AOSP Music app: Handle audio VIEW and PICK

Let Music app be the default AOSP intent handler for
 - android.intent.action.PICK for vnd.android.cursor.dir/audio
 - android.intent.action.VIEW for mimeType audio/* and ogg/x-ogg
In TrackBrowserActivity, use intent.getParcelableExtra() to prevent NPE
In MediaPlaybackActivity, add null check to prevent NPE

Bug: 78229083
Test: run CtsProviderTestCases
Change-Id: I42fcd31b1b16c02ad9b887d986013184daf7ef09
(cherry picked from commit 6ca14bc397b314e8c7d48988e6bcb455ac716264)
diff --git a/src/com/android/music/MusicPicker.java b/src/com/android/music/MusicPicker.java
new file mode 100644
index 0000000..ea32ec9
--- /dev/null
+++ b/src/com/android/music/MusicPicker.java
@@ -0,0 +1,688 @@
+/*
+ * Copyright (C) 2008 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.ListActivity;
+import android.content.AsyncQueryHandler;
+import android.content.ContentUris;
+import android.content.Context;
+import android.content.Intent;
+import android.database.CharArrayBuffer;
+import android.database.Cursor;
+import android.media.AudioManager;
+import android.media.MediaPlayer;
+import android.media.RingtoneManager;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Parcelable;
+import android.provider.MediaStore;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.Window;
+import android.view.animation.AnimationUtils;
+import android.widget.ImageView;
+import android.widget.ListView;
+import android.widget.RadioButton;
+import android.widget.SectionIndexer;
+import android.widget.SimpleCursorAdapter;
+import android.widget.TextView;
+
+import java.io.IOException;
+import java.text.Collator;
+import java.util.Formatter;
+import java.util.Locale;
+
+/**
+ * Activity allowing the user to select a music track on the device, and
+ * return it to its caller.  The music picker user interface is fairly
+ * extensive, providing information about each track like the music
+ * application (title, author, album, duration), as well as the ability to
+ * previous tracks and sort them in different orders.
+ *
+ * <p>This class also illustrates how you can load data from a content
+ * provider asynchronously, providing a good UI while doing so, perform
+ * indexing of the content for use inside of a {@link FastScrollView}, and
+ * perform filtering of the data as the user presses keys.
+ */
+public class MusicPicker
+        extends ListActivity implements View.OnClickListener, MediaPlayer.OnCompletionListener {
+    static final boolean DBG = false;
+    static final String TAG = "MusicPicker";
+
+    /** Holds the previous state of the list, to restore after the async
+     * query has completed. */
+    static final String LIST_STATE_KEY = "liststate";
+    /** Remember whether the list last had focus for restoring its state. */
+    static final String FOCUS_KEY = "focused";
+    /** Remember the last ordering mode for restoring state. */
+    static final String SORT_MODE_KEY = "sortMode";
+
+    /** Arbitrary number, doesn't matter since we only do one query type. */
+    static final int MY_QUERY_TOKEN = 42;
+
+    /** Menu item to sort the music list by track title. */
+    static final int TRACK_MENU = Menu.FIRST;
+    /** Menu item to sort the music list by album title. */
+    static final int ALBUM_MENU = Menu.FIRST + 1;
+    /** Menu item to sort the music list by artist name. */
+    static final int ARTIST_MENU = Menu.FIRST + 2;
+
+    /** These are the columns in the music cursor that we are interested in. */
+    static final String[] CURSOR_COLS = new String[] {MediaStore.Audio.Media._ID,
+            MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.TITLE_KEY,
+            MediaStore.Audio.Media.DATA, MediaStore.Audio.Media.ALBUM,
+            MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.ARTIST_ID,
+            MediaStore.Audio.Media.DURATION, MediaStore.Audio.Media.TRACK};
+
+    /** Formatting optimization to avoid creating many temporary objects. */
