/Examples/AppFundamentalsVideoSourceExamples/src/MediaPlaybackService.java

/*
 * Copyright (C) 2007 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.android.music;

import android.app.Notification;
import android.app.PendingIntent;
import android.app.Service;
import android.appwidget.AppWidgetManager;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.BroadcastReceiver;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.database.sqlite.SQLiteException;
import android.graphics.Bitmap;
import android.media.audiofx.AudioEffect;
import android.media.AudioManager;
import android.media.AudioManager.OnAudioFocusChangeListener;
import android.media.MediaMetadataRetriever;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.RemoteControlClient;
import android.media.RemoteControlClient.MetadataEditor;
import android.net.Uri;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.PowerManager;
import android.os.SystemClock;
import android.os.PowerManager.WakeLock;
import android.provider.MediaStore;
import android.util.Log;
import android.widget.RemoteViews;
import android.widget.Toast;

import java.io.FileDescriptor;
import java.io.IOException;
import java.io.PrintWriter;
import java.lang.ref.WeakReference;
import java.util.Random;
import java.util.Vector;

/**
 * Provides "background" audio playback capabilities, allowing the
 * user to switch between activities without stopping playback.
 */
public class MediaPlaybackService extends Service {
    /** used to specify whether enqueue() should start playing
     * the new list of files right away, next or once all the currently
     * queued files have been played
     */
    public static final int NOW = 1;
    public static final int NEXT = 2;
    public static final int LAST = 3;
    public static final int PLAYBACKSERVICE_STATUS = 1;
    
    public static final int SHUFFLE_NONE = 0;
    public static final int SHUFFLE_NORMAL = 1;
    public static final int SHUFFLE_AUTO = 2;
    
    public static final int REPEAT_NONE = 0;
    public static final int REPEAT_CURRENT = 1;
    public static final int REPEAT_ALL = 2;

    public static final String PLAYSTATE_CHANGED = "com.android.music.playstatechanged";
    public static final String META_CHANGED = "com.android.music.metachanged";
    public static final String QUEUE_CHANGED = "com.android.music.queuechanged";

    public static final String SERVICECMD = "com.android.music.musicservicecommand";
    public static final String CMDNAME = "command";
    public static final String CMDTOGGLEPAUSE = "togglepause";
    public static final String CMDSTOP = "stop";
    public static final String CMDPAUSE = "pause";
    public static final String CMDPLAY = "play";
    public static final String CMDPREVIOUS = "previous";
    public static final String CMDNEXT = "next";

    public static final String TOGGLEPAUSE_ACTION = "com.android.music.musicservicecommand.togglepause";
    public static final String PAUSE_ACTION = "com.android.music.musicservicecommand.pause";
    public static final String PREVIOUS_ACTION = "com.android.music.musicservicecommand.previous";
    public static final String NEXT_ACTION = "com.android.music.musicservicecommand.next";

    private static final int TRACK_ENDED = 1;
    private static final int RELEASE_WAKELOCK = 2;
    private static final int SERVER_DIED = 3;
    private static final int FOCUSCHANGE = 4;
    private static final int FADEDOWN = 5;
    private static final int FADEUP = 6;
    private static final int TRACK_WENT_TO_NEXT = 7;
    private static final int MAX_HISTORY_SIZE = 100;
    
    private MultiPlayer mPlayer;
    private String mFileToPlay;
    private int mShuffleMode = SHUFFLE_NONE;
    private int mRepeatMode = REPEAT_NONE;
    private int mMediaMountedCount = 0;
    private long [] mAutoShuffleList = null;
    private long [] mPlayList = null;
    private int mPlayListLen = 0;
    private Vector<Integer> mHistory = new Vector<Integer>(MAX_HISTORY_SIZE);
    private Cursor mCursor;
    private int mPlayPos = -1;
    private int mNextPlayPos = -1;
    private static final String LOGTAG = "MediaPlaybackService";
    private final Shuffler mRand = new Shuffler();
    private int mOpenFailedCounter = 0;
    String[] mCursorCols = new String[] {
            "audio._id AS _id",             // index must match IDCOLIDX below
            MediaStore.Audio.Media.ARTIST,
            MediaStore.Audio.Media.ALBUM,
            MediaStore.Audio.Media.TITLE,
            MediaStore.Audio.Media.DATA,
            MediaStore.Audio.Media.MIME_TYPE,
            MediaStore.Audio.Media.ALBUM_ID,
            MediaStore.Audio.Media.ARTIST_ID,
            MediaStore.Audio.Media.IS_PODCAST, // index must match PODCASTCOLIDX below
            MediaStore.Audio.Media.BOOKMARK    // index must match BOOKMARKCOLIDX below
    };
    private final static int IDCOLIDX = 0;
    private final static int PODCASTCOLIDX = 8;
    private final static int BOOKMARKCOLIDX = 9;
    private BroadcastReceiver mUnmountReceiver = null;
    private WakeLock mWakeLock;
    private int mServiceStartId = -1;
    private boolean mServiceInUse = false;
    private boolean mIsSupposedToBePlaying = false;
    private boolean mQuietMode = false;
    private AudioManager mAudioManager;
    private boolean mQueueIsSaveable = true;
    // used to track what type of audio focus loss caused the playback to pause
    private boolean mPausedByTransientLossOfFocus = false;

    private SharedPreferences mPreferences;
    // We use this to distinguish between different cards when saving/restoring playlists.
    // This will have to change if we want to support multiple simultaneous cards.
    private int mCardId;
    
    private MediaAppWidgetProvider mAppWidgetProvider = MediaAppWidgetProvider.getInstance();
    
