A traffic light in Java, have fun.
import java.awt.*; public class Ampel { // Anfang Attribute private boolean rot = true; private boolean gelb = false; private boolean gruen = false; private int x; private int y; // Ende Attribute public Ampel (int x,int y) { this.x = x; this.y = y; } public void rot(){ rot = true; gelb = false; gruen = false; } public void rotgelb(){ rot = true; gelb = true; gruen = false; } public void gruen(){ rot = false; gelb = false; gruen = true; } public void gelb(){ rot = false; gelb = true; gruen = false; } // Anfang Methoden public void paint(Graphics g) { ((Graphics2D)g).setRenderingHint (RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g.setColor(Color.WHITE); g.fillRect(10,30,245,730); g.setColor(Color.BLACK); g.fillRect(x,y, 200,400); if (rot) { g.setColor(Color.RED); g.fillOval(x + 55, y + 30,100,100); } else { g.setColor(Color.DARK_GRAY); g.fillOval(x + 55, y + 30,100,100); } if (gelb) { g.setColor(Color.YELLOW); g.fillOval(x + 55,y + 150,100,100); } else { g.setColor(Color.DARK_GRAY); g.fillOval(x + 55,y + 150,100,100); } if (gruen) { g.setColor(Color.GREEN); g.fillOval(x + 55,y + 270,100,100); } else { g.setColor(Color.DARK_GRAY); g.fillOval(x + 55,y + 270,100,100); } } public static void main (String[] args) throws InterruptedException{ } // Ende Methoden }