Make DefaultMediaNotificationProvider more configurable

Add a Builder to constructor DefaultMediaNotificationProvider. The
Builder can also set the provider's:
- notification ID
- notification channel ID
- notification channel name

The change adds an API for apps to set the small icon in notifications.

#minor-release
Issue: androidx/media#104
PiperOrigin-RevId: 462111536
(cherry picked from commit 436ff6d86a4b8de5324d3b3b08bb655b75ca6632)

RELEASENOTES.md

@@ -19,6 +19,12 @@
     *   Ensure commands are always executed in the correct order even if some
         require asynchronous resolution
         ([#85](https://github.com/androidx/media/issues/85)).
+    *   Add `DefaultNotificationProvider.Builder` to build
+        `DefaultNotificationProvider` instances. The builder can configure the
+        notification ID, the notification channel ID and the notification
+        channel name used by the provider. Also, add method
+        `DefaultNotificationProvider.setSmallIcon(int)` to set the notifications
+        small icon ([#104](https://github.com/androidx/media/issues/104)).
 
 ### 1.0.0-beta02 (2022-07-15)
 

libraries/session/build.gradle

@@ -32,6 +32,7 @@ android {
 }
 dependencies {
     api project(modulePrefix + 'lib-common')
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     implementation 'androidx.collection:collection:' + androidxCollectionVersion

libraries/session/src/main/java/androidx/media3/session/DefaultMediaNotificationProvider.java

@@ -36,7 +36,9 @@ import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import androidx.annotation.DrawableRes;
 import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
 import androidx.core.app.NotificationCompat;
 import androidx.core.graphics.drawable.IconCompat;
 import androidx.media.app.NotificationCompat.MediaStyle;
@@ -51,6 +53,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -89,12 +92,115 @@ import java.util.concurrent.ExecutionException;
  *   <li><b>{@code media3_notification_seek_to_previous}</b> - The previous icon.
  *   <li><b>{@code media3_notification_seek_to_next}</b> - The next icon.
  *   <li><b>{@code media3_notification_small_icon}</b> - The {@link
- *       NotificationCompat.Builder#setSmallIcon(int) small icon}.
+ *       NotificationCompat.Builder#setSmallIcon(int) small icon}. A different icon can be set with
+ *       {@link #setSmallIcon(int)}.
+ * </ul>
+ *
+ * <h2>String resources</h2>
+ *
+ * String resources used can be overridden by resources with the same names defined the application.
+ * These are:
+ *
+ * <ul>
+ *   <li><b>{@code media3_controls_play_description}</b> - The description of the play icon.
+ *   <li><b>{@code media3_controls_pause_description}</b> - The description of the pause icon.
+ *   <li><b>{@code media3_controls_seek_to_previous_description}</b> - The description of the
+ *       previous icon.
+ *   <li><b>{@code media3_controls_seek_to_next_description}</b> - The description of the next icon.
+ *   <li><b>{@code default_notification_channel_name}</b> The name of the {@link
+ *       NotificationChannel} on which created notifications are posted. A different string resource
+ *       can be set when constructing the provider with {@link
+ *       DefaultMediaNotificationProvider.Builder#setChannelName(int)}.
  * </ul>
  */
 @UnstableApi
 public class DefaultMediaNotificationProvider implements MediaNotification.Provider {
 