    // interval after which we stop the service when idle
    private static final int IDLE_DELAY = 60000;

    private RemoteControlClient mRemoteControlClient;

    private Handler mMediaplayerHandler = new Handler() {
        float mCurrentVolume = 1.0f;
        @Override
        public void handleMessage(Message msg) {
            MusicUtils.debugLog("mMediaplayerHandler.handleMessage " + msg.what);
            switch (msg.what) {
                case FADEDOWN:
                    mCurrentVolume -= .05f;
                    if (mCurrentVolume > .2f) {
                        mMediaplayerHandler.sendEmptyMessageDelayed(FADEDOWN, 10);
                    } else {
                        mCurrentVolume = .2f;
                    }
                    mPlayer.setVolume(mCurrentVolume);
                    break;
                case FADEUP:
                    mCurrentVolume += .01f;
                    if (mCurrentVolume < 1.0f) {
                        mMediaplayerHandler.sendEmptyMessageDelayed(FADEUP, 10);
                    } else {
                        mCurrentVolume = 1.0f;
                    }
                    mPlayer.setVolume(mCurrentVolume);
                    break;
                case SERVER_DIED:
                    if (mIsSupposedToBePlaying) {
                        gotoNext(true);
                    } else {
                        // the server died when we were idle, so just
                        // reopen the same song (it will start again
                        // from the beginning though when the user
                        // restarts)
                        openCurrentAndNext();
                    }
                    break;
                case TRACK_WENT_TO_NEXT:
                    mPlayPos = mNextPlayPos;
                    if (mCursor != null) {
                        mCursor.close();
                        mCursor = null;
                    }
                    mCursor = getCursorForId(mPlayList[mPlayPos]);
                    notifyChange(META_CHANGED);
                    updateNotification();
                    setNextTrack();
                    break;
                case TRACK_ENDED:
                    if (mRepeatMode == REPEAT_CURRENT) {
                        seek(0);
                        play();
                    } else {
                        gotoNext(false);
                    }
                    break;
                case RELEASE_WAKELOCK:
                    mWakeLock.release();
                    break;

                case FOCUSCHANGE:
                    // This code is here so we can better synchronize it with the code that
                    // handles fade-in
                    switch (msg.arg1) {
                        case AudioManager.AUDIOFOCUS_LOSS:
                            Log.v(LOGTAG, "AudioFocus: received AUDIOFOCUS_LOSS");
                            if(isPlaying()) {
                                mPausedByTransientLossOfFocus = false;
                            }
                            pause();
                            break;
                        case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                            mMediaplayerHandler.removeMessages(FADEUP);
                            mMediaplayerHandler.sendEmptyMessage(FADEDOWN);
                            break;
                        case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
                            Log.v(LOGTAG, "AudioFocus: received AUDIOFOCUS_LOSS_TRANSIENT");
                            if(isPlaying()) {
                                mPausedByTransientLossOfFocus = true;
                            }
                            pause();
                            break;
                        case AudioManager.AUDIOFOCUS_GAIN:
                            Log.v(LOGTAG, "AudioFocus: received AUDIOFOCUS_GAIN");
                            if(!isPlaying() && mPausedByTransientLossOfFocus) {
                                mPausedByTransientLossOfFocus = false;
                                mCurrentVolume = 0f;
                                mPlayer.setVolume(mCurrentVolume);
                                play(); // also queues a fade-in
                            } else {
                                mMediaplayerHandler.removeMessages(FADEDOWN);
                                mMediaplayerHandler.sendEmptyMessage(FADEUP);
                            }
                            break;
                        default:
                            Log.e(LOGTAG, "Unknown audio focus change code");
                    }
                    break;

                default:
                    break;
            }
        }
    };

    private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            String cmd = intent.getStringExtra("command");
            MusicUtils.debugLog("mIntentReceiver.onReceive " + action + " / " + cmd);
            if (CMDNEXT.equals(cmd) || NEXT_ACTION.equals(action)) {
                gotoNext(true);
            } else if (CMDPREVIOUS.equals(cmd) || PREVIOUS_ACTION.equals(action)) {
                prev();
            } else if (CMDTOGGLEPAUSE.equals(cmd) || TOGGLEPAUSE_ACTION.equals(action)) {
                if (isPlaying()) {
                    pause();
                    mPausedByTransientLossOfFocus = false;
                } else {
                    play();
                }
            } else if (CMDPAUSE.equals(cmd) || PAUSE_ACTION.equals(action)) {
                pause();
                mPausedByTransientLossOfFocus = false;
            } else if (CMDPLAY.equals(cmd)) {
                play();
            } else if (CMDSTOP.equals(cmd)) {
                pause();
                mPausedByTransientLossOfFocus = false;
                seek(0);
            } else if (MediaAppWidgetProvider.CMDAPPWIDGETUPDATE.equals(cmd)) {
                // Someone asked us to refresh a set of specific widgets, probably
                // because they were just added.
                int[] appWidgetIds = intent.getIntArrayExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS);
                mAppWidgetProvider.performUpdate(MediaPlaybackService.this, appWidgetIds);
            }
        }
    };

