am d0e6d6f7: am 6f24f89c: Merge "Adds the Random Music Player sample." into honeycomb-mr2

* commit 'd0e6d6f71fe5aab3c9faeecfc480ea7d69c5a080':
  Adds the Random Music Player sample.

build/sdk.atree

@@ -166,6 +166,7 @@ development/samples/JetBoy                     samples/${PLATFORM_NAME}/JetBoy
 development/samples/LunarLander                samples/${PLATFORM_NAME}/LunarLander
 development/samples/MultiResolution            samples/${PLATFORM_NAME}/MultiResolution
 development/samples/NotePad                    samples/${PLATFORM_NAME}/NotePad
+development/samples/RandomMusicPlayer          samples/${PLATFORM_NAME}/RandomMusicPlayer
 development/samples/SampleSyncAdapter          samples/${PLATFORM_NAME}/SampleSyncAdapter
 development/samples/SearchableDictionary       samples/${PLATFORM_NAME}/SearchableDictionary
 development/samples/SipDemo                    samples/${PLATFORM_NAME}/SipDemo

samples/RandomMusicPlayer/AndroidManifest.xml

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+      package="com.example.android.musicplayer"
+      android:versionCode="1"
+      android:versionName="1.0">
+
+    <uses-sdk android:minSdkVersion="7" android:targetSdkVersion="8" />
+    <uses-permission android:name="android.permission.WAKE_LOCK"/>
+
+    <application android:icon="@drawable/ic_launcher" android:label="Random Music Player">
+        <activity android:name=".MainActivity"
+                  android:label="Random Music Player"
+                  android:theme="@android:style/Theme.Black.NoTitleBar">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <service android:exported="false" android:name=".MusicService">
+            <intent-filter>
+                <action android:name="com.example.android.musicplayer.action.PLAY" />
+                <action android:name="com.example.android.musicplayer.action.PAUSE" />
+                <action android:name="com.example.android.musicplayer.action.SKIP" />
+                <action android:name="com.example.android.musicplayer.action.REWIND" />
+                <action android:name="com.example.android.musicplayer.action.STOP" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="com.example.android.musicplayer.action.URL" />
+                <data android:scheme="http" />
+            </intent-filter>
+        </service>
+
+        <receiver android:name=".MusicIntentReceiver">
+            <intent-filter>
+                <action android:name="android.media.AUDIO_BECOMING_NOISY" />
+            </intent-filter>
+        </receiver>
+    </application>
+</manifest>

samples/RandomMusicPlayer/_index.html

@@ -0,0 +1,8 @@
+<p>A simple music player that illustrates how to make a multimedia application
+that manages media playback from a service. It allows the user to play music
+available on the device or specify a URL from which the media should be
+streamed.  It also illustrates how to use the notification system to indicate
+an ongoing task and how to deal with audio focus changes.</p>
+
+<img alt="" src="../images/randommusicplayer.png" />
+

samples/RandomMusicPlayer/default.properties

@@ -0,0 +1,11 @@
+# This file is automatically generated by Android Tools.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+#
+# This file must be checked in Version Control Systems.
+#
+# To customize properties used by the Ant build system use,
+# "build.properties", and override values to adapt the script to your
+# project structure.
+
+# Project target.
+target=android-8

samples/RandomMusicPlayer/res/drawable-hdpi/selector_eject.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/eject_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/eject_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/eject" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-hdpi/selector_ff.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/ff_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/ff_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/ff" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-hdpi/selector_pause.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/pause_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/pause_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/pause" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-hdpi/selector_play.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/play_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/play_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/play" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-hdpi/selector_rew.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/rew_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/rew_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/rew" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-hdpi/selector_stop.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/stop_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/stop_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/stop" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-mdpi/selector_eject.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/eject_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/eject_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/eject" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-mdpi/selector_ff.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/ff_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/ff_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/ff" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-mdpi/selector_pause.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/pause_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/pause_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/pause" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-mdpi/selector_play.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/play_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/play_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/play" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-mdpi/selector_rew.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/rew_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/rew_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/rew" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/drawable-mdpi/selector_stop.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+ <selector xmlns:android="http://schemas.android.com/apk/res/android">
+     <item android:state_pressed="true"
+           android:drawable="@drawable/stop_pressed" /> <!-- pressed -->
+     <item android:state_focused="true"
+           android:drawable="@drawable/stop_pressed" /> <!-- focused -->
+     <item android:drawable="@drawable/stop" /> <!-- default -->
+ </selector>

