Problem with threads and simulation: please help

Question

please help me figure this out..
i have something like this:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DrawShapes extends JApplet{
     private JButton choices[];
     private String names[]={"line", "square", "oval"};
     private JPanel buttonPanel;
     private DrawPanel drawingArea;
     private int width=300, height=200;
     public void init(){
          drawingArea=new DrawPanel(width, height);
          choices=new JButton[names.length];
          buttonPanel=new JPanel();
          buttonPanel.setLayout(new GridLayout(1, choices.length));
          ButtonHandler handler=new ButtonHandler();
          for(int i=0; i<choices.length; i++){
               choices=new JButton(names[i]);
               buttonPanel.add(choices[i]);
               choices[i].addActionListener(handler);
          Container c=getContentPane();
          c.add(buttonPanel, BorderLayout.NORTH);
          c.add(drawingArea, BorderLayout.CENTER);
     }//end init
     public void setWidth(int w){
          width=(w>=0 ? w : 300);
     public void setHeight(int h){
          height=(h>=0 ? h : 200);
     /*public static void main(String args[]){
          int width, height;
          if(args.length!=2){
               height=200; width=300;
          else{
                    width=Integer.parseInt(args[0]);
                    height=Integer.parseInt(args[1]);
          JFrame appWindow=new JFrame("An applet running as an application");
          appWindow.addWindowListener(
               new WindowAdapter(){
                    public void windowClosing(WindowEvent e){
                         System.exit(0);
          DrawShapes appObj=new DrawShapes();
          appObj.setWidth(width);
          appObj.setHeight(height);
          appObj.init();          
          appObj.start();
          appWindow.getContentPane().add(appObj);
          appWindow.setSize(width, height);
          appWindow.show();
     }//end main*/
     private class ButtonHandler implements ActionListener{
          public void actionPerformed(ActionEvent e){
               for(int i=0; i<choices.length; i++){
                    if(e.getSource()==choices[i]){
                         drawingArea.setCurrentChoice(i);
                         break;
}//end class DrawShapes
class DrawPanel extends JPanel{
     private int currentChoice=-1;
     private int width=100, height=100;
     public DrawPanel(int w, int h){
          width=(w>=0 ? w : 100);
          height=(h>=0 ? h : 100);
     public void paintComponent(Graphics g){
          super.paintComponent(g);
          switch(currentChoice){
               case 0:     g.drawLine(randomX(), randomY(), randomX(), randomY());
                         break;
               case 1: g.drawRect(randomX(), randomY(), randomX(), randomY());
                         break;
               case 2: g.drawOval(randomX(), randomY(), randomX(), randomY());
                         break;
     public void setCurrentChoice(int c){
          currentChoice=c;
          repaint();          
     private int randomX(){
          return (int) (Math.random()*width);
     private int randomY(){
          return (int) (Math.random()*height);
}//end class drawPanel
That one's from a book. I used that code to start with my applet. Mine calls different merthod from the switch cases. Say I have:
case 0: drawStart(g); break;
public void drawStart(Graphics g){
  /* something here */
drawMain(g);
public void drawMain(graphics g){
g.drawString("test", x, y);
//here's where i'm trying to pause
//i've tried placing Thread.sleep between these lines
g.drawLine(x, y, a, b);
//Thread.sleep here
g.drawRect(x, y, 50, 70);
}I also need to put delays between method calls but I need to synchronize them. Am I doing it all wrong? The application pauses or sleeps but afterwards, it still drew everything all at once. Thanks a lot!

Answer 1

It is. Sorry about that. Just answer any if you want to. I'd appreciate your help. Sorry again if it caused you anything or whatever. .n_n.