Add In-Car Listening possible through MirrorLink using the MediaBrowserService

AndroidManifest.xml

@@ -34,6 +34,7 @@ THE SOFTWARE.
 	<application
 		android:icon="@drawable/icon"
 		android:label="@string/app_name">
+
 		<activity
 			android:name="FullPlaybackActivity"
 			android:launchMode="singleTask" />
@@ -132,6 +133,15 @@ THE SOFTWARE.
 				<action android:name="ch.blinkenlights.android.vanilla.action.PREVIOUS_SONG" />
 			</intent-filter>
 		</service>
+
+		<service
+			android:name=".MirrorLinkMediaBrowserService"
+			android:exported="true">
+			<intent-filter>
+				<action android:name="android.media.browse.MediaBrowserService" />
+			</intent-filter>
+		</service>
+
 		<activity
 			android:name="PreferencesActivity" />
 		<activity

src/ch/blinkenlights/android/vanilla/MirrorLinkMediaBrowserService.java

@@ -0,0 +1,814 @@
+/*
+ * Copyright (C) 2013 - 2015 Adrian Ulrich <adrian@blinkenlights.ch>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>. 
+ */
+
+package ch.blinkenlights.android.vanilla;
+
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.BroadcastReceiver;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.graphics.Bitmap;
+import android.provider.MediaStore;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.media.MediaDescription;
+import android.media.MediaMetadata;
+import android.media.browse.MediaBrowser;
+import android.media.browse.MediaBrowser.MediaItem;
+import android.media.session.MediaSession;
+import android.media.session.PlaybackState;
+import android.service.media.MediaBrowserService;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.os.Bundle;
+import android.os.Message;
+import android.os.Looper;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Process;
+import android.os.SystemClock;
+import android.util.Log;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Handles Music Playback through MirrorLink(tm) by implementing a MediaBrowserService.
+ */
+public class MirrorLinkMediaBrowserService extends MediaBrowserService implements Handler.Callback {
+
+	private static final String TAG = "MirrorLinkMediaBrowserService";
+	// Action to change the repeat mode
+	private static final String CUSTOM_ACTION_REPEAT = "ch.blinkenlights.android.vanilla.REPEAT";
+	// Action to change the repeat mode
+	private static final String CUSTOM_ACTION_SHUFFLE = "ch.blinkenlights.android.vanilla.SHUFFLE";
+
+	// Media managers
+	private MediaAdapter mArtistAdapter;
+	private MediaAdapter mAlbumAdapter;
+	private MediaAdapter mSongAdapter;
+	private MediaAdapter mPlaylistAdapter;
+	private MediaAdapter mGenreAdapter;
+	private MediaAdapter[] mMediaAdapters = new MediaAdapter[MediaUtils.TYPE_GENRE + 1];
+	private List<MediaBrowser.MediaItem> mAlbums = new ArrayList<MediaBrowser.MediaItem>();
+	private List<MediaBrowser.MediaItem> mArtists = new ArrayList<MediaBrowser.MediaItem>();
+	private List<MediaBrowser.MediaItem> mSongs = new ArrayList<MediaBrowser.MediaItem>();
+	private List<MediaBrowser.MediaItem> mPlaylists = new ArrayList<MediaBrowser.MediaItem>();
+	private List<MediaBrowser.MediaItem> mGenres = new ArrayList<MediaBrowser.MediaItem>();
+	private List<MediaBrowser.MediaItem> mFiltered = new ArrayList<MediaBrowser.MediaItem>();
+	private boolean mCatalogReady = false;
+
+	private final List<MediaBrowser.MediaItem> mMediaRoot = new ArrayList<MediaBrowser.MediaItem>();
+
+	// Media Session
+	private MediaSession mSession;
+	private Bundle mSessionExtras;
+
+	// Indicates whether the service was started.
+	private boolean mServiceStarted;
+
+	private Looper mLooper;
+	private Handler mHandler;
+
+	@Override
+	public void onCreate() {
+		Log.d("VanillaMusic", "MediaBrowserService#onCreate");
+		super.onCreate();
+
+		HandlerThread thread = new HandlerThread("MediaBrowserService", Process.THREAD_PRIORITY_DEFAULT);
+		thread.start();
+
+		// Prep the Media Adapters (caches the top categories)
+		mArtistAdapter = new MediaAdapter(this, MediaUtils.TYPE_ARTIST, null ,null, null);
+		mAlbumAdapter = new MediaAdapter(this, MediaUtils.TYPE_ALBUM, null, null, null);
+		mSongAdapter = new MediaAdapter(this, MediaUtils.TYPE_SONG, null, null, null);
+		mPlaylistAdapter = new MediaAdapter(this, MediaUtils.TYPE_PLAYLIST, null, null, null);
+		mGenreAdapter = new MediaAdapter(this, MediaUtils.TYPE_GENRE, null, null, null);
+		mMediaAdapters[MediaUtils.TYPE_ARTIST] = mArtistAdapter;
+		mMediaAdapters[MediaUtils.TYPE_ALBUM] = mAlbumAdapter;
+		mMediaAdapters[MediaUtils.TYPE_SONG] = mSongAdapter;
+		mMediaAdapters[MediaUtils.TYPE_PLAYLIST] = mPlaylistAdapter;
+		mMediaAdapters[MediaUtils.TYPE_GENRE] = mGenreAdapter;
+
+		// Fill and cache the top queries
+
+		mMediaRoot.add(new MediaBrowser.MediaItem(
+				new MediaDescription.Builder()
+					.setMediaId(Integer.toString(MediaUtils.TYPE_ARTIST))
+					.setTitle(getString(R.string.artists))
+					.setIconUri(Uri.parse("android.resource://" +
+							"ch.blinkenlights.android.vanilla/drawable/ic_menu_music_library"))
+					.setSubtitle(getString(R.string.artists))
+					.build(), MediaBrowser.MediaItem.FLAG_BROWSABLE
+		));
+
+		mMediaRoot.add(new MediaBrowser.MediaItem(
+				new MediaDescription.Builder()
+					.setMediaId(Integer.toString(MediaUtils.TYPE_ALBUM))
+					.setTitle(getString(R.string.albums))
+					.setIconUri(Uri.parse("android.resource://" +