samples/RandomMusicPlayer/res/layout-land/main.xml

@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:gravity="center"
+    android:background="#000040"
+    >
+
+<TextView android:text="Random Music Player"
+          android:layout_width="wrap_content"
+          android:layout_height="wrap_content"
+          android:padding="20dp"
+          android:textColor="#ffffff"
+          android:textSize="20sp"
+          android:textStyle="bold"
+          />
+
+<LinearLayout
+    android:orientation="horizontal"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:gravity="center"
+    >
+<Button
+    android:id="@+id/rewindbutton"
+    android:background="@drawable/selector_rew"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/playbutton"
+    android:background="@drawable/selector_play"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/pausebutton"
+    android:background="@drawable/selector_pause"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/skipbutton"
+    android:background="@drawable/selector_ff"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/stopbutton"
+    android:background="@drawable/selector_stop"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/ejectbutton"
+    android:background="@drawable/selector_eject"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+
+</LinearLayout>
+</LinearLayout>

samples/RandomMusicPlayer/res/layout-port/main.xml

@@ -0,0 +1,93 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:gravity="center"
+    android:background="#000040"
+    >
+
+<TextView android:text="Random Music Player"
+          android:layout_width="wrap_content"
+          android:layout_height="wrap_content"
+          android:padding="20dp"
+          android:textColor="#ffffff"
+          android:textSize="20sp"
+          android:textStyle="bold"
+          />
+
+<LinearLayout
+    android:orientation="horizontal"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:gravity="center"
+    android:layout_margin="10dp"
+    >
+<Button
+    android:id="@+id/rewindbutton"
+    android:background="@drawable/selector_rew"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/playbutton"
+    android:background="@drawable/selector_play"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/pausebutton"
+    android:background="@drawable/selector_pause"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/skipbutton"
+    android:background="@drawable/selector_ff"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+</LinearLayout>
+
+<LinearLayout
+    android:orientation="horizontal"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:gravity="center"
+    android:layout_margin="10dp"
+    >
+<Button
+    android:id="@+id/stopbutton"
+    android:background="@drawable/selector_stop"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+<Button
+    android:id="@+id/ejectbutton"
+    android:background="@drawable/selector_eject"
+    android:layout_width="64dp"
+    android:layout_height="64dp"
+    android:layout_margin="5dp"
+    />
+
+</LinearLayout>
+</LinearLayout>

samples/RandomMusicPlayer/src/com/example/android/musicplayer/AudioFocusHelper.java

@@ -0,0 +1,71 @@
+/*   
+ * 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 android.content.Context;
+import android.media.AudioManager;
+
+/** 
+ * Convenience class to deal with audio focus. This class deals with everything related to audio
+ * focus: it can request and abandon focus, and will intercept focus change events and deliver
+ * them to a MusicFocusable interface (which, in our case, is implemented by {@link MusicService}).
+ *
+ * This class can only be used on SDK level 8 and above, since it uses API features that are not
+ * available on previous SDK's.
+ */
+public class AudioFocusHelper implements AudioManager.OnAudioFocusChangeListener {
+    AudioManager mAM;
+    MusicFocusable mFocusable;
+
+    public AudioFocusHelper(Context ctx, MusicFocusable focusable) {
+        mAM = (AudioManager) ctx.getSystemService(Context.AUDIO_SERVICE);
+        mFocusable = focusable;
+    }
+
+    /** Requests audio focus. Returns whether request was successful or not. */
+    public boolean requestFocus() {
+        return AudioManager.AUDIOFOCUS_REQUEST_GRANTED ==
+            mAM.requestAudioFocus(this, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
+    }
+
+    /** Abandons audio focus. Returns whether request was successful or not. */
+    public boolean abandonFocus() {
+        return AudioManager.AUDIOFOCUS_REQUEST_GRANTED == mAM.abandonAudioFocus(this);
+    }
+
+    /** 
+     * Called by AudioManager on audio focus changes. We implement this by calling our
+     * MusicFocusable appropriately to relay the message.
+     */
+    @Override
+    public void onAudioFocusChange(int focusChange) {
+        if (mFocusable == null) return;
+        switch (focusChange) {
+            case AudioManager.AUDIOFOCUS_GAIN:
+                mFocusable.onGainedAudioFocus();
+                break;
+            case AudioManager.AUDIOFOCUS_LOSS:
+            case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
+                mFocusable.onLostAudioFocus(false);
+                break;
+            case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
+                mFocusable.onLostAudioFocus(true);
+                break;
+             default:
+        }
+    }
+}

