previous | start | next

## Change Listeners

- Display adds itself as a change listener to the invoice
- Display updates itself when invoice object changes state

      final Invoice invoice = new Invoice();
      final JTextArea textArea = new JTextArea(20, 40);
      ChangeListener listener = new
         ChangeListener()
         {
            public void stateChanged(ChangeEvent event)
            {
               textArea.setText(...);
            }
         };

previous | start | next