avoid unexpected state changes with certain playlist states

With the internal playlist some new situation may happen that were not possible before:

- handlePlaylistInfoRefreshed in EPII called in IDLE state
- handlePlaylistInfoRefreshed in EPII called in ENDED state with an empty playlist
- seeks in ENDED state with an empty playlist

PiperOrigin-RevId: 270316681

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

@@ -690,7 +690,14 @@ import java.util.concurrent.atomic.AtomicBoolean;
     long operationStartTimeMs = clock.uptimeMillis();
     updatePeriods();
 
-    MediaPeriodHolder playingPeriodHolder = queue.getPlayingPeriod();
+    if (playbackInfo.playbackState == Player.STATE_IDLE
+        || playbackInfo.playbackState == Player.STATE_ENDED) {
+      // Remove all messages. Prepare (in case of IDLE) or seek (in case of ENDED) will resume.
+      handler.removeMessages(MSG_DO_SOME_WORK);
+      return;
+    }
+
+    @Nullable MediaPeriodHolder playingPeriodHolder = queue.getPlayingPeriod();
     if (playingPeriodHolder == null) {
       // We're still waiting until the playing period is available.
       scheduleNextWork(operationStartTimeMs, ACTIVE_INTERVAL_MS);
@@ -870,7 +877,9 @@ import java.util.concurrent.atomic.AtomicBoolean;
       throws ExoPlaybackException {
     stopRenderers();
     rebuffering = false;
-    setState(Player.STATE_BUFFERING);
+    if (playbackInfo.playbackState != Player.STATE_IDLE && !playbackInfo.timeline.isEmpty()) {
+      setState(Player.STATE_BUFFERING);
+    }
 
     // Clear the timeline, but keep the requested period if it is already prepared.
     MediaPeriodHolder oldPlayingPeriodHolder = queue.getPlayingPeriod();
@@ -1511,7 +1520,9 @@ import java.util.concurrent.atomic.AtomicBoolean;
   }
 
   private void handleSourceInfoRefreshEndedPlayback() {
-    setState(Player.STATE_ENDED);
+    if (playbackInfo.playbackState != Player.STATE_IDLE) {
+      setState(Player.STATE_ENDED);
+    }
     // Reset, but retain the playlist so that it can still be used should a seek occur.
     resetInternal(
         /* resetRenderers= */ false,

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

@@ -192,6 +192,27 @@ public abstract class Action {
     }
   }
 
+  /** Calls {@link SimpleExoPlayer#addMediaItems(List)}. */
+  public static final class AddMediaItems extends Action {
+
+    private final MediaSource[] mediaSources;
+
+    /**
+     * @param tag A tag to use for logging.
+     * @param mediaSources The media sources to be added to the playlist.
+     */
+    public AddMediaItems(String tag, MediaSource... mediaSources) {
+      super(tag, /* description= */ "AddMediaItems");
+      this.mediaSources = mediaSources;
+    }
+
+    @Override
+    protected void doActionImpl(
+        SimpleExoPlayer player, DefaultTrackSelector trackSelector, Surface surface) {
+      player.addMediaItems(Arrays.asList(mediaSources));
+    }
+  }
+
   /** Calls {@link SimpleExoPlayer#setMediaItems(List, boolean)}. */
   public static final class SetMediaItemsResetPosition extends Action {
 

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

@@ -341,12 +341,22 @@ public final class ActionSchedule {
     /**
      * Schedules a set media items action to be executed.
      *
+     * @param mediaSources The media sources to add.
      * @return The builder, for convenience.
      */
-    public Builder setMediaItems(MediaSource... sources) {
+    public Builder setMediaItems(MediaSource... mediaSources) {
       return apply(
           new Action.SetMediaItems(
-              tag, /* windowIndex */ C.INDEX_UNSET, /* positionUs */ C.TIME_UNSET, sources));
+              tag, /* windowIndex= */ C.INDEX_UNSET, /* positionMs= */ C.TIME_UNSET, mediaSources));
+    }
+    /**
+     * Schedules a add media items action to be executed.
+     *
+     * @param mediaSources The media sources to add.
+     * @return The builder, for convenience.
+     */
+    public Builder addMediaItems(MediaSource... mediaSources) {
+      return apply(new Action.AddMediaItems(tag, mediaSources));
     }
 
     /**
@@ -595,9 +605,7 @@ public final class ActionSchedule {
     }
   }
 
-  /**
-   * Wraps an {@link Action}, allowing a delay and a next {@link Action} to be specified.
-   */
+  /** Wraps an {@link Action}, allowing a delay and a next {@link Action} to be specified. */
   /* package */ static final class ActionNode implements Runnable {
 
     private final Action action;

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

@@ -400,12 +400,23 @@ public final class ExoPlayerTestRunner implements Player.EventListener, ActionSc
 
   /**
    * Starts the test runner on its own thread. This will trigger the creation of the player, the
-   * listener registration, the start of the action schedule, and the preparation of the player
-   * with the provided media source.
+   * listener registration, the start of the action schedule, the initial set of media items and the
+   * preparation of the player.
    *
    * @return This test runner.
    */
   public ExoPlayerTestRunner start() {
+    return start(/* doPrepare= */ true);
+  }
+
+  /**
+   * Starts the test runner on its own thread. This will trigger the creation of the player, the
+   * listener registration, the start of the action schedule and the initial set of media items.
+   *
+   * @param doPrepare Whether the player should be prepared.
+   * @return This test runner.
+   */
+  public ExoPlayerTestRunner start(boolean doPrepare) {
     handler.post(
         () -> {
           try {
@@ -424,7 +435,9 @@ public final class ExoPlayerTestRunner implements Player.EventListener, ActionSc
               actionSchedule.start(player, trackSelector, null, handler, ExoPlayerTestRunner.this);
             }
             player.setMediaItems(mediaSources, /* resetPosition= */ false);
-            player.prepare();
+            if (doPrepare) {
+              player.prepare();
+            }
           } catch (Exception e) {
             handleException(e);
           }