iconButton.setOpaque(false);
if (!frame.isIconifiable()) iconButton.setVisible(false);
  protected void createButtons()  {    closeButton = new PaneButton(closeAction);    closeButton.setOpaque(false);    iconButton = new PaneButton(iconifyAction);    iconButton.setOpaque(false);    maxButton = new PaneButton(maximizeAction);    maxButton.setOpaque(false);  }