_STOP = "action_stop"; public enum State { IDLE, INITIALIZED, PREPARING, PREPARED, STARTED, STOPPED, PAUSED, COMPLETED, END, ERROR } private MediaPlayer mediaPlayer; private MediaSessionCompat mediaSession; private State currentState; private WifiManager.WifiLock wifiLock; private Callbacks callbacks; private ArrayList<Track> trackQueue; private int currentTrackIndex = 0; private boolean isInitialized = false; private int smallIcon; private PendingIntent contentIntent; public class LocalBinder extends Binder { public MusicService getService() { return MusicService.this; } } final Set<Target> temporaryTargets = new HashSet<>(); private final IBinder binder = new LocalBinder(); private void initialize() { trackQueue = new ArrayList<>(); mediaPlayer = new MediaPlayer(); mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); mediaPlayer.setOnCompletionListener(this); mediaPlayer.setOnErrorListener(this); mediaPlayer.setOnPreparedListener(this); mediaPlayer.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK); wifiLock = ((WifiManager) getSystemService(Context.WIFI_SERVICE)).createWifiLock(WifiManager.WIFI_MODE_FULL, "music lock"); ComponentName receiver = new ComponentName(getPackageName(), MediaButtonEventReceiver.class.getName()); mediaSession = new MediaSessionCompat(this, TAG_MUSIC_SERVICE, receiver, null); mediaSession.setFlags( MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS | MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS); mediaSession.setCallback(new SimpleSessionCallback(this)); currentState = State.IDLE; mediaSession.setActive(true); isInitialized = true; Log.d(TAG_MUSIC_SERVICE, "Initialized..."); } public boolean hasPermission(String permission) { return ContextCompat.checkSelfPermission(this, permission) == PackageManager.PERMISSION_GRANTED; } public State getCurrentState() { return currentState; } public void setContentIntent(PendingIntent contentIntent) { this.contentIntent = contentIntent; } @Override public int onStartCommand(Intent intent, int flags, int startId) { if (!isInitialized) { initialize(); } handleIntent(intent); return super.onStartCommand(intent, flags, startId); } private void handleIntent(Intent intent) { if (intent == null || intent.getAction() == null) return; String action = intent.getAction(); if (action.equalsIgnoreCase(ACTION_PLAY)) { play(); } else if (action.equalsIgnoreCase(ACTION_PAUSE)) { pause(); } else if (action.equalsIgnoreCase(ACTION_FAST_FORWARD)) { fastForward(); } else if (action.equalsIgnoreCase(ACTION_REWIND)) { rewind(); } else if (action.equalsIgnoreCase(ACTION_PREVIOUS)) { previous(); } else if (action.equalsIgnoreCase(ACTION_NEXT)) { next(); } else if (action.equalsIgnoreCase(ACTION_STOP)) { stop(); } } @Nullable @Override public IBinder onBind(Intent intent) { return binder; } @Override public void onPrepared(MediaPlayer mp) { Log.d(TAG_MUSIC_SERVICE, "prepared"); currentState = State.PREPARED; updateSessionState(PlaybackStateCompat.STATE_BUFFERING); showNotification(); play(); } @Override public void onCompletion(MediaPlayer mp) { if (!mp.isLooping()) { currentState = State.COMPLETED; if (hasNext()) { next(); } else { stop(); } } } @Override public boolean onError(MediaPlayer mp, int what, int extra) { currentState = State.ERROR; mp.reset(); currentState = State.IDLE; if (callbacks != null) callbacks.onError(); return true; } @Override public void onDestroy() { Log.d(TAG_MUSIC_SERVICE, "onDestroy()"); stop(); mediaPlayer.release(); mediaPlayer = null; currentState = State.END; mediaSession.release(); } public List<Track> getTracks() { return trackQueue; } public void