/* PropertyChangeEvent.java -- describes a change in a property
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package cc.kune.common.client.actions;
// TODO: Auto-generated Javadoc
/**
* PropertyChangeEvents are fired in the PropertyChange and VetoableChange event
* classes. They represent the old and new values as well as the source Bean. If
* the old or new value is a primitive type, it must be wrapped in the
* appropriate wrapper type (java.lang.Integer for int, etc., etc.).
*
* <p>
* If the old or new values are unknown (although why that would be I do not
* know), they may be null. Also, if the set of properties itself has changed,
* the name should be null, and the old and new values may also be null. Right
* now Sun put in a propagationId, reserved for future use. Read the comments on
* the constructor and on setPropagationId for more information.
*
* @author John Keiser
* @author Eric Blake (ebb9@email.byu.edu)
* @author Adapted version for GWT (C) The kune development team
* @since 1.1
* @status udpated to 1.4
*/
public class PropertyChangeEvent {
/**
* The name of the property that changed, may be null. Package visible for use
* by PropertyChangeSupport.
*
* @serial the changed property name
*/
final String propertyName;
/**
* The new value of the property, may be null. Package visible for use by
* PropertyChangeSupport.
*
* @serial the new property value
*/
final Object newValue;
/**
* The old value of the property, may be null. Package visible for use by
* PropertyChangeSupport.
*
* @serial the old property value
*/
final Object oldValue;
/**
* The propagation ID, reserved for future use. May be null.
*
* @see #getPropagationId()
* @serial the Propagation ID
*/
private Object propagationId;
/** The source. */
private final Object source;
/**
* Create a new PropertyChangeEvent. Remember that if you received a
* PropertyChangeEvent and are sending a new one, you should also set the
* propagation ID from the old PropertyChangeEvent.
*
* @param source the Bean containing the property
* @param propertyName the property's name
* @param oldVal the old value of the property
* @param newVal the new value of the property
*/
public PropertyChangeEvent(final Object source, final String propertyName, final Object oldVal,
final Object newVal) {
this.source = source;
this.propertyName = propertyName;
this.oldValue = oldVal;
this.newValue = newVal;
}
/**
* Get the property's new value. May be null if multiple properties changed.
*
* @return the property's new value
*/
public Object getNewValue() {
return newValue;
}
/**
* Get the property's old value. May be null if multiple properties changed.
*
* @return the property's old value
*/
public Object getOldValue() {
return oldValue;
}
/**
* Get the propagation ID. Right now, it is not used for anything.
*
* @return the propagation ID
* @see #setPropagationId(Object)
*/
public Object getPropagationId() {
return propagationId;
}
/**
* Get the property name. May be null if multiple properties changed.
*
* @return the property name
*/
public String getPropertyName() {
return propertyName;
}
/**
* Gets the source.
*
* @return the source
*/
public Object getSource() {
return source;
}
/**
* Set the propagation ID. This is a way for the event to be passed from hand
* to hand and retain a little extra state. Right now it is unused, but it
* should be propagated anyway so that future versions of JavaBeans can use
* it, for God knows what.
*
* @param propagationId
* the propagation ID
* @see #getPropagationId()
*/
public void setPropagationId(final Object propagationId) {
this.propagationId = propagationId;
}
/**
* Utility method to rollback a change.
*
* @return a new event with old and new swapped
*/
PropertyChangeEvent rollback() {
PropertyChangeEvent result = new PropertyChangeEvent(source, propertyName, newValue, oldValue);
result.propagationId = propagationId;
return result;
}
} // class PropertyChangeEvent