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Diffstat (limited to 'MusicDemo/src/main/java/com/example/android/musicservicedemo/MusicService.java')
| -rw-r--r-- | MusicDemo/src/main/java/com/example/android/musicservicedemo/MusicService.java | 878 |
1 files changed, 878 insertions, 0 deletions
diff --git a/MusicDemo/src/main/java/com/example/android/musicservicedemo/MusicService.java b/MusicDemo/src/main/java/com/example/android/musicservicedemo/MusicService.java new file mode 100644 index 0000000..c2c535d --- /dev/null +++ b/MusicDemo/src/main/java/com/example/android/musicservicedemo/MusicService.java @@ -0,0 +1,878 @@ +/* + * Copyright (C) 2014 Google Inc. All Rights Reserved. + * + * 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.example.android.musicservicedemo; + +import android.content.Context; +import android.media.AudioManager; +import android.media.MediaDescription; +import android.media.MediaMetadata; +import android.media.MediaPlayer; +import android.media.MediaPlayer.OnCompletionListener; +import android.media.MediaPlayer.OnErrorListener; +import android.media.MediaPlayer.OnPreparedListener; +import android.media.browse.MediaBrowser; +import android.media.browse.MediaBrowser.MediaItem; +import android.media.session.MediaSession; +import android.media.session.PlaybackState; +import android.net.Uri; +import android.net.wifi.WifiManager; +import android.net.wifi.WifiManager.WifiLock; +import android.os.Bundle; +import android.os.PowerManager; +import android.os.SystemClock; +import android.service.media.MediaBrowserService; + +import com.example.android.musicservicedemo.model.MusicProvider; +import com.example.android.musicservicedemo.utils.LogHelper; +import com.example.android.musicservicedemo.utils.MediaIDHelper; +import com.example.android.musicservicedemo.utils.QueueHelper; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.List; + +import static com.example.android.musicservicedemo.utils.MediaIDHelper.MEDIA_ID_MUSICS_BY_GENRE; +import static com.example.android.musicservicedemo.utils.MediaIDHelper.MEDIA_ID_ROOT; +import static com.example.android.musicservicedemo.utils.MediaIDHelper.createBrowseCategoryMediaID; +import static com.example.android.musicservicedemo.utils.MediaIDHelper.extractBrowseCategoryFromMediaID; + +/** + * Main entry point for the Android Automobile integration. This class needs to: + * + * <ul> + * + * <li> Extend {@link android.service.media.MediaBrowserService}, implementing the media browsing + * related methods {@link android.service.media.MediaBrowserService#onGetRoot} and + * {@link android.service.media.MediaBrowserService#onLoadChildren}; + * <li> Start a new {@link android.media.session.MediaSession} and notify its parent with the + * session's token {@link android.service.media.MediaBrowserService#setSessionToken}; + * + * <li> Set a callback on the + * {@link android.media.session.MediaSession#setCallback(android.media.session.MediaSession.Callback)}. + * The callback will receive all the user's actions, like play, pause, etc; + * + * <li> Handle all the actual music playing using any method your app prefers (for example, + * {@link android.media.MediaPlayer}) + * + * <li> Update playbackState, "now playing" metadata and queue, using MediaSession proper methods + * {@link android.media.session.MediaSession#setPlaybackState(android.media.session.PlaybackState)} + * {@link android.media.session.MediaSession#setMetadata(android.media.MediaMetadata)} and + * {@link android.media.session.MediaSession#setQueue(java.util.List)}) + * + * <li> Be declared in AndroidManifest as an intent receiver for the action + * android.media.browse.MediaBrowserService + * + * <li> Declare a meta-data tag in AndroidManifest.xml linking to a xml resource + * with a <automotiveApp> root element. For a media app, this must include + * an <uses name="media"/> element as a child. + * For example, in AndroidManifest.xml: + * <meta-data android:name="com.google.android.gms.car.application" + * android:resource="@xml/automotive_app_desc"/> + * And in res/values/automotive_app_desc.xml: + * <automotiveApp> + * <uses name="media"/> + * </automotiveApp> + * + * </ul> + + * <p> + * Customization: + * + * <li> Add custom actions in the state passed to setPlaybackState(state) + * <li> Handle custom actions in the MediaSession.Callback.onCustomAction + * <li> Use UI theme primaryColor to set the player color + * + * @see <a href="README.txt">README.txt</a> for more details. + * + */ + +public class MusicService extends MediaBrowserService implements OnPreparedListener, + OnCompletionListener, OnErrorListener, AudioManager.OnAudioFocusChangeListener { + + private static final String TAG = "MusicService"; + + // Action to thumbs up a media item + private static final String CUSTOM_ACTION_THUMBS_UP = "thumbs_up"; + + // The volume we set the media player to when we lose audio focus, but are + // allowed to reduce the volume instead of stopping playback. + public static final float VOLUME_DUCK = 0.2f; + + // The volume we set the media player when we have audio focus. + public static final float VOLUME_NORMAL = 1.0f; + public static final String ANDROID_AUTO_PACKAGE_NAME = "com.google.android.projection.gearhead"; + public static final String ANDROID_AUTO_EMULATOR_PACKAGE_NAME = "com.example.android.media"; + + // Music catalog manager + private MusicProvider mMusicProvider; + + private MediaSession mSession; + private MediaPlayer mMediaPlayer; + + // "Now playing" queue: + private List<MediaSession.QueueItem> mPlayingQueue; + private int mCurrentIndexOnQueue; + + // Current local media player state + private int mState = PlaybackState.STATE_NONE; + + // Wifi lock that we hold when streaming files from the internet, in order + // to prevent the device from shutting off the Wifi radio + private WifiLock mWifiLock; + + private MediaNotification mMediaNotification; + + enum AudioFocus { + NoFocusNoDuck, // we don't have audio focus, and can't duck + NoFocusCanDuck, // we don't have focus, but can play at a low volume + // ("ducking") + Focused // we have full audio focus + } + + // Type of audio focus we have: + private AudioFocus mAudioFocus = AudioFocus.NoFocusNoDuck; + private AudioManager mAudioManager; + + // Indicates if we should start playing immediately after we gain focus. + private boolean mPlayOnFocusGain; + + + /* + * (non-Javadoc) + * @see android.app.Service#onCreate() + */ + @Override + public void onCreate() { + super.onCreate(); + LogHelper.d(TAG, "onCreate"); + + mPlayingQueue = new ArrayList<>(); + + // Create the Wifi lock (this does not acquire the lock, this just creates it) + mWifiLock = ((WifiManager) getSystemService(Context.WIFI_SERVICE)) + .createWifiLock(WifiManager.WIFI_MODE_FULL, "MusicDemo_lock"); + + // Create the music catalog metadata provider + mMusicProvider = new MusicProvider(); + mMusicProvider.retrieveMedia(new MusicProvider.Callback() { + @Override + public void onMusicCatalogReady(boolean success) { + mState = success ? PlaybackState.STATE_STOPPED : PlaybackState.STATE_ERROR; + } + }); + + mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE); + + // Start a new MediaSession + mSession = new MediaSession(this, "MusicService"); + setSessionToken(mSession.getSessionToken()); + mSession.setCallback(new MediaSessionCallback()); + updatePlaybackState(null); + + mMediaNotification = new MediaNotification(this); + } + + /* + * (non-Javadoc) + * @see android.app.Service#onDestroy() + */ + @Override + public void onDestroy() { + LogHelper.d(TAG, "onDestroy"); + + // Service