import java.awt.*;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class ball extends JPanel implements Runnable {

	/* Konstruktor */

	int x_pos = 25;
	int y_pos = 100;
	int radius = 20;

	
	public ball () {}
	
	public void paintComponent(Graphics g) {
		Graphics2D g2d = (Graphics2D)g;
		g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
		

		g.setColor(new java.awt.color.Color(255,255,255));
		g.fillRect(0, 0, 300, 300);
		g.setColor(Color.RED);
		g.fillOval(x_pos - radius, y_pos - radius, 2 * radius, 2 * radius);
		

	}
	
	public void run() {

		/* Geringe Priorität setzen */
		//Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
		while (true) {
			/* Neuzeichnen */
			
			this.repaint();
			/* Verändern der X-Koordinate des Balles */
			x_pos++;
			try {
				Thread.sleep(20);
			} catch (InterruptedException e) {
			}
			/* Priorität wieder auf maximum */
			//Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
		}

	}

	public static void main(String[] args) {
		ball b = new ball();
		Thread th = new Thread(b);
		th.start();
		 JFrame win = new JFrame("Ball");
	        win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	        win.setContentPane(b);
   	        win.setSize(300, 300);
	        win.setVisible(true); 
	}

}