+							"ch.blinkenlights.android.vanilla/drawable/ic_menu_music_library"))
+					.setSubtitle(getString(R.string.albums))
+					.build(), MediaBrowser.MediaItem.FLAG_BROWSABLE
+		));
+
+		mMediaRoot.add(new MediaBrowser.MediaItem(
+				new MediaDescription.Builder()
+					.setMediaId(Integer.toString(MediaUtils.TYPE_SONG))
+					.setTitle(getString(R.string.songs))
+					.setIconUri(Uri.parse("android.resource://" +
+							"ch.blinkenlights.android.vanilla/drawable/ic_menu_music_library"))
+					.setSubtitle(getString(R.string.songs))
+					.build(), MediaBrowser.MediaItem.FLAG_BROWSABLE
+		));
+
+		mMediaRoot.add(new MediaBrowser.MediaItem(
+				new MediaDescription.Builder()
+					.setMediaId(Integer.toString(MediaUtils.TYPE_GENRE))
+					.setTitle(getString(R.string.genres))
+					.setIconUri(Uri.parse("android.resource://" +
+							"ch.blinkenlights.android.vanilla/drawable/ic_menu_music_library"))
+					.setSubtitle(getString(R.string.genres))
+					.build(), MediaBrowser.MediaItem.FLAG_BROWSABLE
+		));
+
+		mMediaRoot.add(new MediaBrowser.MediaItem(
+				new MediaDescription.Builder()
+					.setMediaId(Integer.toString(MediaUtils.TYPE_PLAYLIST))
+					.setTitle(getString(R.string.playlists))
+					.setIconUri(Uri.parse("android.resource://" +
+							"ch.blinkenlights.android.vanilla/drawable/ic_menu_music_library"))
+					.setSubtitle(getString(R.string.playlists))
+					.build(), MediaBrowser.MediaItem.FLAG_BROWSABLE
+		));
+
+
+		// Start a new MediaSession
+		mSession = new MediaSession(this, "VanillaMediaBrowserService");
+		setSessionToken(mSession.getSessionToken());
+		mSession.setCallback(new MediaSessionCallback());
+		mSession.setFlags(MediaSession.FLAG_HANDLES_MEDIA_BUTTONS | MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS);
+		mSessionExtras = new Bundle();
+		mSession.setExtras(mSessionExtras);
+
+		// Register with the PlaybackService
+		PlaybackService.registerService(this);
+
+		// Make sure the PlaybackService is running
+		if(!PlaybackService.hasInstance()) {
+			Thread t = new Thread(new Runnable() {
+				@Override
+				public void run() {
+					PlaybackService.get(MirrorLinkMediaBrowserService.this);
+				}
+			});
+			t.start();
+		}
+
+		mLooper = thread.getLooper();
+		mHandler = new Handler(mLooper, this);
+
+		updatePlaybackState(null);
+	}
+
+	@Override
+	public int onStartCommand(Intent startIntent, int flags, int startId) {
+		Log.d("VanillaMusic", "MediaBrowserService#onStartCommand");
+		return START_STICKY;
+	}
+
+	@Override
+	public void onDestroy() {
+		Log.d("VanillaMusic", "MediaBrowserService#onDestroy");
+		mServiceStarted = false;
+		PlaybackService.unregisterService();
+		mSession.release();
+	}
+
+	/**
+	 * Helper class to encode/decode item references
+	 * derived from queries in a string
+	 */
+	private static class MediaID {
+    	// Separators used to build MediaIDs for the MediaBrowserService
+		public static final String ID_TYPE_ROOT = Integer.toString(MediaUtils.TYPE_INVALID);
+		public static final String MEDIATYPE_SEPARATOR = "/";
+		public static final String FILTER_SEPARATOR = "#";
+
+		final int mType;
+		final long mId;
+		final String mLabel;
+
+		public MediaID(int type, long id, String label) {
+			mType = type;
+			mId = id;
+			mLabel = label;
+		}
+
+		public MediaID(String mediaId) {
+			int type = MediaUtils.TYPE_INVALID;
+			long id = -1;
+			String label = null;
+			if(mediaId != null) {
+				String[] items = mediaId.split(MEDIATYPE_SEPARATOR);
+				type = items.length > 0 ? Integer.parseInt(items[0]) : MediaUtils.TYPE_INVALID;
+				if(items.length > 1) {
+					items = items[1].split(FILTER_SEPARATOR);
+					if(items.length >= 2) {
+						label = items[1];
+						id = Long.parseLong(items[0]);
+					}
+				}
+			}
+			mType = type;
+			mId = id;
+			mLabel = label;
+		}
+
+		public boolean isTopAdapter() {
+			return mId == -1;
+		}
+
+		public boolean isInvalid() {
+			return mType == MediaUtils.TYPE_INVALID;
+		}
+
+		@Override
+		public String toString() {
+		   	return toString(mType, mId, mLabel);
+		}
+
+		public static boolean isTopAdapter(String mediaId) {
+			return mediaId.indexOf(MEDIATYPE_SEPARATOR) == -1;
+		}
+
+		public static String toString(int type, long id, String label) {
+		   	return Integer.toString(type)
+			   							 + (id == -1 ? "" : (
+											   MEDIATYPE_SEPARATOR
+											 + id
+											 + (label == null ? "" :
+												   FILTER_SEPARATOR
+												 + label
+											   )
+											 )
+										   );
+		}
+	}
+
+	private static Limiter buildLimiterFromMediaID(MediaID parent) {
+		Limiter limiter = null;
+		String[] fields;
+		Object data;
+		if(!parent.isInvalid() && !parent.isTopAdapter()) {
+			switch(parent.mType) {
+				case MediaUtils.TYPE_ARTIST:
+					// expand using a album query limited by artist
+					fields = new String[] { parent.mLabel };
+					data = String.format("%s=%d", MediaStore.Audio.Media.ARTIST_ID, parent.mId);
+					limiter = new Limiter(MediaUtils.TYPE_ARTIST, fields, data);
+				break;
+				case MediaUtils.TYPE_ALBUM:
+					// expand using a song query limited by album
+					fields = new String[] { parent.mLabel };
+					data = String.format("%s=%d",  MediaStore.Audio.Media.ALBUM_ID, parent.mId);
+					limiter = new Limiter(MediaUtils.TYPE_SONG, fields, data);
+				break;
+				case MediaUtils.TYPE_GENRE:
+					// expand using an artist limiter by genere
