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PropertyChangeEvent.javaAPI DocJava SE 5 API3798Fri Aug 26 14:56:56 BST 2005java.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 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.

Fields Summary
private String
propertyName
name of the property that changed. May be null, if not known.
private Object
newValue
New value for property. May be null if not known.
private Object
oldValue
Previous value for property. May be null if not known.
private Object
propagationId
Propagation ID. May be null.
Constructors Summary
public PropertyChangeEvent(Object source, String propertyName, Object oldValue, Object newValue)
Constructs a new PropertyChangeEvent.

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

	super(source);
	this.propertyName = propertyName;
	this.newValue = newValue;
	this.oldValue = oldValue;
Methods Summary
public java.lang.ObjectgetNewValue()
Sets the new value for the property, expressed as an Object.

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

	return newValue;
public java.lang.ObjectgetOldValue()
Gets the old value for the property, expressed as an Object.

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

	return oldValue;
public java.lang.ObjectgetPropagationId()
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.

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

	return propagationId;
public java.lang.StringgetPropertyName()
Gets the programmatic name of the property that was changed.

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

	return propertyName;
public voidsetPropagationId(java.lang.Object propagationId)
Sets the propagationId object for the event.

param
propagationId The propagationId object for the event.

	this.propagationId = propagationId;