+    static StringBuilder sFormatBuilder = new StringBuilder();
+    /** Formatting optimization to avoid creating many temporary objects. */
+    static Formatter sFormatter = new Formatter(sFormatBuilder, Locale.getDefault());
+    /** Formatting optimization to avoid creating many temporary objects. */
+    static final Object[] sTimeArgs = new Object[5];
+
+    /** Uri to the directory of all music being displayed. */
+    Uri mBaseUri;
+
+    /** This is the adapter used to display all of the tracks. */
+    TrackListAdapter mAdapter;
+    /** Our instance of QueryHandler used to perform async background queries. */
+    QueryHandler mQueryHandler;
+
+    /** Used to keep track of the last scroll state of the list. */
+    Parcelable mListState = null;
+    /** Used to keep track of whether the list last had focus. */
+    boolean mListHasFocus;
+
+    /** The current cursor on the music that is being displayed. */
+    Cursor mCursor;
+    /** The actual sort order the user has selected. */
+    int mSortMode = -1;
+    /** SQL order by string describing the currently selected sort order. */
+    String mSortOrder;
+
+    /** Container of the in-screen progress indicator, to be able to hide it
+     * when done loading the initial cursor. */
+    View mProgressContainer;
+    /** Container of the list view hierarchy, to be able to show it when done
+     * loading the initial cursor. */
+    View mListContainer;
+    /** Set to true when the list view has been shown for the first time. */
+    boolean mListShown;
+
+    /** View holding the okay button. */
+    View mOkayButton;
+    /** View holding the cancel button. */
+    View mCancelButton;
+
+    /** Which track row ID the user has last selected. */
+    long mSelectedId = -1;
+    /** Completel Uri that the user has last selected. */
+    Uri mSelectedUri;
+
+    /** If >= 0, we are currently playing a track for preview, and this is its
+     * row ID. */
+    long mPlayingId = -1;
+
+    /** This is used for playing previews of the music files. */
+    MediaPlayer mMediaPlayer;
+
+    /**
+     * A special implementation of SimpleCursorAdapter that knows how to bind
+     * our cursor data to our list item structure, and takes care of other
+     * advanced features such as indexing and filtering.
+     */
+    class TrackListAdapter extends SimpleCursorAdapter implements SectionIndexer {
+        final ListView mListView;
+
+        private final StringBuilder mBuilder = new StringBuilder();
+        private final String mUnknownArtist;
+        private final String mUnknownAlbum;
+
+        private int mIdIdx;
+        private int mTitleIdx;
+        private int mArtistIdx;
+        private int mAlbumIdx;
+        private int mDurationIdx;
+
+        private boolean mLoading = true;
+        private int mIndexerSortMode;
+        private MusicAlphabetIndexer mIndexer;
+
+        class ViewHolder {
+            TextView line1;
+            TextView line2;
+            TextView duration;
+            RadioButton radio;
+            ImageView play_indicator;
+            CharArrayBuffer buffer1;
+            char[] buffer2;
+        }
+
+        TrackListAdapter(Context context, ListView listView, int layout, String[] from, int[] to) {
+            super(context, layout, null, from, to);
+            mListView = listView;
+            mUnknownArtist = context.getString(R.string.unknown_artist_name);
+            mUnknownAlbum = context.getString(R.string.unknown_album_name);
+        }
+
+        /**
+         * The mLoading flag is set while we are performing a background
+         * query, to avoid displaying the "No music" empty view during
+         * this time.
+         */
+        public void setLoading(boolean loading) {
+            mLoading = loading;
+        }
+
+        @Override
+        public boolean isEmpty() {
+            if (mLoading) {
+                // We don't want the empty state to show when loading.