+					fields = new String[] { parent.mLabel };
+					data = parent.mId;
+					limiter = new Limiter(MediaUtils.TYPE_GENRE, fields, data);
+				break;
+				case MediaUtils.TYPE_PLAYLIST:
+					// don't build much, a a playlist is playable but not expandable
+				case MediaUtils.TYPE_SONG:
+					// don't build much, a song is playable but not expandable
+				case MediaUtils.TYPE_INVALID:
+				break;
+			}
+		}
+		return limiter;
+	}
+
+	private QueryTask buildQueryFromMediaID(MediaID parent, boolean empty, boolean all)
+	{
+		String[] projection;
+
+		if (parent.mType == MediaUtils.TYPE_PLAYLIST) {
+			projection = empty ? Song.EMPTY_PLAYLIST_PROJECTION : Song.FILLED_PLAYLIST_PROJECTION;
+		} else {
+			projection = empty ? Song.EMPTY_PROJECTION : Song.FILLED_PROJECTION;
+		}
+
+		QueryTask query;
+		if (all && (parent.mType != MediaUtils.TYPE_PLAYLIST)) {
+			query = (mMediaAdapters[parent.mType]).buildSongQuery(projection);
+			query.data = parent.mId;
+			query.mode = SongTimeline.MODE_PLAY_ID_FIRST;
+		} else {
+			query = MediaUtils.buildQuery(parent.mType, parent.mId, projection, null);
+			query.mode = SongTimeline.MODE_PLAY;
+		}
+
+		return query;
+	}
+
+	private void loadChildrenAsync( final MediaID parent,
+									final Result<List<MediaItem>> result) {
+
+		// Asynchronously load the music catalog in a separate thread
+		final Limiter limiter = buildLimiterFromMediaID(parent);
+		new AsyncTask<Void, Void, Integer>() {
+			private static final int ASYNCTASK_SUCCEEDED = 1;
+			private static final int ASYNCTASK_FAILED = 0;
+
+			@Override
+			protected Integer doInBackground(Void... params) {
+				int result = ASYNCTASK_FAILED;
+				try {
+					if(!mCatalogReady) {
+						runQuery(mArtists, MediaUtils.TYPE_ARTIST , mArtistAdapter);
+						runQuery(mAlbums, MediaUtils.TYPE_ALBUM, mAlbumAdapter);
+						runQuery(mSongs, MediaUtils.TYPE_SONG, mSongAdapter);
+						runQuery(mGenres, MediaUtils.TYPE_GENRE, mGenreAdapter);
+						runQuery(mPlaylists, MediaUtils.TYPE_PLAYLIST, mPlaylistAdapter);
+						mCatalogReady = true;
+					}
+					if(limiter != null) {
+						mFiltered.clear();
+						switch(limiter.type) {
+							case MediaUtils.TYPE_ALBUM:
+								mSongAdapter.setLimiter(limiter);
+								runQuery(mFiltered, MediaUtils.TYPE_SONG, mSongAdapter);
+							break;
+							case MediaUtils.TYPE_ARTIST:
+								mAlbumAdapter.setLimiter(limiter);
+								runQuery(mFiltered, MediaUtils.TYPE_ALBUM, mAlbumAdapter);
+							break;
+							case MediaUtils.TYPE_SONG:
+								mSongAdapter.setLimiter(limiter);
+								runQuery(mFiltered, MediaUtils.TYPE_SONG, mSongAdapter);
+							break;
+							case MediaUtils.TYPE_PLAYLIST:
+								mPlaylistAdapter.setLimiter(limiter);
+								runQuery(mFiltered, MediaUtils.TYPE_PLAYLIST, mPlaylistAdapter);
+							break;
+							case MediaUtils.TYPE_GENRE:
+								mSongAdapter.setLimiter(limiter);
+								runQuery(mFiltered, MediaUtils.TYPE_SONG, mSongAdapter);
+							break;
+						}
+					}
+					result = ASYNCTASK_SUCCEEDED;
+				} catch (Exception e) {
+					Log.d("VanillaMusic","Failed retrieving Media");
+				}
+				return Integer.valueOf(result);
+			}
+
+			@Override
+			protected void onPostExecute(Integer current) {
+				List<MediaBrowser.MediaItem> items = null;
+				if (result != null) {
+					if(parent.isTopAdapter()) {
+						switch(parent.mType) {
+							case MediaUtils.TYPE_ALBUM:
+								items = mAlbums;
+								mAlbumAdapter.setLimiter(null);
+							break;
+							case MediaUtils.TYPE_ARTIST:
+								items = mArtists;
+								mArtistAdapter.setLimiter(null);
+							break;
+							case MediaUtils.TYPE_SONG:
+								items = mSongs;
+								mSongAdapter.setLimiter(null);
+							break;
+							case MediaUtils.TYPE_PLAYLIST:
+								items = mPlaylists;
+								mPlaylistAdapter.setLimiter(null);
+							break;
+							case MediaUtils.TYPE_GENRE:
+								items = mGenres;
+								mGenreAdapter.setLimiter(null);
+							break;
+						}
+					} else {
+						items = mFiltered;
+					}
+					if (current == ASYNCTASK_SUCCEEDED) {
+						result.sendResult(items);
+					} else {
+						result.sendResult(Collections.<MediaItem>emptyList());
+					}
+				}
+			}
+		}.execute();
+	}
+
+	private Uri getArtUri(int mediaType, String id) {
+		switch(mediaType) {
+			case MediaUtils.TYPE_SONG:
+				return Uri.parse("content://media/external/audio/media/" + id + "/albumart");
+			case MediaUtils.TYPE_ALBUM:
+				return Uri.parse("content://media/external/audio/albumart/" + id);
+		}
+		return Uri.parse("android.resource://ch.blinkenlights.android.vanilla/drawable/fallback_cover");
+	}
+
+	private String  subtitleForMediaType(int mediaType) {
+		switch(mediaType) {
+			case MediaUtils.TYPE_ARTIST:
+				return getString(R.string.artists);
+			case MediaUtils.TYPE_SONG:
+				return getString(R.string.songs);
+			case MediaUtils.TYPE_PLAYLIST:
+				return getString(R.string.playlists);
+			case MediaUtils.TYPE_GENRE:
+				return getString(R.string.genres);
+			case MediaUtils.TYPE_ALBUM:
+				return getString(R.string.albums);
+		}
+		return "";
+	}
+
+	private void runQuery(List<MediaBrowser.MediaItem> populateMe, int mediaType, MediaAdapter adapter) {
+		populateMe.clear();
+		try {
+			Cursor cursor = adapter.query();
+
+			if (cursor == null) {
+				return;
+			}
+
