Mask ExoPlayer.isLoading when it transitions to IDLE or ENDED states

In some cases, the ExoPlayer immediately transitions to `STATE_IDLE` or `STATE_ENDED` on application thread, while `isLoading` can still remain as `true` before it is finally updated from playback thread.

Issue: androidx/media#2133

#cherrypick

PiperOrigin-RevId: 728724157

RELEASENOTES.md

@@ -7,6 +7,9 @@
         it easier to handle updates in other classes
         ([#2128](https://github.com/androidx/media/issues/2128)).
 *   ExoPlayer:
+    *   Fix a bug where `ExoPlayer.isLoading()` remains `true` while it has
+        transitioned to `STATE_IDLE` or `STATE_ENDED`
+        ([#2133](https://github.com/androidx/media/issues/2133)).
 *   Transformer:
 *   Track Selection:
 *   Extractors:

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/ExoPlayerImpl.java

@@ -531,8 +531,8 @@ import java.util.concurrent.CopyOnWriteArraySet;
     }
     PlaybackInfo playbackInfo = this.playbackInfo.copyWithPlaybackError(null);
     playbackInfo =
-        playbackInfo.copyWithPlaybackState(
+        maskPlaybackState(
-            playbackInfo.timeline.isEmpty() ? STATE_ENDED : STATE_BUFFERING);
+            playbackInfo, playbackInfo.timeline.isEmpty() ? STATE_ENDED : STATE_BUFFERING);
     // Trigger internal prepare first before updating the playback info and notifying external
     // listeners to ensure that new operations issued in the listener notifications reach the
     // player after this prepare. The internal player can't change the playback info immediately
@@ -905,7 +905,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
     PlaybackInfo newPlaybackInfo = playbackInfo;
     if (playbackInfo.playbackState == Player.STATE_READY
         || (playbackInfo.playbackState == Player.STATE_ENDED && !timeline.isEmpty())) {
-      newPlaybackInfo = playbackInfo.copyWithPlaybackState(Player.STATE_BUFFERING);
+      newPlaybackInfo = maskPlaybackState(playbackInfo, Player.STATE_BUFFERING);
     }
     int oldMaskingMediaItemIndex = getCurrentMediaItemIndex();
     newPlaybackInfo =
@@ -1051,7 +1051,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
     if (playbackInfo.sleepingForOffload) {
       playbackInfo = playbackInfo.copyWithEstimatedPosition();
     }
-    playbackInfo = playbackInfo.copyWithPlaybackState(Player.STATE_IDLE);
+    playbackInfo = maskPlaybackState(playbackInfo, Player.STATE_IDLE);
     playbackInfo = playbackInfo.copyWithLoadingMediaPeriodId(playbackInfo.periodId);
     playbackInfo.bufferedPositionUs = playbackInfo.positionUs;
     playbackInfo.totalBufferedDurationUs = 0;
@@ -1882,7 +1882,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
         this.playbackInfo.copyWithLoadingMediaPeriodId(this.playbackInfo.periodId);
     playbackInfo.bufferedPositionUs = playbackInfo.positionUs;
     playbackInfo.totalBufferedDurationUs = 0;
-    playbackInfo = playbackInfo.copyWithPlaybackState(Player.STATE_IDLE);
+    playbackInfo = maskPlaybackState(playbackInfo, Player.STATE_IDLE);
     if (error != null) {
       playbackInfo = playbackInfo.copyWithPlaybackError(error);
     }
@@ -2360,7 +2360,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
         maskingPlaybackState = STATE_BUFFERING;
       }
     }
-    newPlaybackInfo = newPlaybackInfo.copyWithPlaybackState(maskingPlaybackState);
+    newPlaybackInfo = maskPlaybackState(newPlaybackInfo, maskingPlaybackState);
     internalPlayer.setMediaSources(
         holders, startWindowIndex, Util.msToUs(startPositionMs), shuffleOrder);
     boolean positionDiscontinuity =
@@ -2434,7 +2434,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
             && toIndex == currentMediaSourceCount
             && currentIndex >= newPlaybackInfo.timeline.getWindowCount();
     if (transitionsToEnded) {
-      newPlaybackInfo = newPlaybackInfo.copyWithPlaybackState(STATE_ENDED);
+      newPlaybackInfo = maskPlaybackState(newPlaybackInfo, STATE_ENDED);
     }
     internalPlayer.removeMediaSources(fromIndex, toIndex, shuffleOrder);
     return newPlaybackInfo;
@@ -2558,6 +2558,14 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return playbackInfo;
   }
 