+  /** A builder for {@link DefaultMediaNotificationProvider} instances. */
+  public static final class Builder {
+    private final Context context;
+    private int notificationId;
+    private String channelId;
+    @StringRes private int channelNameResourceId;
+    private BitmapLoader bitmapLoader;
+    private boolean built;
+
+    /**
+     * Creates a builder.
+     *
+     * @param context Any {@link Context}.
+     */
+    public Builder(Context context) {
+      this.context = context;
+      notificationId = DEFAULT_NOTIFICATION_ID;
+      channelId = DEFAULT_CHANNEL_ID;
+      channelNameResourceId = DEFAULT_CHANNEL_NAME_RESOURCE_ID;
+      bitmapLoader = new SimpleBitmapLoader();
+    }
+
+    /**
+     * Sets the {@link MediaNotification#notificationId} used for the created notifications. By
+     * default this is set to {@link #DEFAULT_NOTIFICATION_ID}.
+     *
+     * @param notificationId The notification ID.
+     * @return This builder.
+     */
+    @CanIgnoreReturnValue
+    public Builder setNotificationId(int notificationId) {
+      this.notificationId = notificationId;
+      return this;
+    }
+
+    /**
+     * Sets the ID of the {@link NotificationChannel} on which created notifications are posted on.
+     * By default this is set to {@link #DEFAULT_CHANNEL_ID}.
+     *
+     * @param channelId The channel ID.
+     * @return This builder.
+     */
+    @CanIgnoreReturnValue
+    public Builder setChannelId(String channelId) {
+      this.channelId = channelId;
+      return this;
+    }
+
+    /**
+     * Sets the name of the {@link NotificationChannel} on which created notifications are posted
+     * on. By default this is set to {@link #DEFAULT_CHANNEL_NAME_RESOURCE_ID}.
+     *
+     * @param channelNameResourceId The string resource ID with the channel name.
+     * @return This builder.
+     */
+    @CanIgnoreReturnValue
+    public Builder setChannelName(@StringRes int channelNameResourceId) {
+      this.channelNameResourceId = channelNameResourceId;
+      return this;
+    }
+
+    /**
+     * Sets the {@link BitmapLoader} used load artwork. By default, a {@link SimpleBitmapLoader}
+     * will be used.
+     *
+     * @param bitmapLoader The bitmap loader.
+     * @return This builder.
+     */
+    @CanIgnoreReturnValue
+    public Builder setBitmapLoader(BitmapLoader bitmapLoader) {
+      this.bitmapLoader = bitmapLoader;
+      return this;
+    }
+
+    /**
+     * Builds the {@link DefaultMediaNotificationProvider}. The method can be called at most once.
+     */
+    public DefaultMediaNotificationProvider build() {
+      checkState(!built);
+      DefaultMediaNotificationProvider provider = new DefaultMediaNotificationProvider(this);
+      built = true;
+      return provider;
+    }
+  }
+
   /**
    * An extras key that can be used to define the index of a {@link CommandButton} in {@linkplain
    * Notification.MediaStyle#setShowActionsInCompactView(int...) compact view}.
@@ -102,12 +208,27 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
   public static final String COMMAND_KEY_COMPACT_VIEW_INDEX =
       "androidx.media3.session.command.COMPACT_VIEW_INDEX";
 
+  /** The default ID used for the {@link MediaNotification#notificationId}. */
+  public static final int DEFAULT_NOTIFICATION_ID = 1001;
+  /**
+   * The default ID used for the {@link NotificationChannel} on which created notifications are
+   * posted on.
+   */
+  public static final String DEFAULT_CHANNEL_ID = "default_channel_id";
+  /**
+   * The default name used for the {@link NotificationChannel} on which created notifications are
+   * posted on.
+   */
+  @StringRes
+  public static final int DEFAULT_CHANNEL_NAME_RESOURCE_ID =
+      R.string.default_notification_channel_name;
+
   private static final String TAG = "NotificationProvider";
-  private static final int NOTIFICATION_ID = 1001;
-  private static final String NOTIFICATION_CHANNEL_ID = "default_channel_id";
-  private static final String NOTIFICATION_CHANNEL_NAME = "Now playing";
 
   private final Context context;
+  private final int notificationId;
+  private final String channelId;
+  @StringRes private final int channelNameResourceId;
   private final NotificationManager notificationManager;
   private final BitmapLoader bitmapLoader;
   // Cache the last loaded bitmap to avoid reloading the bitmap again, particularly useful when
@@ -116,24 +237,25 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
   private final Handler mainHandler;
 
   private OnBitmapLoadedFutureCallback pendingOnBitmapLoadedFutureCallback;
+  @DrawableRes private int smallIconResourceId;
 
-  /** Creates an instance that uses a {@link SimpleBitmapLoader} for loading artwork images. */
+  private DefaultMediaNotificationProvider(Builder builder) {
-  public DefaultMediaNotificationProvider(Context context) {
+    this.context = builder.context;
-    this(context, new SimpleBitmapLoader());
+    this.notificationId = builder.notificationId;
-  }
+    this.channelId = builder.channelId;
-
+    this.channelNameResourceId = builder.channelNameResourceId;
-  /** Creates an instance that uses the {@code bitmapLoader} for loading artwork images. */
+    this.bitmapLoader = builder.bitmapLoader;
-  public DefaultMediaNotificationProvider(Context context, BitmapLoader bitmapLoader) {
-    this.context = context.getApplicationContext();
-    this.bitmapLoader = bitmapLoader;
-    lastLoadedBitmapInfo = new LoadedBitmapInfo();
-    mainHandler = new Handler(Looper.getMainLooper());
     notificationManager =
         checkStateNotNull(
             (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE));
+    lastLoadedBitmapInfo = new LoadedBitmapInfo();
+    mainHandler = new Handler(Looper.getMainLooper());
     pendingOnBitmapLoadedFutureCallback = new OnBitmapLoadedFutureCallback(bitmap -> {});
+    smallIconResourceId = R.drawable.media3_notification_small_icon;
   }
 
