1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.music;
18 
19 import android.app.ListActivity;
20 import android.content.AsyncQueryHandler;
21 import android.content.ContentUris;
22 import android.content.Context;
23 import android.content.Intent;
24 import android.database.CharArrayBuffer;
25 import android.database.Cursor;
26 import android.media.AudioManager;
27 import android.media.MediaPlayer;
28 import android.media.RingtoneManager;
29 import android.net.Uri;
30 import android.os.Bundle;
31 import android.os.Parcelable;
32 import android.provider.MediaStore;
33 import android.text.TextUtils;
34 import android.util.Log;
35 import android.view.Menu;
36 import android.view.MenuItem;
37 import android.view.View;
38 import android.view.ViewGroup;
39 import android.view.Window;
40 import android.view.animation.AnimationUtils;
41 import android.widget.ImageView;
42 import android.widget.ListView;
43 import android.widget.RadioButton;
44 import android.widget.SectionIndexer;
45 import android.widget.SimpleCursorAdapter;
46 import android.widget.TextView;
47 
48 import java.io.IOException;
49 import java.text.Collator;
50 import java.util.Formatter;
51 import java.util.Locale;
52 
53 /**
54  * Activity allowing the user to select a music track on the device, and
55  * return it to its caller.  The music picker user interface is fairly
56  * extensive, providing information about each track like the music
57  * application (title, author, album, duration), as well as the ability to
58  * previous tracks and sort them in different orders.
59  *
60  * <p>This class also illustrates how you can load data from a content
61  * provider asynchronously, providing a good UI while doing so, perform
62  * indexing of the content for use inside of a {@link FastScrollView}, and
63  * perform filtering of the data as the user presses keys.
64  */
65 public class MusicPicker extends ListActivity
66         implements View.OnClickListener, MediaPlayer.OnCompletionListener,
67         MusicUtils.Defs {
68     static final boolean DBG = false;
69     static final String TAG = "MusicPicker";
70 
71     /** Holds the previous state of the list, to restore after the async
72      * query has completed. */
73     static final String LIST_STATE_KEY = "liststate";
74     /** Remember whether the list last had focus for restoring its state. */
75     static final String FOCUS_KEY = "focused";
76     /** Remember the last ordering mode for restoring state. */
77     static final String SORT_MODE_KEY = "sortMode";
78 
79     /** Arbitrary number, doesn't matter since we only do one query type. */
80     static final int MY_QUERY_TOKEN = 42;
81 
82     /** Menu item to sort the music list by track title. */
83     static final int TRACK_MENU = Menu.FIRST;
84     /** Menu item to sort the music list by album title. */
85     static final int ALBUM_MENU = Menu.FIRST+1;
86     /** Menu item to sort the music list by artist name. */
87     static final int ARTIST_MENU = Menu.FIRST+2;
88 
89     /** These are the columns in the music cursor that we are interested in. */
90     static final String[] CURSOR_COLS = new String[] {
91             MediaStore.Audio.Media._ID,
92             MediaStore.Audio.Media.TITLE,
93             MediaStore.Audio.Media.TITLE_KEY,
94             MediaStore.Audio.Media.DATA,
95             MediaStore.Audio.Media.ALBUM,
96             MediaStore.Audio.Media.ARTIST,
97             MediaStore.Audio.Media.ARTIST_ID,
98             MediaStore.Audio.Media.DURATION,
99             MediaStore.Audio.Media.TRACK
100     };
101 
102     /** Formatting optimization to avoid creating many temporary objects. */
103     static StringBuilder sFormatBuilder = new StringBuilder();
104     /** Formatting optimization to avoid creating many temporary objects. */
105     static Formatter sFormatter = new Formatter(sFormatBuilder, Locale.getDefault());
106     /** Formatting optimization to avoid creating many temporary objects. */
107     static final Object[] sTimeArgs = new Object[5];
108 
109     /** Uri to the directory of all music being displayed. */
110     Uri mBaseUri;
111 
112     /** This is the adapter used to display all of the tracks. */
113     TrackListAdapter mAdapter;
114     /** Our instance of QueryHandler used to perform async background queries. */
115     QueryHandler mQueryHandler;
116 
117     /** Used to keep track of the last scroll state of the list. */
118     Parcelable mListState = null;
119     /** Used to keep track of whether the list last had focus. */
120     boolean mListHasFocus;
121 
122     /** The current cursor on the music that is being displayed. */
123     Cursor mCursor;
124     /** The actual sort order the user has selected. */
125     int mSortMode = -1;
126     /** SQL order by string describing the currently selected sort order. */
127     String mSortOrder;
128 
129     /** Container of the in-screen progress indicator, to be able to hide it
130      * when done loading the initial cursor. */
131     View mProgressContainer;
132     /** Container of the list view hierarchy, to be able to show it when done
133      * loading the initial cursor. */
134     View mListContainer;
135     /** Set to true when the list view has been shown for the first time. */
136     boolean mListShown;
137 
138     /** View holding the okay button. */
139     View mOkayButton;
140     /** View holding the cancel button. */