samples/RandomMusicPlayer/src/com/example/android/musicplayer/MainActivity.java

@@ -0,0 +1,122 @@
+/*   
+ * 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 android.app.Activity;
+import android.app.AlertDialog;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Bundle;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.Button;
+import android.widget.EditText;
+
+/** 
+ * Main activity: shows media player buttons. This activity shows the media player buttons and
+ * lets the user click them. No media handling is done here -- everything is done by passing
+ * Intents to our {@link MusicService}.
+ * */
+public class MainActivity extends Activity implements OnClickListener {
+    /**
+     * The URL we suggest as default when adding by URL. This is just so that the user doesn't
+     * have to find an URL to test this sample.
+     */
+    final String SUGGESTED_URL = "http://www.vorbis.com/music/Epoq-Lepidoptera.ogg";
+
+    Button mPlayButton;
+    Button mPauseButton;
+    Button mSkipButton;
+    Button mRewindButton;
+    Button mStopButton;
+    Button mEjectButton;
+
+    /**
+     * Called when the activity is first created. Here, we simply set the event listeners and
+     * start the background service ({@link MusicService}) that will handle the actual media
+     * playback.
+     */
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main);
+
+        mPlayButton = (Button) findViewById(R.id.playbutton);
+        mPauseButton = (Button) findViewById(R.id.pausebutton);
+        mSkipButton = (Button) findViewById(R.id.skipbutton);
+        mRewindButton = (Button) findViewById(R.id.rewindbutton);
+        mStopButton = (Button) findViewById(R.id.stopbutton);
+        mEjectButton = (Button) findViewById(R.id.ejectbutton);
+
+        mPlayButton.setOnClickListener(this);
+        mPauseButton.setOnClickListener(this);
+        mSkipButton.setOnClickListener(this);
+        mRewindButton.setOnClickListener(this);
+        mStopButton.setOnClickListener(this);
+        mEjectButton.setOnClickListener(this);
+    }
+
+    @Override
+    public void onClick(View target) {
+        // Send the correct intent to the MusicService, according to the button that was clicked
+        if (target == mPlayButton)
+            startService(new Intent(MusicService.ACTION_PLAY));
+        else if (target == mPauseButton)
+            startService(new Intent(MusicService.ACTION_PAUSE));
+        else if (target == mSkipButton)
+            startService(new Intent(MusicService.ACTION_SKIP));
+        else if (target == mRewindButton)
+            startService(new Intent(MusicService.ACTION_REWIND));
+        else if (target == mStopButton)
+            startService(new Intent(MusicService.ACTION_STOP));
+        else if (target == mEjectButton) {
+            showUrlDialog();
+        }
+    }
+
+    /** 
+     * Shows an alert dialog where the user can input a URL. After showing the dialog, if the user
+     * confirms, sends the appropriate intent to the {@link MusicService} to cause that URL to be
+     * played.
+     */
+    void showUrlDialog() {
+        AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
+        alertBuilder.setTitle("Manual Input");
+        alertBuilder.setMessage("Enter a URL (must be http://)");
+        final EditText input = new EditText(this);
+        alertBuilder.setView(input);
+
+        input.setText(SUGGESTED_URL);
+
+        alertBuilder.setPositiveButton("Play!", new DialogInterface.OnClickListener() {
+            public void onClick(DialogInterface dlg, int whichButton) {
+                // Send an intent with the URL of the song to play. This is expected by
+                // MusicService.
+                Intent i = new Intent(MusicService.ACTION_URL);
+                Uri uri = Uri.parse(input.getText().toString());
+                i.setData(uri);
+                startService(i);
+            }
+        });
+        alertBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
+            public void onClick(DialogInterface dlg, int whichButton) {}
+        });
+
+        alertBuilder.show();
+    }
+}

samples/RandomMusicPlayer/src/com/example/android/musicplayer/MusicFocusable.java

@@ -0,0 +1,35 @@
+/*   
+ * 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;
+
+/**
+ * Represents something that can react to audio focus events. We implement this instead of just
+ * using AudioManager.OnAudioFocusChangeListener because that interface is only available in SDK
+ * level 8 and above, and we want our application to work on previous SDKs.
+ */
+public interface MusicFocusable {
+    /** Signals that audio focus was gained. */
+    public void onGainedAudioFocus();
+
+    /**
+     * Signals that audio focus was lost.
+     *
+     * @param canDuck If true, audio can continue in "ducked" mode (low volume). Otherwise, all
+     * audio must stop.
+     */
+    public void onLostAudioFocus(boolean canDuck);
+}

samples/RandomMusicPlayer/src/com/example/android/musicplayer/MusicIntentReceiver.java

