public SimpleButton(Shape s, Image up, Image down, Sound click) {
        shape = s;
        setShape(s);
        this.up = up;
        this.down = down;
        current = up;
        this.click = click;
        clickListener = NullListener.getSingleton();
        buttonListener = NullListener.getSingleton();
        super.addListener((ButtonListener) this);
        super.addListener((ClickListener) this);
    }