Add Player.Listener.onPlayerErrorChanged

Equivalent to onPlayerError, except it's also called for null.

PiperOrigin-RevId: 381015336

extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoaderTest.java

@@ -273,7 +273,9 @@ public final class ImaAdsLoaderTest {
     adEventListener.onAdEvent(getAdEvent(AdEventType.STARTED, mockPrerollSingleAd));
     videoAdPlayer.pauseAd(TEST_AD_MEDIA_INFO);
     videoAdPlayer.stopAd(TEST_AD_MEDIA_INFO);
-    imaAdsLoader.onPlayerError(ExoPlaybackException.createForSource(new IOException()));
+    ExoPlaybackException anException = ExoPlaybackException.createForSource(new IOException());
+    imaAdsLoader.onPlayerErrorChanged(anException);
+    imaAdsLoader.onPlayerError(anException);
     imaAdsLoader.onPositionDiscontinuity(
         new Player.PositionInfo(
             /* windowUid= */ new Object(),

library/common/src/main/java/com/google/android/exoplayer2/ForwardingPlayer.java

@@ -685,6 +685,11 @@ public class ForwardingPlayer implements Player {
       eventListener.onPlayerError(error);
     }
 
+    @Override
+    public void onPlayerErrorChanged(@Nullable PlaybackException error) {
+      eventListener.onPlayerErrorChanged(error);
+    }
+
     @Override
     public void onPositionDiscontinuity(@DiscontinuityReason int reason) {
       eventListener.onPositionDiscontinuity(reason);

library/common/src/main/java/com/google/android/exoplayer2/Player.java

@@ -274,6 +274,19 @@ public interface Player {
      */
     default void onPlayerError(PlaybackException error) {}
 
+    /**
+     * Called when the {@link PlaybackException} returned by {@link #getPlayerError()} changes.
+     *
+     * <p>{@link #onEvents(Player, Events)} will also be called to report this event along with
+     * other events that happen in the same {@link Looper} message queue iteration.
+     *
+     * <p>Implementations of Player may pass an instance of a subclass of {@link PlaybackException}
+     * to this method in order to include more information about the error.
+     *
+     * @param error The new error, or null if the error is being cleared.
+     */
+    default void onPlayerErrorChanged(@Nullable PlaybackException error) {}
+
     /**
      * @deprecated Use {@link #onPositionDiscontinuity(PositionInfo, PositionInfo, int)} instead.
      */

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

@@ -1314,12 +1314,16 @@ import java.util.concurrent.CopyOnWriteArraySet;
           Player.EVENT_MEDIA_ITEM_TRANSITION,
           listener -> listener.onMediaItemTransition(finalMediaItem, mediaItemTransitionReason));
     }
-    if (previousPlaybackInfo.playbackError != newPlaybackInfo.playbackError
-        && newPlaybackInfo.playbackError != null) {
+    if (previousPlaybackInfo.playbackError != newPlaybackInfo.playbackError) {
+      listeners.queueEvent(
+          Player.EVENT_PLAYER_ERROR,
+          listener -> listener.onPlayerErrorChanged(newPlaybackInfo.playbackError));
+      if (newPlaybackInfo.playbackError != null) {
         listeners.queueEvent(
             Player.EVENT_PLAYER_ERROR,
             listener -> listener.onPlayerError(newPlaybackInfo.playbackError));
       }
+    }
     if (previousPlaybackInfo.trackSelectorResult != newPlaybackInfo.trackSelectorResult) {
       trackSelector.onSelectionActivated(newPlaybackInfo.trackSelectorResult.info);
       TrackSelectionArray newSelection =

library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java

@@ -44,6 +44,7 @@ import static com.google.android.exoplayer2.Player.COMMAND_SET_VIDEO_SURFACE;
 import static com.google.android.exoplayer2.Player.COMMAND_SET_VOLUME;
 import static com.google.android.exoplayer2.Player.DEFAULT_FAST_FORWARD_INCREMENT_MS;
 import static com.google.android.exoplayer2.Player.DEFAULT_REWIND_INCREMENT_MS;
+import static com.google.android.exoplayer2.Player.STATE_ENDED;
 import static com.google.android.exoplayer2.robolectric.RobolectricUtil.runMainLooperUntil;
 import static com.google.android.exoplayer2.robolectric.TestPlayerRunHelper.playUntilPosition;
 import static com.google.android.exoplayer2.robolectric.TestPlayerRunHelper.playUntilStartOfWindow;
@@ -69,6 +70,7 @@ import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.robolectric.Shadows.shadowOf;
@@ -161,6 +163,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
 import org.mockito.ArgumentMatcher;
+import org.mockito.ArgumentMatchers;
 import org.mockito.InOrder;
 import org.mockito.Mockito;
 import org.robolectric.shadows.ShadowAudioManager;
@@ -2855,6 +2858,38 @@ public final class ExoPlayerTest {
     assertThat(position[0]).isEqualTo(0L);
   }
 
+  @Test
+  public void onPlayerErrorChanged_isNotifiedForNullError() throws Exception {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    player.addMediaSource(
+        new FakeMediaSource(/* timeline= */ null) {
+          @Override
+          public void maybeThrowSourceInfoRefreshError() throws IOException {
+            throw new IOException();
+          }
+        });
+    Player.Listener mockListener = mock(Player.Listener.class);
+    player.addListener(mockListener);
+
+    player.prepare();
+    player.play();
+    ExoPlaybackException error = TestPlayerRunHelper.runUntilError(player);
+    // The media source fails preparation, so we expect both methods to be called.
+    verify(mockListener).onPlayerErrorChanged(error);
+    verify(mockListener).onPlayerError(error);
+
+    reset(mockListener);
+
+    player.setMediaSource(new FakeMediaSource());
+    player.prepare();
+    player.play();
+    TestPlayerRunHelper.runUntilPlaybackState(player, STATE_ENDED);
+    // Now the player, which had a playback error, was re-prepared causing the error to be cleared.
+    // We expect the change to null to be notified, but not onPlayerError.
+    verify(mockListener).onPlayerErrorChanged(ArgumentMatchers.isNull());
+    verify(mockListener, never()).onPlayerError(any());
+  }
+
   @Test
   public void recursivePlayerChangesReportConsistentValuesForAllListeners() throws Exception {
     // We add two listeners to the player. The first stops the player as soon as it's ready and both
@@ -9408,6 +9443,7 @@ public final class ExoPlayerTest {
     verify(listener, atLeastOnce()).onStaticMetadataChanged(any());
     verify(listener, atLeastOnce()).onPlayWhenReadyChanged(anyBoolean(), anyInt());
     verify(listener, atLeastOnce()).onIsPlayingChanged(anyBoolean());
+    verify(listener, atLeastOnce()).onPlayerErrorChanged(any());
     verify(listener, atLeastOnce()).onPlayerError(any());
 
     // Verify all the same events have been recorded with onEvents.