Updater.java 文件源码

/**
 * Destroys all listeners of the current state (use before creating a new state)
 */
private void destroyListeners() {
    for (EventListener e : eventListeners) {
        if (e instanceof KeyListener) {
            canvas.removeKeyListener((KeyListener) e);
        } else if (e instanceof MouseMotionListener) {
            canvas.removeMouseMotionListener((MouseMotionListener) e);
        } else if (e instanceof MouseListener) {
            canvas.removeMouseListener((MouseListener) e);
        } else if (e instanceof CommandListener); //No need to do anything here yet
        else {
            System.err.println("Warning: Unimplemented listener removed from Updater");
        }
    }
    eventListeners.clear();
}