addTrack(Track track) throws Exception { trackQueue.add(track); try { cueTrack(); } catch (Exception e) { stop(); throw e; } } public void addTrack(List<Track> tracks) { trackQueue.addAll(tracks); } public void clearTrackQueue() { trackQueue.clear(); } private void cueTrack() throws IOException, IndexOutOfBoundsException { Log.d(TAG_MUSIC_SERVICE, "Cue Track..."); AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE); int result = audioManager.requestAudioFocus(this, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN); if (result != AudioManager.AUDIOFOCUS_GAIN) { return; //Failed to gain audio focus } if (getCurrentState() == State.STOPPED) { mediaPlayer.reset(); currentState = State.IDLE; } if (getCurrentState() == State.IDLE) { if (trackQueue.size() == 0) { return; //nothing to play } if (hasPermission(Manifest.permission.WAKE_LOCK)) { if (!wifiLock.isHeld()) { wifiLock.acquire(); } Track track = trackQueue.get(currentTrackIndex); mediaPlayer.setDataSource(track.getUrl()); currentState = State.INITIALIZED; mediaPlayer.prepareAsync(); currentState = State.PREPARING; if (callbacks != null) callbacks.onLoading(); } else { Log.e(TAG_MUSIC_SERVICE, "need permission " + Manifest.permission.WAKE_LOCK); if (callbacks != null) { callbacks.onPermissionRequired(REQUEST_PERMISSION_WAKE_LOCK, Manifest.permission.WAKE_LOCK, RATIONALE_WAKE_LOCK); } } } } private void updateSessionState(int state) { int position = 0; if (currentState == State.STARTED || currentState == State.PAUSED) { position = mediaPlayer.getCurrentPosition(); } PlaybackStateCompat.Builder builder = new PlaybackStateCompat.Builder(); builder.setState(state, position, 1f); mediaSession.setPlaybackState(builder.build()); } @Override public void onAudioFocusChange(int focusChange) { switch (focusChange) { case AudioManager.AUDIOFOCUS_LOSS: stop(); break; case AudioManager.AUDIOFOCUS_REQUEST_FAILED: stopSelf(); break; case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT: pause(); break; case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK: lowerVolume(); break; case AudioManager.AUDIOFOCUS_GAIN_TRANSIENT: case AudioManager.AUDIOFOCUS_GAIN: restoreVolume(); break; } } private void lowerVolume() { mediaPlayer.setVolume(0.5f, 0.5f); } private void restoreVolume() { mediaPlayer.setVolume(1f, 1f); } public void play() { Log.d(TAG_MUSIC_SERVICE, "play()"); if (currentState == State.PREPARED || currentState == State.PAUSED) { mediaPlayer.start(); currentState = State.STARTED; updateSessionState(PlaybackStateCompat.STATE_PLAYING); showNotification(); if (callbacks != null) callbacks.onPlaybackStarted(); } if (currentState == State.STOPPED || currentState == State.COMPLETED) { try { cueTrack(); } catch (IOException e) { stop(); } } } public void pause() { if (currentState == State.STARTED) { mediaPlayer.pause(); currentState = State.PAUSED; updateSessionState(PlaybackStateCompat.STATE_PAUSED); showNotification(); } } public void stop() { Log.d(TAG_MUSIC_SERVICE, "stop()"); if (currentState == State.STARTED || currentState == State.PAUSED || currentState == State.PREPARED || currentState == State.COMPLETED) { mediaPlayer.stop(); currentState = State.STOPPED; updateSessionState(PlaybackStateCompat.STATE_STOPPED); currentTrackIndex = 0; trackQueue = new ArrayList<>(); removeNotification(); if (wifiLock.isHeld()) { wifiLock.release(); } if (callbacks != null) callbacks.onPlaybackStopped(); } } public void next() { if (hasNext()) { if (currentState == State.STARTED || currentState == State.PAUSED) { mediaPlayer.stop(); currentState = State.STOPPED; updateSessionState(PlaybackStateCompat.STATE_STOPPED); } if (currentState == State.STOPPED || currentState == State.COMPLETED) { mediaPlayer.reset(); currentState = State.IDLE; updateSessionState(PlaybackStateCompat.STATE_STOPPED); showNotification(); } if (currentState == State.IDLE) { try { updateSessionState(PlaybackStateCompat.STATE_SKIPPING_TO_NEXT); currentTrackIndex++; cueTrack(); } catch (Exception e) { stop(); } } } } public void previous() { if (hasPrevious()) { if (currentState == State.STARTED || currentState == State.PAUSED) { mediaPlayer.stop(); currentState = State.STOPPED; updateSessionState(PlaybackStateCompat.STATE_STOPPED); } if (currentState == State.STOPPED) { mediaPlayer.reset(); currentState = State.IDLE; updateSessionState(PlaybackStateCompat.STATE_STOPPED); showNotification(); } if (currentState == State.IDLE) { try { currentTrackIndex--; updateSessionState(PlaybackStateCompat.STATE_SKIPPING_TO_PREVIOUS); cueTrack(); } catch (Exception e) { stop(); } } } } public void fastForward() { if (currentState == State.STARTED || currentState == State.PAUSED || currentState == State.PREPARED || currentState == State.COMPLETED) { if (mediaPlayer.getCurrentPosition() < mediaPlayer.getDuration() + TIME_FFWD_RWD) { mediaPlayer.seekTo(mediaPlayer.getCurrentPosition() + TIME_FFWD_RWD); updateSessionState(PlaybackStateCompat.STATE_FAST_FORWARDING); } } } public void seekTo(int position) { if (currentState == State.STARTED || currentState == State.PAUSED || currentState == State.PREPARED || currentState == State.COMPLETED) { mediaPlayer.seekTo(position); updateSessionState(PlaybackStateCompat.STATE_FAST_FORWARDING); } } public void rewind() { if (currentState == State.STARTED || currentState == State.PAUSED || currentState == State.PREPARED || currentState == State.COMPLETED) { if (mediaPlayer.getCurrentPosition() > TIME_FFWD_RWD) { mediaPlayer.seekTo(mediaPlayer.getCurrentPosition() - TIME_FFWD_RWD); updateSessionState(PlaybackStateCompat.STATE_REWINDING); } } } public MediaSessionCompat.Token getMediaSessionToken() { return mediaSession.getSessionToken(); } public Track getCurrentTrack() throws IllegalStateException { try { return trackQueue.get(currentTrackIndex); } catch (IndexOutOfBoundsException e) { throw new IllegalStateException("No tracks have been added"); } } private NotificationCompat.Action generateAction(int icon, String title, String intentAction) { Intent intent = new Intent(getApplicationContext(), MusicService.class); intent.setAction(intentAction); PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 1, intent, 0); return new NotificationCompat.Action.Builder(icon, title, pendingIntent).build(); } private void showNotification() { updateMetadata(); Track track; try { track = getCurrentTrack(); } catch (IllegalStateException e) { return; } Intent intent = new Intent(getApplicationContext(), MusicService.class); intent.setAction(ACTION_STOP); PendingIntent cancelIntent = PendingIntent.getService(getApplicationContext(), 1, intent, 0); final NotificationCompat.Builder builder = new NotificationCompat.Builder(getApplicationContext()); NotificationCompat.MediaStyle style = new NotificationCompat.MediaStyle(builder); style.setMediaSession(getMediaSessionToken()); style.setShowCancelButton(true); style.setCancelButtonIntent(cancelIntent); style.setShowActionsInCompactView(1); builder.addAction(generateAction(android.R.drawable.ic_media_previous, "Previous", ACTION_PREVIOUS)); //0 if (!isPlaying()) { builder.addAction(generateAction(android.R.drawable.ic_media_play, "Play", ACTION_PLAY)); // 1 } else { builder.addAction(generateAction(android.R.drawable.ic_media_pause, "Pause", ACTION_PAUSE)); //1 } builder.addAction(generateAction(android.R.drawable.ic_media_next, "Next", ACTION_NEXT)); //2 builder.setSmallIcon(smallIcon).setContentTitle(track.getTitle()).setContentText(track.getArtist()) .setDeleteIntent(cancelIntent).setVisibility(NotificationCompat.VISIBILITY_PUBLIC).setStyle(style); if (!track.getArtworkUrl().isEmpty()) { try { Target artTarget = new Target() { @Override public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) { builder.setLargeIcon(bitmap); publishNotification(builder); temporaryTargets.remove(this); } @Override public void onBitmapFailed(Drawable errorDrawable) { publishNotification(builder); temporaryTargets.remove(this); } @Override public void onPrepareLoad(Drawable placeHolderDrawable) { } }; temporaryTargets.add(artTarget); Picasso.with(this).load(track.getArtworkUrl()).into(artTarget); } catch (IllegalArgumentException e) { //no artwork. Ignore. publishNotification(builder); } } else { publishNotification(builder); } } private void publishNotification(NotificationCompat.Builder builder) { if (contentIntent != null) { builder.setContentIntent(contentIntent); } else { Log.e(TAG_MUSIC_SERVICE, "Did you forget to setContentIntent()? Nothing will happen " + "when you touch the notification."); } NotificationManagerCompat notificationManager = NotificationManagerCompat.from(getApplicationContext()); try { notificationManager.notify(ID_NOTIFICATION, builder.build()); } catch (IllegalStateException e) { Log.e(TAG_MUSIC_SERVICE, "Did you forget to setSmallIconResource() in your onBind()?"); } } public boolean hasNext() { return (trackQueue.size() > 0) && (currentTrackIndex < trackQueue.size() - 1); } public boolean hasPrevious() { return (trackQueue.size() > 0) && (currentTrackIndex > 0); } public PlaybackStateCompat getPlaybackState() { return mediaSession.getController().getPlaybackState(); } public boolean isPlaying() { int state = getPlaybackState().getState(); return state == PlaybackStateCompat.STATE_BUFFERING || state == PlaybackStateCompat.STATE_FAST_FORWARDING || state == PlaybackStateCompat.STATE_PLAYING || state == PlaybackStateCompat.STATE_REWINDING; } public void setSmallIconResource(int resId) { this.smallIcon = resId; } private void updateMetadata() { if (getCurrentState() == State.PREPARED) { Track track; try { track = getCurrentTrack(); MediaMetadataCompat.Builder builder = new MediaMetadataCompat.Builder(); builder.putText(MediaMetadataCompat.METADATA_KEY_ALBUM_ART_URI, track.getArtworkUrl()); builder.putText(MediaMetadataCompat.METADATA_KEY_ALBUM_ARTIST, track.getArtist()); builder.putText(MediaMetadataCompat.METADATA_KEY_TITLE, track.getTitle()); builder.putLong(MediaMetadataCompat.METADATA_KEY_DURATION, mediaPlayer.getDuration()); mediaSession.setMetadata(builder.build()); } catch (IllegalStateException e) { //nothing to update } } } private void removeNotification() { NotificationManagerCompat manager = NotificationManagerCompat.from(getApplicationContext()); manager.cancel(ID_NOTIFICATION); } public void setCallback(Callbacks callback) { this.callbacks = callback; } public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { if (requestCode == REQUEST_PERMISSION_WAKE_LOCK) { if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { try { cueTrack(); } catch (IOException e) { Log.e(TAG_MUSIC_SERVICE, e.getMessage()); stop(); } } else { //TODO cannot get wifi lock stop(); } return; } } public interface Callbacks { void onPermissionRequired(int requestCode, String permission, String rationale); void onLoading(); void onPlaybackStarted(); void onPlaybackStopped(); void onError(); } }