Screen Flickering

[dewitrydan]

Hey there
I am following a java tutorial on youtube.
It is supposed to display a image when you move your mouse around or something.
But I just get a flickering green screen with a flickering image on it.
Can you please help me? thanks
heres my code:

Look Class:

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

public class Look extends Core implements MouseMotionListener, KeyListener, MouseListener {

    public static void main(String[] args) {
        new Look().run();
    }
    private Image bg;
    private Robot robot;
    private Point mouse;
    private Point center;
    private Point image;
    private boolean centering;

    public void init() {
        super.init();
        mouse = new Point();
        center = new Point();
        image = new Point();
        centering = false;

        try {
            robot = new Robot();
            recenterMouse();
            mouse.x = center.x;
            mouse.y = center.y;
        } catch (Exception ex) {
            System.out.println("exception 1");
        }

        Window w = s.getFullScreenWinodw();
        w.addMouseListener(this);
        w.addKeyListener(this);
        bg = new ImageIcon("D:\\Users\\test\\Desktop\\JAVA STUFF\\Netbeans projects\\game\\src\\images\\face_up.png").getImage();
    }

    public synchronized void draw(Graphics2D g) {
        int w = s.getWidth();
        int h = s.getHeight();
        image.x %= w;
        image.y %= h;
        if (image.x < 0) {
            image.x += w;
        }
        if (image.y < 0) {
            image.y += h;
        }
        int x = image.x;
        int y = image.y;
        g.drawImage(bg, x, y, null);
        g.drawImage(bg, x - w, y, null);
        g.drawImage(bg, x, y - h, null);
        g.drawImage(bg, x - w, y - h, null);
    }

    //recenter mouse using robot
    private synchronized void recenterMouse() {
        Window w = s.getFullScreenWinodw();
        if (robot != null && w.isShowing()) {
            center.x = w.getWidth() / 2;
            center.y = w.getHeight() / 2;
            SwingUtilities.convertPointToScreen(center, w);
            centering = true;
            robot.mouseMove(center.x, center.y);
        }
    }
    //mousemotion
    public void mouseDragged(MouseEvent e){
        mouseMoved(e);
    }
    public synchronized void mouseMoved(MouseEvent e){
        if(centering && center.x == e.getX() && center.y == e.getY()){
            centering = false;
        }else{
            int dx = e.getX() - mouse.x;
            int dy = e.getY() - mouse.y;
            image.x += dx;
            image.y += dy;
            recenterMouse();
        }
        mouse.x = e.getX();
        mouse.y = e.getY();
    }

    //keylistener interface
    public void keyPressed(KeyEvent e){
        if(e.getKeyCode() == KeyEvent.VK_ESCAPE){
            stop();
        }
    }

    public void keyReleased(KeyEvent e){}
    public void keyTyped(KeyEvent e){}
    public void MouseExited(MouseEvent e){}

    public void mouseClicked(MouseEvent e) {}

    public void mousePressed(MouseEvent e) {}

    public void mouseReleased(MouseEvent e) {}

    public void mouseEntered(MouseEvent e) {}

    public void mouseExited(MouseEvent e) {}
}

Core class:

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

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


public abstract class Core {
    private static DisplayMode modes[] = {
        new DisplayMode(800, 600, 32, 0),
        new DisplayMode(800, 600, 24, 0),
        new DisplayMode(800, 600, 16, 0),
        new DisplayMode(640, 480, 32, 0),
        new DisplayMode(640, 480, 24, 0),
        new DisplayMode(640, 480, 16, 0),
    };

    private boolean running;
    protected ScreenManager s;
    private long startTime;

    //stop method
    public void stop(){
        running = false;
    }

    //call init and gameloop
    public void run(){
        try{
            init();
            gameLoop();
        }finally{
            s.restoreScreen();
        }
    }

    //set to full screen
    public void init(){
        s = new ScreenManager();
        DisplayMode dm = s.findFirstCompatibleMode(modes);
        s.setFullScreen(dm);

        Window w = s.getFullScreenWinodw();
        w.setFont(new Font("Arial", Font.PLAIN, 20));
        w.setBackground(Color.GREEN);
        w.setForeground(Color.WHITE);
        running = true;

