musicutils.java

Android平台上的media player, iPhone风格

                MediaStore.Audio.Media.DATA, MediaStore.Audio.Media.ALBUM_ID };
        StringBuilder where = new StringBuilder();
        where.append(MediaStore.Audio.Media._ID + " IN (");
        for (int i = 0; i < list.length; i++) {
            where.append(list[i]);
            if (i < list.length - 1) {
                where.append(",");
            }
        }
        where.append(")");
        Cursor c = query(context, MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, cols,
                where.toString(), null, null);

        if (c != null) {

            // step 1: remove selected tracks from the current playlist, as well
            // as from the album art cache
            try {
                c.moveToFirst();
                while (! c.isAfterLast()) {
                    // remove from current playlist
                    int id = c.getInt(0);
                    sService.removeTrack(id);
                    // remove from album art cache
                    int artIndex = c.getInt(2);
                    synchronized(sArtCache) {
                        sArtCache.remove(artIndex);
                    }
                    c.moveToNext();
                }
            } catch (RemoteException ex) {
            }

            // step 2: remove selected tracks from the database
            context.getContentResolver().delete(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, where.toString(), null);

            // step 3: remove files from card
            c.moveToFirst();
            while (! c.isAfterLast()) {
                String name = c.getString(1);
                File f = new File(name);
                try {  // File.delete can throw a security exception
                    if (!f.delete()) {
                        // I'm not sure if we'd ever get here (deletion would
                        // have to fail, but no exception thrown)
                        Log.e("MusicUtils", "Failed to delete file " + name);
                    }
                    c.moveToNext();
                } catch (SecurityException ex) {
                    c.moveToNext();
                }
            }
//            c.commitUpdates();
            c.close();
        }

        String message = context.getResources().getQuantityString(
                R.plurals.NNNtracksdeleted, list.length, Integer.valueOf(list.length));
        
        Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
        // We deleted a number of tracks, which could affect any number of things
        // in the media content domain, so update everything.
        context.getContentResolver().notifyChange(Uri.parse("content://media"), null);
    }
    
    public static void addToCurrentPlaylist(Context context, int [] list) {
        if (sService == null) {
            return;
        }
        try {
            sService.enqueue(list, MediaPlaybackService.LAST);
            String message = context.getResources().getQuantityString(
                    R.plurals.NNNtrackstoplaylist, list.length, Integer.valueOf(list.length));
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
        } catch (RemoteException ex) {
        }
    }
    
    public static void addToPlaylist(Context context, int [] ids, long playlistid) {
        if (ids == null) {
            // this shouldn't happen (the menuitems shouldn't be visible
            // unless the selected item represents something playable
            Log.e("MusicBase", "ListSelection null");
        } else {
            int size = ids.length;
            ContentValues values [] = new ContentValues[size];
            ContentResolver resolver = context.getContentResolver();
            // need to determine the number of items currently in the playlist,
            // so the play_order field can be maintained.
            String[] cols = new String[] {
                    "count(*)"
            };
            Uri uri = MediaStore.Audio.Playlists.Members.getContentUri("external", playlistid);
            Cursor cur = resolver.query(uri, cols, null, null, null);
            cur.moveToFirst();
            int base = cur.getInt(0);
            cur.close();

            for (int i = 0; i < size; i++) {
                values[i] = new ContentValues();
                values[i].put(MediaStore.Audio.Playlists.Members.PLAY_ORDER, Integer.valueOf(base + i));
                values[i].put(MediaStore.Audio.Playlists.Members.AUDIO_ID, ids[i]);
            }
            resolver.bulkInsert(uri, values);
            String message = context.getResources().getQuantityString(
                    R.plurals.NNNtrackstoplaylist, size, Integer.valueOf(size));
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
            //mLastPlaylistSelected = playlistid;
        }
    }

    public static Cursor query(Context context, Uri uri, String[] projection,
            String selection, String[] selectionArgs, String sortOrder) {
        try {
            ContentResolver resolver = context.getContentResolver();
            if (resolver == null) {
                return null;
            }
            return resolver.query(uri, projection, selection, selectionArgs, sortOrder);
         } catch (UnsupportedOperationException ex) {
            return null;
        }
        
