Problem displaying my dialog box

Question

Hi everyone.
I have a very annoying problem. I have a GUI frame that my application runs in. It implements a WindowListener interface and I override the windowClosing() method so when the window is closed I perform some memory clean up procedures.
So I want to have a dialog box pop up when the window is closing which displays some information about what's going on while my closing procedures are being executed.
The problem is that the dialog box appears, which I do by:
shutdownDialog.setVisible(true);but it has nothing in it. No components at all. Now I used Netbeans to make the dialog box so I know they should be there.
I even put the shutdownDialog.setVisible(true) into another part of my program and when the box pops up it has all the components like it should.
Is there a reason why components of the dialog box don't show up when it's called from the windowClosing() method?
Is there any other way I could accomplish that?

Answer 1

If the components don't appear possible causes could be: they haven't been added to the dialog, they haven't been laid out within the dialog, they aren't being painted.
Now I used Netbeans to make the dialog box so I know they should be there.It isn't my intention to stand between someone and their belief systems. But neither can I stand aside silent when I know that skepticism is more effective in tracking down bugs: abandon "they should be there" in favour of "they are not there" and try and figure out why.
I don't know Netbeans, but the following is effective:
import java.awt.Dimension;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class CloseEg {
    private JFrame gui;
    public CloseEg() {
        gui = new JFrame("Close example");
        gui.setSize(new Dimension(300, 300));
        gui.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
        gui.addWindowListener(appCloser);
        shutdownDialog = new JDialog((JFrame)null);
        shutdownDialog.setUndecorated(true);
        shutdownDialog.add(new JLabel("Close down initiated.  Please be patient"));
        shutdownDialog.setLocationRelativeTo(null);
        shutdownDialog.pack();
        gui.setVisible(true);
    private WindowListener appCloser = new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
            shutdownDialog.setVisible(true);
            Thread closerThread = new Thread(new Runnable() {
                public void run() {
                    doCloseDown();
            closerThread.start();
    private JDialog shutdownDialog;
    private void doCloseDown() {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        System.exit(0);
    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new CloseEg();
}If I don't pack() the dialog, I don't see it at all. If I try and do the closedown on the EDT - ie don't create a new thread for it - then the sleep() (or other lengthy operation) stops the dialog's components from being drawn.
You will get better help more quickly in the [Swing forum|http://forums.sun.com/forum.jspa?forumID=57]. Although having started here, you might as well continue.
If nothing suggested by my code helps, you might like to post an example that can be compiled to illustrate the problem. (But teh Netbeans is a jealous god and sometimes makes that difficult;)