fix fullscreen button on popup

app/src/main/java/org/schabi/newpipe/player/PopupVideoPlayer.java

@@ -44,6 +44,7 @@ import android.view.Gravity;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.WindowManager;
+import android.widget.ImageButton;
 import android.widget.PopupMenu;
 import android.widget.RemoteViews;
 import android.widget.SeekBar;
@@ -401,6 +402,7 @@ public final class PopupVideoPlayer extends Service {
 
     protected class VideoPlayerImpl extends VideoPlayer {
         private TextView resizingIndicator;
+        private ImageButton fullScreenButton;
 
         @Override
         public void handleIntent(Intent intent) {
@@ -418,6 +420,13 @@ public final class PopupVideoPlayer extends Service {
         public void initViews(View rootView) {
             super.initViews(rootView);
             resizingIndicator = rootView.findViewById(R.id.resizing_indicator);
+            fullScreenButton = rootView.findViewById(R.id.fullScreenButton);
+            fullScreenButton.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    onFullScreenButtonClicked();
+                }
+            });
         }
 
         @Override

app/src/main/java/org/schabi/newpipe/player/VideoPlayer.java

@@ -75,7 +75,13 @@ import static org.schabi.newpipe.util.AnimationUtils.animateView;
  * @author mauriciocolli
  */
 @SuppressWarnings({"WeakerAccess", "unused"})
-public abstract class VideoPlayer extends BasePlayer implements SimpleExoPlayer.VideoListener, SeekBar.OnSeekBarChangeListener, View.OnClickListener, Player.EventListener, PopupMenu.OnMenuItemClickListener, PopupMenu.OnDismissListener {
+public abstract class VideoPlayer extends BasePlayer
+        implements SimpleExoPlayer.VideoListener,
+        SeekBar.OnSeekBarChangeListener,
+        View.OnClickListener,
+        Player.EventListener,
+        PopupMenu.OnMenuItemClickListener,
+        PopupMenu.OnDismissListener {
     public static final boolean DEBUG = BasePlayer.DEBUG;
     public final String TAG;
 

app/src/main/res/layout/player_popup.xml

@@ -92,6 +92,7 @@
                 android:layout_alignParentRight="true"
                 android:background="#00ffffff"
                 android:clickable="true"
+                android:focusable="true"
                 android:scaleType="fitCenter"
                 android:src="@drawable/ic_fullscreen_white"
                 tools:ignore="ContentDescription,RtlHardcoded"/>