import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.Ellipse2D;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class BallRoom {
public static void main(String[] a){
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(200, 300);
PaintSurface canvas = new PaintSurface();
ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(3);
executor.scheduleAtFixedRate(canvas, 0L, 100L, TimeUnit.MILLISECONDS);
f.getContentPane().add(canvas);
f.setVisible(true);
}
}
class PaintSurface extends JComponent implements Runnable{
int i = 0;
public void run() {
repaint();
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
Shape ball = new Ellipse2D.Float(i++, i++, 5, 5);
g2.setColor(Color.RED);
g2.fill(ball);
}
}