    private OnAudioFocusChangeListener mAudioFocusListener = new OnAudioFocusChangeListener() {
        public void onAudioFocusChange(int focusChange) {
            mMediaplayerHandler.obtainMessage(FOCUSCHANGE, focusChange, 0).sendToTarget();
        }
    };

    public MediaPlaybackService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();

        mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        ComponentName rec = new ComponentName(getPackageName(),
                MediaButtonIntentReceiver.class.getName());
        mAudioManager.registerMediaButtonEventReceiver(rec);
        // TODO update to new constructor
//        mRemoteControlClient = new RemoteControlClient(rec);
//        mAudioManager.registerRemoteControlClient(mRemoteControlClient);
//
//        int flags = RemoteControlClient.FLAG_KEY_MEDIA_PREVIOUS
//                | RemoteControlClient.FLAG_KEY_MEDIA_NEXT
//                | RemoteControlClient.FLAG_KEY_MEDIA_PLAY
//                | RemoteControlClient.FLAG_KEY_MEDIA_PAUSE
//                | RemoteControlClient.FLAG_KEY_MEDIA_PLAY_PAUSE
//                | RemoteControlClient.FLAG_KEY_MEDIA_STOP;
//        mRemoteControlClient.setTransportControlFlags(flags);
        
        mPreferences = getSharedPreferences("Music", MODE_WORLD_READABLE | MODE_WORLD_WRITEABLE);
        mCardId = MusicUtils.getCardId(this);
        
        registerExternalStorageListener();

        // Needs to be done in this thread, since otherwise ApplicationContext.getPowerManager() crashes.
        mPlayer = new MultiPlayer();
        mPlayer.setHandler(mMediaplayerHandler);

        reloadQueue();
        notifyChange(QUEUE_CHANGED);
        notifyChange(META_CHANGED);

        IntentFilter commandFilter = new IntentFilter();
        commandFilter.addAction(SERVICECMD);
        commandFilter.addAction(TOGGLEPAUSE_ACTION);
        commandFilter.addAction(PAUSE_ACTION);
        commandFilter.addAction(NEXT_ACTION);
        commandFilter.addAction(PREVIOUS_ACTION);
        registerReceiver(mIntentReceiver, commandFilter);
        
        PowerManager pm = (PowerManager)getSystemService(Context.POWER_SERVICE);
        mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, this.getClass().getName());
        mWakeLock.setReferenceCounted(false);

        // If the service was idle, but got killed before it stopped itself, the
        // system will relaunch it. Make sure it gets stopped again in that case.
        Message msg = mDelayedStopHandler.obtainMessage();
        mDelayedStopHandler.sendMessageDelayed(msg, IDLE_DELAY);
    }

    @Override
    public void onDestroy() {
        // Check that we're not being destroyed while something is still playing.
        if (isPlaying()) {
            Log.e(LOGTAG, "Service being destroyed while still playing.");
        }
        // release all MediaPlayer resources, including the native player and wakelocks
        Intent i = new Intent(AudioEffect.ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION);
        i.putExtra(AudioEffect.EXTRA_AUDIO_SESSION, getAudioSessionId());
        i.putExtra(AudioEffect.EXTRA_PACKAGE_NAME, getPackageName());
        sendBroadcast(i);
        mPlayer.release();
        mPlayer = null;

        mAudioManager.abandonAudioFocus(mAudioFocusListener);
        //mAudioManager.unregisterRemoteControlClient(mRemoteControlClient);
        
        // make sure there aren't any other messages coming
        mDelayedStopHandler.removeCallbacksAndMessages(null);
        mMediaplayerHandler.removeCallbacksAndMessages(null);

        if (mCursor != null) {
            mCursor.close();
            mCursor = null;
        }

        unregisterReceiver(mIntentReceiver);
        if (mUnmountReceiver != null) {
            unregisterReceiver(mUnmountReceiver);
            mUnmountReceiver = null;
        }
        mWakeLock.release();
        super.onDestroy();
    }
    
    private final char hexdigits [] = new char [] {
            '0', '1', '2', '3',
            '4', '5', '6', '7',
            '8', '9', 'a', 'b',
            'c', 'd', 'e', 'f'
    };

    private void saveQueue(boolean full) {
        if (!mQueueIsSaveable) {
            return;
        }

        Editor ed = mPreferences.edit();
        //long start = System.currentTimeMillis();
        if (full) {
            StringBuilder q = new StringBuilder();
            
            // The current playlist is saved as a list of "reverse hexadecimal"
            // numbers, which we can generate faster than normal decimal or
            // hexadecimal numbers, which in turn allows us to save the playlist
            // more often without worrying too much about performance.
            // (saving the full state takes about 40 ms under no-load conditions
            // on the phone)
            int len = mPlayListLen;
            for (int i = 0; i < len; i++) {
                long n = mPlayList[i];
                if (n < 0) {
                    continue;
                } else if (n == 0) {
                    q.append("0;");
                } else {
                    while (n != 0) {
                        int digit = (int)(n & 0xf);
                        n >>>= 4;
                        q.append(hexdigits[digit]);
                    }
                    q.append(";");
                }
            }
            //Log.i("@@@@ service", "created queue string in " + (System.currentTimeMillis() - start) + " ms");
            ed.putString("queue", q.toString());
            ed.putInt("cardid", mCardId);
            if (mShuffleMode != SHUFFLE_NONE) {
                // In shuffle mode we need to save the history too
                len = mHistory.size();
                q.setLength(0);
                for (int i = 0; i < len; i++) {
                    int n = mHistory.get(i);
                    if (n == 0) {
                        q.append("0;");
                    } else {
                        while (n != 0) {
                            int digit = (n & 0xf);
                            n >>>= 4;
                            q.append(hexdigits[digit]);
                        }
                        q.append(";");
                    }
                }
                ed.putString("history", q.toString());
            }
        }
        ed.putInt("curpos", mPlayPos);
        if (mPlayer.isInitialized()) {
            ed.putLong("seekpos", mPlayer.position());
        }
        ed.putInt("repeatmode", mRepeatMode);
        ed.putInt("shufflemode", mShuffleMode);
        SharedPreferencesCompat.apply(ed);

