modeless JDialog?

What kind of code do I have to update so that the About dialog allows me to select items within the main panel, since the following code seems to enable a modal dialog anyway?

Moved from Beginning Java.

How does the code snippet you've shown us know that it's creating a JDialog?

since the following code seems to enable a modal dialog anyway?

Post your SSCCE demonstrating the problem.

Rob Camick wrote:

since the following code seems to enable a modal dialog anyway?

Post your SSCCE demonstrating the problem.

I don't know, that's why I asked

Let's start back at the top:

You could create a method to create and return a modal JDialog with JFrame owner as the owner:

I say, you could. I don't know if that's what you need to do or if it works well in your design. It's one possibility of many.

You made the statement:

"since the following code seems to enable a modal dialog anyway?

So prove your statement by posting the code you tested that demonstrated this behaviour.

Then we can look at the code to see what you might be doing wrong.

One line of code doesn't help us.

If you want help then start making an effort by posting a proper SSCCE with your questions showing what you have tried and the results that you get.

Greg Brannon wrote:How does the code snippet you've shown us know that it's creating a JDialog?

The whole code is here...

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

/**
 * @version 1.33 2007-06-12
 * @author Cay Horstmann
 */
public class DialogTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(new Runnable()
         {
            public void run()
            {
               DialogFrame frame = new DialogFrame();
               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               frame.setVisible(true);
            }
         });
   }
}

/**
 * A frame with a menu whose File->About action shows a dialog.
 */
class DialogFrame extends JFrame
{
   public DialogFrame()
   {
      setTitle("DialogTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

// construct a File menu

JMenuBar menuBar = new JMenuBar();
      setJMenuBar(menuBar);
      JMenu fileMenu = new JMenu("File");
      menuBar.add(fileMenu);

// add About and Exit menu items

// The About item shows the About dialog

JMenuItem aboutItem = new JMenuItem("About");
      aboutItem.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               if (dialog == null) // first time
               dialog = new AboutDialog(DialogFrame.this);
               dialog.setVisible(true); // pop up dialog
            }
         });
      fileMenu.add(aboutItem);

// The Exit item exits the program

JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               System.exit(0);
            }
         });
      fileMenu.add(exitItem);
   }

public static final int DEFAULT_WIDTH = 300;
   public static final int DEFAULT_HEIGHT = 200;

private AboutDialog dialog;
}

/**
 * A sample modal dialog that displays a message and waits for the user to click the Ok button.
 */
class AboutDialog extends JDialog
{
   public AboutDialog(JFrame owner)
   {
      super(owner, "About DialogTest", true);

// add HTML label to center

add(
            new JLabel(
                  "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann and Gary Cornell</html>"),
            BorderLayout.CENTER);

// Ok button closes the dialog

JButton ok = new JButton("Ok");
      ok.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               setVisible(false);
            }
         });

// add Ok button to southern border

JPanel panel = new JPanel();
      panel.add(ok);
      add(panel, BorderLayout.SOUTH);

setSize(250, 150);
   }
}

"Please keep in mind that you get a free default constructor only when your class has no other constructors."
Core Java Vol 1 (8th Ed) P.146.

Does it work = compile and run then do what you want?

Why are you using Runnable() in your main() method? Would it work without it, just using lines 17 - 19?

I suspect you're having a problem with line 51.

Greg Brannon wrote:Does it work = compile and run then do what you want?

Why are you using Runnable() in your main() method? Would it work without it, just using lines 17 - 19?

I suspect you're having a problem with line 51.

Happy hour?

On line 84 you're passing true to the super constructor, indicating the dialog will be modal. If you turn that into false it will no longer be modal. It will remain in front of your frame but that's how dialogs work.

Greg Brannon wrote:Why are you using Runnable() in your main() method?

Because all GUI related code should run on the EDT, and using a Runnable with EventQueue.invokeLater will cause the code of the Runnable to run on the EDT.

Rob Spoor wrote:On line 84 you're passing true to the super constructor, indicating the dialog will be modal. If you turn that into false it will no longer be modal. It will remain in front of your frame but that's how dialogs work.

Greg Brannon wrote:Why are you using Runnable() in your main() method?

Because all GUI related code should run on the EDT, and using a Runnable with EventQueue.invokeLater will cause the code of the Runnable to run on the EDT.

What does EDT stand for?

Hence, the dialog will be popped up and not leave the user any other choice than to close the dialog by selecting OK.

EDT = Event Dispatching Thread.

Rob Spoor wrote:
Because all GUI related code should run on the EDT, and using a Runnable with EventQueue.invokeLater will cause the code of the Runnable to run on the EDT.

Ummmm. I've written a lot of Swing without using Runnable(). I'll have to think on that one.

I'll have to think on that one.

There is nothing to think about. That is the way it should be done.

Yes, if all you are dong is creating and showing a simple GUI it will probably work 99% of the time without using the Runnable. However, when problems appear they will be random and those are the hardest problems to solve. So play it safe and don't worry.

Read the section from the Swing tutorial on Concurrency for more information.

Thinking . . . studying . . . learning, steps leading to understanding. Didn't mean to sound flippant.