    }
    
    public static boolean isMediaScannerScanning(Context context) {
        boolean result = false;
        Uri uri = MediaStore.getMediaScannerUri();
        Cursor cursor = query(context, MediaStore.getMediaScannerUri(), 
                new String [] { MediaStore.MEDIA_SCANNER_VOLUME }, null, null, null);
        if (cursor != null) {
            if (cursor.getCount() == 1) {
                cursor.moveToFirst();
                result = "external".equals(cursor.getString(0));
            }
            cursor.close(); 
        } 

        return result;
    }
    
    public static void setSpinnerState(Activity a) {
        if (isMediaScannerScanning(a)) {
            // start the progress spinner
            a.getWindow().setFeatureInt(
                    Window.FEATURE_INDETERMINATE_PROGRESS,
                    Window.PROGRESS_INDETERMINATE_ON);

            a.getWindow().setFeatureInt(
                    Window.FEATURE_INDETERMINATE_PROGRESS,
                    Window.PROGRESS_VISIBILITY_ON);
        } else {
            // stop the progress spinner
            a.getWindow().setFeatureInt(
                    Window.FEATURE_INDETERMINATE_PROGRESS,
                    Window.PROGRESS_VISIBILITY_OFF);
        }
    }
    
    public static void displayDatabaseError(Activity a) {
        String status = Environment.getExternalStorageState();
        int title = R.string.sdcard_error_title;
        int message = R.string.sdcard_error_message;
        
        if (status.equals(Environment.MEDIA_SHARED)) {
            title = R.string.sdcard_busy_title;
            message = R.string.sdcard_busy_message;
        } else if (status.equals(Environment.MEDIA_REMOVED)) {
            title = R.string.sdcard_missing_title;
            message = R.string.sdcard_missing_message;
        } else if (status.equals(Environment.MEDIA_MOUNTED)){
            // The card is mounted, but we didn't get a valid cursor.
            // This probably means the mediascanner hasn't started scanning the
            // card yet (there is a small window of time during boot where this
            // will happen).
            a.setTitle("");
            Intent intent = new Intent();
            intent.setClass(a, ScanningProgress.class);
            a.startActivityForResult(intent, Defs.SCAN_DONE);
        } else {
            Log.d(TAG, "sd card: " + status);
        }

        a.setTitle(title);
        if (a instanceof ExpandableListActivity) {
            a.setContentView(R.layout.no_sd_card_expanding);
        } else {
            a.setContentView(R.layout.no_sd_card);
        }
        TextView tv = (TextView) a.findViewById(R.id.sd_message);
        tv.setText(message);
    }

    static protected Uri getContentURIForPath(String path) {
        return Uri.fromFile(new File(path));
    }

    
    /*  Try to use String.format() as little as possible, because it creates a
     *  new Formatter every time you call it, which is very inefficient.
     *  Reusing an existing Formatter more than tripled the speed of
     *  makeTimeString().
     *  This Formatter/StringBuilder are also used by makeAlbumSongsLabel()
     */
    private static StringBuilder sFormatBuilder = new StringBuilder();
    private static Formatter sFormatter = new Formatter(sFormatBuilder, Locale.getDefault());
    private static final Object[] sTimeArgs = new Object[5];

    public static String makeTimeString(Context context, long secs) {
        String durationformat = context.getString(R.string.durationformat);
        
        /* Provide multiple arguments so the format can be changed easily
         * by modifying the xml.
         */
        sFormatBuilder.setLength(0);

        final Object[] timeArgs = sTimeArgs;
        timeArgs[0] = secs / 3600;
        timeArgs[1] = secs / 60;
        timeArgs[2] = (secs / 60) % 60;
        timeArgs[3] = secs;
        timeArgs[4] = secs % 60;

        return sFormatter.format(durationformat, timeArgs).toString();
    }
    
    public static void shuffleAll(Context context, Cursor cursor) {
        playAll(context, cursor, 0, true);
    }

    public static void playAll(Context context, Cursor cursor) {
        playAll(context, cursor, 0, false);
    }
    
    public static void playAll(Context context, Cursor cursor, int position) {
        playAll(context, cursor, position, false);
    }
    
    public static void playAll(Context context, int [] list, int position) {
        playAll(context, list, position, false);
    }
    
