import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.*;
public class SnakeGame extends JPanel {
    private int snakeY, snakeX;
    private int direction=4;    //1 hoch, 2, runter, 3 links, 4 rechts
    Thread t=new Thread(new drawSnake());


    public SnakeGame() {
        setFocusable(true);
        addKeyListener(new Listener());

    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.fillRect(snakeX, snakeY, 10, 10);
    }

    public void speed() {
        try {
            Thread.sleep(150);
        }
        catch(Exception e) {}
    }

    class drawSnake implements Runnable {

        public void run() {
            while(direction==1) {
                snakeY-=10;
                speed();
                repaint();
                System.out.println(snakeY);

            }
            while(direction==2) {
                snakeY+=10;
                speed();
                repaint();
            }
            while(direction==3) {
                snakeX-=10;
                speed();
                repaint();
            }
            while(direction==4) {
                snakeX+=10;
                speed();
                repaint();
            }
        }
    }

    public class Listener implements KeyListener {

        @Override
        public void keyPressed(KeyEvent e) {
            t.interrupt();
            if(e.getKeyCode()==KeyEvent.VK_UP){
                direction=1;
                t.start();
            }
            else if(e.getKeyCode()==KeyEvent.VK_DOWN){
                direction=2;
                t.start();
            }
            else if(e.getKeyCode()==KeyEvent.VK_LEFT){
                direction=3;
                t.start();
            }
            else if(e.getKeyCode()==KeyEvent.VK_RIGHT){
                direction=4;
                t.start();
            }
        }

        @Override
        public void keyReleased(KeyEvent e) {

        }

        @Override
        public void keyTyped(KeyEvent e) {

        }

    }

}