+			final int flags =      (mediaType != MediaUtils.TYPE_SONG)
+								&& (mediaType != MediaUtils.TYPE_PLAYLIST) ?
+								    MediaBrowser.MediaItem.FLAG_BROWSABLE  : MediaBrowser.MediaItem.FLAG_PLAYABLE;
+
+			final int count = cursor.getCount();
+
+			for (int j = 0; j != count; ++j) {
+				cursor.moveToPosition(j);
+				final String id = cursor.getString(0);
+				final String label = cursor.getString(2);
+				MediaBrowser.MediaItem item = new MediaBrowser.MediaItem(
+					new MediaDescription.Builder()
+						.setMediaId(MediaID.toString(mediaType, Long.parseLong(id), label))
+						.setTitle(label)
+						.setSubtitle(subtitleForMediaType(mediaType))
+						.setIconUri(getArtUri(mediaType, id))
+						.build(),
+						flags);
+				populateMe.add(item);
+			}
+
+			cursor.close();
+		} catch (Exception e) {
+			Log.d("VanillaMusic","Failed retrieving Media");
+		}
+	}
+
+	/*
+	 ** MediaBrowserService APIs
+	 */
+
+	@Override
+	public BrowserRoot onGetRoot(String clientPackageName, int clientUid, Bundle rootHints) {
+		return new BrowserRoot(MediaID.ID_TYPE_ROOT, null);
+	}
+
+	@Override
+	public void onLoadChildren(final String parentMediaId, final Result<List<MediaItem>> result) {
+		// Use result.detach to allow calling result.sendResult from another thread:
+		result.detach();
+		if (!MediaID.ID_TYPE_ROOT.equals(parentMediaId)) {
+			loadChildrenAsync(new MediaID(parentMediaId), result);
+		} else {
+			result.sendResult(mMediaRoot);
+		}
+	}
+
+	private void setSessionActive() {
+		if (!mServiceStarted) {
+			// The MirrorLinkMediaBrowserService needs to keep running even after the calling MediaBrowser
+			// is disconnected. Call startService(Intent) and then stopSelf(..) when we no longer
+			// need to play media.
+			startService(new Intent(getApplicationContext(), MirrorLinkMediaBrowserService.class));
+			mServiceStarted = true;
+		}
+
+		if (!mSession.isActive()) {
+			mSession.setActive(true);
+		}
+	}
+
+	private void setSessionInactive() {
+		if(mServiceStarted) {
+			// service is no longer necessary. Will be started again if needed.
+			MirrorLinkMediaBrowserService.this.stopSelf();
+			mServiceStarted = false;
+		}
+
+		if(mSession.isActive()) {
+			mSession.setActive(false);
+		}
+	}
+
+	private static final int MSG_PLAY = 1;
+	private static final int MSG_PLAY_QUERY = 2;
+	private static final int MSG_PAUSE = 3;
+	private static final int MSG_STOP = 4;
+	private static final int MSG_SEEKTO = 5;
+	private static final int MSG_NEXTSONG = 6;
+	private static final int MSG_PREVSONG = 7;
+	private static final int MSG_SEEKFW = 8;
+	private static final int MSG_SEEKBW = 9;
+	private static final int MSG_REPEAT = 10;
+	private static final int MSG_SHUFFLE = 11;
+	private static final int MSG_UPDATE_STATE = 12;
+
+	@Override
+	public boolean handleMessage(Message message)
+	{
+		switch (message.what) {
+		case MSG_PLAY:
+			setSessionActive();
+
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).play();
+			}
+		break;
+		case MSG_PLAY_QUERY:
+			setSessionActive();
+			if(PlaybackService.hasInstance()) {
+				QueryTask query = buildQueryFromMediaID(new MediaID((String)message.obj), false, true);
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).addSongs(query);
+			}
+		break;
+		case MSG_PAUSE:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).pause();
+			}
+		break;
+		case MSG_STOP:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).pause();
+			}
+			setSessionInactive();
+		break;
+		case MSG_SEEKTO:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).seekToProgress(message.arg1);
+			}
+		break;
+		case MSG_NEXTSONG:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).performAction(Action.NextSong, null);
+			}
+		break;
+		case MSG_PREVSONG:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).performAction(Action.SeekForward, null);
+			}
+		break;
+		case MSG_SEEKFW:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).performAction(Action.SeekBackward, null);
+			}
+		break;
+		case MSG_SEEKBW:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).performAction(Action.Repeat, null);
+			}
+		break;
+		case MSG_REPEAT:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).performAction(Action.Shuffle, null);
+			}
+		break;
+		case MSG_SHUFFLE:
+			if(PlaybackService.hasInstance()) {
+				PlaybackService.get(MirrorLinkMediaBrowserService.this).performAction(Action.NextSong, null);
+			}
+		break;
+		case MSG_UPDATE_STATE:
+			updatePlaybackState((String)message.obj);
+		break;
+		default:
+			return false;
+		}
+
+		return true;
+	}
+	/*
+	 ** MediaSession.Callback
+	 */
+	private final class MediaSessionCallback extends MediaSession.Callback {
+
+		@Override
+		public void onPlay() {
+			mHandler.sendEmptyMessage(MSG_PLAY);
+		}
+
+		@Override
+		public void onSeekTo(long position) {
+			mHandler.sendMessage(mHandler.obtainMessage(MSG_SEEKTO, (int) position ,0));
+		}
+
+		@Override
+		public void onPlayFromMediaId(final String mediaId, Bundle extras) {
+			mHandler.sendMessage(mHandler.obtainMessage(MSG_PLAY_QUERY, mediaId));
+		}
+
+		@Override
+		public void onPause() {
+			mHandler.sendEmptyMessage(MSG_PAUSE);
+		}
+
+		@Override
+		public void onStop() {
+			mHandler.sendEmptyMessage(MSG_STOP);
+		}
+
+		@Override
+		public void onSkipToNext() {
+			mHandler.sendEmptyMessage(MSG_NEXTSONG);
+		}
+
+		@Override