@@ -0,0 +1,40 @@
+/*   
+ * 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 android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.widget.Toast;
+
+/**
+ * Receives broadcasted intents. In particular, we are interested in the
+ * android.media.AUDIO_BECOMING_NOISY intent, which is broadcast, for example, when the user
+ * disconnects the headphones. This class works because we are declaring it in a <receiver>
+ * tag in AndroidManifest.xml.
+ */
+public class MusicIntentReceiver extends BroadcastReceiver {
+    @Override
+    public void onReceive(Context ctx, Intent intent) {
+        if (intent.getAction().equals(android.media.AudioManager.ACTION_AUDIO_BECOMING_NOISY)) {
+            Toast.makeText(ctx, "Headphones disconnected.", Toast.LENGTH_SHORT).show();
+
+            // send an intent to our MusicService to telling it to pause the audio
+            ctx.startService(new Intent(MusicService.ACTION_PAUSE));
+        }
+    }
+}

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);
+        }
+    }
+}

samples/RandomMusicPlayer/src/com/example/android/musicplayer/MusicService.java

@@ -0,0 +1,511 @@
+/*   
+ * 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.io.IOException;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.media.AudioManager;
+import android.media.MediaPlayer;
+import android.media.MediaPlayer.OnCompletionListener;
+import android.media.MediaPlayer.OnErrorListener;
+import android.media.MediaPlayer.OnPreparedListener;
+import android.net.Uri;
+import android.net.wifi.WifiManager;
+import android.net.wifi.WifiManager.WifiLock;
+import android.os.IBinder;
+import android.os.PowerManager;
+import android.util.Log;
+import android.widget.Toast;
+
+/**
+ * Service that handles media playback. This is the Service through which we perform all the media
+ * handling in our application. Upon initialization, it starts a {@link MediaRetriever} to scan
+ * the user's media. Then, it waits for Intents (which come from our main activity,
+ * {@link MainActivity}, which signal the service to perform specific operations: Play, Pause,
+ * Rewind, Skip, etc.
+ */
+public class MusicService extends Service implements OnCompletionListener, OnPreparedListener,
+                OnErrorListener, MusicFocusable,
+                PrepareMusicRetrieverTask.MusicRetrieverPreparedListener {
+
+    NotificationManager mNotificationManager;
+
+    // our media player
+    MediaPlayer mPlayer = null;
+
+    // our AudioFocusHelper object, if it's available (it's available on SDK level >= 8)
+    // If not available, this will be null. Always check for null before using!
+    AudioFocusHelper mAudioFocusHelper = null;
+
+    // indicates the state our service:
+    enum State {
+        Retrieving, // the MediaRetriever is retrieving music
+        Stopped,    // media player is stopped and not prepared to play
+        Preparing,  // media player is preparing...
+        Playing,    // playback active (media player ready!). (but the media player may actually be
+                    // paused in this state if we don't have audio focus. But we stay in this state
+                    // so that we know we have to resume playback once we get focus back)
+        Paused      // playback paused (media player ready!)
+    };
+
+    State mState = State.Retrieving;
+
+    // if in Retrieving mode, this flag indicates whether we should start playing immediately
+    // when we are ready or not.
+    boolean mStartPlayingAfterRetrieve = false;
+
+    // if mStartPlayingAfterRetrieve is true, this variable indicates the URL that we should
+    // start playing when we are ready. If null, we should play a random song from the device
+    Uri mWhatToPlayAfterRetrieve = null;
+
+    enum PauseReason {
+        UserRequest,  // paused by user request
+        FocusLoss,    // paused because of audio focus loss
+    };
+
+    // why did we pause? (only relevant if mState == State.Paused)
+    PauseReason mPauseReason = PauseReason.UserRequest;
+
+    // do we have audio focus?
+    enum AudioFocus {
+        NoFocusNoDuck,    // we don't have audio focus, and can't duck
+        NoFocusCanDuck,   // we don't have focus, but can play at a low volume ("ducking")
+        Focused           // we have full audio focus
+    }
+    AudioFocus mAudioFocus = AudioFocus.NoFocusNoDuck;
+
+    // title of the song we are currently playing
+    String mSongTitle = "";
+
+    // whether the song we are playing is streaming from the network
+    boolean mIsStreaming = false;
+
+    // Wifi lock that we hold when streaming files from the internet, in order to prevent the
+    // device from shutting off the Wifi radio
+    WifiLock mWifiLock;
+
+    // The tag we put on debug messages
+    final static String TAG = "RandomMusicPlayer";
+
+    // These are the Intent actions that we are prepared to handle. Notice that the fact these
+    // constants exist in our class is a mere convenience: what really defines the actions our
+    // service can handle are the <action> tags in the <intent-filters> tag for our service in
+    // AndroidManifest.xml.
+    public static final String ACTION_PLAY = "com.example.android.musicplayer.action.PLAY";
+    public static final String ACTION_PAUSE = "com.example.android.musicplayer.action.PAUSE";
+    public static final String ACTION_STOP = "com.example.android.musicplayer.action.STOP";
+    public static final String ACTION_SKIP = "com.example.android.musicplayer.action.SKIP";