is being killed, so make sure we release our resources + handleStopRequest(null); + + // In particular, always release the MediaSession to clean up resources + // and notify associated MediaController(s). + mSession.release(); + } + + + // ********* MediaBrowserService methods: + + @Override + public BrowserRoot onGetRoot(String clientPackageName, int clientUid, Bundle rootHints) { + LogHelper.d(TAG, "OnGetRoot: clientPackageName=" + clientPackageName, + "; clientUid=" + clientUid + " ; rootHints=", rootHints); + // To ensure you are not allowing any arbitrary app to browse your app's contents, you + // need to check the origin: + if (!ANDROID_AUTO_PACKAGE_NAME.equals(clientPackageName) && + !ANDROID_AUTO_EMULATOR_PACKAGE_NAME.equals(clientPackageName)) { + // If the request comes from an untrusted package, return null. No further calls will + // be made to other media browsing methods. + LogHelper.w(TAG, "OnGetRoot: IGNORING request from untrusted package " + clientPackageName); + return null; + } + return new BrowserRoot(MEDIA_ID_ROOT, null); + } + + @Override + public void onLoadChildren(final String parentMediaId, final Result<List<MediaItem>> result) { + if (!mMusicProvider.isInitialized()) { + // Use result.detach to allow calling result.sendResult from another thread: + result.detach(); + + mMusicProvider.retrieveMedia(new MusicProvider.Callback() { + @Override + public void onMusicCatalogReady(boolean success) { + if (success) { + loadChildrenImpl(parentMediaId, result); + } else { + updatePlaybackState(getString(R.string.error_no_metadata)); + result.sendResult(new ArrayList<MediaItem>()); + } + } + }); + + } else { + // If our music catalog is already loaded/cached, load them into result immediately + loadChildrenImpl(parentMediaId, result); + } + } + + /** + * Actual implementation of onLoadChildren that assumes that MusicProvider is already + * initialized. + */ + private void loadChildrenImpl(final String parentMediaId, + final Result<List<MediaBrowser.MediaItem>> result) { + LogHelper.d(TAG, "OnLoadChildren: parentMediaId=", parentMediaId); + + List<MediaBrowser.MediaItem> mediaItems = new ArrayList<>(); + + if (MEDIA_ID_ROOT.equals(parentMediaId)) { + LogHelper.d(TAG, "OnLoadChildren.ROOT"); + mediaItems.add(new MediaBrowser.MediaItem( + new MediaDescription.Builder() + .setMediaId(MEDIA_ID_MUSICS_BY_GENRE) + .setTitle(getString(R.string.browse_genres)) + .setIconUri(Uri.parse("android.resource://com.example.android.musicservicedemo/drawable/ic_by_genre")) + .setSubtitle(getString(R.string.browse_genre_subtitle)) + .build(), MediaBrowser.MediaItem.FLAG_BROWSABLE + )); + + } else if (MEDIA_ID_MUSICS_BY_GENRE.equals(parentMediaId)) { + LogHelper.d(TAG, "OnLoadChildren.GENRES"); + for (String genre: mMusicProvider.getGenres()) { + MediaBrowser.MediaItem item = new MediaBrowser.MediaItem( + new MediaDescription.Builder() + .setMediaId(createBrowseCategoryMediaID(MEDIA_ID_MUSICS_BY_GENRE, genre)) + .setTitle(genre) + .setSubtitle(getString(R.string.browse_musics_by_genre_subtitle, genre)) + .build(), MediaBrowser.MediaItem.FLAG_BROWSABLE + ); + mediaItems.add(item); + } + + } else if (parentMediaId.startsWith(MEDIA_ID_MUSICS_BY_GENRE)) { + String genre = extractBrowseCategoryFromMediaID(parentMediaId)[1]; + LogHelper.d(TAG, "OnLoadChildren.SONGS_BY_GENRE genre=", genre); + for (MediaMetadata track: mMusicProvider.getMusicsByGenre(genre)) { + // Since mediaMetadata fields are immutable, we need to create a copy, so we + // can set a hierarchy-aware mediaID. We will need to know the media hierarchy + // when we get a onPlayFromMusicID call, so we can create the proper queue based + // on where the music was selected from (by artist, by genre, random, etc) + String