+                return false;
+            } else {
+                return super.isEmpty();
+            }
+        }
+
+        @Override
+        public View newView(Context context, Cursor cursor, ViewGroup parent) {
+            View v = super.newView(context, cursor, parent);
+            ViewHolder vh = new ViewHolder();
+            vh.line1 = (TextView) v.findViewById(R.id.line1);
+            vh.line2 = (TextView) v.findViewById(R.id.line2);
+            vh.duration = (TextView) v.findViewById(R.id.duration);
+            vh.radio = (RadioButton) v.findViewById(R.id.radio);
+            vh.play_indicator = (ImageView) v.findViewById(R.id.play_indicator);
+            vh.buffer1 = new CharArrayBuffer(100);
+            vh.buffer2 = new char[200];
+            v.setTag(vh);
+            return v;
+        }
+
+        @Override
+        public void bindView(View view, Context context, Cursor cursor) {
+            ViewHolder vh = (ViewHolder) view.getTag();
+
+            cursor.copyStringToBuffer(mTitleIdx, vh.buffer1);
+            vh.line1.setText(vh.buffer1.data, 0, vh.buffer1.sizeCopied);
+
+            int secs = cursor.getInt(mDurationIdx) / 1000;
+            if (secs == 0) {
+                vh.duration.setText("");
+            } else {
+                vh.duration.setText(MusicUtils.makeTimeString(context, secs));
+            }
+
+            final StringBuilder builder = mBuilder;
+            builder.delete(0, builder.length());
+
+            String name = cursor.getString(mAlbumIdx);
+            if (name == null || name.equals("<unknown>")) {
+                builder.append(mUnknownAlbum);
+            } else {
+                builder.append(name);
+            }
+            builder.append('\n');
+            name = cursor.getString(mArtistIdx);
+            if (name == null || name.equals("<unknown>")) {
+                builder.append(mUnknownArtist);
+            } else {
+                builder.append(name);
+            }
+            int len = builder.length();
+            if (vh.buffer2.length < len) {
+                vh.buffer2 = new char[len];
+            }
+            builder.getChars(0, len, vh.buffer2, 0);
+            vh.line2.setText(vh.buffer2, 0, len);
+
+            // Update the checkbox of the item, based on which the user last
+            // selected.  Note that doing it this way means we must have the
+            // list view update all of its items when the selected item
+            // changes.
+            final long id = cursor.getLong(mIdIdx);
+            vh.radio.setChecked(id == mSelectedId);
+            if (DBG)
+                Log.v(TAG,
+                        "Binding id=" + id + " sel=" + mSelectedId + " playing=" + mPlayingId
+                                + " cursor=" + cursor);
+
+            // Likewise, display the "now playing" icon if this item is
+            // currently being previewed for the user.
+            ImageView iv = vh.play_indicator;
+            if (id == mPlayingId) {
+                iv.setImageResource(R.drawable.indicator_ic_mp_playing_list);
+                iv.setVisibility(View.VISIBLE);
+            } else {
+                iv.setVisibility(View.GONE);
+            }
+        }
+
+        /**
+         * This method is called whenever we receive a new cursor due to
+         * an async query, and must take care of plugging the new one in
+         * to the adapter.
+         */
+        @Override
+        public void changeCursor(Cursor cursor) {
+            super.changeCursor(cursor);
+            if (DBG)
+                Log.v(TAG, "Setting cursor to: " + cursor + " from: " + MusicPicker.this.mCursor);
+
+            MusicPicker.this.mCursor = cursor;
+
+            if (cursor != null) {
+                // Retrieve indices of the various columns we are interested in.
+                mIdIdx = cursor.getColumnIndex(MediaStore.Audio.Media._ID);
+                mTitleIdx = cursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
+                mArtistIdx = cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);
+                mAlbumIdx = cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM);
+                mDurationIdx = cursor.getColumnIndex(MediaStore.Audio.Media.DURATION);
+
+                // If the sort mode has changed, or we haven't yet created an
+                // indexer one, then create a new one that is indexing the
+                // appropriate column based on the sort mode.
+                if (mIndexerSortMode != mSortMode || mIndexer == null) {
+                    mIndexerSortMode = mSortMode;
+                    int idx = mTitleIdx;
+                    switch (mIndexerSortMode) {
+                        case ARTIST_MENU:
+                            idx = mArtistIdx;
+                            break;
+                        case ALBUM_MENU:
+                            idx = mAlbumIdx;
+                            break;
+                    }
+                    mIndexer = new MusicAlphabetIndexer(
+                            cursor, idx, getResources().getString(R.string.fast_scroll_alphabet));
+
+                    // If we have a valid indexer, but the cursor has changed since
+                    // its last use, then point it to the current cursor.
