Java Swing - how to update GUI Objects ie. JTextField value from sub class in same package

Question

I have a GUI designed in Swing with all of the Components laid out. For example I have a JComboBox with a JList and a JTextField,

When I select a different item from the JComboBox I am trying to use a ListSelectionListener to call a method in a subclass to update the JTextField based on the choice,

How would I go about doing that properly? How do I call the subclass and then from the subclass update the GUI object's value?

Answer 1

public class Parent {

    private void init() {
        // ...
        combo.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                Object selected = combo.getSelectedItem();
                textField.setText(getTextBasedOnSelection(selected));
            }
        });
        // ...
    }

    /**
     * Returns the text to display when the given object is selected.
     * Subclasses may override this method to display what they want
     */
    protected String getTextBasedOnSelection(Object selected) {
        return selected.toString();
    }
    // ...
}