public class MyApplet extends JApplet implements Runnable {

    private boolean moving;

    public void start() {
        moving = true;
        run();
    }

    public void stop() {
        moving = false;
    }

    public void run() {
        if (moving) {
            nextCycle();
            //temporarily returning control to AWT thread
            //allowing all ui events to be delivered
            SwingUtilities.invokeLater(this);
        }
    }

    public void nextCycle() {
        //All animation is performed here
    }
}