+                } else {
+                    mIndexer.setCursor(cursor);
+                }
+            }
+
+            // Ensure that the list is shown (and initial progress indicator
+            // hidden) in case this is the first cursor we have gotten.
+            makeListShown();
+        }
+
+        /**
+         * This method is called from a background thread by the list view
+         * when the user has typed a letter that should result in a filtering
+         * of the displayed items.  It returns a Cursor, when will then be
+         * handed to changeCursor.
+         */
+        @Override
+        public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
+            if (DBG) Log.v(TAG, "Getting new cursor...");
+            return doQuery(true, constraint.toString());
+        }
+
+        public int getPositionForSection(int section) {
+            Cursor cursor = getCursor();
+            if (cursor == null) {
+                // No cursor, the section doesn't exist so just return 0
+                return 0;
+            }
+
+            return mIndexer.getPositionForSection(section);
+        }
+
+        public int getSectionForPosition(int position) {
+            return 0;
+        }
+
+        public Object[] getSections() {
+            if (mIndexer != null) {
+                return mIndexer.getSections();
+            }
+            return null;
+        }
+    }
+
+    /**
+     * This is our specialization of AsyncQueryHandler applies new cursors
+     * to our state as they become available.
+     */
+    private final class QueryHandler extends AsyncQueryHandler {
+        public QueryHandler(Context context) {
+            super(context.getContentResolver());
+        }
+
+        @Override
+        protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
+            if (!isFinishing()) {
+                // Update the adapter: we are no longer loading, and have
+                // a new cursor for it.
+                mAdapter.setLoading(false);
+                mAdapter.changeCursor(cursor);
+                setProgressBarIndeterminateVisibility(false);
+
+                // Now that the cursor is populated again, it's possible to restore the list state
+                if (mListState != null) {
+                    getListView().onRestoreInstanceState(mListState);
+                    if (mListHasFocus) {
+                        getListView().requestFocus();
+                    }
+                    mListHasFocus = false;
+                    mListState = null;
+                }
+            } else {
+                cursor.close();
+            }
+        }
+    }
+
+    /** Called when the activity is first created. */
+    @Override
+    public void onCreate(Bundle icicle) {
+        super.onCreate(icicle);
+
+        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
+
+        int sortMode = TRACK_MENU;
+        if (icicle == null) {
+            mSelectedUri =
+                    getIntent().getParcelableExtra(RingtoneManager.EXTRA_RINGTONE_EXISTING_URI);
+        } else {
+            mSelectedUri = (Uri) icicle.getParcelable(RingtoneManager.EXTRA_RINGTONE_EXISTING_URI);
+            // Retrieve list state. This will be applied after the
+            // QueryHandler has run
+            mListState = icicle.getParcelable(LIST_STATE_KEY);
+            mListHasFocus = icicle.getBoolean(FOCUS_KEY);
+            sortMode = icicle.getInt(SORT_MODE_KEY, sortMode);
+        }
+        if (Intent.ACTION_GET_CONTENT.equals(getIntent().getAction())) {
+            mBaseUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
+        } else {
+            mBaseUri = getIntent().getData();
+            if (mBaseUri == null) {
+                Log.w("MusicPicker", "No data URI given to PICK action");
+                finish();
+                return;
+            }
+        }
+
+        setContentView(R.layout.music_picker);
+
+        mSortOrder = MediaStore.Audio.Media.TITLE_KEY;
+
+        final ListView listView = getListView();
+
+        listView.setItemsCanFocus(false);
+
+        mAdapter = new TrackListAdapter(
+                this, listView, R.layout.music_picker_item, new String[] {}, new int[] {});
+
+        setListAdapter(mAdapter);
+
+        listView.setTextFilterEnabled(true);
+
+        // We manually save/restore the listview state
+        listView.setSaveEnabled(false);
+
+        mQueryHandler = new QueryHandler(this);
+
+        mProgressContainer = findViewById(R.id.progressContainer);
+        mListContainer = findViewById(R.id.listContainer);
+
+        mOkayButton = findViewById(R.id.okayButton);
+        mOkayButton.setOnClickListener(this);
+        mCancelButton = findViewById(R.id.cancelButton);
+        mCancelButton.setOnClickListener(this);
+
+        // If there is a currently selected Uri, then try to determine who
+        // it is.
