mediaplaybackservice.java

来自「Android平台上的media player, iPhone风格」· Java 代码 · 共 1,619 行 · 第 1/4 页

            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_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 void onStart(Intent intent, int startId) {
        mServiceStartId = startId;
        mDelayedStopHandler.removeCallbacksAndMessages(null);
        String cmd = intent.getStringExtra("command");
        if (CMDNEXT.equals(cmd)) {
            next(true);
        } else if (CMDTOGGLEPAUSE.equals(cmd)) {
            if (isPlaying()) {
                pause();
            } else {
                play();
            }
        } else if (CMDPAUSE.equals(cmd)) {
            pause();
        }
        // 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);
    }
    
    @Override
    public boolean onUnbind(Intent intent) {
        mServiceInUse = false;

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

        if (isPlaying() || mResumeAfterCall) {
            // something is currently playing, or will be playing once 
            // an in-progress call 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() || mResumeAfterCall || mServiceInUse
                    || mMediaplayerHandler.hasMessages(TRACK_ENDED)) {
                return;
            }
            // save the queue again, because it might have change
            // 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);
                        mOneShot = true; // This makes us not save the state again later,
                                         // which would be wrong because the song ids and
                                         // card id might not match. 
                        closeExternalStorageFiles(intent.getData().getPath());
                    } else if (action.equals(Intent.ACTION_MEDIA_MOUNTED)) {
                        mMediaMountedCount++;
                        mCardId = FileUtils.getFatVolumeId(intent.getData().getPath());
                        reloadQueue();
                        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.imusic.metachanged"
     * "com.android.imusic.queuechanged",
     * "com.android.imusic.playbackcomplete"
     * "com.android.imusic.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", Integer.valueOf(getAudioId()));
        i.putExtra("artist", getArtistName());
        i.putExtra("album",getAlbumName());
        i.putExtra("track", getTrackName());
        sendBroadcast(i);
        
        if (what.equals(QUEUE_CHANGED)) {
            saveQueue(true);
        } else {
            saveQueue(false);
        }
    }

    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
            int [] newlist = new int[size * 2];
            int len = 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
    }
    
    private void addToPlayList(int id) {
        synchronized(this) {
            ensurePlayListCapacity(mPlayListLen + 1);
            mPlayList[mPlayListLen++] = id;
        }
    }
    
    private void addToPlayList(int [] 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;
    }
    
    /**
     * 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(int [] 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;
                    openCurrent();
                    play();
                    notifyChange(META_CHANGED);
                    return;
                }
            }
            if (mPlayPos < 0) {
                mPlayPos = 0;
                openCurrent();
                play();
                notifyChange(META_CHANGED);
            }
        }
    }

    /**
     * Replaces the current playlist with a new list,
     * and prepares for starting playback at the specified
     * position in the list.
     * @param list The new list of tracks.
     */
    public void open(int [] list, int position) {
        synchronized (this) {
            if (mShuffleMode == SHUFFLE_AUTO) {
                mShuffleMode = SHUFFLE_NORMAL;
            }
            addToPlayList(list, -1);
            mPlayPos = position;
            mHistory.clear();

            openCurrent();
        }
    }
    
    /**
     * 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) {
                int 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) {
                int 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 int [] getQueue() {
        synchronized (this) {
            int len = mPlayListLen;
            int [] list = new int[len];
            for (int i = 0; i < len; i++) {
                list[i] = mPlayList[i];
            }
            return list;
        }
    }

    private void openCurrent() {
        synchronized (this) {
            if (mCursor != null) {
                mCursor.close();
                mCursor = null;
            }
            if (mPlayListLen == 0) {
                return;
            }
            stop(false);

            String id = String.valueOf(mPlayList[mPlayPos]);
            
            mCursor = getContentResolver().query(
                    MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                    mCursorCols, "_id=" + id , null, null);
            if (mCursor != null) {
                mCursor.moveToFirst();
                open(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI + "/" + id, false);
            }
        }
    }

    public void openAsync(String path) {
        synchronized (this) {
            if (path == null) {
                return;
            }
            
            mRepeatMode = REPEAT_NONE;
            ensurePlayListCapacity(1);
            mPlayListLen = 1;
            mPlayPos = -1;
            
            mFileToPlay = path;
            mCursor = null;
            mPlayer.setDataSourceAsync(mFileToPlay);
            mOneShot = true;
        }
    }
    
    /**
     * Opens the specified file and readies it for playback.
     *
     * @param path The full path of the file to be opened.
     * @param oneshot when set to true, playback will stop after this file completes, instead
     * of moving on to the next track in the list 
     */
    public void open(String path, boolean oneshot) {
        synchronized (this) {
            if (path == null) {
                return;
            }
            
            if (oneshot) {
                mRepeatMode = REPEAT_NONE;
                ensurePlayListCapacity(1);
                mPlayListLen = 1;
                mPlayPos = -1;
            }
            
            // 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);