Remove ExoPlayerImpl inheritance from BasePlayer.

This inheritance is really confusing because ExoPlayerImpl is not
a full Player interface implementation. It also claims to be an
ExoPlayer implementation in the Javadoc which isn't true in its
current state.

Removing the inheritance also allows to clean up some unused methods.

PiperOrigin-RevId: 411756963

extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastPlayer.java

@@ -1092,7 +1092,7 @@ public final class CastPlayer extends BasePlayer {
 
   private void updateAvailableCommandsAndNotifyIfChanged() {
     Commands previousAvailableCommands = availableCommands;
-    availableCommands = getAvailableCommands(PERMANENT_AVAILABLE_COMMANDS);
+    availableCommands = Util.getAvailableCommands(/* player= */ this, PERMANENT_AVAILABLE_COMMANDS);
     if (!availableCommands.equals(previousAvailableCommands)) {
       listeners.queueEvent(
           Player.EVENT_AVAILABLE_COMMANDS_CHANGED,

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

@@ -382,37 +382,6 @@ public abstract class BasePlayer implements Player {
         : timeline.getWindow(getCurrentMediaItemIndex(), window).getDurationMs();
   }
 
-  /**
-   * Returns the {@link Commands} available in the player.
-   *
-   * @param permanentAvailableCommands The commands permanently available in the player.
-   * @return The available {@link Commands}.
-   */
-  protected Commands getAvailableCommands(Commands permanentAvailableCommands) {
-    return new Commands.Builder()
-        .addAll(permanentAvailableCommands)
-        .addIf(COMMAND_SEEK_TO_DEFAULT_POSITION, !isPlayingAd())
-        .addIf(COMMAND_SEEK_IN_CURRENT_MEDIA_ITEM, isCurrentMediaItemSeekable() && !isPlayingAd())
-        .addIf(COMMAND_SEEK_TO_PREVIOUS_MEDIA_ITEM, hasPreviousMediaItem() && !isPlayingAd())
-        .addIf(
-            COMMAND_SEEK_TO_PREVIOUS,
-            !getCurrentTimeline().isEmpty()
-                && (hasPreviousMediaItem()
-                    || !isCurrentMediaItemLive()
-                    || isCurrentMediaItemSeekable())
-                && !isPlayingAd())
-        .addIf(COMMAND_SEEK_TO_NEXT_MEDIA_ITEM, hasNextMediaItem() && !isPlayingAd())
-        .addIf(
-            COMMAND_SEEK_TO_NEXT,
-            !getCurrentTimeline().isEmpty()
-                && (hasNextMediaItem() || (isCurrentMediaItemLive() && isCurrentMediaItemDynamic()))
-                && !isPlayingAd())
-        .addIf(COMMAND_SEEK_TO_MEDIA_ITEM, !isPlayingAd())
-        .addIf(COMMAND_SEEK_BACK, isCurrentMediaItemSeekable() && !isPlayingAd())
-        .addIf(COMMAND_SEEK_FORWARD, isCurrentMediaItemSeekable() && !isPlayingAd())
-        .build();
-  }
-
   @RepeatMode
   private int getRepeatModeForNavigation() {
     @RepeatMode int repeatMode = getRepeatMode();

library/common/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -16,6 +16,15 @@
 package com.google.android.exoplayer2.util;
 
 import static android.content.Context.UI_MODE_SERVICE;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_BACK;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_FORWARD;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_IN_CURRENT_MEDIA_ITEM;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_TO_DEFAULT_POSITION;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_TO_MEDIA_ITEM;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_TO_NEXT;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_TO_NEXT_MEDIA_ITEM;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_TO_PREVIOUS;
+import static com.google.android.exoplayer2.Player.COMMAND_SEEK_TO_PREVIOUS_MEDIA_ITEM;
 import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
 import static java.lang.Math.abs;
 import static java.lang.Math.max;
@@ -63,6 +72,8 @@ import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.PlaybackException;
+import com.google.android.exoplayer2.Player;
+import com.google.android.exoplayer2.Player.Commands;
 import com.google.common.base.Ascii;
 import com.google.common.base.Charsets;
 import java.io.ByteArrayOutputStream;
@@ -2477,6 +2488,43 @@ public final class Util {
     }
   }
 
+  /**
+   * Returns the {@link Commands} available in the {@link Player}.
+   *
+   * @param player The {@link Player}.
+   * @param permanentAvailableCommands The commands permanently available in the player.
+   * @return The available {@link Commands}.
+   */
+  public static Commands getAvailableCommands(Player player, Commands permanentAvailableCommands) {
+    boolean isPlayingAd = player.isPlayingAd();
+    boolean isCurrentMediaItemSeekable = player.isCurrentMediaItemSeekable();
+    boolean hasPreviousMediaItem = player.hasPreviousMediaItem();
+    boolean hasNextMediaItem = player.hasNextMediaItem();
+    boolean isCurrentMediaItemLive = player.isCurrentMediaItemLive();
+    boolean isCurrentMediaItemDynamic = player.isCurrentMediaItemDynamic();
+    boolean isTimelineEmpty = player.getCurrentTimeline().isEmpty();
+    return new Commands.Builder()
+        .addAll(permanentAvailableCommands)
+        .addIf(COMMAND_SEEK_TO_DEFAULT_POSITION, !isPlayingAd)
+        .addIf(COMMAND_SEEK_IN_CURRENT_MEDIA_ITEM, isCurrentMediaItemSeekable && !isPlayingAd)
+        .addIf(COMMAND_SEEK_TO_PREVIOUS_MEDIA_ITEM, hasPreviousMediaItem && !isPlayingAd)
+        .addIf(
+            COMMAND_SEEK_TO_PREVIOUS,
+            !isTimelineEmpty
+                && (hasPreviousMediaItem || !isCurrentMediaItemLive || isCurrentMediaItemSeekable)
+                && !isPlayingAd)
+        .addIf(COMMAND_SEEK_TO_NEXT_MEDIA_ITEM, hasNextMediaItem && !isPlayingAd)
+        .addIf(
+            COMMAND_SEEK_TO_NEXT,
+            !isTimelineEmpty
+                && (hasNextMediaItem || (isCurrentMediaItemLive && isCurrentMediaItemDynamic))
+                && !isPlayingAd)
+        .addIf(COMMAND_SEEK_TO_MEDIA_ITEM, !isPlayingAd)
+        .addIf(COMMAND_SEEK_BACK, isCurrentMediaItemSeekable && !isPlayingAd)
+        .addIf(COMMAND_SEEK_FORWARD, isCurrentMediaItemSeekable && !isPlayingAd)
+        .build();
+  }
+
   @Nullable
   private static String getSystemProperty(String name) {
     try {

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

@@ -1351,7 +1351,6 @@ public class SimpleExoPlayer extends BasePlayer
   }
 
   @Override
-  @Nullable
   public TrackSelector getTrackSelector() {
     verifyApplicationThread();
     return player.getTrackSelector();