+        if (mSelectedUri != null) {
+            Uri.Builder builder = mSelectedUri.buildUpon();
+            String path = mSelectedUri.getEncodedPath();
+            int idx = path.lastIndexOf('/');
+            if (idx >= 0) {
+                path = path.substring(0, idx);
+            }
+            builder.encodedPath(path);
+            Uri baseSelectedUri = builder.build();
+            if (DBG) Log.v(TAG, "Selected Uri: " + mSelectedUri);
+            if (DBG) Log.v(TAG, "Selected base Uri: " + baseSelectedUri);
+            if (DBG) Log.v(TAG, "Base Uri: " + mBaseUri);
+            if (baseSelectedUri.equals(mBaseUri)) {
+                // If the base Uri of the selected Uri is the same as our
+                // content's base Uri, then use the selection!
+                mSelectedId = ContentUris.parseId(mSelectedUri);
+            }
+        }
+
+        setSortMode(sortMode);
+    }
+
+    @Override
+    public void onRestart() {
+        super.onRestart();
+        doQuery(false, null);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (setSortMode(item.getItemId())) {
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        super.onCreateOptionsMenu(menu);
+        menu.add(Menu.NONE, TRACK_MENU, Menu.NONE, R.string.sort_by_track);
+        menu.add(Menu.NONE, ALBUM_MENU, Menu.NONE, R.string.sort_by_album);
+        menu.add(Menu.NONE, ARTIST_MENU, Menu.NONE, R.string.sort_by_artist);
+        return true;
+    }
+
+    @Override
+    protected void onSaveInstanceState(Bundle icicle) {
+        super.onSaveInstanceState(icicle);
+        // Save list state in the bundle so we can restore it after the
+        // QueryHandler has run
+        icicle.putParcelable(LIST_STATE_KEY, getListView().onSaveInstanceState());
+        icicle.putBoolean(FOCUS_KEY, getListView().hasFocus());
+        icicle.putInt(SORT_MODE_KEY, mSortMode);
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        stopMediaPlayer();
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+
+        // We don't want the list to display the empty state, since when we
+        // resume it will still be there and show up while the new query is
+        // happening. After the async query finishes in response to onResume()
+        // setLoading(false) will be called.
+        mAdapter.setLoading(true);
+        mAdapter.changeCursor(null);
+    }
+
+    /**
+     * Changes the current sort order, building the appropriate query string
+     * for the selected order.
+     */
+    boolean setSortMode(int sortMode) {
+        if (sortMode != mSortMode) {
+            switch (sortMode) {
+                case TRACK_MENU:
+                    mSortMode = sortMode;
+                    mSortOrder = MediaStore.Audio.Media.TITLE_KEY;
+                    doQuery(false, null);
+                    return true;
+                case ALBUM_MENU:
+                    mSortMode = sortMode;
+                    mSortOrder = MediaStore.Audio.Media.ALBUM_KEY + " ASC, "
+                            + MediaStore.Audio.Media.TRACK + " ASC, "
+                            + MediaStore.Audio.Media.TITLE_KEY + " ASC";
+                    doQuery(false, null);
+                    return true;
+                case ARTIST_MENU:
+                    mSortMode = sortMode;
+                    mSortOrder = MediaStore.Audio.Media.ARTIST_KEY + " ASC, "
+                            + MediaStore.Audio.Media.ALBUM_KEY + " ASC, "
+                            + MediaStore.Audio.Media.TRACK + " ASC, "
+                            + MediaStore.Audio.Media.TITLE_KEY + " ASC";
+                    doQuery(false, null);
+                    return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * The first time this is called, we hide the large progress indicator
+     * and show the list view, doing fade animations between them.
+     */
+    void makeListShown() {
+        if (!mListShown) {
+            mListShown = true;
+            mProgressContainer.startAnimation(
+                    AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
+            mProgressContainer.setVisibility(View.GONE);
+            mListContainer.startAnimation(
+                    AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
+            mListContainer.setVisibility(View.VISIBLE);
+        }
+    }
+
+    /**
+     * Common method for performing a query of the music database, called for
+     * both top-level queries and filtering.