+    public static final String ACTION_REWIND = "com.example.android.musicplayer.action.REWIND";
+    public static final String ACTION_URL = "com.example.android.musicplayer.action.URL";
+
+    // The volume we set the media player to when we lose audio focus, but are allowed to reduce
+    // the volume instead of stopping playback.
+    public final float DUCK_VOLUME = 0.1f;
+
+    // The ID we use for the notification (the onscreen alert that appears at the notification
+    // area at the top of the screen as an icon -- and as text as well if the user expands the
+    // notification area).
+    final int NOTIFICATION_ID = 1;
+
+    // Our instance of our MusicRetriever, which handles scanning for media and
+    // providing titles and URIs as we need.
+    MusicRetriever mRetriever;
+
+    Notification mNotification = null;
+
+    /**
+     * Makes sure the media player exists and has been reset. This will create the media player
+     * if needed, or reset the existing media player if one already exists.
+     */
+    void createMediaPlayerIfNeeded() {
+        if (mPlayer == null) {
+            mPlayer = new MediaPlayer();
+
+            // Make sure the media player will acquire a wake-lock while playing. If we don't do
+            // that, the CPU might go to sleep while the song is playing, causing playback to stop.
+            //
+            // Remember that to use this, we have to declare the android.permission.WAKE_LOCK
+            // permission in AndroidManifest.xml.
+            mPlayer.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
+
+            // we want the media player to notify us when it's ready preparing, and when it's done
+            // playing:
+            mPlayer.setOnPreparedListener(this);
+            mPlayer.setOnCompletionListener(this);
+            mPlayer.setOnErrorListener(this);
+        }
+        else
+            mPlayer.reset();
+    }
+
+    @Override
+    public void onCreate() {
+        Log.i(TAG, "debug: Creating service");
+
+        // Create the Wifi lock (this does not acquire the lock, this just creates it)
+        mWifiLock = ((WifiManager) getSystemService(Context.WIFI_SERVICE))
+                        .createWifiLock(WifiManager.WIFI_MODE_FULL, "mylock");
+
+        mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+
+        // Create the retriever and start an asynchronous task that will prepare it.
+        mRetriever = new MusicRetriever(getContentResolver());
+        (new PrepareMusicRetrieverTask(mRetriever,this)).execute();
+
+        // create the Audio Focus Helper, if the Audio Focus feature is available (SDK 8 or above)
+        if (android.os.Build.VERSION.SDK_INT >= 8)
+            mAudioFocusHelper = new AudioFocusHelper(getApplicationContext(), this);
+        else
+            mAudioFocus = AudioFocus.Focused; // no focus feature, so we always "have" audio focus
+    }
+
+    /**
+     * Called when we receive an Intent. When we receive an intent sent to us via startService(),
+     * this is the method that gets called. So here we react appropriately depending on the
+     * Intent's action, which specifies what is being requested of us.
+     */
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        String action = intent.getAction();
+        if (action.equals(ACTION_PLAY)) processPlayRequest();
+        else if (action.equals(ACTION_PAUSE)) processPauseRequest();
+        else if (action.equals(ACTION_SKIP)) processSkipRequest();
+        else if (action.equals(ACTION_STOP)) processStopRequest();
+        else if (action.equals(ACTION_REWIND)) processRewindRequest();
+        else if (action.equals(ACTION_URL)) processAddRequest(intent);
+
+        return START_NOT_STICKY; // Means we started the service, but don't want it to
+                                 // restart in case it's killed.
+    }
+
+    void processPlayRequest() {
+        if (mState == State.Retrieving) {
+            // If we are still retrieving media, just set the flag to start playing when we're
+            // ready
+            mWhatToPlayAfterRetrieve = null; // play a random song
+            mStartPlayingAfterRetrieve = true;
+            return;
+        }
+
+        tryToGetAudioFocus();
+
+        if (mState == State.Stopped) {
+            // If we're stopped, just go ahead to the next song and start playing
+            playNextSong(null);
+        }
+        else if (mState == State.Paused) {
+            // If we're paused, just continue playback and restore the 'foreground service' state.
+            mState = State.Playing;
+            setUpAsForeground(mSongTitle + " (playing)");
+            configAndStartMediaPlayer();
+        }
+    }
+
+    void processPauseRequest() {
+        if (mState == State.Retrieving) {
+            // If we are still retrieving media, clear the flag that indicates we should start
+            // playing when we're ready
+            mStartPlayingAfterRetrieve = false;
+            return;
+        }
+
+        if (mState == State.Playing) {
+            // Pause media player and cancel the 'foreground service' state.
+            mState = State.Paused;
+            mPlayer.pause();
+            relaxResources(false); // while paused, we always retain the MediaPlayer
+            giveUpAudioFocus();
+        }
+    }
+
+    void processRewindRequest() {
+        if (mState == State.Playing || mState == State.Paused)
+            mPlayer.seekTo(0);
+    }
+
+    void processSkipRequest() {
