Adds the Random Music Player sample.

This sample illustrates how to write an application that plays media in the background, handles streaming media from the network and reacts appropriately to system events like headphone disconnection and audio focus changes, and also uses the notification system to keep the user informed about what is happening. This CL is a cherrypick of the old CL 104495 (originally in honeycomb-mr1) into honeycomb-mr2. Original CL: https://android-git.corp.google.com/g/#change,104495 Change-Id: Ib8b15ee920300adc093a8b52c17bd9c251ac74ca
2011-06-07 01:09:21 -04:00
parent 193d98ec18
commit b30a3010f5
58 changed files with 1461 additions and 0 deletions
--- a/samples/RandomMusicPlayer/src/com/example/android/musicplayer/MusicRetriever.java
+++ b/samples/RandomMusicPlayer/src/com/example/android/musicplayer/MusicRetriever.java
@@ -0,0 +1,118 @@
+/*   
+ * Copyright (C) 2011 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.example.android.musicplayer;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+
+/**
+ * Retrieves and organizes media to play. Before being used, you must call {@link #prepare()},
+ * which will retrieve all of the music on the user's device (by performing a query on a content
+ * resolver). After that, it's ready to retrieve a random song, with its title and URI, upon
+ * request.
+ */
+public class MusicRetriever {
+    final String TAG = "MusicRetriever";
+
+    ContentResolver mContentResolver;
+
+    // the items (songs) we have queried
+    List<Item> mItems = new ArrayList<Item>();
+
+    Random mRandom = new Random();
+
+    public MusicRetriever(ContentResolver cr) {
+        mContentResolver = cr;
+    }
+
+    /**
+     * Loads music data. This method may take long, so be sure to call it asynchronously without
+     * blocking the main thread.
+     */
+    public void prepare() {
+        Uri uri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
+        Log.i(TAG, "Querying media...");
+        Log.i(TAG, "URI: " + uri.toString());
+
+        // Perform a query on the content resolver. The URI we're passing specifies that we
+        // want to query for all audio media on external storage (e.g. SD card)
+        Cursor cur = mContentResolver.query(uri, null, null, null, null);
+        Log.i(TAG, "Query finished. " + (cur == null ? "Returned NULL." : "Returned a cursor."));
+
+        if (cur == null) {
+            // Query failed...
+            Log.e(TAG, "Failed to retrieve music: cursor is null :-(");
+            return;
+        }
+        if (!cur.moveToFirst()) {
+            // Nothing to query. There is no music on the device. How boring.
+            Log.e(TAG, "Failed to move cursor to first row (no query results).");
+            return;
+        }
+
+        Log.i(TAG, "Listing...");
+
+        // retrieve the indices of the columns where the ID and title of the song are
+        int titleColumn = cur.getColumnIndex(android.provider.MediaStore.Audio.Media.TITLE);
+        int idColumn = cur.getColumnIndex(android.provider.MediaStore.Audio.Media._ID);
+
+        Log.i(TAG, "Title column index: " + String.valueOf(titleColumn));
+        Log.i(TAG, "ID column index: " + String.valueOf(titleColumn));
+
+        // add each song to mItems
+        do {
+            Log.i(TAG, "ID: " + cur.getString(idColumn) + " Title: " + cur.getString(titleColumn));
+            mItems.add(new Item(cur.getLong(idColumn), cur.getString(titleColumn)));
+        } while (cur.moveToNext());
+
+        Log.i(TAG, "Done querying media. MusicRetriever is ready.");
+    }
+
+    public ContentResolver getContentResolver() {
+        return mContentResolver;
+    }
+
+    /** Returns a random Item. If there are no items available, returns null. */
+    public Item getRandomItem() {
+        if (mItems.size() <= 0) return null;
+        return mItems.get(mRandom.nextInt(mItems.size()));
+    }
+
+    public class Item {
+        long id;
+        String title;
+
+        public Item(long id, String title) {
+            this.id = id;
+            this.title = title;
+        }
+
+        public long getId() { return id; }
+        public String getTitle() { return title; }
+        public Uri getURI() {
+            return ContentUris.withAppendedId(
+                    android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, id);
+        }
+    }
+}