141     View mCancelButton;
142 
143     /** Which track row ID the user has last selected. */
144     long mSelectedId = -1;
145     /** Completel Uri that the user has last selected. */
146     Uri mSelectedUri;
147 
148     /** If >= 0, we are currently playing a track for preview, and this is its
149      * row ID. */
150     long mPlayingId = -1;
151 
152     /** This is used for playing previews of the music files. */
153     MediaPlayer mMediaPlayer;
154 
155     /**
156      * A special implementation of SimpleCursorAdapter that knows how to bind
157      * our cursor data to our list item structure, and takes care of other
158      * advanced features such as indexing and filtering.
159      */
160     class TrackListAdapter extends SimpleCursorAdapter
161             implements SectionIndexer {
162         final ListView mListView;
163 
164         private final StringBuilder mBuilder = new StringBuilder();
165         private final String mUnknownArtist;
166         private final String mUnknownAlbum;
167 
168         private int mIdIdx;
169         private int mTitleIdx;
170         private int mArtistIdx;
171         private int mAlbumIdx;
172         private int mDurationIdx;
173 
174         private boolean mLoading = true;
175         private int mIndexerSortMode;
176         private MusicAlphabetIndexer mIndexer;
177 
178         class ViewHolder {
179             TextView line1;
180             TextView line2;
181             TextView duration;
182             RadioButton radio;
183             ImageView play_indicator;
184             CharArrayBuffer buffer1;
185             char [] buffer2;
186         }
187 
TrackListAdapter(Context context, ListView listView, int layout, String[] from, int[] to)188         TrackListAdapter(Context context, ListView listView, int layout,
189                 String[] from, int[] to) {
190             super(context, layout, null, from, to);
191             mListView = listView;
192             mUnknownArtist = context.getString(R.string.unknown_artist_name);
193             mUnknownAlbum = context.getString(R.string.unknown_album_name);
194         }
195 
196         /**
197          * The mLoading flag is set while we are performing a background
198          * query, to avoid displaying the "No music" empty view during
199          * this time.
200          */
setLoading(boolean loading)201         public void setLoading(boolean loading) {
202             mLoading = loading;
203         }
204 
205         @Override
isEmpty()206         public boolean isEmpty() {
207             if (mLoading) {
208                 // We don't want the empty state to show when loading.
209                 return false;
210             } else {
211                 return super.isEmpty();
212             }
213         }
214 
215         @Override
newView(Context context, Cursor cursor, ViewGroup parent)216         public View newView(Context context, Cursor cursor, ViewGroup parent) {
217             View v = super.newView(context, cursor, parent);
218             ViewHolder vh = new ViewHolder();
219             vh.line1 = (TextView) v.findViewById(R.id.line1);
220             vh.line2 = (TextView) v.findViewById(R.id.line2);
221             vh.duration = (TextView) v.findViewById(R.id.duration);
222             vh.radio = (RadioButton) v.findViewById(R.id.radio);
223             vh.play_indicator = (ImageView) v.findViewById(R.id.play_indicator);
224             vh.buffer1 = new CharArrayBuffer(100);
225             vh.buffer2 = new char[200];
226             v.setTag(vh);
227             return v;
228         }
229 
230         @Override
bindView(View view, Context context, Cursor cursor)231         public void bindView(View view, Context context, Cursor cursor) {
232             ViewHolder vh = (ViewHolder) view.getTag();
233 
234             cursor.copyStringToBuffer(mTitleIdx, vh.buffer1);
235             vh.line1.setText(vh.buffer1.data, 0, vh.buffer1.sizeCopied);
236 
237             int secs = cursor.getInt(mDurationIdx) / 1000;
238             if (secs == 0) {
239                 vh.duration.setText("");
240             } else {
241                 vh.duration.setText(MusicUtils.makeTimeString(context, secs));
242             }
243 
244             final StringBuilder builder = mBuilder;
245             builder.delete(0, builder.length());
246 
247             String name = cursor.getString(mAlbumIdx);
248             if (name == null || name.equals("<unknown>")) {
249                 builder.append(mUnknownAlbum);
250             } else {
251                 builder.append(name);
252             }
253             builder.append('\n');
254             name = cursor.getString(mArtistIdx);
255             if (name == null || name.equals("<unknown>")) {
256                 builder.append(mUnknownArtist);
257             } else {
258                 builder.append(name);
259             }
260             int len = builder.length();
261             if (vh.buffer2.length < len) {
262                 vh.buffer2 = new char[len];
263             }
264             builder.getChars(0, len, vh.buffer2, 0);
265             vh.line2.setText(vh.buffer2, 0, len);
266 
267             // Update the checkbox of the item, based on which the user last
268             // selected.  Note that doing it this way means we must have the
269             // list view update all of its items when the selected item
270             // changes.