hierarchyAwareMediaID = MediaIDHelper.createTrackMediaID( + MEDIA_ID_MUSICS_BY_GENRE, genre, track); + MediaMetadata trackCopy = new MediaMetadata.Builder(track) + .putString(MediaMetadata.METADATA_KEY_MEDIA_ID, hierarchyAwareMediaID) + .build(); + MediaBrowser.MediaItem bItem = new MediaBrowser.MediaItem( + trackCopy.getDescription(), MediaItem.FLAG_PLAYABLE); + mediaItems.add(bItem); + } + } else { + LogHelper.w(TAG, "Skipping unmatched parentMediaId: ", parentMediaId); + } + result.sendResult(mediaItems); + } + + + + // ********* MediaSession.Callback implementation: + + private final class MediaSessionCallback extends MediaSession.Callback { + @Override + public void onPlay() { + LogHelper.d(TAG, "play"); + + if (mPlayingQueue == null || mPlayingQueue.isEmpty()) { + mPlayingQueue = QueueHelper.getRandomQueue(mMusicProvider); + mSession.setQueue(mPlayingQueue); + mSession.setQueueTitle(getString(R.string.random_queue_title)); + // start playing from the beginning of the queue + mCurrentIndexOnQueue = 0; + } + + if (mPlayingQueue != null && !mPlayingQueue.isEmpty()) { + handlePlayRequest(); + } + } + + @Override + public void onSkipToQueueItem(long queueId) { + LogHelper.d(TAG, "OnSkipToQueueItem:" + queueId); + if (mPlayingQueue != null && !mPlayingQueue.isEmpty()) { + + // set the current index on queue from the music Id: + mCurrentIndexOnQueue = QueueHelper.getMusicIndexOnQueue(mPlayingQueue, queueId); + + // play the music + handlePlayRequest(); + } + } + + @Override + public void onPlayFromMediaId(String mediaId, Bundle extras) { + LogHelper.d(TAG, "playFromMediaId mediaId:", mediaId, " extras=", extras); + + // The mediaId used here is not the unique musicId. This one comes from the + // MediaBrowser, and is actually a "hierarchy-aware mediaID": a concatenation of + // the hierarchy in MediaBrowser and the actual unique musicID. This is necessary + // so we can build the correct playing queue, based on where the track was + // selected from. + mPlayingQueue = QueueHelper.getPlayingQueue(mediaId, mMusicProvider); + mSession.setQueue(mPlayingQueue); + String queueTitle = getString(R.string.browse_musics_by_genre_subtitle, + MediaIDHelper.extractBrowseCategoryValueFromMediaID(mediaId)); + mSession.setQueueTitle(queueTitle); + + if (mPlayingQueue != null && !mPlayingQueue.isEmpty()) { + String uniqueMusicID = MediaIDHelper.extractMusicIDFromMediaID(mediaId); + // set the current index on queue from the music Id: + mCurrentIndexOnQueue = QueueHelper.getMusicIndexOnQueue( + mPlayingQueue, uniqueMusicID); + + // play the music + handlePlayRequest(); + } + } + + @Override + public void onPause() { + LogHelper.d(TAG, "pause. current state=" + mState); + handlePauseRequest(); + } + + @Override + public void onStop() { + LogHelper.d(TAG, "stop. current state=" + mState); + handleStopRequest(null); + } + + @Override + public void onSkipToNext() { + LogHelper.d(TAG, "skipToNext"); + mCurrentIndexOnQueue++; + if (mPlayingQueue != null && mCurrentIndexOnQueue >= mPlayingQueue.size()) { + mCurrentIndexOnQueue = 0; + } + if (QueueHelper.isIndexPlayable(mCurrentIndexOnQueue, mPlayingQueue)) { + mState = PlaybackState.STATE_PLAYING; + handlePlayRequest(); + } else { + LogHelper.e(TAG, "skipToNext: cannot skip to next. next Index=" + + mCurrentIndexOnQueue + " queue length=" + + (mPlayingQueue == null ? "null" : mPlayingQueue.size())); + handleStopRequest("Cannot skip"); + } + } + + @Override + public void onSkipToPrevious() { + LogHelper.d(TAG, "skipToPrevious"); + + mCurrentIndexOnQueue--; + if (mPlayingQueue != null && mCurrentIndexOnQueue < 0) { + // This sample's behavior: skipping to previous when in first song restarts the + // first song. + mCurrentIndexOnQueue = 0; + } + if (QueueHelper.isIndexPlayable(mCurrentIndexOnQueue, mPlayingQueue)) { + mState = PlaybackState.STATE_PLAYING; + handlePlayRequest(); + } else { + LogHelper.e(TAG, "skipToPrevious: cannot skip to previous. previous Index=" + + mCurrentIndexOnQueue + " queue length=" + + (mPlayingQueue == null ? "null" : mPlayingQueue.size())); + handleStopRequest("Cannot skip"); + } + } + + @Override + public void onCustomAction(String action, Bundle extras) { + if (CUSTOM_ACTION_THUMBS_UP.equals(action)) { + LogHelper.i(TAG, "onCustomAction: favorite for current track"); + MediaMetadata track = getCurrentPlayingMusic(); + if (track != null) { + String mediaId = track.getString(MediaMetadata.METADATA_KEY_MEDIA_ID); + mMusicProvider.setFavorite(mediaId, !mMusicProvider.isFavorite(mediaId)); + } + updatePlaybackState(null); + } else { + LogHelper.e(TAG, "Unsupported action: ", action); + } + + } + + @Override + public void onPlayFromSearch(String query, Bundle extras) { + LogHelper.d(TAG, "playFromSearch query=", query); + + mPlayingQueue = QueueHelper.getPlayingQueueFromSearch(query, mMusicProvider); + LogHelper.d(TAG, "playFromSearch playqueue.length=" + mPlayingQueue.size()); + mSession.setQueue(mPlayingQueue); + + if (mPlayingQueue != null && !mPlayingQueue.isEmpty()) { + + // start playing from the beginning of the queue + mCurrentIndexOnQueue = 0; + + handlePlayRequest(); + } + } + } + + + + // ********* MediaPlayer listeners: + + /* + * Called when media player is done playing current song. + * @see android.media.MediaPlayer.OnCompletionListener + */ + @Override + public void onCompletion(MediaPlayer player) { + LogHelper.d(TAG, "onCompletion from MediaPlayer"); + // The media player finished playing the current song, so we go ahead + // and start the next. + if (mPlayingQueue != null && !mPlayingQueue.isEmpty()) { + // In this sample, we restart the playing queue when it gets to the end: + mCurrentIndexOnQueue++; + if (mCurrentIndexOnQueue >= mPlayingQueue.size()) { + mCurrentIndexOnQueue = 0; + } + handlePlayRequest(); + } else { + // If there is nothing to play, we stop and release the resources: + handleStopRequest(null); + } + } + + /* + * Called when media player is done preparing. + * @see android.media.MediaPlayer.OnPreparedListener + */ + @Override + public void onPrepared(MediaPlayer player) { + LogHelper.d(TAG, "onPrepared from MediaPlayer"); + // The media player is done preparing. That means we can start playing if we + // have audio focus. + configMediaPlayerState(); + } + + /** + * Called when there's an error playing media. When this happens, the media + * player goes to the Error state. We warn the user about the error and + * reset the media player. + * + * @see android.media.MediaPlayer.OnErrorListener + */ + @Override + public boolean onError(MediaPlayer mp, int what, int extra) { + LogHelper.e(TAG, "Media player error: what=" + what + ", extra=" + extra); + handleStopRequest("MediaPlayer error " + what + " (" + extra + ")"); + return true; // true indicates we handled the error + } + + + + + // ********* OnAudioFocusChangeListener listener: + + + /** + * Called by AudioManager on audio focus changes. + */ + @Override + public void onAudioFocusChange(int focusChange) { + LogHelper.d(TAG, "onAudioFocusChange. focusChange=" + focusChange); + if (focusChange == AudioManager.AUDIOFOCUS_GAIN) { + // We have gained focus: + mAudioFocus = AudioFocus.Focused; + + } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS || + focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT || + focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK) { + // We have lost focus. If we can duck (low playback volume), we can keep playing. + // Otherwise, we need to pause the playback. + boolean canDuck = focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK; + mAudioFocus = canDuck ? AudioFocus.NoFocusCanDuck : AudioFocus.NoFocusNoDuck; + + // If we are playing, we need to reset media player by calling configMediaPlayerState + // with mAudioFocus properly set. + if (mState == PlaybackState.STATE_PLAYING && !canDuck) { + // If we don't have audio focus and can't duck, we save the information that + // we were playing, so that we can resume playback once we get the focus back. + mPlayOnFocusGain = true; + } + } else { + LogHelper.e(TAG, "onAudioFocusChange: Ignoring unsupported focusChange: " + focusChange); + } + + configMediaPlayerState(); + } + + + + // ********* private methods: + + /** + * Handle a request to play music + */ + private void handlePlayRequest() { + LogHelper.d(TAG, "handlePlayRequest: mState=" + mState); + + mPlayOnFocusGain = true; + tryToGetAudioFocus(); + + if (!mSession.isActive()) { + mSession.setActive(true); + } + + // actually play the song + if (mState == PlaybackState.STATE_PAUSED) { + // If we're paused, just continue playback and restore the + // 'foreground service' state. + configMediaPlayerState(); + } else { + // If we're stopped or playing a song, + // just go ahead to the new song and (re)start playing + playCurrentSong(); + } + } + + + /** + * Handle a request to pause music + */ + private void handlePauseRequest() { + LogHelper.d(TAG, "handlePauseRequest: mState=" + mState); + + if (mState == PlaybackState.STATE_PLAYING) { + // Pause media player and cancel the 'foreground service' state. + mState = PlaybackState.STATE_PAUSED; + if (mMediaPlayer.isPlaying()) { + mMediaPlayer.pause(); + } + // while paused, retain the MediaPlayer but give up audio focus + relaxResources(false); + giveUpAudioFocus(); + } + updatePlaybackState(null); + } + + /** + * Handle a request to stop music + */ + private void handleStopRequest(String withError) { + LogHelper.d(TAG, "handleStopRequest: mState=" + mState + " error=", withError); + mState = PlaybackState.STATE_STOPPED; + + // let go of all resources... + relaxResources(true); + giveUpAudioFocus(); + updatePlaybackState(withError); + + mMediaNotification.stopNotification(); + + // service is no longer necessary. Will be started again if needed. + stopSelf(); + } + + /** + * Releases resources used by the service for playback. This includes the + * "foreground service" status, the wake locks and possibly the MediaPlayer. + * + * @param releaseMediaPlayer Indicates whether the Media Player should also + * be released or not + */ + private void relaxResources(boolean releaseMediaPlayer) { + LogHelper.d(TAG, "relaxResources. releaseMediaPlayer=" + releaseMediaPlayer); + // stop being a foreground service + stopForeground(true); + + // stop and release the Media Player, if it's available + if (releaseMediaPlayer && mMediaPlayer != null) { + mMediaPlayer.reset(); + mMediaPlayer.release(); + mMediaPlayer = null; + } + + // we can also release the Wifi lock, if we're holding it + if (mWifiLock.isHeld()) { + mWifiLock.release(); + } + } + + /** + * Reconfigures MediaPlayer according to audio focus settings and + * starts/restarts it. This method starts/restarts the MediaPlayer + * respecting the current audio focus state. So if we have focus, it will + * play normally; if we don't have focus, it will either leave the + * MediaPlayer paused or set it to a low volume, depending on what is + * allowed by the current focus settings. This method assumes mPlayer != + * null, so if you are calling it, you have to do so from a context where + * you are sure this is the case. + */ + private void configMediaPlayerState() { + LogHelper.d(TAG, "configAndStartMediaPlayer. mAudioFocus=" + mAudioFocus); + if (mAudioFocus == AudioFocus.NoFocusNoDuck) { + // If we don't have audio focus and can't duck, we have to