java.lang.Object
|
+----java.util.EventObject
|
+----java.beans.PropertyChangeEvent
public class PropertyChangeEvent
extends EventObject
A "PropertyChange" event gets delivered whenever a bean changes a "bound" or "constrained" property. A PropertyChangeEvent object is sent as an argument to the PropertyChangeListener and VetoableChangeListener methods.
Normally PropertyChangeEvents are accompanied by the name and the old and new value of the changed property. If the new value is a builtin type (such as int or boolean) it must be wrapped as the corresponding java.lang.* Object type (such as Integer or Boolean).
Null values may be provided for the old and the new values if their true values are not known.
An event source may send a null object as the name to indicate that an arbitrary set of if its properties have changed. In this case the old and new values should also be null.