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

public class Robot
{

int blickrichtung;
int xkoordinate, ykoordinate;

public Robot()
{
blickrichtung = 1; //1=rechts 2=hinten 3=links 4=vorne
xkoordinate = 100;
ykoordinate = 100;
}

public void linksdrehen()
{
blickrichtung = blickrichtung + 1;
if (blickrichtung > 4)
blickrichtung = 1;
}

public void rechtsdrehen()
{
blickrichtung = blickrichtung - 1;
if (blickrichtung < 1)
blickrichtung = 4;
}

public void vor()
{
if (blickrichtung == 1)
xkoordinate = xkoordinate +30;
else
if (blickrichtung == 2)
ykoordinate = ykoordinate -30;
else
if (blickrichtung == 3)
xkoordinate = xkoordinate -30;
else
if (blickrichtung == 4)
ykoordinate = ykoordinate +30;
else
if (blickrichtung > 4)
blickrichtung = 1;
}

public void zurueck()
{
if (blickrichtung == 1)
xkoordinate = xkoordinate -30;
else
if (blickrichtung == 2)
ykoordinate = ykoordinate +30;
else
if (blickrichtung == 3)
xkoordinate = xkoordinate +30;
else
if (blickrichtung == 4)
ykoordinate = ykoordinate -30;
else
if (blickrichtung > 4)
blickrichtung = 1;
}

public void anzeigen(Graphics g)
{ if ((blickrichtung == 2) || (blickrichtung == 4))
{
g.setColor(Color.gray);
g.fillRect(xkoordinate,ykoordinate,40,40); //Kopf
g.fillRect(xkoordinate-40,ykoordinate+45,20,40); //Hand
g.fillRect(xkoordinate+60,ykoordinate+45,20,40); //Hand
g.fillRect(xkoordinate-20,ykoordinate+120,80,40);

g.setColor(Color.black);
g.drawRect(xkoordinate,ykoordinate,40,40);
g.drawRect(xkoordinate-40,ykoordinate+45,20,40);
g.drawRect(xkoordinate+60,ykoordinate+45,20,40);
g.drawRect(xkoordinate-20,ykoordinate+120,40,40);
g.drawRect(xkoordinate+20,ykoordinate+120,40,40);
g.drawRect(xkoordinate-20,ykoordinate+40,80,80);
g.fillRect(xkoordinate-20,ykoordinate+40,80,80);
if (blickrichtung == 4)
{
g.fillOval(xkoordinate+10,ykoordinate+10,4,4);
g.fillOval(xkoordinate+30,ykoordinate+10,4,4);
}
}

if ((blickrichtung == 1) || (blickrichtung == 3))
{
g.setColor(Color.black);
g.fillRect(xkoordinate-4,ykoordinate+40,28,80);

g.drawRect(xkoordinate-4,ykoordinate+40,28,80);
g.drawRect(xkoordinate,ykoordinate,20,40);
g.drawRect(xkoordinate,ykoordinate+45,20,40);
g.drawRect(xkoordinate,ykoordinate,20,40);
g.drawRect(xkoordinate,ykoordinate+120,20,40);

g.setColor(Color.gray);
g.fillRect(xkoordinate,ykoordinate,20,40);
g.fillRect(xkoordinate,ykoordinate+45,20,40);
g.fillRect(xkoordinate,ykoordinate,20,40);
g.fillRect(xkoordinate,ykoordinate+120,20,40);
}


}
}

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

public class Roboter extends JApplet
implements ActionListener
{ private Button btn1;
private Button btn2;
private Button btn3;
private Button btn4;
private Robot robo;

public void init()
{
robo = new Robot();

btn1 = new Button ("Vor");
Container contentPane = getContentPane();
contentPane.setLayout(null);
contentPane.add(btn1);
btn1.setBounds(180,230,150,30);
btn1.addActionListener(this);
btn2 = new Button ("Links um");
contentPane.add(btn2);
btn2.setBounds(180,280,150,30);
btn2.addActionListener(this);
btn3 = new Button ("Rechts um");
contentPane.add(btn3);
btn3.setBounds(180,330,150,30);
btn3.addActionListener(this);
btn4 = new Button ("Zurück");
contentPane.add(btn4);
btn4.setBounds(180,380,150,30);
btn4.addActionListener(this);
}

public void actionPerformed(ActionEvent evt)
{
if(evt.getSource() == btn1)
{
robo.vor();
paint(getGraphics());
}
else
if(evt.getSource() == btn2)
{
robo.linksdrehen();
paint(getGraphics());
}
else
if(evt.getSource() == btn3)
{
robo.rechtsdrehen();
paint(getGraphics());
}
else
if(evt.getSource() == btn4)
{
robo.zurueck();
paint(getGraphics());
}
}

public void paint(Graphics g)
{
g.setColor(Color.white);
g.fillRect(0,0,2000,2000);
robo.anzeigen(g);
}

}