setting Swing JDialog to non modal

Question

I'm having an issue with setting a JDialog to non-modal. I need to display a pop-up while not blocking the rest of the application. I tried using SwingUtilities.invokeLater() but as the name suggests it was invoked much later, after the work of the main thread is done. To simplify, here's my code:

BufferedReader reader = new BufferedReader(new FileReader(log));
        JLabel validator = new JLabel("Validating  - please wait");
        JOptionPane pane = new JOptionPane(validator, JOptionPane.INFORMATION_MESSAGE,JOptionPane.NO_OPTION,null, new String[]{"Close"});
        final JDialog dialog = pane.createDialog(null, "title");
        dialog.setModal(false);
        dialog.setVisible(true);
        dialog.setVisible(true);
        writer = validate(reader);
        dialog.dispose();

The dialog shows up but it's empty. If I use it as modal, it shows up fine. I tried using it with certain variations, such as this:

JLabel validator = new JLabel("Validating - please wait");
            JOptionPane pane = new JOptionPane(validator, JOptionPane.INFORMATION_MESSAGE,JOptionPane.NO_OPTION,null, new String[]{"Close"});
            final JDialog dialog = pane.createDialog(null, "Validation in progress");
            Runnable run = new Runnable() {

                @Override
                public void run() {
                    // TODO Auto-generated method stub
                    dialog.setModal(false);
                    dialog.setVisible(true);
                }

            };
            SwingUtilities.invokeLater(run);
            writer = validate(reader);

But as I said, the dialog is invoked much too late for me. (I also tried invokeAndWait but seeing as I can't invoke it from the main thread I had to create a new one so the result was pretty much the same.

Do you have any suggestions?

Answer 1

You need to start your code process before showing the modal JDialog, and then show the dialog. You can perhaps use a background thread if the validate method will take a long time. Something like this:

BufferedReader reader = new BufferedReader(new FileReader(log));
JLabel validator = new JLabel("Validating  - please wait");
JOptionPane pane = new JOptionPane(validator, JOptionPane.INFORMATION_MESSAGE,JOptionPane.NO_OPTION,null, new String[]{"Close"});
final JDialog dialog = pane.createDialog(null, "title");
dialog.setModal(true);

SwingWorker myWorker = new SwingWorker<String, Void>() {
  public void doInBackground() {
     // do long running process
     // perhaps including
     writer = validate(reader);

     // ....

     return yourString;
  }

  public void done() {  
    update JLabel
    dispose of dialog here!
  }
};
myWorker.execute();
dialog.setVisible(true);