        //Log.i("@@@@ service", "saved state in " + (System.currentTimeMillis() - start) + " ms");
    }

    private void reloadQueue() {
        String q = null;
        
        boolean newstyle = false;
        int id = mCardId;
        if (mPreferences.contains("cardid")) {
            newstyle = true;
            id = mPreferences.getInt("cardid", ~mCardId);
        }
        if (id == mCardId) {
            // Only restore the saved playlist if the card is still
            // the same one as when the playlist was saved
            q = mPreferences.getString("queue", "");
        }
        int qlen = q != null ? q.length() : 0;
        if (qlen > 1) {
            //Log.i("@@@@ service", "loaded queue: " + q);
            int plen = 0;
            int n = 0;
            int shift = 0;
            for (int i = 0; i < qlen; i++) {
                char c = q.charAt(i);
                if (c == ';') {
                    ensurePlayListCapacity(plen + 1);
                    mPlayList[plen] = n;
                    plen++;
                    n = 0;
                    shift = 0;
                } else {
                    if (c >= '0' && c <= '9') {
                        n += ((c - '0') << shift);
                    } else if (c >= 'a' && c <= 'f') {
                        n += ((10 + c - 'a') << shift);
                    } else {
                        // bogus playlist data
                        plen = 0;
                        break;
                    }
                    shift += 4;
                }
            }
            mPlayListLen = plen;

            int pos = mPreferences.getInt("curpos", 0);
            if (pos < 0 || pos >= mPlayListLen) {
                // The saved playlist is bogus, discard it
                mPlayListLen = 0;
                return;
            }
            mPlayPos = pos;
            
            // When reloadQueue is called in response to a card-insertion,
            // we might not be able to query the media provider right away.
            // To deal with this, try querying for the current file, and if
            // that fails, wait a while and try again. If that too fails,
            // assume there is a problem and don't restore the state.
            Cursor crsr = MusicUtils.query(this,
                        MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                        new String [] {"_id"}, "_id=" + mPlayList[mPlayPos] , null, null);
            if (crsr == null || crsr.getCount() == 0) {
                // wait a bit and try again
                SystemClock.sleep(3000);
                crsr = getContentResolver().query(
                        MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                        mCursorCols, "_id=" + mPlayList[mPlayPos] , null, null);
            }
            if (crsr != null) {
                crsr.close();
            }

            // Make sure we don't auto-skip to the next song, since that
            // also starts playback. What could happen in that case is:
            // - music is paused
            // - go to UMS and delete some files, including the currently playing one
            // - come back from UMS
            // (time passes)
            // - music app is killed for some reason (out of memory)
            // - music service is restarted, service restores state, doesn't find
            //   the "current" file, goes to the next and: playback starts on its
            //   own, potentially at some random inconvenient time.
            mOpenFailedCounter = 20;
            mQuietMode = true;
            openCurrentAndNext();
            mQuietMode = false;
            if (!mPlayer.isInitialized()) {
                // couldn't restore the saved state
                mPlayListLen = 0;
                return;
            }
            
            long seekpos = mPreferences.getLong("seekpos", 0);
            seek(seekpos >= 0 && seekpos < duration() ? seekpos : 0);
            Log.d(LOGTAG, "restored queue, currently at position "
                    + position() + "/" + duration()
                    + " (requested " + seekpos + ")");
            
            int repmode = mPreferences.getInt("repeatmode", REPEAT_NONE);
            if (repmode != REPEAT_ALL && repmode != REPEAT_CURRENT) {
                repmode = REPEAT_NONE;
            }
            mRepeatMode = repmode;

            int shufmode = mPreferences.getInt("shufflemode", SHUFFLE_NONE);
            if (shufmode != SHUFFLE_AUTO && shufmode != SHUFFLE_NORMAL) {
                shufmode = SHUFFLE_NONE;
            }
            if (shufmode != SHUFFLE_NONE) {
                // in shuffle mode we need to restore the history too
                q = mPreferences.getString("history", "");
                qlen = q != null ? q.length() : 0;
                if (qlen > 1) {
                    plen = 0;
                    n = 0;
                    shift = 0;
                    mHistory.clear();
                    for (int i = 0; i < qlen; i++) {
                        char c = q.charAt(i);
                        if (c == ';') {
                            if (n >= mPlayListLen) {
                                // bogus history data
                                mHistory.clear();
                                break;
                            }
                            mHistory.add(n);
                            n = 0;
                            shift = 0;
                        } else {
                            if (c >= '0' && c <= '9') {
                                n += ((c - '0') << shift);
                            } else if (c >= 'a' && c <= 'f') {
                                n += ((10 + c - 'a') << shift);
                            } else {
                                // bogus history data
                                mHistory.clear();
                                break;
                            }
                            shift += 4;
                        }
                    }
                }
            }
            if (shufmode == SHUFFLE_AUTO) {
                if (! makeAutoShuffleList()) {
                    shufmode = SHUFFLE_NONE;
                }
            }
            mShuffleMode = shufmode;
        }
    }
    