+		public void onSkipToPrevious() {
+			mHandler.sendEmptyMessage(MSG_PREVSONG);
+		}
+
+		@Override
+		public void onFastForward() {
+			mHandler.sendEmptyMessage(MSG_SEEKFW);
+		}
+
+		@Override
+		public void onRewind() {
+			mHandler.sendEmptyMessage(MSG_SEEKBW);
+		}
+
+		@Override
+		public void onCustomAction(String action, Bundle extras) {
+			if (CUSTOM_ACTION_REPEAT.equals(action)) {
+				mHandler.sendEmptyMessage(MSG_REPEAT);
+			} else if (CUSTOM_ACTION_SHUFFLE.equals(action)) {
+				mHandler.sendEmptyMessage(MSG_SHUFFLE);
+			}
+		}
+	}
+
+	/**
+	 * Update the current media player state, optionally showing an error message.
+	 *
+	 * @param error if not null, error message to present to the user.
+	 */
+	private void updatePlaybackState(String error) {
+		long position = PlaybackState.PLAYBACK_POSITION_UNKNOWN;
+		int state = PlaybackState.STATE_PAUSED;
+
+		if(PlaybackService.hasInstance()) {
+			if (PlaybackService.get(this).isPlaying()) {
+				state = PlaybackState.STATE_PLAYING;
+			}
+			position = PlaybackService.get(this).getPosition();
+		}
+
+		PlaybackState.Builder stateBuilder = new PlaybackState.Builder()
+				.setActions(getAvailableActions());
+
+		setCustomAction(stateBuilder);
+
+		// If there is an error message, send it to the playback state:
+		if (error != null) {
+			// Error states are really only supposed to be used for errors that cause playback to
+			// stop unexpectedly and persist until the user takes action to fix it.
+			stateBuilder.setErrorMessage(error);
+			state = PlaybackState.STATE_ERROR;
+		}
+		stateBuilder.setState(state, position, 1.0f, SystemClock.elapsedRealtime());
+		mSession.setPlaybackState(stateBuilder.build());
+
+	}
+	// 'DriveSafe' icons need to meet contrast requirement, and as such are usually
+	// monochrome in nature, hence the new repeat_inactive_service and shuffle_inactive_service
+	// artwork
+
+	private static final int[] FINISH_ICONS =
+		{	R.drawable.repeat_inactive_service
+		  , R.drawable.repeat_active
+		  , R.drawable.repeat_current_active
+		  , R.drawable.stop_current_active
+		  , R.drawable.random_active };
+
+	private static final int[] SHUFFLE_ICONS =
+		{ 	R.drawable.shuffle_inactive_service
+		  , R.drawable.shuffle_active
+		  , R.drawable.shuffle_active
+		  , R.drawable.shuffle_album_active };
+
+	private void setCustomAction(PlaybackState.Builder stateBuilder) {
+		if(PlaybackService.hasInstance()) {
+			Bundle customActionExtras = new Bundle();
+			final int finishMode = PlaybackService.finishAction(PlaybackService.get(this).getState());
+			final int shuffleMode = PlaybackService.shuffleMode(PlaybackService.get(this).getState());
+
+			stateBuilder.addCustomAction(new PlaybackState.CustomAction.Builder(
+					CUSTOM_ACTION_REPEAT, getString(R.string.cycle_repeat_mode), FINISH_ICONS[finishMode])
+					.setExtras(customActionExtras)
+					.build());
+
+			stateBuilder.addCustomAction(new PlaybackState.CustomAction.Builder(
+					CUSTOM_ACTION_SHUFFLE, getString(R.string.cycle_shuffle_mode), SHUFFLE_ICONS[shuffleMode])
+					.setExtras(customActionExtras)
+					.build());
+		}
+	}
+
+	private long getAvailableActions() {
+		long actions =   PlaybackState.ACTION_PLAY | PlaybackState.ACTION_PLAY_FROM_MEDIA_ID
+					   | PlaybackState.ACTION_SKIP_TO_PREVIOUS | PlaybackState.ACTION_SKIP_TO_NEXT;
+
+		if(PlaybackService.hasInstance()) {
+			if (PlaybackService.get(this).isPlaying()) {
+				actions |= PlaybackState.ACTION_PAUSE;
+				actions |= PlaybackState.ACTION_FAST_FORWARD;
+				actions |= PlaybackState.ACTION_REWIND;
+			}
+		}
+		return actions;
+	}
+
+	/**
+	 * Implementation of the PlaybackService callbacks
+	 */
+	public void onTimelineChanged() {
+		mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATE, null));
+		// updatePlaybackState(null);
+	}
+
+	public void setState(long uptime, int state) {
+		mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATE, null));
+		// updatePlaybackState(null);
+	}
+
+	public void setSong(long uptime, Song song) {
+		mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATE, null));
+//		updatePlaybackState(null);
+		if(song == null) {
+			if(PlaybackService.hasInstance()) {
+				song = PlaybackService.get(this).getSong(0);
+			}
+		}
+
+		if(song != null) {
+			MediaMetadata metadata = new MediaMetadata.Builder()
+				.putString(MediaMetadata.METADATA_KEY_MEDIA_ID, Long.toString(song.id))
+				.putString(MediaMetadata.METADATA_KEY_ALBUM, song.album)
+				.putString(MediaMetadata.METADATA_KEY_ARTIST, song.artist)
+				.putLong(MediaMetadata.METADATA_KEY_DURATION, song.duration)
+				.putString(MediaMetadata.METADATA_KEY_ALBUM_ART_URI, "content://media/external/audio/media/" + Long.toString(song.id) + "/albumart")
+				.putString(MediaMetadata.METADATA_KEY_TITLE, song.title)
+				.putLong(MediaMetadata.METADATA_KEY_TRACK_NUMBER, song.trackNumber)
+				.build();
+			mSession.setMetadata(metadata);
+		}
+	}
+
+	public void onPositionInfoChanged() {
+		mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATE, null));
+		// updatePlaybackState(null);
+	}
+
+	public void onError(String error) {
+		mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATE, error));
+		// updatePlaybackState(error);
+	}
+
+	public void onMediaChanged() {
+		if(PlaybackService.hasInstance()) {
+			setSong(0,PlaybackService.get(this).getSong(0));
+		}
+
+	}
+}