+     *
+     * @param sync If true, this query should be done synchronously and the
+     * resulting cursor returned.  If false, it will be done asynchronously and
+     * null returned.
+     * @param filterstring If non-null, this is a filter to apply to the query.
+     */
+    Cursor doQuery(boolean sync, String filterstring) {
+        // Cancel any pending queries
+        mQueryHandler.cancelOperation(MY_QUERY_TOKEN);
+
+        StringBuilder where = new StringBuilder();
+        where.append(MediaStore.Audio.Media.TITLE + " != ''");
+
+        // We want to show all audio files, even recordings.  Enforcing the
+        // following condition would hide recordings.
+        // where.append(" AND " + MediaStore.Audio.Media.IS_MUSIC + "=1");
+
+        Uri uri = mBaseUri;
+        if (!TextUtils.isEmpty(filterstring)) {
+            uri = uri.buildUpon().appendQueryParameter("filter", Uri.encode(filterstring)).build();
+        }
+
+        if (sync) {
+            try {
+                return getContentResolver().query(
+                        uri, CURSOR_COLS, where.toString(), null, mSortOrder);
+            } catch (UnsupportedOperationException ex) {
+            }
+        } else {
+            mAdapter.setLoading(true);
+            setProgressBarIndeterminateVisibility(true);
+            mQueryHandler.startQuery(
+                    MY_QUERY_TOKEN, null, uri, CURSOR_COLS, where.toString(), null, mSortOrder);
+        }
+        return null;
+    }
+
+    @Override
+    protected void onListItemClick(ListView l, View v, int position, long id) {
+        mCursor.moveToPosition(position);
+        if (DBG)
+            Log.v(TAG,
+                    "Click on " + position + " (id=" + id + ", cursid="
+                            + mCursor.getLong(mCursor.getColumnIndex(MediaStore.Audio.Media._ID))
+                            + ") in cursor " + mCursor + " adapter=" + l.getAdapter());
+        setSelected(mCursor);
+    }
+
+    void setSelected(Cursor c) {
+        Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
+        long newId = mCursor.getLong(mCursor.getColumnIndex(MediaStore.Audio.Media._ID));
+        mSelectedUri = ContentUris.withAppendedId(uri, newId);
+
+        mSelectedId = newId;
+        if (newId != mPlayingId || mMediaPlayer == null) {
+            stopMediaPlayer();
+            mMediaPlayer = new MediaPlayer();
+            try {
+                mMediaPlayer.setDataSource(this, mSelectedUri);
+                mMediaPlayer.setOnCompletionListener(this);
+                mMediaPlayer.setAudioStreamType(AudioManager.STREAM_RING);
+                mMediaPlayer.prepare();
+                mMediaPlayer.start();
+                mPlayingId = newId;
+                getListView().invalidateViews();
+            } catch (IOException e) {
+                Log.w("MusicPicker", "Unable to play track", e);
+            }
+        } else if (mMediaPlayer != null) {
+            stopMediaPlayer();
+            getListView().invalidateViews();
+        }
+    }
+
+    public void onCompletion(MediaPlayer mp) {
+        if (mMediaPlayer == mp) {
+            mp.stop();
+            mp.release();
+            mMediaPlayer = null;
+            mPlayingId = -1;
+            getListView().invalidateViews();
+        }
+    }
+
+    void stopMediaPlayer() {
+        if (mMediaPlayer != null) {
+            mMediaPlayer.stop();
+            mMediaPlayer.release();
+            mMediaPlayer = null;
+            mPlayingId = -1;
+        }
+    }
+
+    public void onClick(View v) {
+        switch (v.getId()) {
+            case R.id.okayButton:
+                if (mSelectedId >= 0) {
+                    setResult(RESULT_OK, new Intent().setData(mSelectedUri));
+                    finish();
+                }
+                break;
+
+            case R.id.cancelButton:
+                finish();
+                break;
+        }
+    }
+}
\ No newline at end of file