+        if (mState == State.Playing || mState == State.Paused) {
+            tryToGetAudioFocus();
+            playNextSong(null);
+        }
+    }
+
+    void processStopRequest() {
+        if (mState == State.Playing || mState == State.Paused) {
+            mState = State.Stopped;
+
+            // let go of all resources...
+            relaxResources(true);
+            giveUpAudioFocus();
+
+            // service is no longer necessary. Will be started again if needed.
+            stopSelf();
+        }
+    }
+
+    /**
+     * Releases resources used by the service for playback. This includes the "foreground service"
+     * status and notification, the wake locks and possibly the MediaPlayer.
+     *
+     * @param releaseMediaPlayer Indicates whether the Media Player should also be released or not
+     */
+    void relaxResources(boolean releaseMediaPlayer) {
+        // stop being a foreground service
+        stopForeground(true);
+
+        // stop and release the Media Player, if it's available
+        if (releaseMediaPlayer && mPlayer != null) {
+            mPlayer.reset();
+            mPlayer.release();
+            mPlayer = null;
+        }
+
+        // we can also release the Wifi lock, if we're holding it
+        if (mWifiLock.isHeld()) mWifiLock.release();
+    }
+
+    void giveUpAudioFocus() {
+        if (mAudioFocus == AudioFocus.Focused && mAudioFocusHelper != null
+                                && mAudioFocusHelper.abandonFocus())
+            mAudioFocus = AudioFocus.NoFocusNoDuck;
+    }
+
+    /**
+     * Reconfigures MediaPlayer according to audio focus settings and starts/restarts it. This
+     * method starts/restarts the MediaPlayer respecting the current audio focus state. So if
+     * we have focus, it will play normally; if we don't have focus, it will either leave the
+     * MediaPlayer paused or set it to a low volume, depending on what is allowed by the
+     * current focus settings. This method assumes mPlayer != null, so if you are calling it,
+     * you have to do so from a context where you are sure this is the case.
+     */
+    void configAndStartMediaPlayer() {
+        if (mAudioFocus == AudioFocus.NoFocusNoDuck) {
+            // If we don't have audio focus and can't duck, we have to pause, even if mState
+            // is State.Playing. But we stay in the Playing state so that we know we have to resume
+            // playback once we get the focus back.
+            if (mPlayer.isPlaying()) mPlayer.pause();
+            return;
+        }
+        else if (mAudioFocus == AudioFocus.NoFocusCanDuck)
+            mPlayer.setVolume(DUCK_VOLUME, DUCK_VOLUME);  // we'll be relatively quiet
+        else
+            mPlayer.setVolume(1.0f, 1.0f); // we can be loud
+
+        if (!mPlayer.isPlaying()) mPlayer.start();
+    }
+
+    void processAddRequest(Intent intent) {
+        // user wants to play a song directly by URL or path. The URL or path comes in the "data"
+        // part of the Intent. This Intent is sent by {@link MainActivity} after the user
+        // specifies the URL/path via an alert box.
+        if (mState == State.Retrieving) {
+            // we'll play the requested URL right after we finish retrieving
+            mWhatToPlayAfterRetrieve = intent.getData();
+            mStartPlayingAfterRetrieve = true;
+        }
+        else if (mState == State.Playing || mState == State.Paused || mState == State.Stopped) {
+            Log.i(TAG, "Playing from URL/path: " + intent.getData().toString());
+            tryToGetAudioFocus();
+            playNextSong(intent.getData().toString());
+        }
+    }
+
+    /**
+     * Shortcut to making and displaying a toast. Seemed cleaner than repeating
+     * this code everywhere, at least for this sample.
+     */
+    void say(String message) {
+        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
+    }
+
+    void tryToGetAudioFocus() {
+        if (mAudioFocus != AudioFocus.Focused && mAudioFocusHelper != null
+                        && mAudioFocusHelper.requestFocus())
+            mAudioFocus = AudioFocus.Focused;
+    }
+
+    /**
+     * Starts playing the next song. If manualUrl is null, the next song will be randomly selected
+     * from our Media Retriever (that is, it will be a random song in the user's device). If
+     * manualUrl is non-null, then it specifies the URL or path to the song that will be played
+     * next.
+     */
+    void playNextSong(String manualUrl) {
+        mState = State.Stopped;
+        relaxResources(false); // release everything except MediaPlayer
+
+        try {
+            if (manualUrl != null) {
+                // set the source of the media player to a manual URL or path
+                createMediaPlayerIfNeeded();
+                mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
+                mPlayer.setDataSource(manualUrl);
+                mSongTitle = manualUrl;
+                mIsStreaming = manualUrl.startsWith("http:") || manualUrl.startsWith("https:");
+            }
+            else {
+                mIsStreaming = false; // playing a locally available song
+
+                MusicRetriever.Item item = mRetriever.getRandomItem();
+                if (item == null) {
+                    say("No song to play :-(");
+                    return;
+                }
+
+                // set the source of the media player a a content URI
+                createMediaPlayerIfNeeded();
+                mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
