Add getMediaItemCount() and getMediaItemAt(int)

PiperOrigin-RevId: 331211708

RELEASENOTES.md

@@ -1,6 +1,6 @@
 # Release notes
 
-### 2.12.0 (2020-09-03) ###
+### 2.12.0 (2020-09-11) ###
 
 *   Core library:
     *   `Player`:
@@ -8,8 +8,9 @@
             ([#6161](https://github.com/google/ExoPlayer/issues/6161)). The
             new methods for playlist manipulation are `setMediaItem(s)`,
             `addMediaItem(s)`, `moveMediaItem(s)`, `removeMediaItem(s)` and
-            `clearMediaItems`. This API should be used instead of
-            `ConcatenatingMediaSource` in most cases.
+            `clearMediaItems`. The playlist can be queried using
+            `getMediaItemCount` and `getMediaItemAt`. This API should be used
+            instead of `ConcatenatingMediaSource` in most cases.
         *   Add `getCurrentMediaItem` for getting the currently playing item
             in the playlist.
         *   Add `EventListener.onMediaItemTransition` to report when

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

@@ -185,6 +185,16 @@ public abstract class BasePlayer implements Player {
         : timeline.getWindow(getCurrentWindowIndex(), window).mediaItem;
   }
 
+  @Override
+  public int getMediaItemCount() {
+    return getCurrentTimeline().getWindowCount();
+  }
+
+  @Override
+  public MediaItem getMediaItemAt(int index) {
+    return getCurrentTimeline().getWindow(index, window).mediaItem;
+  }
+
   @Override
   @Nullable
   public final Object getCurrentManifest() {

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

@@ -1284,6 +1284,12 @@ public interface Player {
   @Nullable
   MediaItem getCurrentMediaItem();
 
+  /** Returns the number of {@link MediaItem media items} in the playlist. */
+  int getMediaItemCount();
+
+  /** Returns the {@link MediaItem} at the given index. */
+  MediaItem getMediaItemAt(int index);
+
   /**
    * Returns the duration of the current content window or ad in milliseconds, or {@link
    * C#TIME_UNSET} if the duration is not known.