pause, + if (mState == PlaybackState.STATE_PLAYING) { + handlePauseRequest(); + } + } else { // we have audio focus: + if (mAudioFocus == AudioFocus.NoFocusCanDuck) { + mMediaPlayer.setVolume(VOLUME_DUCK, VOLUME_DUCK); // we'll be relatively quiet + } else { + mMediaPlayer.setVolume(VOLUME_NORMAL, VOLUME_NORMAL); // we can be loud again + } + // If we were playing when we lost focus, we need to resume playing. + if (mPlayOnFocusGain) { + if (!mMediaPlayer.isPlaying()) { + LogHelper.d(TAG, "configAndStartMediaPlayer startMediaPlayer."); + mMediaPlayer.start(); + } + mPlayOnFocusGain = false; + mState = PlaybackState.STATE_PLAYING; + } + } + updatePlaybackState(null); + } + + /** + * Makes sure the media player exists and has been reset. This will create + * the media player if needed, or reset the existing media player if one + * already exists. + */ + private void createMediaPlayerIfNeeded() { + LogHelper.d(TAG, "createMediaPlayerIfNeeded. needed? " + (mMediaPlayer==null)); + if (mMediaPlayer == null) { + mMediaPlayer = new MediaPlayer(); + + // Make sure the media player will acquire a wake-lock while + // playing. If we don't do that, the CPU might go to sleep while the + // song is playing, causing playback to stop. + mMediaPlayer.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK); + + // we want the media player to notify us when it's ready preparing, + // and when it's done playing: + mMediaPlayer.setOnPreparedListener(this); + mMediaPlayer.setOnCompletionListener(this); + mMediaPlayer.setOnErrorListener(this); + } else { + mMediaPlayer.reset(); + } + } + + /** + * Starts playing the current song in the playing queue. + */ + void playCurrentSong() { + MediaMetadata track = getCurrentPlayingMusic(); + if (track == null) { + LogHelper.e(TAG, "playSong: ignoring request to play next song, because cannot" + + " find it." + + " currentIndex=" + mCurrentIndexOnQueue + + " playQueue.size=" + (mPlayingQueue==null?"null": mPlayingQueue.size())); + return; + } + String source = track.getString(MusicProvider.CUSTOM_METADATA_TRACK_SOURCE); + LogHelper.d(TAG, "playSong: current (" + mCurrentIndexOnQueue + ") in playingQueue. " + + " musicId=" + track.getString(MediaMetadata.METADATA_KEY_MEDIA_ID) + + " source=" + source); + + mState = PlaybackState.STATE_STOPPED; + relaxResources(false); // release everything except MediaPlayer + + try { + createMediaPlayerIfNeeded(); + + mState = PlaybackState.STATE_BUFFERING; + + mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); + LogHelper.d(TAG, "****** playCurrentSong: about to call setDataSource. If no" + + "'finished' log message shows up right after this, it's because the media " + + "player is stuck in a deadlock. This is a known issue. In the meantime, you " + + "will need to restart the device."); + try { + mMediaPlayer.setDataSource(source); + } finally { + LogHelper.d(TAG, "****** playCurrentSong: setDataSource finished, no deadlock :-)"); + } + + // Starts preparing the media player in the background. When + // it's done, it will call our OnPreparedListener (that is, + // the onPrepared() method on this class, since we set the + // listener to 'this'). Until the media player is prepared, + // we *cannot* call start() on it! + mMediaPlayer.prepareAsync(); + + // If we are streaming from the internet, we want to hold a + // Wifi lock, which prevents the Wifi radio from going to + // sleep while the song is playing. + mWifiLock.acquire(); + + updatePlaybackState(null); + updateMetadata(); + + } catch (IOException ex) { + LogHelper.e(TAG, ex, "IOException playing song"); + updatePlaybackState(ex.getMessage()); + } + } + + + + private void updateMetadata() { + if (!QueueHelper.isIndexPlayable(mCurrentIndexOnQueue, mPlayingQueue)) { + LogHelper.e(TAG, "Can't