private int layoutButtonHorizontal( JButton button, int wu, int x, int y, int h, boolean leftToRight ) {
			if( button.isVisible() ) {
				int w = scale( wu );
				if( leftToRight )
					x -= w;
				button.setBounds( x, y, w, h );
				if( !leftToRight )
					x += w;
			}
			return x;
		}
Actually does nearly the same as super.paintContentBorder() but
  - not invoking paintContentBorder*Edge() methods
  - repaint selection
flatlaf-jide-oss/src/main/java/com/formdev/flatlaf/jideoss/ui/FlatJideTabbedPaneUI.java