How to close a modal JDialog when user clicks outside of JDialog?

Question

I have a Undecorated Modal JDialog which I want to setVisible(false) when the user clicks outside of the modal dialog.

Is this possible in Swing?

What I am doing is popping up a custom editor for a text field like a date selector. Is there an easier way to do what I want?

EDIT

Remember that modal blocks on the call to setVisible(true), so you can't just say "don't use a modal dialog"

And I've tried focus listeners on the dialog, they don't trigger when its modal.

Answer 1

EDIT: Changed to use WindowFocusListener instead of FocusListener, as well as check for descending components on the focus lost in order to not hide if a child component gains focus.

A simple way would be to add a window focus listener on the dialog that hides it when focus is lost. I don't see the need for modality in this case. For example:

import javax.swing.*;
import java.awt.*;
import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class ClickAwayDialog extends JDialog {

    public ClickAwayDialog(final Frame owner) {
        super(owner);
        JPanel pnl = new JPanel(new BorderLayout());
        pnl.add(new JLabel("Click outside this dialog in the parent frame to close it"), BorderLayout.NORTH);
        JButton btn = new JButton("Click Me");
        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(ClickAwayDialog.this, "New Child Window");
            }
        });
        pnl.add(btn, BorderLayout.CENTER);
        this.setContentPane(pnl);
        this.pack();
        this.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        this.setLocationRelativeTo(owner);
        this.setAlwaysOnTop(true);
        this.addWindowFocusListener(new WindowFocusListener() {

            public void windowGainedFocus(WindowEvent e) {
                //do nothing
            }

            public void windowLostFocus(WindowEvent e) {
                if (SwingUtilities.isDescendingFrom(e.getOppositeWindow(), ClickAwayDialog.this)) {
                    return;
                }
                ClickAwayDialog.this.setVisible(false);
            }

        });
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame parent = new JFrame();
                parent.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
                parent.setSize(300, 300);
                parent.setLocationByPlatform(true);
                parent.setVisible(true);
                ClickAwayDialog dlg = new ClickAwayDialog(parent);
                dlg.setVisible(true);                
            }
        });
    }
}