public ScreenCreditController(WorldWindow wwd) { if (wwd == null) { String msg = Logging.getMessage("nullValue.WorldWindow"); Logging.logger().severe(msg); throw new ArgumentException(msg); } this.wwd = wwd; if (wwd.getSceneController().getScreenCreditController() != null) { wwd.getSceneController().getScreenCreditController().dispose(); } wwd.getSceneController().setScreenCreditController(this); wwd.addSelectListener(this); }