src/ch/blinkenlights/android/vanilla/PlaybackService.java

@@ -72,12 +72,12 @@ import java.util.ArrayList;
  */
 public final class PlaybackService extends Service
 	implements Handler.Callback
-	         , MediaPlayer.OnCompletionListener
-	         , MediaPlayer.OnErrorListener
-	         , SharedPreferences.OnSharedPreferenceChangeListener
-	         , SongTimeline.Callback
-	         , SensorEventListener
-	         , AudioManager.OnAudioFocusChangeListener
+			 , MediaPlayer.OnCompletionListener
+			 , MediaPlayer.OnErrorListener
+			 , SharedPreferences.OnSharedPreferenceChangeListener
+			 , SongTimeline.Callback
+			 , SensorEventListener
+			 , AudioManager.OnAudioFocusChangeListener
 {
 	/**
 	 * Name of the state file.
@@ -99,7 +99,7 @@ public final class PlaybackService extends Service
 	 * Rewind song if we already played more than 2.5 sec
 	*/
 	private static final int REWIND_AFTER_PLAYED_MS = 2500;
-	
+
 	/**
 	 * Action for startService: toggle playback on/off.
 	 */
@@ -255,12 +255,12 @@ public final class PlaybackService extends Service
 	 *     g:   {@link PlaybackService#FLAG_DUCKING}
 	 */
 	int mState;
-	
+
 	/**
 	 * How many broken songs we did already skip
 	 */
 	int mSkipBroken;
-	
+
 	/**
 	 * Object used for state-related locking.
 	 */
@@ -277,6 +277,10 @@ public final class PlaybackService extends Service
 	 * Static referenced-array to PlaybackActivities, used for callbacks
 	 */
 	private static final ArrayList<PlaybackActivity> sActivities = new ArrayList<PlaybackActivity>(5);
+	/**
+	 * Static reference to MirrorLinkMediaBrowserService, used for callbacks
+	 */
+	private static MirrorLinkMediaBrowserService sMirrorLinkMediaBrowserService = null;
 	/**
 	 * Cached app-wide SharedPreferences instance.
 	 */
@@ -432,7 +436,7 @@ public final class PlaybackService extends Service
 		mBastpUtil = new BastpUtil();
 		mReadahead = new ReadaheadThread();
 		mReadahead.start();
-		
+
 		mNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
 		mAudioManager = (AudioManager)getSystemService(AUDIO_SERVICE);
 
