Visit your friendly neighborhood API and look up PropertyChangeEvent in
the java.beans package.  And PropertyChangeListener,
PropertyChangeSupport or its descendant SwingPropertyChangeSupport.

This is where you can notify interested parties of changes to bound
properties.  So if you want to use an event mechanism, it's a good way
to go.  Your "data object" will likely need to carry one of the
"support" objects as a member variable.  It will need to include methods
to add and remove property change listeners.  And when properties of
interest change, it'll need to be able to have its support object fire
the notification to all registered listeners, which will carry the
PropertyChangeEvent with details.

If you need additional complexity -- that is, queueing to remove dupes,
etc. -- it can be built around this very simple approach.

HTH.

= Steve =