    @Override
    public IBinder onBind(Intent intent) {
        mDelayedStopHandler.removeCallbacksAndMessages(null);
        mServiceInUse = true;
        return mBinder;
    }

    @Override
    public void onRebind(Intent intent) {
        mDelayedStopHandler.removeCallbacksAndMessages(null);
        mServiceInUse = true;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        mServiceStartId = startId;
        mDelayedStopHandler.removeCallbacksAndMessages(null);

        if (intent != null) {
            String action = intent.getAction();
            String cmd = intent.getStringExtra("command");
            MusicUtils.debugLog("onStartCommand " + action + " / " + cmd);

            if (CMDNEXT.equals(cmd) || NEXT_ACTION.equals(action)) {
                gotoNext(true);
            } else if (CMDPREVIOUS.equals(cmd) || PREVIOUS_ACTION.equals(action)) {
                if (position() < 2000) {
                    prev();
                } else {
                    seek(0);
                    play();
                }
            } else if (CMDTOGGLEPAUSE.equals(cmd) || TOGGLEPAUSE_ACTION.equals(action)) {
                if (isPlaying()) {
                    pause();
                    mPausedByTransientLossOfFocus = false;
                } else {
                    play();
                }
            } else if (CMDPAUSE.equals(cmd) || PAUSE_ACTION.equals(action)) {
                pause();
                mPausedByTransientLossOfFocus = false;
            } else if (CMDPLAY.equals(cmd)) {
                play();
            } else if (CMDSTOP.equals(cmd)) {
                pause();
                mPausedByTransientLossOfFocus = false;
                seek(0);
            }
        }
        
        // make sure the service will shut down on its own if it was
        // just started but not bound to and nothing is playing
        mDelayedStopHandler.removeCallbacksAndMessages(null);
        Message msg = mDelayedStopHandler.obtainMessage();
        mDelayedStopHandler.sendMessageDelayed(msg, IDLE_DELAY);
        return START_STICKY;
    }
    
    @Override
    public boolean onUnbind(Intent intent) {
        mServiceInUse = false;

        // Take a snapshot of the current playlist
        saveQueue(true);

        if (isPlaying() || mPausedByTransientLossOfFocus) {
            // something is currently playing, or will be playing once 
            // an in-progress action requesting audio focus ends, so don't stop the service now.
            return true;
        }
        
        // If there is a playlist but playback is paused, then wait a while
        // before stopping the service, so that pause/resume isn't slow.
        // Also delay stopping the service if we're transitioning between tracks.
        if (mPlayListLen > 0  || mMediaplayerHandler.hasMessages(TRACK_ENDED)) {
            Message msg = mDelayedStopHandler.obtainMessage();
            mDelayedStopHandler.sendMessageDelayed(msg, IDLE_DELAY);
            return true;
        }
        
        // No active playlist, OK to stop the service right now
        stopSelf(mServiceStartId);
        return true;
    }
    
    private Handler mDelayedStopHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            // Check again to make sure nothing is playing right now
            if (isPlaying() || mPausedByTransientLossOfFocus || mServiceInUse
                    || mMediaplayerHandler.hasMessages(TRACK_ENDED)) {
                return;
            }
            // save the queue again, because it might have changed
            // since the user exited the music app (because of
            // party-shuffle or because the play-position changed)
            saveQueue(true);
            stopSelf(mServiceStartId);
        }
    };

    /**
     * Called when we receive a ACTION_MEDIA_EJECT notification.
     *
     * @param storagePath path to mount point for the removed media
     */
    public void closeExternalStorageFiles(String storagePath) {
        // stop playback and clean up if the SD card is going to be unmounted.
        stop(true);
        notifyChange(QUEUE_CHANGED);
        notifyChange(META_CHANGED);
    }

    /**
     * Registers an intent to listen for ACTION_MEDIA_EJECT notifications.
     * The intent will call closeExternalStorageFiles() if the external media
     * is going to be ejected, so applications can clean up any files they have open.
     */
    public void registerExternalStorageListener() {
        if (mUnmountReceiver == null) {
            mUnmountReceiver = new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {
                    String action = intent.getAction();
                    if (action.equals(Intent.ACTION_MEDIA_EJECT)) {
                        saveQueue(true);
                        mQueueIsSaveable = false;
                        closeExternalStorageFiles(intent.getData().getPath());
                    } else if (action.equals(Intent.ACTION_MEDIA_MOUNTED)) {
                        mMediaMountedCount++;
                        mCardId = MusicUtils.getCardId(MediaPlaybackService.this);
                        reloadQueue();
                        mQueueIsSaveable = true;
                        notifyChange(QUEUE_CHANGED);
                        notifyChange(META_CHANGED);
                    }
                }
            };
            IntentFilter iFilter = new IntentFilter();
            iFilter.addAction(Intent.ACTION_MEDIA_EJECT);
            iFilter.addAction(Intent.ACTION_MEDIA_MOUNTED);
            iFilter.addDataScheme("file");
            registerReceiver(mUnmountReceiver, iFilter);
        }
    }

