Add getRenderer method to ExoPlayer.

This allows access to custom renderers, for example to send messages
or to access custom fields and methods.

PiperOrigin-RevId: 424878963

RELEASENOTES.md

@@ -41,6 +41,8 @@
         multiple codecs are supported by primary, hardware-accelerated decoders
         ([#4835](https://github.com/google/ExoPlayer/issues/4835)).
     *   Rename `DecoderCounters#inputBufferCount` to `queuedInputBufferCount`.
+    *   Make `SimpleExoPlayer.renderers` private. Renderers can be accessed via
+        `ExoPlayer.getRenderer`.
 *   Android 12 compatibility:
     *   Upgrade the Cast extension to depend on
         `com.google.android.gms:play-services-cast-framework:20.1.0`. Earlier

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayer.java

@@ -1087,6 +1087,14 @@ public interface ExoPlayer extends Player {
   @C.TrackType
   int getRendererType(int index);
 
+  /**
+   * Returns the renderer at the given index.
+   *
+   * @param index The index of the renderer.
+   * @return The renderer at this index.
+   */
+  Renderer getRenderer(int index);
+
   /**
    * Returns the track selector that this player uses, or null if track selection is not supported.
    */

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java

@@ -944,6 +944,10 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return renderers[index].getTrackType();
   }
 
+  public Renderer getRenderer(int index) {
+    return renderers[index];
+  }
+
   public TrackSelector getTrackSelector() {
     return trackSelector;
   }

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -347,8 +347,7 @@ public class SimpleExoPlayer extends BasePlayer
 
   private static final String TAG = "SimpleExoPlayer";
 
-  protected final Renderer[] renderers;
-
+  private final Renderer[] renderers;
   private final ConditionVariable constructorFinished;
   private final Context applicationContext;
   private final ExoPlayerImpl player;
@@ -1349,6 +1348,12 @@ public class SimpleExoPlayer extends BasePlayer
     return player.getRendererType(index);
   }
 
+  @Override
+  public Renderer getRenderer(int index) {
+    verifyApplicationThread();
+    return player.getRenderer(index);
+  }
+
   @Override
   public TrackSelector getTrackSelector() {
     verifyApplicationThread();

testutils/src/main/java/com/google/android/exoplayer2/testutil/StubExoPlayer.java

@@ -22,6 +22,7 @@ import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.PlayerMessage;
+import com.google.android.exoplayer2.Renderer;
 import com.google.android.exoplayer2.SeekParameters;
 import com.google.android.exoplayer2.analytics.AnalyticsCollector;
 import com.google.android.exoplayer2.analytics.AnalyticsListener;
@@ -291,6 +292,11 @@ public class StubExoPlayer extends StubPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
+  @Override
+  public Renderer getRenderer(int index) {
+    throw new UnsupportedOperationException();
+  }
+
   @Override
   @Nullable
   public TrackSelector getTrackSelector() {