+                mPlayer.setDataSource(getApplicationContext(), item.getURI());
+                mSongTitle = item.getTitle();
+            }
+
+
+            mState = State.Preparing;
+            setUpAsForeground(mSongTitle + " (loading)");
+
+            // starts preparing the media player in the background. When it's done, it will call
+            // our OnPreparedListener (that is, the onPrepared() method on this class, since we set
+            // the listener to 'this').
+            //
+            // Until the media player is prepared, we *cannot* call start() on it!
+            mPlayer.prepareAsync();
+
+            // If we are streaming from the internet, we want to hold a Wifi lock, which prevents
+            // the Wifi radio from going to sleep while the song is playing. If, on the other hand,
+            // we are *not* streaming, we want to release the lock if we were holding it before.
+            if (mIsStreaming) mWifiLock.acquire();
+            else if (mWifiLock.isHeld()) mWifiLock.release();
+        }
+        catch (IOException ex) {
+            Log.e("MusicService", "IOException playing next song: " + ex.getMessage());
+            ex.printStackTrace();
+        }
+    }
+
+    /** Called when media player is done playing current song. */
+    @Override
+    public void onCompletion(MediaPlayer player) {
+        // The media player finished playing the current song, so we go ahead and start the next.
+        playNextSong(null);
+    }
+
+    /** Called when media player is done preparing. */
+    @Override
+    public void onPrepared(MediaPlayer player) {
+        // The media player is done preparing. That means we can start playing!
+        mState = State.Playing;
+        updateNotification(mSongTitle + " (playing)");
+        configAndStartMediaPlayer();
+    }
+
+    /** Updates the notification. */
+    void updateNotification(String text) {
+        PendingIntent pi = PendingIntent.getActivity(getApplicationContext(), 0,
+                new Intent(getApplicationContext(), MainActivity.class),
+                PendingIntent.FLAG_UPDATE_CURRENT);
+        mNotification.setLatestEventInfo(getApplicationContext(), "RandomMusicPlayer", text, pi);
+        mNotificationManager.notify(NOTIFICATION_ID, mNotification);
+    }
+
+    /**
+     * Configures service as a foreground service. A foreground service is a service that's doing
+     * something the user is actively aware of (such as playing music), and must appear to the
+     * user as a notification. That's why we create the notification here.
+     */
+    void setUpAsForeground(String text) {
+        PendingIntent pi = PendingIntent.getActivity(getApplicationContext(), 0,
+                new Intent(getApplicationContext(), MainActivity.class),
+                PendingIntent.FLAG_UPDATE_CURRENT);
+        mNotification = new Notification();
+        mNotification.tickerText = text;
+        mNotification.icon = R.drawable.ic_stat_playing;
+        mNotification.flags |= Notification.FLAG_ONGOING_EVENT;
+        mNotification.setLatestEventInfo(getApplicationContext(), "RandomMusicPlayer",
+                text, pi);
+        startForeground(NOTIFICATION_ID, mNotification);
+    }
+
+    /**
+     * Called when there's an error playing media. When this happens, the media player goes to
+     * the Error state. We warn the user about the error and reset the media player.
+     */
+    @Override
+    public boolean onError(MediaPlayer mp, int what, int extra) {
+        Toast.makeText(getApplicationContext(), "Media player error! Resetting.",
+            Toast.LENGTH_SHORT).show();
+        Log.e(TAG, "Error: what=" + String.valueOf(what) + ", extra=" + String.valueOf(extra));
+
+        mState = State.Stopped;
+        relaxResources(true);
+        giveUpAudioFocus();
+        return true; // true indicates we handled the error
+    }
+
+    @Override
+    public void onGainedAudioFocus() {
+        Toast.makeText(getApplicationContext(), "gained audio focus.", Toast.LENGTH_SHORT).show();
+        mAudioFocus = AudioFocus.Focused;
+
+        // restart media player with new focus settings
+        if (mState == State.Playing)
+            configAndStartMediaPlayer();
+    }
+
+    @Override
+    public void onLostAudioFocus(boolean canDuck) {
+        Toast.makeText(getApplicationContext(), "lost audio focus." + (canDuck ? "can duck" :
+            "no duck"), Toast.LENGTH_SHORT).show();
+        mAudioFocus = canDuck ? AudioFocus.NoFocusCanDuck : AudioFocus.NoFocusNoDuck;
+
+        // start/restart/pause media player with new focus settings
+        if (mPlayer != null && mPlayer.isPlaying())
+            configAndStartMediaPlayer();
+    }
+
+    @Override
+    public void onMusicRetrieverPrepared() {
+        // Done retrieving!
+        mState = State.Stopped;
+
+        // If the flag indicates we should start playing after retrieving, let's do that now.
+        if (mStartPlayingAfterRetrieve) {
+            tryToGetAudioFocus();
+            playNextSong(mWhatToPlayAfterRetrieve == null ?
+                    null : mWhatToPlayAfterRetrieve.toString());
+        }
+    }
+
+
+    @Override
+    public void onDestroy() {
+        // Service is being killed, so make sure we release our resources
+        mState = State.Stopped;
+        relaxResources(true);
+        giveUpAudioFocus();
+    }
+
+    @Override
+    public IBinder onBind(Intent arg0) {
+        return null;
+    }
+}