    /**
     * Notify the change-receivers that something has changed.
     * The intent that is sent contains the following data
     * for the currently playing track:
     * "id" - Integer: the database row ID
     * "artist" - String: the name of the artist
     * "album" - String: the name of the album
     * "track" - String: the name of the track
     * The intent has an action that is one of
     * "com.android.music.metachanged"
     * "com.android.music.queuechanged",
     * "com.android.music.playbackcomplete"
     * "com.android.music.playstatechanged"
     * respectively indicating that a new track has
     * started playing, that the playback queue has
     * changed, that playback has stopped because
     * the last file in the list has been played,
     * or that the play-state changed (paused/resumed).
     */
    private void notifyChange(String what) {

        Intent i = new Intent(what);
        i.putExtra("id", Long.valueOf(getAudioId()));
        i.putExtra("artist", getArtistName());
        i.putExtra("album",getAlbumName());
        i.putExtra("track", getTrackName());
        i.putExtra("playing", isPlaying());
        sendStickyBroadcast(i);

        if (what.equals(PLAYSTATE_CHANGED)) {
//            mRemoteControlClient.setPlaybackState(isPlaying() ?
//                    RemoteControlClient.PLAYSTATE_PLAYING : RemoteControlClient.PLAYSTATE_PAUSED);
        } else if (what.equals(META_CHANGED)) {
//            RemoteControlClient.MetadataEditor ed = mRemoteControlClient.editMetadata(true);
//            ed.putString(MediaMetadataRetriever.METADATA_KEY_TITLE, getTrackName());
//            ed.putString(MediaMetadataRetriever.METADATA_KEY_ALBUM, getAlbumName());
//            ed.putString(MediaMetadataRetriever.METADATA_KEY_ARTIST, getArtistName());
//            ed.putLong(MediaMetadataRetriever.METADATA_KEY_DURATION, duration());
//            Bitmap b = MusicUtils.getArtwork(this, getAudioId(), getAlbumId(), false);
//            if (b != null) {
//                ed.putBitmap(MetadataEditor.BITMAP_KEY_ARTWORK, b);
//            }
//            ed.apply();
        }

        if (what.equals(QUEUE_CHANGED)) {
            saveQueue(true);
        } else {
            saveQueue(false);
        }
        
        // Share this notification directly with our widgets
        mAppWidgetProvider.notifyChange(this, what);
    }

    private void ensurePlayListCapacity(int size) {
        if (mPlayList == null || size > mPlayList.length) {
            // reallocate at 2x requested size so we don't
            // need to grow and copy the array for every
            // insert
            long [] newlist = new long[size * 2];
            int len = mPlayList != null ? mPlayList.length : mPlayListLen;
            for (int i = 0; i < len; i++) {
                newlist[i] = mPlayList[i];
            }
            mPlayList = newlist;
        }
        // FIXME: shrink the array when the needed size is much smaller
        // than the allocated size
    }
    
    // insert the list of songs at the specified position in the playlist
    private void addToPlayList(long [] list, int position) {
        int addlen = list.length;
        if (position < 0) { // overwrite
            mPlayListLen = 0;
            position = 0;
        }
        ensurePlayListCapacity(mPlayListLen + addlen);
        if (position > mPlayListLen) {
            position = mPlayListLen;
        }
        
        // move part of list after insertion point
        int tailsize = mPlayListLen - position;
        for (int i = tailsize ; i > 0 ; i--) {
            mPlayList[position + i] = mPlayList[position + i - addlen]; 
        }
        
        // copy list into playlist
        for (int i = 0; i < addlen; i++) {
            mPlayList[position + i] = list[i];
        }
        mPlayListLen += addlen;
        if (mPlayListLen == 0) {
            mCursor.close();
            mCursor = null;
            notifyChange(META_CHANGED);
        }
    }
    
    /**
     * Appends a list of tracks to the current playlist.
     * If nothing is playing currently, playback will be started at
     * the first track.
     * If the action is NOW, playback will switch to the first of
     * the new tracks immediately.
     * @param list The list of tracks to append.
     * @param action NOW, NEXT or LAST
     */
    public void enqueue(long [] list, int action) {
        synchronized(this) {
            if (action == NEXT && mPlayPos + 1 < mPlayListLen) {
                addToPlayList(list, mPlayPos + 1);
                notifyChange(QUEUE_CHANGED);
            } else {
                // action == LAST || action == NOW || mPlayPos + 1 == mPlayListLen
                addToPlayList(list, Integer.MAX_VALUE);
                notifyChange(QUEUE_CHANGED);
                if (action == NOW) {
                    mPlayPos = mPlayListLen - list.length;
                    openCurrentAndNext();
                    play();
                    notifyChange(META_CHANGED);
                    return;
                }
            }
            if (mPlayPos < 0) {
                mPlayPos = 0;
                openCurrentAndNext();
                play();
                notifyChange(META_CHANGED);
            }
        }
    }

