Document Listener firing some times but not others

this one has been puzzling me for a few days now and I feel that I have barely been able to narrow it down.

I am using Java and have a wizard for the user to step through. One of the steps allows the user to select a start time & date and an end time & date to schedule some work. I thought I had the validation on the dates complete (so that the end date must be after the start date & start date must be after current date etc). However, my validation method only fired once focus was lost on either date TextField so if the user selected a new date and immediately clicked next, an invalid choice could continue -- bug!

The start and end date selectors are widgets which are made up of a JSpinner and a calendar dialog which pops up if button is clicked. I have attached a Document Listener to the text field of the JSpinner:

DocumentListener docListener = new DocumentListener() {

        @Override
        public void insertUpdate(DocumentEvent e) {
            dateChanged();

            System.out.println("insertUpdate");

        }

        @Override
        public void removeUpdate(DocumentEvent e) {
            dateChanged();
            System.out.println("removeUpdate");
        }

        @Override
        public void changedUpdate(DocumentEvent e) {
            dateChanged();
            System.out.println("changedUpdate");
        }

    };
    ((JSpinner.DefaultEditor) jSpinner1.getEditor()).getTextField().getDocument().addDocumentListener(
            docListener);

When I run this class using its own main method to test:

public static void main(String[] args) {

    DateSelectorWidget test = new DateSelectorWidget();
    JFr开发者_开发技巧ame f = new JFrame("T E S T ");
    f.getContentPane().setLayout(new BorderLayout());
    f.getContentPane().add(test, BorderLayout.CENTER);
    f.pack();
    f.setVisible(true);

}

The DocListener fires each time and everything is fine. However this class is part of a bigger program and when it is called in it - the DocListener simply does not fire at all. An instance of the class is simply added to a panel in the wizard and yet it does not function the way it does when tested independently.

Any ideas anyone?

Thanks

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My guess is that you directly or indirectly change the editor on the JSpinner after your line to retrieve, cast, get component, get model and add listener.