import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.geom.*;

public class TransAnim extends JApplet {
    public static void main(String args[]) {
        JFrame f = new JFrame("TransAnim");
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);}
        });
        JApplet applet = new TransAnim();
        f.getContentPane().add(applet, BorderLayout.CENTER);
        applet.init();
        f.setSize(new Dimension(330,330));
        f.setVisible(true);
    }

    public void init() {
        getContentPane().setLayout(new BorderLayout());
        TransAnimPanel animator = new TransAnimPanel();
        animator.setSize(330, 330);
        getContentPane().add(animator);
        animator.setVisible(true);
        animator.startAnimation();
    }
}

class TransAnimPanel extends JPanel implements Runnable {
    Thread animatorThread;
    int delay;

    AffineTransform mytrans;
    Shape myshape;
    double theta=0.0;

    public TransAnimPanel() {
	mytrans = new AffineTransform();
	myshape = new Arc2D.Float(-10,-10,20,20,45,270, Arc2D.PIE);// Its an Arc2D so you can see it spinning!

        delay = 100;
    }

    //Draw the current frame of animation.
    public void paintComponent(Graphics g) {
      super.paintComponent(g);

      Graphics2D g2 = (Graphics2D)g;
      theta +=0.1;

      mytrans.setToTranslation(150.0,150.0); // Rough center of the screen
      mytrans.rotate(theta);	           // Orbit angle
      g2.draw(mytrans.createTransformedShape(myshape));
    }


    public void startAnimation() {
      //Start the animating thread.
      if (animatorThread == null) {
	animatorThread = new Thread(this);
      }
      animatorThread.start();
    }

    public void stopAnimation() {
      //Stop the animating thread.
      animatorThread = null;
    }

    public void run() {
        //Just to be nice, lower this thread's priority
        //so it can't interfere with other processing going on.
        Thread.currentThread().setPriority(Thread.MIN_PRIORITY);

        //Remember the starting time.
        long startTime = System.currentTimeMillis();

        //Remember which thread we are.
        Thread currentThread = Thread.currentThread();

        //This is the animation loop.
        while (currentThread == animatorThread) {
            //Advance the animation frame.
            //Display it.
            repaint();

            //Delay depending on how far we are behind.
            try {
                startTime += delay;
                Thread.sleep(Math.max(0, 
                             startTime-System.currentTimeMillis()));
            } catch (InterruptedException e) {
                break;
            }
        }
    }
}