    /**
     * Replaces the current playlist with a new list,
     * and prepares for starting playback at the specified
     * position in the list, or a random position if the
     * specified position is 0.
     * @param list The new list of tracks.
     */
    public void open(long [] list, int position) {
        synchronized (this) {
            if (mShuffleMode == SHUFFLE_AUTO) {
                mShuffleMode = SHUFFLE_NORMAL;
            }
            long oldId = getAudioId();
            int listlength = list.length;
            boolean newlist = true;
            if (mPlayListLen == listlength) {
                // possible fast path: list might be the same
                newlist = false;
                for (int i = 0; i < listlength; i++) {
                    if (list[i] != mPlayList[i]) {
                        newlist = true;
                        break;
                    }
                }
            }
            if (newlist) {
                addToPlayList(list, -1);
                notifyChange(QUEUE_CHANGED);
            }
            int oldpos = mPlayPos;
            if (position >= 0) {
                mPlayPos = position;
            } else {
                mPlayPos = mRand.nextInt(mPlayListLen);
            }
            mHistory.clear();

            saveBookmarkIfNeeded();
            openCurrentAndNext();
            if (oldId != getAudioId()) {
                notifyChange(META_CHANGED);
            }
        }
    }
    
    /**
     * Moves the item at index1 to index2.
     * @param index1
     * @param index2
     */
    public void moveQueueItem(int index1, int index2) {
        synchronized (this) {
            if (index1 >= mPlayListLen) {
                index1 = mPlayListLen - 1;
            }
            if (index2 >= mPlayListLen) {
                index2 = mPlayListLen - 1;
            }
            if (index1 < index2) {
                long tmp = mPlayList[index1];
                for (int i = index1; i < index2; i++) {
                    mPlayList[i] = mPlayList[i+1];
                }
                mPlayList[index2] = tmp;
                if (mPlayPos == index1) {
                    mPlayPos = index2;
                } else if (mPlayPos >= index1 && mPlayPos <= index2) {
                        mPlayPos--;
                }
            } else if (index2 < index1) {
                long tmp = mPlayList[index1];
                for (int i = index1; i > index2; i--) {
                    mPlayList[i] = mPlayList[i-1];
                }
                mPlayList[index2] = tmp;
                if (mPlayPos == index1) {
                    mPlayPos = index2;
                } else if (mPlayPos >= index2 && mPlayPos <= index1) {
                        mPlayPos++;
                }
            }
            notifyChange(QUEUE_CHANGED);
        }
    }

    /**
     * Returns the current play list
     * @return An array of integers containing the IDs of the tracks in the play list
     */
    public long [] getQueue() {
        synchronized (this) {
            int len = mPlayListLen;
            long [] list = new long[len];
            for (int i = 0; i < len; i++) {
                list[i] = mPlayList[i];
            }
            return list;
        }
    }

    private Cursor getCursorForId(long lid) {
        String id = String.valueOf(lid);

        Cursor c = getContentResolver().query(
                MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                mCursorCols, "_id=" + id , null, null);
        if (c != null) {
            c.moveToFirst();
        }
        return c;
    }

    private void openCurrentAndNext() {
        synchronized (this) {
            if (mCursor != null) {
                mCursor.close();
                mCursor = null;
            }

            if (mPlayListLen == 0) {
                return;
            }
            stop(false);

            mCursor = getCursorForId(mPlayList[mPlayPos]);
            while(true) {
                if (mCursor != null && mCursor.getCount() != 0 &&
                        open(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI + "/" +
                                mCursor.getLong(IDCOLIDX))) {
                    break;
                }
                // if we get here then opening the file failed. We can close the cursor now, because
                // we're either going to create a new one next, or stop trying
                if (mCursor != null) {
                    mCursor.close();
                    mCursor = null;
                }
                if (mOpenFailedCounter++ < 10 &&  mPlayListLen > 1) {
                    int pos = getNextPosition(false);
                    if (pos < 0) {
                        gotoIdleState();
                        if (mIsSupposedToBePlaying) {
                            mIsSupposedToBePlaying = false;
                            notifyChange(PLAYSTATE_CHANGED);
                        }
                        return;
                    }
                    mPlayPos = pos;
                    stop(false);
                    mPlayPos = pos;
                    mCursor = getCursorForId(mPlayList[mPlayPos]);
                } else {
                    mOpenFailedCounter = 0;
                    if (!mQuietMode) {
                        Toast.makeText(this, R.string.playback_failed, Toast.LENGTH_SHORT).show();
                    }
                    Log.d(LOGTAG, "Failed to open file for playback");
                    gotoIdleState();
                    if (mIsSupposedToBePlaying) {
                        mIsSupposedToBePlaying = false;
                        notifyChange(PLAYSTATE_CHANGED);
                    }
                    return;
                }
            }

            // go to bookmark if needed
            if (isPodcast()) {
                long bookmark = getBookmark();
                // Start playing a little bit before the bookmark,
                // so it's easier to get back in to the narrative.
                seek(bookmark - 5000);
            }
            setNextTrack();
        }
    }

    private void setNextTrack() {
        mNextPlayPos = getNextPosition(false);
        if (mNextPlayPos >= 0) {
            long id = mPlayList[mNextPlayPos];
            mPlayer.setNextDataSource(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI + "/" + id);
        }
    }

    /**
     * Opens the specified file and readies it for playback.
     *
     * @param path The full path of the file to be opened.
     */
    public boolean open(String path) {
        synchronized (this) {
            if (path == null) {
                return false;
            }
            
            // if mCursor is null, try to associate path with a database cursor
            if (mCursor == null) {

