PropertyChangeEvent

public class PropertyChangeEvent extends EventObject

Known Direct Subclasses IndexedPropertyChangeEvent IndexedPropertyChangeEvent An "IndexedPropertyChange" event gets delivered whenever a component that conforms to the JavaBeans™ specification (a "bean") changes a bound indexed property.

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 primitive 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.

Inherited Field Summary

From class java.util.EventObject

protected Object

source

The object on which the Event initially occurred.

Public Constructor Summary

PropertyChangeEvent(Object source, String propertyName, Object oldValue, Object newValue) Constructs a new PropertyChangeEvent.

Public Method Summary

Object	getNewValue() Gets the new value for the property, expressed as an Object.
Object	getOldValue() Gets the old value for the property, expressed as an Object.
Object	getPropagationId() The "propagationId" field is reserved for future use.
String	getPropertyName() Gets the programmatic name of the property that was changed.
void	setPropagationId(Object propagationId) Sets the propagationId object for the event.
String	toString() Returns a string representation of the object.

Inherited Method Summary

From class java.util.EventObject

Object	getSource() The object on which the Event initially occurred.
String	toString() Returns a String representation of this EventObject.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public PropertyChangeEvent (Object source, String propertyName, Object oldValue, Object newValue)

Constructs a new PropertyChangeEvent.

Parameters

source	the bean that fired the event
propertyName	the programmatic name of the property that was changed
oldValue	the old value of the property
newValue	the new value of the property

Throws

IllegalArgumentException	if source is null

Public Methods

public Object getNewValue ()

Gets the new value for the property, expressed as an Object.

Returns

• The new value for the property, expressed as an Object. May be null if multiple properties have changed.

public Object getOldValue ()

Gets the old value for the property, expressed as an Object.

Returns

• The old value for the property, expressed as an Object. May be null if multiple properties have changed.

public Object getPropagationId ()

The "propagationId" field is reserved for future use. In Beans 1.0 the sole requirement is that if a listener catches a PropertyChangeEvent and then fires a PropertyChangeEvent of its own, then it should make sure that it propagates the propagationId field from its incoming event to its outgoing event.

Returns

• the propagationId object associated with a bound/constrained property update.

public String getPropertyName ()

Gets the programmatic name of the property that was changed.

Returns

• The programmatic name of the property that was changed. May be null if multiple properties have changed.

public void setPropagationId (Object propagationId)

Sets the propagationId object for the event.

Parameters

propagationId	The propagationId object for the event.

public String toString ()

Returns a string representation of the object.

Returns

• a string representation of the object