@@ -618,14 +622,14 @@ public final class PlaybackService extends Service
 		mp.setOnErrorListener(this);
 		return mp;
 	}
-	
+
 	public void prepareMediaPlayer(VanillaMediaPlayer mp, String path) throws IOException{
 		mp.setDataSource(path);
 		mp.prepare();
 		applyReplayGain(mp);
 	}
-	
-	
+
+
 	/**
 	 * Make sure that the current ReplayGain volume matches
 	 * the (maybe just changed) user settings
@@ -646,20 +650,20 @@ public final class PlaybackService extends Service
 	 * and adjusts the volume
 	 */
 	private void applyReplayGain(VanillaMediaPlayer mp) {
-		
+
 		float[] rg = getReplayGainValues(mp.getDataSource()); /* track, album */
 		float adjust = 0f;
-		
+
 		if(mReplayGainAlbumEnabled) {
 			adjust = (rg[0] != 0 ? rg[0] : adjust); /* do we have track adjustment ? */
 			adjust = (rg[1] != 0 ? rg[1] : adjust); /* ..or, even better, album adj? */
 		}
-		
+
 		if(mReplayGainTrackEnabled || (mReplayGainAlbumEnabled && adjust == 0)) {
 			adjust = (rg[1] != 0 ? rg[1] : adjust); /* do we have album adjustment ? */
 			adjust = (rg[0] != 0 ? rg[0] : adjust); /* ..or, even better, track adj? */
 		}
-		
+
 		if(adjust == 0) {
 			/* No RG value found: decrease volume for untagged song if requested by user */
 			adjust = (mReplayGainUntaggedDeBump-150)/10f;
@@ -669,12 +673,12 @@ public final class PlaybackService extends Service
 			** But we want -15 <-> +15, so 75 shall be zero */
 			adjust += 2*(mReplayGainBump-75)/10f; /* 2* -> we want +-15, not +-7.5 */
 		}
-		
+
 		if(mReplayGainAlbumEnabled == false && mReplayGainTrackEnabled == false) {
 			/* Feature is disabled: Make sure that we are going to 100% volume */
 			adjust = 0f;
 		}
-		
+
 		float rg_result = ((float)Math.pow(10, (adjust/20) ))*mFadeOut;
 		if(rg_result > 1.0f) {
 			rg_result = 1.0f; /* android would IGNORE the change if this is > 1 and we would end up with the wrong volume */
@@ -685,7 +689,7 @@ public final class PlaybackService extends Service
 	}
 
 	/**
-	 * Returns the (hopefully cached) replaygain 
+	 * Returns the (hopefully cached) replaygain
 	 * values of given file
 	 */
 	public float[] getReplayGainValues(String path) {
@@ -718,7 +722,7 @@ public final class PlaybackService extends Service
 	private void triggerGaplessUpdate() {
 		if(mMediaPlayerInitialized != true)
 			return;
-		
+
 		if(Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN)
 			return; /* setNextMediaPlayer is supported since JB */
 
@@ -1017,6 +1021,11 @@ public final class PlaybackService extends Service
 			ArrayList<PlaybackActivity> list = sActivities;
 			for (int i = list.size(); --i != -1; )
 				list.get(i).setState(uptime, state);
+
+			MirrorLinkMediaBrowserService service = sMirrorLinkMediaBrowserService;
+			if(service != null) {
+				service.setState(uptime, state);
+			}
 		}
 
 		if (song != null) {
@@ -1025,6 +1034,11 @@ public final class PlaybackService extends Service
 				list.get(i).setSong(uptime, song);
 		}
 
+		MirrorLinkMediaBrowserService service = sMirrorLinkMediaBrowserService;
+		if(service != null) {
+			service.setSong(uptime, song);
+		}
+
 		updateWidgets();
 
 		if (mReadaheadEnabled)
@@ -1105,6 +1119,23 @@ public final class PlaybackService extends Service
 			mNotificationManager.cancel(NOTIFICATION_ID);
 	}
 
+	/**
+	 * When playing through MirrorLink(tm) don't interact
+	 * with the User directly as this is considered distracting
+	 * while driving
+	 */
+	private void showMirrorLinkSafeToast(int resId, int duration) {
+		if(sMirrorLinkMediaBrowserService == null) {
+			Toast.makeText(this, resId, duration).show();
+		}
+	}
+
+	private void showMirrorLinkSafeToast(CharSequence text, int duration) {
+		if(sMirrorLinkMediaBrowserService == null) {
+			Toast.makeText(this, text, duration).show();
+		}
+	}
+
 	/**
 	 * Start playing if currently paused.
 	 *
@@ -1116,7 +1147,7 @@ public final class PlaybackService extends Service
 			if ((mState & FLAG_EMPTY_QUEUE) != 0) {
 				setFinishAction(SongTimeline.FINISH_RANDOM);
 				setCurrentSong(0);
-				Toast.makeText(this, R.string.random_enabling, Toast.LENGTH_SHORT).show();
+				showMirrorLinkSafeToast(R.string.random_enabling, Toast.LENGTH_SHORT);
 			}
 