    }

    //main game loop
    public void gameLoop(){
        long startTIme = System.currentTimeMillis();
        long cumTime = startTime;

        while(running){
            long timePassed = System.currentTimeMillis() - cumTime;
            cumTime += timePassed;

            update(timePassed);
            Graphics2D g = s.getGraphics();
            draw(g);
            g.dispose();
            s.update();

            try{
                Thread.sleep(20);

            }catch(Exception e){}
        }
    }

    //update animation
    public void update(long timePassed){
          }

    //draw to screen
    public abstract void draw(Graphics2D g);{}


}

ScreenManager class:

import java.awt.*;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.lang.reflect.InvocationTargetException;
import javax.swing.JFrame;

public class ScreenManager {

    private GraphicsDevice vc;

    //give vc access to monitor
    public ScreenManager() {
        GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
        vc = e.getDefaultScreenDevice();
    }

    public DisplayMode[] getCompatibleDisplayModes() {
        return vc.getDisplayModes();
    }

    //compares dm passed in...
    public DisplayMode findFirstCompatibleMode(DisplayMode modes[]) {
        DisplayMode goodModes[] = vc.getDisplayModes();
        for (int x = 0; x < modes.length; x++) {
            for (int y = 0; y < goodModes.length; y++) {
                if (displayModesMatch(modes[x], goodModes[y])) {
                    return modes[x];
                }
            }
        }
        return null;
    }

    //get current dm
    public DisplayMode getCurrentDisplayMode() {
        return vc.getDisplayMode();
    }

    //chechs if two modes match eachother
    public boolean displayModesMatch(DisplayMode m1, DisplayMode m2) {
        if (m1.getWidth() != m2.getWidth() || m1.getHeight() != m2.getHeight()) {
            return false;
        }
        if (m1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI && m2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI && m1.getBitDepth() != m2.getBitDepth()) {
            return false;
        }
        if (m1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN && m2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN && m1.getRefreshRate() != m2.getRefreshRate()) {
            return false;
        }

        return true;
    }

    //make frame full screen
    public void setFullScreen(DisplayMode dm) {
        JFrame f = new JFrame();
        f.setUndecorated(true);
        f.setIgnoreRepaint(true);
        f.setResizable(false);
        vc.setFullScreenWindow(f);

        if (dm != null && vc.isDisplayChangeSupported()) {
            try {
                vc.setDisplayMode(dm);
            } catch (Exception ex) {
            }
        }
        f.createBufferStrategy(2);
    }
    //we will set Graphics object =  to this

    public Graphics2D getGraphics() {
        Window w = vc.getFullScreenWindow();
        if (w != null) {
            BufferStrategy s = w.getBufferStrategy();
            return (Graphics2D) s.getDrawGraphics();
        } else {
            return null;
        }
    }

    //updates display
    public void update() {
        Window w = vc.getFullScreenWindow();
        if (w != null) {
            BufferStrategy s = w.getBufferStrategy();
            if (!s.contentsLost()) {
                s.show();

            }
        }
    }

    public Window getFullScreenWinodw() {
        return vc.getFullScreenWindow();
    }

    public int getWidth() {
        Window w = vc.getFullScreenWindow();
        if (w != null) {
            return w.getWidth();
        } else {
            return 0;
        }
    }

     public int getHeight() {
        Window w = vc.getFullScreenWindow();
        if (w != null) {
            return w.getHeight();
        } else {
            return 0;
        }
    }



     public void restoreScreen(){
         Window w = vc.getFullScreenWindow();
         if(w != null){
             w.dispose();
         }
         vc.setFullScreenWindow(null);
     }

     //create image compatible with monitor

     public BufferedImage createCompatibleImage(int w, int h, int t){
         Window win = vc.getFullScreenWindow();
         if(win != null){
             GraphicsConfiguration gc = win.getGraphicsConfiguration();
             return gc.createCompatibleImage(w, h, t);
         }
         return null;
     }
}

[Norm]

Do you have some doc describing what the code is supposed to do?
How are you sure that it is not doing what it is supposed to do?

[dewitrydan]

all I have got is:
YouTube - Java Game Development - 35 - Using the Robot
YouTube - Java Game Development - 36 - Final Mouselook Program