// utility method to set mark on board in event-dispatch thread private void setMark(final Square squareToMark, final String mark) { // SwingUtilities.invokeLater(new Runnable() { // public void run() { squareToMark.setMark(mark); // set mark in square // } // end method run // } // end anonymous inner class // ); // end call to SwingUtilities.invokeLater } // end method setMark