Создание фрактала по нажатии на кнопку

public class Fractal extends JPanel {
    public static void main(String[] args) {
        JFrame window = new JFrame();
        window.setSize(600, 600);
        window.setContentPane(new Fractal());
        window.setBackground(Color.WHITE);
        window.setResizable(false);
        window.setDefaultCloseOperation(EXIT_ON_CLOSE);
        window.setVisible(true);
    }

            
            public void paintComponent (Graphics g){
                setLayout(null);
                setFocusable(true);
                grabFocus();
                Graphics2D graphic = (Graphics2D) g;
                g.setColor(Color.black);
                graphic.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);   //сглаживание
                Circle(300, 280, 200, g);
                

            }


            public void Circle ( double x, double y, int size, Graphics g){

                int num = 6, nrad = 3, radius = 0, den = 0;
                g.drawOval((int) x - size, (int) y - size, 2 * size, 2 * size);
                if (size > 0) {
                    den = Math.round(size * (nrad - 1) / nrad);
                    radius = Math.round(size / nrad);
                    Circle(x, y, radius, g);
                    for (int i = 0; i < num; i++) {
                        Circle(x + Math.round(den * Math.sin(2* Math.PI / num * i)), y + Math.round(den * Math.cos(2 * Math.PI / num * i)), radius, g);
                    }

                }

            }
}