samples/RandomMusicPlayer/src/com/example/android/musicplayer/PrepareMusicRetrieverTask.java

@@ -0,0 +1,50 @@
+/*   
+ * 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 android.os.AsyncTask;
+
+/**
+ * Asynchronous task that prepares a MusicRetriever. This asynchronous task essentially calls
+ * {@link MusicRetriever#prepare()} on a {@link MusicRetriever}, which may take some time to
+ * run. Upon finishing, it notifies the indicated {@MusicRetrieverPreparedListener}.
+ */
+public class PrepareMusicRetrieverTask extends AsyncTask<Void, Void, Void> {
+    MusicRetriever mRetriever;
+    MusicRetrieverPreparedListener mListener;
+
+    public PrepareMusicRetrieverTask(MusicRetriever retriever,
+            MusicRetrieverPreparedListener listener) {
+        mRetriever = retriever;
+        mListener = listener;
+    }
+
+    @Override
+    protected Void doInBackground(Void... arg0) {
+        mRetriever.prepare();
+        return null;
+    }
+
+    @Override
+    protected void onPostExecute(Void result) {
+        mListener.onMusicRetrieverPrepared();
+    }
+
+    public interface MusicRetrieverPreparedListener {
+        public void onMusicRetrieverPrepared();
+    }
+}