271             final long id = cursor.getLong(mIdIdx);
272             vh.radio.setChecked(id == mSelectedId);
273             if (DBG) Log.v(TAG, "Binding id=" + id + " sel=" + mSelectedId
274                     + " playing=" + mPlayingId + " cursor=" + cursor);
275 
276             // Likewise, display the "now playing" icon if this item is
277             // currently being previewed for the user.
278             ImageView iv = vh.play_indicator;
279             if (id == mPlayingId) {
280                 iv.setImageResource(R.drawable.indicator_ic_mp_playing_list);
281                 iv.setVisibility(View.VISIBLE);
282             } else {
283                 iv.setVisibility(View.GONE);
284             }
285         }
286 
287         /**
288          * This method is called whenever we receive a new cursor due to
289          * an async query, and must take care of plugging the new one in
290          * to the adapter.
291          */
292         @Override
changeCursor(Cursor cursor)293         public void changeCursor(Cursor cursor) {
294             super.changeCursor(cursor);
295             if (DBG) Log.v(TAG, "Setting cursor to: " + cursor
296                     + " from: " + MusicPicker.this.mCursor);
297 
298             MusicPicker.this.mCursor = cursor;
299 
300             if (cursor != null) {
301                 // Retrieve indices of the various columns we are interested in.
302                 mIdIdx = cursor.getColumnIndex(MediaStore.Audio.Media._ID);
303                 mTitleIdx = cursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
304                 mArtistIdx = cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);
305                 mAlbumIdx = cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM);
306                 mDurationIdx = cursor.getColumnIndex(MediaStore.Audio.Media.DURATION);
307 
308                 // If the sort mode has changed, or we haven't yet created an
309                 // indexer one, then create a new one that is indexing the
310                 // appropriate column based on the sort mode.
311                 if (mIndexerSortMode != mSortMode || mIndexer == null) {
312                     mIndexerSortMode = mSortMode;
313                     int idx = mTitleIdx;
314                     switch (mIndexerSortMode) {
315                         case ARTIST_MENU:
316                             idx = mArtistIdx;
317                             break;
318                         case ALBUM_MENU:
319                             idx = mAlbumIdx;
320                             break;
321                     }
322                     mIndexer = new MusicAlphabetIndexer(cursor, idx,
323                             getResources().getString(R.string.fast_scroll_alphabet));
324 
325                 // If we have a valid indexer, but the cursor has changed since
326                 // its last use, then point it to the current cursor.
327                 } else {
328                     mIndexer.setCursor(cursor);
329                 }
330             }
331 
332             // Ensure that the list is shown (and initial progress indicator
333             // hidden) in case this is the first cursor we have gotten.
334             makeListShown();
335         }
336 
337         /**
338          * This method is called from a background thread by the list view
339          * when the user has typed a letter that should result in a filtering
340          * of the displayed items.  It returns a Cursor, when will then be
341          * handed to changeCursor.
