// JdbcPropertyChangeSupport.java
// $Id: JdbcPropertyChangeSupport.java,v 1.1 2000/09/06 11:57:43 bmahe Exp $
// (c) COPYRIGHT MIT, INRIA and Keio, 2000.
// Please first read the full copyright statement in file COPYRIGHT.html
package org.w3c.tools.jdbc;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.Hashtable;
import java.util.Vector;
/**
* This subclass of java.beans.PropertyChangeSupport is identical
* in functionality except that it fire a PropertyChangeEvent even if the
* old value and the new value are identicals.
* @version $Revision: 1.1 $
* @author Benot Mah (bmahe@w3.org)
*/
public class JdbcPropertyChangeSupport extends PropertyChangeSupport {
/**
* Our listeners
*/
private Vector listeners = null;
/**
* Our listeners for specific properties
*/
private Hashtable children = null;
/**
* Our Bean
*/
private Object source = null;
/**
* Add a PropertyChangeListener to the listener list.
* The listener is registered for all properties.
* @param listener The PropertyChangeListener to be added
*/
public synchronized void
addPropertyChangeListener(PropertyChangeListener listener)
{
if (listeners == null) {
listeners = new Vector();
}
listeners.addElement(listener);
}
/**
* Remove a PropertyChangeListener from the listener list.
* This removes a PropertyChangeListener that was registered
* for all properties.
* @param listener The PropertyChangeListener to be removed
*/
public synchronized void
removePropertyChangeListener(PropertyChangeListener listener)
{
if (listeners == null) {
return;
}
listeners.removeElement(listener);
}
/**
* Add a PropertyChangeListener for a specific property. The listener
* will be invoked only when a call on firePropertyChange names that
* specific property.
* @param propertyName The name of the property to listen on.
* @param listener The PropertyChangeListener to be added
*/
public synchronized void
addPropertyChangeListener(String propertyName,
PropertyChangeListener listener)
{
if (children == null) {
children = new Hashtable();
}
JdbcPropertyChangeSupport child =
(JdbcPropertyChangeSupport)children.get(propertyName);
if (child == null) {
child = new JdbcPropertyChangeSupport(source);
children.put(propertyName, child);
}
child.addPropertyChangeListener(listener);
}
/**
* Remove a PropertyChangeListener for a specific property.
* @param propertyName The name of the property that was listened on.
* @param listener The PropertyChangeListener to be removed
*/
public synchronized void
removePropertyChangeListener(String propertyName,
PropertyChangeListener listener)
{
if (children == null) {
return;
}
JdbcPropertyChangeSupport child =
(JdbcPropertyChangeSupport)children.get(propertyName);
if (child == null) {
return;
}
child.removePropertyChangeListener(listener);
}
/**
* Report a bound property update to any registered listeners.
* No event is fired if old and new are equal and non-null.
* @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.
*/
public void firePropertyChange(String propertyName,
Object oldValue,
Object newValue)
{
Vector targets = null;
JdbcPropertyChangeSupport child = null;
synchronized (this) {
if (listeners != null) {
targets = (Vector) listeners.clone();
}
if (children != null && propertyName != null) {
child = (JdbcPropertyChangeSupport)children.get(propertyName);
}
}
PropertyChangeEvent evt =
new PropertyChangeEvent(source, propertyName, oldValue, newValue);
if (targets != null) {
for (int i = 0; i < targets.size(); i++) {
PropertyChangeListener target =
(PropertyChangeListener)targets.elementAt(i);
target.propertyChange(evt);
}
}
if (child != null) {
child.firePropertyChange(evt);
}
}
/**
* Report an int bound property update to any registered listeners.
* No event is fired if old and new are equal and non-null.
* <p>
* This is merely a convenience wrapper around the more general
* firePropertyChange method that takes Object values.
* @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.
*/
public void firePropertyChange(String propertyName,
int oldValue,
int newValue)
{
firePropertyChange(propertyName,
new Integer(oldValue),
new Integer(newValue));
}
/**
* Report a boolean bound property update to any registered listeners.
* No event is fired if old and new are equal and non-null.
* <p>
* This is merely a convenience wrapper around the more general
* firePropertyChange method that takes Object values.
* @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.
*/
public void firePropertyChange(String propertyName,
boolean oldValue,
boolean newValue)
{
firePropertyChange(propertyName,
new Boolean(oldValue),
new Boolean(newValue));
}
/**
* Fire an existing PropertyChangeEvent to any registered listeners.
* No event is fired if the given event's old and new values are
* equal and non-null.
* @param evt The PropertyChangeEvent object.
*/
public void firePropertyChange(PropertyChangeEvent evt) {
String propertyName = evt.getPropertyName();
Vector targets = null;
JdbcPropertyChangeSupport child = null;
synchronized (this) {
if (listeners != null) {
targets = (Vector) listeners.clone();
}
if (children != null && propertyName != null) {
child = (JdbcPropertyChangeSupport)children.get(propertyName);
}
}
if (targets != null) {
for (int i = 0; i < targets.size(); i++) {
PropertyChangeListener target =
(PropertyChangeListener)targets.elementAt(i);
target.propertyChange(evt);
}
}
if (child != null) {
child.firePropertyChange(evt);
}
}
/**
* Check if there are any listeners for a specific property.
* @param propertyName the property name.
* @return true if there are ore or more listeners for the given property
*/
public synchronized boolean hasListeners(String propertyName) {
if (listeners != null && !listeners.isEmpty()) {
return true;
}
if (children != null) {
JdbcPropertyChangeSupport child =
(JdbcPropertyChangeSupport)children.get(propertyName);
if (child != null && child.listeners != null) {
return !child.listeners.isEmpty();
}
}
return false;
}
/**
* Constructor
* @param sourceBean our bean
*/
public JdbcPropertyChangeSupport(Object sourceBean) {
super(sourceBean);
this.source = sourceBean;
}
}
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