gann-cdf / graphics

public class Ball {

    private double dx, dy;

    public Ball(DrawingPanel panel) {

        double heading = Math.random() * Math.PI * 2;

        dx = Math.cos(heading);

        dy = Math.sin(heading);

        ball = new Ellipse(

                Math.random() * panel.getWidth(),

                Math.random() * panel.getHeight(),

                20, 20,

                panel

        );

        ball.setFillColor(new Color((float) Math.random(), (float) Math.random(), (float) Math.random()));

        ball.setStrokeColor(ball.getFillColor());

    }

    public void move() {

        ball.translate(dx, dy);

        if (ball.getX() < 0 || ball.getX() + ball.getWidth() > ball.getDrawingPanel().getWidth()) {

            dx = -dx;

        }

        if (ball.getY() < 0 || ball.getY() + ball.getWidth() > ball.getDrawingPanel().getHeight()) {

            dy = -dy;