342          */
343         @Override
runQueryOnBackgroundThread(CharSequence constraint)344         public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
345             if (DBG) Log.v(TAG, "Getting new cursor...");
346             return doQuery(true, constraint.toString());
347         }
348 
getPositionForSection(int section)349         public int getPositionForSection(int section) {
350             Cursor cursor = getCursor();
351             if (cursor == null) {
352                 // No cursor, the section doesn't exist so just return 0
353                 return 0;
354             }
355 
356             return mIndexer.getPositionForSection(section);
357         }
358 
getSectionForPosition(int position)359         public int getSectionForPosition(int position) {
360             return 0;
361         }
362 
getSections()363         public Object[] getSections() {
364             if (mIndexer != null) {
365                 return mIndexer.getSections();
366             }
367             return null;
368         }
369     }
370 
371     /**
372      * This is our specialization of AsyncQueryHandler applies new cursors
373      * to our state as they become available.
374      */
375     private final class QueryHandler extends AsyncQueryHandler {
QueryHandler(Context context)376         public QueryHandler(Context context) {
377             super(context.getContentResolver());
378         }
379 
380         @Override
onQueryComplete(int token, Object cookie, Cursor cursor)381         protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
382             if (!isFinishing()) {
383                 // Update the adapter: we are no longer loading, and have
384                 // a new cursor for it.
385                 mAdapter.setLoading(false);
386                 mAdapter.changeCursor(cursor);
387                 setProgressBarIndeterminateVisibility(false);
388 
389                 // Now that the cursor is populated again, it's possible to restore the list state
390                 if (mListState != null) {
391                     getListView().onRestoreInstanceState(mListState);
392                     if (mListHasFocus) {
393                         getListView().requestFocus();
394                     }
395                     mListHasFocus = false;
396                     mListState = null;
397                 }
398             } else {
399                 cursor.close();
400             }
401         }
402     }
403 
404     /** Called when the activity is first created. */
405     @Override
onCreate(Bundle icicle)406     public void onCreate(Bundle icicle) {
407         super.onCreate(icicle);
408 
409         requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
410 
411         int sortMode = TRACK_MENU;
412         if (icicle == null) {
413             mSelectedUri = getIntent().getParcelableExtra(
414                     RingtoneManager.EXTRA_RINGTONE_EXISTING_URI);
415         } else {
416             mSelectedUri = (Uri)icicle.getParcelable(
417                     RingtoneManager.EXTRA_RINGTONE_EXISTING_URI);
418             // Retrieve list state. This will be applied after the
419             // QueryHandler has run
420             mListState = icicle.getParcelable(LIST_STATE_KEY);
421             mListHasFocus = icicle.getBoolean(FOCUS_KEY);
422             sortMode = icicle.getInt(SORT_MODE_KEY, sortMode);
423         }
424         if (Intent.ACTION_GET_CONTENT.equals(getIntent().getAction())) {
425             mBaseUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
426         } else {
427             mBaseUri = getIntent().getData();
428             if (mBaseUri == null) {
429                 Log.w("MusicPicker", "No data URI given to PICK action");
430                 finish();
431                 return;
432             }
433         }
434 
435         setContentView(R.layout.music_picker);
436 
437         mSortOrder = MediaStore.Audio.Media.TITLE_KEY;
438 
439         final ListView listView = getListView();
440 
441         listView.setItemsCanFocus(false);
442 
443         mAdapter = new TrackListAdapter(this, listView,
444                 R.layout.music_picker_item, new String[] {},
445                 new int[] {});
446 
447         setListAdapter(mAdapter);
448 
449         listView.setTextFilterEnabled(true);
450 
451         // We manually save/restore the listview state
452         listView.setSaveEnabled(false);
453 
454         mQueryHandler = new QueryHandler(this);
455 
456         mProgressContainer = findViewById(R.id.progressContainer);
457         mListContainer = findViewById(R.id.listContainer);
458 
459         mOkayButton = findViewById(R.id.okayButton);
460         mOkayButton.setOnClickListener(this);
461         mCancelButton = findViewById(R.id.cancelButton);
462         mCancelButton.setOnClickListener(this);
463 
464         // If there is a currently selected Uri, then try to determine who
465         // it is.
466         if (mSelectedUri != null) {
467             Uri.Builder builder = mSelectedUri.buildUpon();
468             String path = mSelectedUri.getEncodedPath();
469             int idx = path.lastIndexOf('/');
470             if (idx >= 0) {
471                 path = path.substring(0, idx);
472             }
473             builder.encodedPath(path);
474             Uri baseSelectedUri = builder.build();
475             if (DBG) Log.v(TAG, "Selected Uri: " + mSelectedUri);
476             if (DBG) Log.v(TAG, "Selected base Uri: " + baseSelectedUri);
477             if (DBG) Log.v(TAG, "Base Uri: " + mBaseUri);
478             if (baseSelectedUri.equals(mBaseUri)) {
479                 // If the base Uri of the selected Uri is the same as our
480                 // content's base Uri, then use the selection!