+  // MediaNotification.Provider implementation
+
   @Override
   public final MediaNotification createNotification(
       MediaSession mediaSession,
@@ -143,8 +265,7 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
     ensureNotificationChannel();
 
     Player player = mediaSession.getPlayer();
-    NotificationCompat.Builder builder =
+    NotificationCompat.Builder builder = new NotificationCompat.Builder(context, channelId);
-        new NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID);
 
     MediaStyle mediaStyle = new MediaStyle();
     int[] compactViewIndices =
@@ -173,7 +294,7 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
                 bitmap -> {
                   builder.setLargeIcon(bitmap);
                   onNotificationChangedCallback.onNotificationChanged(
-                      new MediaNotification(NOTIFICATION_ID, builder.build()));
+                      new MediaNotification(notificationId, builder.build()));
                 }),
             // This callback must be executed on the next looper iteration, after this method has
             // returned a media notification.
@@ -200,12 +321,12 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
             .setDeleteIntent(
                 actionFactory.createMediaActionPendingIntent(mediaSession, COMMAND_STOP))
             .setOnlyAlertOnce(true)
-            .setSmallIcon(R.drawable.media3_notification_small_icon)
+            .setSmallIcon(smallIconResourceId)
             .setStyle(mediaStyle)
             .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
             .setOngoing(false)
             .build();
-    return new MediaNotification(NOTIFICATION_ID, notification);
+    return new MediaNotification(notificationId, notification);
   }
 
   @Override
@@ -214,6 +335,18 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
     return false;
   }
 
+  // Other methods
+
+  /**
+   * Sets the small icon of the notification which is also shown in the system status bar.
+   *
+   * @see NotificationCompat.Builder#setSmallIcon(int)
+   * @param smallIconResourceId The resource id of the small icon.
+   */
+  public final void setSmallIcon(@DrawableRes int smallIconResourceId) {
+    this.smallIconResourceId = smallIconResourceId;
+  }
+
   /**
    * Returns the ordered list of {@linkplain CommandButton command buttons} to be used to build the
    * notification.
@@ -367,13 +500,14 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
   }
 
   private void ensureNotificationChannel() {
-    if (Util.SDK_INT < 26
+    if (Util.SDK_INT < 26 || notificationManager.getNotificationChannel(channelId) != null) {
-        || notificationManager.getNotificationChannel(NOTIFICATION_CHANNEL_ID) != null) {
       return;
     }
     NotificationChannel channel =
         new NotificationChannel(
-            NOTIFICATION_CHANNEL_ID, NOTIFICATION_CHANNEL_NAME, NotificationManager.IMPORTANCE_LOW);
+            channelId,
+            context.getString(channelNameResourceId),
+            NotificationManager.IMPORTANCE_LOW);
     notificationManager.createNotificationChannel(channel);
   }
 

libraries/session/src/main/java/androidx/media3/session/MediaSessionService.java

@@ -433,7 +433,8 @@ public abstract class MediaSessionService extends Service {
     synchronized (lock) {
       if (mediaNotificationManager == null) {
         if (mediaNotificationProvider == null) {
-          mediaNotificationProvider = new DefaultMediaNotificationProvider(getApplicationContext());
+          mediaNotificationProvider =
+              new DefaultMediaNotificationProvider.Builder(getApplicationContext()).build();
         }
         mediaNotificationManager =
             new MediaNotificationManager(

libraries/session/src/test/java/androidx/media3/session/DefaultMediaNotificationProviderTest.java

