VetoableChangeListener allows a class to monitor proposed changes to
properties of a Bean and, if desired, prevent them from occurring. A
vetoableChange() event will be fired
after the property change has
been requested, but before it is permanent. If any listener rejects the
change by throwing the PropertyChangeException, a new vetoableChange()
event will be fired to all listeners who received a vetoableChange() event
in the first place, informing them to revert back to the old value. Thus,
the listener that threw the exception the first time should be prepared
to rethrow it the second time. The value, of course, never actually changed.
Note: This class may not be reliably used to determine
whether a property has actually changed. Use the PropertyChangeListener
interface for that instead.
Fired before a Bean's property changes.
Note: This class may not be reliably used to determine whether a property has actually changed. Use the PropertyChangeListener interface for that instead.