481                 mSelectedId = ContentUris.parseId(mSelectedUri);
482             }
483         }
484 
485         setSortMode(sortMode);
486     }
487 
onRestart()488     @Override public void onRestart() {
489         super.onRestart();
490         doQuery(false, null);
491     }
492 
onOptionsItemSelected(MenuItem item)493     @Override public boolean onOptionsItemSelected(MenuItem item) {
494         if (setSortMode(item.getItemId())) {
495             return true;
496         }
497         return super.onOptionsItemSelected(item);
498     }
499 
onCreateOptionsMenu(Menu menu)500     @Override public boolean onCreateOptionsMenu(Menu menu) {
501         super.onCreateOptionsMenu(menu);
502         menu.add(Menu.NONE, TRACK_MENU, Menu.NONE, R.string.sort_by_track);
503         menu.add(Menu.NONE, ALBUM_MENU, Menu.NONE, R.string.sort_by_album);
504         menu.add(Menu.NONE, ARTIST_MENU, Menu.NONE, R.string.sort_by_artist);
505         return true;
506     }
507 
onSaveInstanceState(Bundle icicle)508     @Override protected void onSaveInstanceState(Bundle icicle) {
509         super.onSaveInstanceState(icicle);
510         // Save list state in the bundle so we can restore it after the
511         // QueryHandler has run
512         icicle.putParcelable(LIST_STATE_KEY, getListView().onSaveInstanceState());
513         icicle.putBoolean(FOCUS_KEY, getListView().hasFocus());
514         icicle.putInt(SORT_MODE_KEY, mSortMode);
515     }
516 
onPause()517     @Override public void onPause() {
518         super.onPause();
519         stopMediaPlayer();
520     }
521 
onStop()522     @Override public void onStop() {
523         super.onStop();
524 
525         // We don't want the list to display the empty state, since when we
526         // resume it will still be there and show up while the new query is
527         // happening. After the async query finishes in response to onResume()
528         // setLoading(false) will be called.
529         mAdapter.setLoading(true);
530         mAdapter.changeCursor(null);
531     }
532 
533     /**
534      * Changes the current sort order, building the appropriate query string
535      * for the selected order.
536      */
setSortMode(int sortMode)537     boolean setSortMode(int sortMode) {
538         if (sortMode != mSortMode) {
539             switch (sortMode) {
540                 case TRACK_MENU:
541                     mSortMode = sortMode;
542                     mSortOrder = MediaStore.Audio.Media.TITLE_KEY;
543                     doQuery(false, null);
544                     return true;
545                 case ALBUM_MENU:
546                     mSortMode = sortMode;
547                     mSortOrder = MediaStore.Audio.Media.ALBUM_KEY + " ASC, "
548                             + MediaStore.Audio.Media.TRACK + " ASC, "
549                             + MediaStore.Audio.Media.TITLE_KEY + " ASC";
550                     doQuery(false, null);
551                     return true;
552                 case ARTIST_MENU:
553                     mSortMode = sortMode;
554                     mSortOrder = MediaStore.Audio.Media.ARTIST_KEY + " ASC, "
555                             + MediaStore.Audio.Media.ALBUM_KEY + " ASC, "
556                             + MediaStore.Audio.Media.TRACK + " ASC, "
557                             + MediaStore.Audio.Media.TITLE_KEY + " ASC";
558                     doQuery(false, null);
559                     return true;
560             }
561 
562         }
563         return false;
564     }
565 
566     /**
567      * The first time this is called, we hide the large progress indicator
568      * and show the list view, doing fade animations between them.
569      */
makeListShown()570     void makeListShown() {
571         if (!mListShown) {
572             mListShown = true;
573             mProgressContainer.startAnimation(AnimationUtils.loadAnimation(
574                     this, android.R.anim.fade_out));
575             mProgressContainer.setVisibility(View.GONE);
576             mListContainer.startAnimation(AnimationUtils.loadAnimation(
577                     this, android.R.anim.fade_in));
578             mListContainer.setVisibility(View.VISIBLE);
579         }
580     }
581 
582     /**
583      * Common method for performing a query of the music database, called for
584      * both top-level queries and filtering.