                ContentResolver resolver = getContentResolver();
                Uri uri;
                String where;
                String selectionArgs[];
                if (path.startsWith("content://media/")) {
                    uri = Uri.parse(path);
                    where = null;
                    selectionArgs = null;
                } else {
                   uri = MediaStore.Audio.Media.getContentUriForPath(path);
                   where = MediaStore.Audio.Media.DATA + "=?";
                   selectionArgs = new String[] { path };
                }
                
                try {
                    mCursor = resolver.query(uri, mCursorCols, where, selectionArgs, null);
                    if  (mCursor != null) {
                        if (mCursor.getCount() == 0) {
                            mCursor.close();
                            mCursor = null;
                        } else {
                            mCursor.moveToNext();
                            ensurePlayListCapacity(1);
                            mPlayListLen = 1;
                            mPlayList[0] = mCursor.getLong(IDCOLIDX);
                            mPlayPos = 0;
                        }
                    }
                } catch (UnsupportedOperationException ex) {
                }
            }
            mFileToPlay = path;
            mPlayer.setDataSource(mFileToPlay);
            if (mPlayer.isInitialized()) {
                mOpenFailedCounter = 0;
                return true;
            }
            stop(true);
            return false;
        }
    }

    /**
     * Starts playback of a previously opened file.
     */
    public void play() {
        mAudioManager.requestAudioFocus(mAudioFocusListener, AudioManager.STREAM_MUSIC,
                AudioManager.AUDIOFOCUS_GAIN);
        mAudioManager.registerMediaButtonEventReceiver(new ComponentName(this.getPackageName(),
                MediaButtonIntentReceiver.class.getName()));

        if (mPlayer.isInitialized()) {
            // if we are at the end of the song, go to the next song first
            long duration = mPlayer.duration();
            if (mRepeatMode != REPEAT_CURRENT && duration > 2000 &&
                mPlayer.position() >= duration - 2000) {
                gotoNext(true);
            }

            mPlayer.start();
            // make sure we fade in, in case a previous fadein was stopped because
            // of another focus loss
            mMediaplayerHandler.removeMessages(FADEDOWN);
            mMediaplayerHandler.sendEmptyMessage(FADEUP);

            updateNotification();
            if (!mIsSupposedToBePlaying) {
                mIsSupposedToBePlaying = true;
                notifyChange(PLAYSTATE_CHANGED);
            }

        } else if (mPlayListLen <= 0) {
            // This is mostly so that if you press 'play' on a bluetooth headset
            // without every having played anything before, it will still play
            // something.
            setShuffleMode(SHUFFLE_AUTO);
        }
    }

    private void updateNotification() {
        RemoteViews views = new RemoteViews(getPackageName(), R.layout.statusbar);
        views.setImageViewResource(R.id.icon, R.drawable.stat_notify_musicplayer);
        if (getAudioId() < 0) {
            // streaming
            views.setTextViewText(R.id.trackname, getPath());
            views.setTextViewText(R.id.artistalbum, null);
        } else {
            String artist = getArtistName();
            views.setTextViewText(R.id.trackname, getTrackName());
            if (artist == null || artist.equals(MediaStore.UNKNOWN_STRING)) {
                artist = getString(R.string.unknown_artist_name);
            }
            String album = getAlbumName();
            if (album == null || album.equals(MediaStore.UNKNOWN_STRING)) {
                album = getString(R.string.unknown_album_name);
            }

            views.setTextViewText(R.id.artistalbum,
                    getString(R.string.notification_artist_album, artist, album)
                    );
        }
        Notification status = new Notification();
        status.contentView = views;
        status.flags |= Notification.FLAG_ONGOING_EVENT;
        status.icon = R.drawable.stat_notify_musicplayer;
        status.contentIntent = PendingIntent.getActivity(this, 0,
                new Intent("com.android.music.PLAYBACK_VIEWER")
                .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK), 0);
        startForeground(PLAYBACKSERVICE_STATUS, status);
    }

    private void stop(boolean remove_status_icon) {
        if (mPlayer.isInitialized()) {
            mPlayer.stop();
        }
        mFileToPlay = null;
        if (mCursor != null) {
            mCursor.close();
            mCursor = null;
        }
        if (remove_status_icon) {
            gotoIdleState();
        } else {
            stopForeground(false);
        }
        if (remove_status_icon) {
            mIsSupposedToBePlaying = false;
        }
    }

    /**
     * Stops playback.
     */
    public void stop() {
        stop(true);
    }

    /**
     * Pauses playback (call play() to resume)
     */
    public void pause() {
        synchronized(this) {
            mMediaplayerHandler.removeMessages(FADEUP);
            if (isPlaying()) {
                mPlayer.pause();
                gotoIdleState();
                mIsSupposedToBePlaying = false;
                notifyChange(PLAYSTATE_CHANGED);
                saveBookmarkIfNeeded();
            }
        }
    }

    /** Returns whether something is currently playing
     *
     * @return true if something is playing (or will be playing shortly, in case
     * we're currently transitioning between tracks), false if not.
     */
    public boolean isPlaying() {
        return mIsSupposedToBePlaying;
    }

    /*
      Desired behavior for prev/next/shuffle:

      - NEXT will move to the next track in the list when not shuffling, and to
        a track randomly picked from the not-yet-played tracks when shuffling.
        If all tracks have already been played, pick from the full