Can't get keyboard focus on JTextField in JDialog

I have a Swing app that has a JDialog pop up and ask for a username and password. I thought it'd be good to have the keyboard focus already in the username field, but everything I've tried so far doesn't work (even though one solution I tried works for a different text field in the program), so....I need some help. Here's my code:

//JTextField usernameField = ...
JDialog dialog = pane.createDialog("Password:");
dialog.setVisible(true);


//Take 1
usernameField.requestFocusInWindow();

//Take 2
dialog.addWindowFocusListener(new WindowAdapter() {
        public void windowGainedFocus(WindowEvent e) {
            usernameField.requestFocusInWindow();
        }
});

//Take 3 - This is what I used elsewhere quite successfully
dialog.addComponentListener(new ComponentAdapter() {
    public void componentShown(ComponentEvent e ) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                usernameField.requestFocusInWindow();
            }
        });
    }
});

For what it's worth, this is with Linux / X11 / Openbox. And when I 开发者_运维技巧use GTK, I have to press Tab once to select the appropriate field, but when I use Metal, I have to press it twice.

Thanks in advance.

See Dialog Focus for tips & strategies.