Problem doing Applet exercise

Question

In my (swedish) course literature I am currently supposed to write an Applet that follows the actions of the window when it is resized . The point is to learn ComponentListener and making it runnable to avoid flickering.
the applet is supposed to look like a red rectangle with a white cross.
This is the script so far:
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Main extends Applet implements ComponentListener{
    int left = 10, top = 10, rutbredd, ruth?jd;
    public void init(){
        Dimension appletsize = getSize();
        rutbredd = appletsize.width-20;
        ruth?jd = appletsize.height-20;
        addComponentListener( this);
    public void paint( Graphics g){
        Color col = new Color (255,0,0);
        g.setColor(col);
        g.fillRect(left,top,rutbredd,ruth?jd);
        g.setColor( Color.white);
        g.drawLine(left, top, left+rutbredd,top+rutbredd);
        g.drawLine(left+rutbredd,top,left, top+ruth?jd);
    public void componentResized( ComponentEvent e){
        Dimension appletsize =  getSize();
        if(rutbredd>appletsize.width-20){
            rutbredd=appletsize.width-20;
        if(rutbredd<appletsize.width-20){
            rutbredd=appletsize.width-20;
}My mission is to make it runnable by adding 'Runnable' after 'implements ComponentListener' on the class-line and add these methods to the code:
    public void start(){
        Thread tr?d = new Thread( this);
        tr?d.start();
    public void run (){
        int fartbredd = -1, farth?jd = -1; // growth speed
        while(true){
            rutbredd += fartbredd;
            ruth?jd += farth?jd;
            Dimension appletSize= getSize();
            if(rutbredd <1){
                fartbredd=1;
            if(rutbredd >appletSize.width){
                fartbredd= -1;
            if(ruth?jd<1){
                farth?jd=1;
            if(ruth?jd>appletSize.height){
                farth?jd= -1;
            repaint();
            try { Thread.sleep(10);
            }catch( InterruptedException ie) {}
        }It does not say where to put these methods so I figured that perhaps I could put them just after the ones in script #1. Netbeans however gives an error message and Applet Viewer does not show any output at all.. (I get the usual 'Start: applet not intialized'). Does this work for anyone else?
By the way, after copy-pasting it to another editor and back netbeans gives an error message on the first (originally working) script. This worked before I copied it to and back from another programming editor (bluefish). perhaps it is just netbeans not woking when moving stuff around too much?
I have been trying to solve this for two hours. please help me put this script together!
Thanks in advance.

Answer 1

uj2n wrote:
gives an error messageI'm sorry but I skipped the mind reading class at school. Perhaps you can share the error message(s) with us.