retrieve current metadata."); + mState = PlaybackState.STATE_ERROR; + updatePlaybackState(getResources().getString(R.string.error_no_metadata)); + return; + } + MediaSession.QueueItem queueItem = mPlayingQueue.get(mCurrentIndexOnQueue); + String mediaId = queueItem.getDescription().getMediaId(); + MediaMetadata track = mMusicProvider.getMusic(mediaId); + String trackId = track.getString(MediaMetadata.METADATA_KEY_MEDIA_ID); + if (!mediaId.equals(trackId)) { + throw new IllegalStateException("track ID (" + trackId + ") " + + "should match mediaId (" + mediaId + ")"); + } + LogHelper.d(TAG, "Updating metadata for MusicID= " + mediaId); + mSession.setMetadata(track); + } + + + /** + * 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) { + LogHelper.d(TAG, "updatePlaybackState, setting session playback state to " + mState); + long position = PlaybackState.PLAYBACK_POSITION_UNKNOWN; + if (mMediaPlayer != null && mMediaPlayer.isPlaying()) { + position = mMediaPlayer.getCurrentPosition(); + } + 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); + mState = PlaybackState.STATE_ERROR; + } + stateBuilder.setState(mState, position, 1.0f, SystemClock.elapsedRealtime()); + + mSession.setPlaybackState(stateBuilder.build()); + + if (mState == PlaybackState.STATE_PLAYING || mState == PlaybackState.STATE_PAUSED) { + mMediaNotification.startNotification(); + } + } + + private void setCustomAction(PlaybackState.Builder stateBuilder) { + MediaMetadata currentMusic = getCurrentPlayingMusic(); + if (currentMusic != null) { + // Set appropriate "Favorite" icon on Custom action: + String mediaId = currentMusic.getString(MediaMetadata.METADATA_KEY_MEDIA_ID); + int favoriteIcon = android.R.drawable.btn_star_big_off; + if (mMusicProvider.isFavorite(mediaId)) { + favoriteIcon = android.R.drawable.btn_star_big_on; + } + LogHelper.d(TAG, "updatePlaybackState, setting Favorite custom action of music ", + mediaId, " current favorite=", mMusicProvider.isFavorite(mediaId)); + stateBuilder.addCustomAction(CUSTOM_ACTION_THUMBS_UP, getString(R.string.favorite), + favoriteIcon); + } + } + + private long getAvailableActions() { + long actions = PlaybackState.ACTION_PLAY | PlaybackState.ACTION_PLAY_FROM_MEDIA_ID | + PlaybackState.ACTION_PLAY_FROM_SEARCH; + if (mPlayingQueue == null || mPlayingQueue.isEmpty()) { + return actions; + } + if (mState == PlaybackState.STATE_PLAYING) { + actions |= PlaybackState.ACTION_PAUSE; + } + if (mCurrentIndexOnQueue > 0) { + actions |= PlaybackState.ACTION_SKIP_TO_PREVIOUS; + } + if (mCurrentIndexOnQueue < mPlayingQueue.size() - 1) { + actions |= PlaybackState.ACTION_SKIP_TO_NEXT; + } + return actions; + } + + private MediaMetadata getCurrentPlayingMusic() { + if (QueueHelper.isIndexPlayable(mCurrentIndexOnQueue, mPlayingQueue)) { + MediaSession.QueueItem item = mPlayingQueue.get(mCurrentIndexOnQueue); + if (item != null) { + LogHelper.d(TAG, "getCurrentPlayingMusic for musicId=", + item.getDescription().getMediaId()); + return mMusicProvider.getMusic(item.getDescription().getMediaId()); + } + } + return null; + } + + /** + * Try to get the system audio focus. + */ + void tryToGetAudioFocus() { + LogHelper.d(TAG, "tryToGetAudioFocus"); + if (mAudioFocus != AudioFocus.Focused) { + int result = mAudioManager.requestAudioFocus(this, AudioManager.STREAM_MUSIC, + AudioManager.AUDIOFOCUS_GAIN); + if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) { + mAudioFocus = AudioFocus.Focused; + } + } + + } + + /** + * Give up the audio focus. + */ + void giveUpAudioFocus() { + LogHelper.d(TAG, "giveUpAudioFocus"); + if (mAudioFocus == AudioFocus.Focused) { + if (mAudioManager.abandonAudioFocus(this) == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) { + mAudioFocus = AudioFocus.NoFocusNoDuck; + } + } + } +} |