+  private static PlaybackInfo maskPlaybackState(PlaybackInfo playbackInfo, int playbackState) {
+    playbackInfo = playbackInfo.copyWithPlaybackState(playbackState);
+    if (playbackState == STATE_IDLE || playbackState == STATE_ENDED) {
+      playbackInfo = playbackInfo.copyWithIsLoading(false);
+    }
+    return playbackInfo;
+  }
+
   @Nullable
   private Pair<Object, Long> getPeriodPositionUsAfterTimelineChanged(
       Timeline oldTimeline,

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/ExoPlayerTest.java

@@ -1891,6 +1891,20 @@ public class ExoPlayerTest {
     assertThat(totalBufferedDuration[2]).isEqualTo(0);
   }
 
+  @Test
+  public void stopWhileLoading_correctMaskingIsLoading() throws Exception {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    player.setMediaSource(new FakeMediaSource(new FakeTimeline(/* windowCount= */ 1)));
+    player.prepare();
+    advance(player).untilLoadingIs(true);
+
+    assertThat(player.isLoading()).isTrue();
+    player.stop();
+    assertThat(player.isLoading()).isFalse();
+
+    player.release();
+  }
+
   @Test
   public void stop_releasesMediaSource() throws Exception {
     Timeline timeline = new FakeTimeline();
@@ -2089,6 +2103,18 @@ public class ExoPlayerTest {
     assertThat(totalBufferedDuration[2]).isEqualTo(0);
   }
 
+  @Test
+  public void releaseWhileLoading_correctMaskingIsLoading() throws Exception {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    player.setMediaSource(new FakeMediaSource(new FakeTimeline(/* windowCount= */ 1)));
+    player.prepare();
+    advance(player).untilLoadingIs(true);
+
+    assertThat(player.isLoading()).isTrue();
+    player.release();
+    assertThat(player.isLoading()).isFalse();
+  }
+
   @Test
   public void settingNewStartPositionPossibleAfterStopAndClearMediaItems() throws Exception {
     Timeline timeline = new FakeTimeline();
@@ -8810,6 +8836,29 @@ public class ExoPlayerTest {
         Player.TIMELINE_CHANGE_REASON_SOURCE_UPDATE);
   }
 
+  @Test
+  public void setMediaSourcesWhileLoading_noSeekEmpty_correctMaskingIsLoading() throws Exception {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    player.setMediaSource(new FakeMediaSource(new FakeTimeline(/* windowCount= */ 1)));
+    player.prepare();
+    advance(player).untilLoadingIs(true);
+
+    assertThat(player.isLoading()).isTrue();
+    // Set a media item with empty timeline.
+    FakeMediaSource fakeMediaSource =
+        new FakeMediaSource(Timeline.EMPTY) {
+          @Override
+          @Nullable
+          public Timeline getInitialTimeline() {
+            return getTimeline();
+          }
+        };
+    player.setMediaSource(fakeMediaSource, /* resetPosition= */ false);
+    assertThat(player.isLoading()).isFalse();
+
+    player.release();
+  }
+
   @Test
   public void addMediaSources_whenEmptyInitialSeek_correctPeriodMasking() throws Exception {
     final long[] positions = new long[2];
@@ -9269,6 +9318,27 @@ public class ExoPlayerTest {
     assertThat(bufferedPositions[2]).isEqualTo(0);
   }
 
+  @Test
+  public void removeMediaItemsWhileLoading_currentItemRemovedThatIsTheLast_correctMaskingIsLoading()
+      throws Exception {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    MediaSource firstMediaSource = new FakeMediaSource(new FakeTimeline(/* windowCount= */ 1));
+    MediaSource secondMediaSource = new FakeMediaSource(new FakeTimeline(/* windowCount= */ 1));
+    MediaSource thirdMediaSource = new FakeMediaSource(new FakeTimeline(/* windowCount= */ 1));
+    player.setMediaSources(
+        ImmutableList.of(firstMediaSource, secondMediaSource, thirdMediaSource),
+        /* startMediaItemIndex= */ 2,
+        /* startPositionMs= */ C.TIME_UNSET);
+    player.prepare();
+    advance(player).untilLoadingIs(true);
+
+    assertThat(player.isLoading()).isTrue();
+    player.removeMediaItem(/* index= */ 2);
+    assertThat(player.isLoading()).isFalse();
+
+    player.release();
+  }
+
   @Test
   public void removeMediaItems_removeTailWithCurrentWindow_whenIdle_finishesPlayback()
       throws Exception {