585      *
586      * @param sync If true, this query should be done synchronously and the
587      * resulting cursor returned.  If false, it will be done asynchronously and
588      * null returned.
589      * @param filterstring If non-null, this is a filter to apply to the query.
590      */
doQuery(boolean sync, String filterstring)591     Cursor doQuery(boolean sync, String filterstring) {
592         // Cancel any pending queries
593         mQueryHandler.cancelOperation(MY_QUERY_TOKEN);
594 
595         StringBuilder where = new StringBuilder();
596         where.append(MediaStore.Audio.Media.TITLE + " != ''");
597 
598         // We want to show all audio files, even recordings.  Enforcing the
599         // following condition would hide recordings.
600         //where.append(" AND " + MediaStore.Audio.Media.IS_MUSIC + "=1");
601 
602         Uri uri = mBaseUri;
603         if (!TextUtils.isEmpty(filterstring)) {
604             uri = uri.buildUpon().appendQueryParameter("filter", Uri.encode(filterstring)).build();
605         }
606 
607         if (sync) {
608             try {
609                 return getContentResolver().query(uri, CURSOR_COLS,
610                         where.toString(), null, mSortOrder);
611             } catch (UnsupportedOperationException ex) {
612             }
613         } else {
614             mAdapter.setLoading(true);
615             setProgressBarIndeterminateVisibility(true);
616             mQueryHandler.startQuery(MY_QUERY_TOKEN, null, uri, CURSOR_COLS,
617                     where.toString(), null, mSortOrder);
618         }
619         return null;
620     }
621 
onListItemClick(ListView l, View v, int position, long id)622     @Override protected void onListItemClick(ListView l, View v, int position,
623             long id) {
624         mCursor.moveToPosition(position);
625         if (DBG) Log.v(TAG, "Click on " + position + " (id=" + id
626                 + ", cursid="
627                 + mCursor.getLong(mCursor.getColumnIndex(MediaStore.Audio.Media._ID))
628                 + ") in cursor " + mCursor
629                 + " adapter=" + l.getAdapter());
630         setSelected(mCursor);
631     }
632 
setSelected(Cursor c)633     void setSelected(Cursor c) {
634         Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
635         long newId = mCursor.getLong(mCursor.getColumnIndex(MediaStore.Audio.Media._ID));
636         mSelectedUri = ContentUris.withAppendedId(uri, newId);
637 
638         mSelectedId = newId;
639         if (newId != mPlayingId || mMediaPlayer == null) {
640             stopMediaPlayer();
641             mMediaPlayer = new MediaPlayer();
642             try {
643                 mMediaPlayer.setDataSource(this, mSelectedUri);
644                 mMediaPlayer.setOnCompletionListener(this);
645                 mMediaPlayer.setAudioStreamType(AudioManager.STREAM_RING);
646                 mMediaPlayer.prepare();
647                 mMediaPlayer.start();
648                 mPlayingId = newId;
649                 getListView().invalidateViews();
650             } catch (IOException e) {
651                 Log.w("MusicPicker", "Unable to play track", e);
652             }
653         } else if (mMediaPlayer != null) {
654             stopMediaPlayer();
655             getListView().invalidateViews();
656         }
657     }
658 
onCompletion(MediaPlayer mp)659     public void onCompletion(MediaPlayer mp) {
660         if (mMediaPlayer == mp) {
661             mp.stop();
662             mp.release();
663             mMediaPlayer = null;
664             mPlayingId = -1;
665             getListView().invalidateViews();
666         }
667     }
668 
stopMediaPlayer()669     void stopMediaPlayer() {
670         if (mMediaPlayer != null) {
671             mMediaPlayer.stop();
672             mMediaPlayer.release();
673             mMediaPlayer = null;
674             mPlayingId = -1;
675         }
676     }
677 
onClick(View v)678     public void onClick(View v) {
679         switch (v.getId()) {
680             case R.id.okayButton:
681                 if (mSelectedId >= 0) {
682                     setResult(RESULT_OK, new Intent().setData(mSelectedUri));
683                     finish();
684                 }
685                 break;
686 
687             case R.id.cancelButton:
688                 finish();
689                 break;
690         }
691     }
692 }
693