    private static void playAll(Context context, Cursor cursor, int position, boolean force_shuffle) {
    
        int [] list = getSongListForCursor(cursor);
        playAll(context, list, position, force_shuffle);
    }
    
    private static void playAll(Context context, int [] list, int position, boolean force_shuffle) {
        if (list.length == 0 || sService == null) {
            Log.d("MusicUtils", "attempt to play empty song list");
            // Don't try to play empty playlists. Nothing good will come of it.
            String message = context.getString(R.string.emptyplaylist, list.length);
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
            return;
        }
        try {
            if (force_shuffle) {
                sService.setShuffleMode(MediaPlaybackService.SHUFFLE_NORMAL);
            }
            int curid = sService.getAudioId();
            int curpos = sService.getQueuePosition();
            if (position != -1 && curpos == position && curid == list[position]) {
                // The selected file is the file that's currently playing;
                // figure out if we need to restart with a new playlist,
                // or just launch the playback activity.
                int [] playlist = sService.getQueue();
                if (Arrays.equals(list, playlist)) {
                    // we don't need to set a new list, but we should resume playback if needed
                    sService.play();
                    return; // the 'finally' block will still run
                }
            }
            if (position < 0) {
                position = 0;
            }
            sService.open(list, position);
            sService.play();
        } catch (RemoteException ex) {
        } finally {
            Intent intent = new Intent("com.android.imusic.playing")
                .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            context.startActivity(intent);
        }
    }
    
    public static void clearQueue() {
        try {
            sService.removeTracks(0, Integer.MAX_VALUE);
        } catch (RemoteException ex) {
        }
    }
    
    // A really simple BitmapDrawable-like class, that doesn't do
    // scaling, dithering or filtering.
    private static class FastBitmapDrawable extends Drawable {
        private Bitmap mBitmap;
        public FastBitmapDrawable(Bitmap b) {
            mBitmap = b;
        }
        @Override
        public void draw(Canvas canvas) {
            canvas.drawBitmap(mBitmap, 0, 0, null);
        }
        @Override
        public int getOpacity() {
            return PixelFormat.OPAQUE;
        }
        @Override
        public void setAlpha(int alpha) {
        }
        @Override
        public void setColorFilter(ColorFilter cf) {
        }
    }
    
    private static int sArtId = -2;
    private static byte [] mCachedArt;
    private static Bitmap mCachedBit = null;
    private static final BitmapFactory.Options sBitmapOptionsCache = new BitmapFactory.Options();
    private static final BitmapFactory.Options sBitmapOptions = new BitmapFactory.Options();
    private static final Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");
    private static final HashMap<Integer, Drawable> sArtCache = new HashMap<Integer, Drawable>();
    private static int sArtCacheId = -1;
    
    static {
        // for the cache, 
        // 565 is faster to decode and display
        // and we don't want to dither here because the image will be scaled down later
        sBitmapOptionsCache.inPreferredConfig = Bitmap.Config.RGB_565;
        sBitmapOptionsCache.inDither = false;

        sBitmapOptions.inPreferredConfig = Bitmap.Config.RGB_565;
        sBitmapOptions.inDither = false;
    }

    public static void initAlbumArtCache() {
        try {
            int id = sService.getMediaMountedCount();
            if (id != sArtCacheId) {
                clearAlbumArtCache();
                sArtCacheId = id; 
            }
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    public static void clearAlbumArtCache() {
        synchronized(sArtCache) {
            sArtCache.clear();
        }
    }
    
    public static Drawable getCachedArtwork(Context context, int artIndex, BitmapDrawable defaultArtwork) {
        Drawable d = null;
        synchronized(sArtCache) {
            d = sArtCache.get(artIndex);
        }
        if (d == null) {
            d = defaultArtwork;
            final Bitmap icon = defaultArtwork.getBitmap();
            int w = icon.getWidth();
            int h = icon.getHeight();
            Bitmap b = MusicUtils.getArtworkQuick(context, artIndex, w, h);
            if (b != null) {
                d = new FastBitmapDrawable(b);
                synchronized(sArtCache) {
                    // the cache may have changed since we checked
                    Drawable value = sArtCache.get(artIndex);
                    if (value == null) {
                        sArtCache.put(artIndex, d);
                    } else {
                        d = value;
                    }
                }