@Override
	protected void paintComponent( Graphics g ) {
		if( isFullWindowContent() )
			return;

		g.setColor( getBackground() );
		g.fillRect( 0, 0, getWidth(), getHeight() );
	}
Returns whether the menubar should be embedded into the title pane.
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java