public BBSimulator(String title) throws HeadlessException { super(title); world = new World(this); info = new InfoPane(); worldPane.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0)); worldPane.add(world); infoPane.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0)); infoPane.add(info.getContentPane()); contentPane.setOpaque(true); // content panes must be opaque setContentPane(contentPane); }