@@ -24,10 +24,14 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
 
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.content.Context;
 import android.net.Uri;
 import android.os.Bundle;
 import androidx.annotation.Nullable;
 import androidx.core.app.NotificationCompat;
+import androidx.media3.common.MediaMetadata;
 import androidx.media3.common.Player;
 import androidx.media3.common.Player.Commands;
 import androidx.test.core.app.ApplicationProvider;
@@ -40,6 +44,8 @@ import org.mockito.ArgumentCaptor;
 import org.mockito.InOrder;
 import org.mockito.Mockito;
 import org.robolectric.Robolectric;
+import org.robolectric.Shadows;
+import org.robolectric.shadows.ShadowNotificationManager;
 
 /** Tests for {@link DefaultMediaNotificationProvider}. */
 @RunWith(AndroidJUnit4.class)
@@ -48,7 +54,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void getMediaButtons_playWhenReadyTrueOrFalse_correctPlayPauseResources() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     Commands commands = new Commands.Builder().addAllCommands().build();
 
     List<CommandButton> mediaButtonsWhenPlaying =
@@ -73,7 +80,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void getMediaButtons_allCommandsAvailable_createsPauseSkipNextSkipPreviousButtons() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     Commands commands = new Commands.Builder().addAllCommands().build();
     SessionCommand customSessionCommand = new SessionCommand("", Bundle.EMPTY);
     CommandButton customCommandButton =
@@ -98,7 +106,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void getMediaButtons_noPlayerCommandsAvailable_onlyCustomLayoutButtons() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     Commands commands = new Commands.Builder().build();
     SessionCommand customSessionCommand = new SessionCommand("action1", Bundle.EMPTY);
     CommandButton customCommandButton =
@@ -118,7 +127,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void addNotificationActions_customCompactViewDeclarations_correctCompactViewIndices() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     NotificationCompat.Builder mockNotificationBuilder = mock(NotificationCompat.Builder.class);
     MediaNotification.ActionFactory mockActionFactory = mock(MediaNotification.ActionFactory.class);
     MediaSession mockMediaSession = mock(MediaSession.class);
@@ -185,7 +195,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void addNotificationActions_playPauseCommandNoCustomDeclaration_playPauseInCompactView() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     NotificationCompat.Builder mockNotificationBuilder = mock(NotificationCompat.Builder.class);
     MediaNotification.ActionFactory mockActionFactory = mock(MediaNotification.ActionFactory.class);
     MediaSession mockMediaSession = mock(MediaSession.class);
@@ -230,7 +241,8 @@ public class DefaultMediaNotificationProviderTest {
   public void
       addNotificationActions_noPlayPauseCommandNoCustomDeclaration_emptyCompactViewIndices() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     NotificationCompat.Builder mockNotificationBuilder = mock(NotificationCompat.Builder.class);
     MediaNotification.ActionFactory mockActionFactory = mock(MediaNotification.ActionFactory.class);
     MediaSession mockMediaSession = mock(MediaSession.class);
@@ -259,7 +271,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void addNotificationActions_outOfBoundsCompactViewIndices_ignored() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     NotificationCompat.Builder mockNotificationBuilder = mock(NotificationCompat.Builder.class);
     MediaNotification.ActionFactory mockActionFactory = mock(MediaNotification.ActionFactory.class);
     MediaSession mockMediaSession = mock(MediaSession.class);
@@ -304,7 +317,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void addNotificationActions_unsetLeadingArrayFields_cropped() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     NotificationCompat.Builder mockNotificationBuilder = mock(NotificationCompat.Builder.class);
     MediaNotification.ActionFactory mockActionFactory = mock(MediaNotification.ActionFactory.class);
     MediaSession mockMediaSession = mock(MediaSession.class);
@@ -337,7 +351,8 @@ public class DefaultMediaNotificationProviderTest {
   @Test
   public void addNotificationActions_correctNotificationActionAttributes() {
     DefaultMediaNotificationProvider defaultMediaNotificationProvider =
-        new DefaultMediaNotificationProvider(ApplicationProvider.getApplicationContext());
+        new DefaultMediaNotificationProvider.Builder(ApplicationProvider.getApplicationContext())
+            .build();
     NotificationCompat.Builder mockNotificationBuilder = mock(NotificationCompat.Builder.class);
     DefaultActionFactory defaultActionFactory =
         new DefaultActionFactory(Robolectric.setupService(TestService.class));
@@ -374,6 +389,96 @@ public class DefaultMediaNotificationProviderTest {
     assertThat(actions.get(0).getExtras().size()).isEqualTo(0);
   }
 