 			int state = updateState(mState | FLAG_PLAYING);
@@ -1270,7 +1301,7 @@ public final class PlaybackService extends Service
 	{
 		/* Save our 'current' state as the try block may set the ERROR flag (which clears the PLAYING flag */
 		boolean playing = (mState & FLAG_PLAYING) != 0;
-		
+
 		try {
 			mMediaPlayerInitialized = false;
 			mMediaPlayer.reset();
@@ -1287,7 +1318,7 @@ public final class PlaybackService extends Service
 			else if(song.path != null) {
 				prepareMediaPlayer(mMediaPlayer, song.path);
 			}
-			
+
 
 			mMediaPlayerInitialized = true;
 			// Cancel any pending gapless updates and re-send them
@@ -1310,16 +1341,16 @@ public final class PlaybackService extends Service
 		} catch (IOException e) {
 			mErrorMessage = getResources().getString(R.string.song_load_failed, song.path);
 			updateState(mState | FLAG_ERROR);
-			Toast.makeText(this, mErrorMessage, Toast.LENGTH_LONG).show();
+			showMirrorLinkSafeToast(mErrorMessage, Toast.LENGTH_LONG);
 			Log.e("VanillaMusic", "IOException", e);
-			
+
 			/* Automatically advance to next song IF we are currently playing or already did skip something
 			 * This will stop after skipping 10 songs to avoid endless loops (queue full of broken stuff */
 			if(mTimeline.isEndOfQueue() == false && getSong(1) != null && (playing || (mSkipBroken > 0 && mSkipBroken < 10))) {
 				mSkipBroken++;
 				mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_SKIP_BROKEN_SONG, getTimelinePosition(), 0), 1000);
 			}
-			
+
 		}
 
 		updateNotification();
@@ -1351,6 +1382,10 @@ public final class PlaybackService extends Service
 	public boolean onError(MediaPlayer player, int what, int extra)
 	{
 		Log.e("VanillaMusic", "MediaPlayer error: " + what + ' ' + extra);
+		MirrorLinkMediaBrowserService service = sMirrorLinkMediaBrowserService;
+		if(service != null) {
+			service.onError("MediaPlayer Error");
+		}
 		return true;
 	}
 
@@ -1689,8 +1724,7 @@ public final class PlaybackService extends Service
 		default:
 			throw new IllegalArgumentException("Invalid add mode: " + query.mode);
 		}
-		
-		Toast.makeText(this, getResources().getQuantityString(text, count, count), Toast.LENGTH_SHORT).show();
+		showMirrorLinkSafeToast(getResources().getQuantityString(text, count, count), Toast.LENGTH_SHORT);
 	}
 
 	/**
@@ -1781,6 +1815,11 @@ public final class PlaybackService extends Service
 		ArrayList<PlaybackActivity> list = sActivities;
 		for (int i = list.size(); --i != -1; )
 			list.get(i).onTimelineChanged();
+
+		MirrorLinkMediaBrowserService service = sMirrorLinkMediaBrowserService;
+		if(service != null) {
+			service.onTimelineChanged();
+		}
 	}
 
 	@Override
@@ -1789,6 +1828,11 @@ public final class PlaybackService extends Service
 		ArrayList<PlaybackActivity> list = sActivities;
 		for (int i = list.size(); --i != -1; )
 			list.get(i).onPositionInfoChanged();
+
+		MirrorLinkMediaBrowserService service = sMirrorLinkMediaBrowserService;
+		if(service != null) {
+			service.onPositionInfoChanged();
+		}
 	}
 
 	private final ContentObserver mObserver = new ContentObserver(null) {
@@ -1849,6 +1893,24 @@ public final class PlaybackService extends Service
 		sActivities.remove(activity);
 	}
 
+	/**
+	 * Register a MirrorLinkMediaBrowserService instance
+	 *
+	 * @param service the Service to be registered
+	 */
+	public static void registerService(MirrorLinkMediaBrowserService service) {
+		sMirrorLinkMediaBrowserService = service;
+	}
+
+	/**
+	 * Deregister a MirrorLinkMediaBrowserService instance
+	 *
+	 * @param service the Service to be deregistered
+	 */
+	public static void unregisterService() {
+		sMirrorLinkMediaBrowserService = null;
+	}
+
 	/**
 	 * Initializes the service state, loading songs saved from the disk into the
 	 * song timeline.
@@ -2171,7 +2233,7 @@ public final class PlaybackService extends Service
 			break;
 		case ClearQueue:
 			clearQueue();
-			Toast.makeText(this, R.string.queue_cleared, Toast.LENGTH_SHORT).show();
+			showMirrorLinkSafeToast(R.string.queue_cleared, Toast.LENGTH_SHORT);
 			break;
 		case ShowQueue:
 			Intent intentShowQueue = new Intent(this, ShowQueueActivity.class);
@@ -2203,6 +2265,13 @@ public final class PlaybackService extends Service
 		}
 	}
 
+	/**
+	 * Returns the playing status of the current song
+	 */
+	public boolean isPlaying() {
+		return (mState & FLAG_PLAYING) != 0;
+	}
+
 	/**
 	 * Returns the position of the current song in the song timeline.
 	 */
@@ -2218,14 +2287,14 @@ public final class PlaybackService extends Service
 	{
 		return mTimeline.getLength();
 	}
-	
+
 	/**
 	 * Returns 'Song' with given id from timeline
 	*/
 	public Song getSongByQueuePosition(int id) {
 		return mTimeline.getSongByQueuePosition(id);
 	}
-	
+
 	/**
 	 * Do a 'hard' jump to given queue position
 	*/