+  @Test
+  public void provider_withCustomIds_notificationsUseCustomIds() {
+    Context context = ApplicationProvider.getApplicationContext();
+    DefaultMediaNotificationProvider defaultMediaNotificationProvider =
+        new DefaultMediaNotificationProvider.Builder(context)
+            .setNotificationId(/* notificationId= */ 2)
+            .setChannelId(/* channelId= */ "customChannelId")
+            .setChannelName(/* channelNameResourceId= */ R.string.media3_controls_play_description)
+            .build();
+    MediaSession mockMediaSession = createMockMediaSessionForNotification();
+    DefaultActionFactory defaultActionFactory =
+        new DefaultActionFactory(Robolectric.setupService(TestService.class));
+
+    MediaNotification notification =
+        defaultMediaNotificationProvider.createNotification(
+            mockMediaSession,
+            ImmutableList.of(),
+            defaultActionFactory,
+            mock(MediaNotification.Provider.Callback.class));
+
+    assertThat(notification.notificationId).isEqualTo(2);
+    assertThat(notification.notification.getChannelId()).isEqualTo("customChannelId");
+    ShadowNotificationManager shadowNotificationManager =
+        Shadows.shadowOf(
+            (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE));
+    assertHasNotificationChannel(
+        shadowNotificationManager.getNotificationChannels(),
+        /* channelId= */ "customChannelId",
+        /* channelName= */ context.getString(R.string.media3_controls_play_description));
+  }
+
+  @Test
+  public void setCustomSmallIcon_notificationUsesCustomSmallIcon() {
+    Context context = ApplicationProvider.getApplicationContext();
+    DefaultMediaNotificationProvider defaultMediaNotificationProvider =
+        new DefaultMediaNotificationProvider.Builder(context).build();
+    DefaultActionFactory defaultActionFactory =
+        new DefaultActionFactory(Robolectric.setupService(TestService.class));
+    MediaSession mockMediaSession = createMockMediaSessionForNotification();
+
+    MediaNotification notification =
+        defaultMediaNotificationProvider.createNotification(
+            mockMediaSession,
+            ImmutableList.of(),
+            defaultActionFactory,
+            mock(MediaNotification.Provider.Callback.class));
+    // Change the small icon.
+    defaultMediaNotificationProvider.setSmallIcon(R.drawable.media3_icon_circular_play);
+    MediaNotification notificationWithSmallIcon =
+        defaultMediaNotificationProvider.createNotification(
+            mockMediaSession,
+            ImmutableList.of(),
+            defaultActionFactory,
+            mock(MediaNotification.Provider.Callback.class));
+
+    assertThat(notification.notification.getSmallIcon().getResId())
+        .isEqualTo(R.drawable.media3_notification_small_icon);
+    assertThat(notificationWithSmallIcon.notification.getSmallIcon().getResId())
+        .isEqualTo(R.drawable.media3_icon_circular_play);
+  }
+
+  private static void assertHasNotificationChannel(
+      List<Object> notificationChannels, String channelId, String channelName) {
+    boolean found = false;
+    for (int i = 0; i < notificationChannels.size(); i++) {
+      NotificationChannel notificationChannel = (NotificationChannel) notificationChannels.get(i);
+      found =
+          notificationChannel.getId().equals(channelId)
+              // NotificationChannel.getName() is CharSequence. Use String#contentEquals instead
+              // because CharSequence.equals() has undefined behavior.
+              && channelName.contentEquals(notificationChannel.getName());
+      if (found) {
+        break;
+      }
+    }
+    assertThat(found).isTrue();
+  }
+
+  private static MediaSession createMockMediaSessionForNotification() {
+    Player mockPlayer = mock(Player.class);
+    when(mockPlayer.getAvailableCommands()).thenReturn(Commands.EMPTY);
+    when(mockPlayer.getMediaMetadata()).thenReturn(MediaMetadata.EMPTY);
+    MediaSession mockMediaSession = mock(MediaSession.class);
+    when(mockMediaSession.getPlayer()).thenReturn(mockPlayer);
+    MediaSessionImpl mockMediaSessionImpl = mock(MediaSessionImpl.class);
+    when(mockMediaSession.getImpl()).thenReturn(mockMediaSessionImpl);
+    when(mockMediaSessionImpl.getUri()).thenReturn(Uri.parse("http://example.com"));
+    return mockMediaSession;
+  }
+
   /** A test service for unit tests. */
   private static final class TestService extends MediaLibraryService {
     @Nullable