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java.beans

Class PropertyChangeSupport

java.lang.Object
|
+--java.beans.PropertyChangeSupport

All Implemented Interfaces:

Serializable


public class PropertyChangeSupport

extends Object

implements Serializable

PropertyChangeSupport makes it easy to fire property change events and handle listeners. It allows chaining of listeners, as well as filtering by property name. In addition, it will serialize only those listeners which are serializable, ignoring the others without problem. This class is thread-safe.

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Constructor Summary

PropertyChangeSupport(java.lang.Object source)

Create a PropertyChangeSupport to work with a specific source bean.

Method Summary

synchronized voidaddPropertyChangeListener(java.beans.PropertyChangeListener l)

Adds a PropertyChangeListener to the list of global listeners.
synchronized voidaddPropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener l)

Adds a PropertyChangeListener listening on the specified property.
voidfirePropertyChange(java.lang.String propertyName, java.lang.Object oldVal, java.lang.Object newVal)

Fire a PropertyChangeEvent containing the old and new values of the property to all the global listeners, and to all the listeners for the specified property name.
voidfirePropertyChange(java.lang.String propertyName, int oldVal, int newVal)

Fire a PropertyChangeEvent containing the old and new values of the property to all the global listeners, and to all the listeners for the specified property name.
voidfirePropertyChange(java.lang.String propertyName, boolean oldVal, boolean newVal)

Fire a PropertyChangeEvent containing the old and new values of the property to all the global listeners, and to all the listeners for the specified property name.
voidfirePropertyChange(java.beans.PropertyChangeEvent event)

Fire a PropertyChangeEvent to all the global listeners, and to all the listeners for the specified property name.
synchronized java.beans.PropertyChangeListener[]getPropertyChangeListeners()

Returns an array of all registered property change listeners.
synchronized java.beans.PropertyChangeListener[]getPropertyChangeListeners(java.lang.String propertyName)

Returns an array of all property change listeners registered under the given property name.
synchronized booleanhasListeners(java.lang.String propertyName)

Tell whether the specified property is being listened on or not.
synchronized voidremovePropertyChangeListener(java.beans.PropertyChangeListener l)

Removes a PropertyChangeListener from the list of global listeners.
synchronized voidremovePropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener l)

Removes a PropertyChangeListener from listening to a specific property.

Constructor Details

PropertyChangeSupport

public PropertyChangeSupport(java.lang.Object source)

Create a PropertyChangeSupport to work with a specific source bean.

Parameters:

Throws:


Method Details

addPropertyChangeListener

public synchronized void addPropertyChangeListener(java.beans.PropertyChangeListener l)

Adds a PropertyChangeListener to the list of global listeners. All property change events will be sent to this listener. The listener add is not unique: that is, n adds with the same listener will result in n events being sent to that listener for every property change. Adding a null listener may cause a NullPointerException down the road. This method will unwrap a PropertyChangeListenerProxy, registering the underlying delegate to the named property list.

Parameters:


addPropertyChangeListener

public synchronized void addPropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener l)

Adds a PropertyChangeListener listening on the specified property. Events will be sent to the listener only if the property name matches. The listener add is not unique; that is, n adds on a particular property for a particular listener will result in n events being sent to that listener when that property is changed. The effect is cumulative, too; if you are registered to listen to receive events on all property changes, and then you register on a particular property, you will receive change events for that property twice. Adding a null listener may cause a NullPointerException down the road. This method will unwrap a PropertyChangeListenerProxy, registering the underlying delegate to the named property list if the names match, and discarding it otherwise.

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firePropertyChange

public void firePropertyChange(java.beans.PropertyChangeEvent event)

Fire a PropertyChangeEvent to all the global listeners, and to all the listeners for the specified property name. This does nothing if old and new values of the event are equal.

Parameters:

Throws:


firePropertyChange

public void firePropertyChange(java.lang.String propertyName, boolean oldVal, boolean newVal)

Fire a PropertyChangeEvent containing the old and new values of the property to all the global listeners, and to all the listeners for the specified property name. This does nothing if old and new are equal.

Parameters:


firePropertyChange

public void firePropertyChange(java.lang.String propertyName, int oldVal, int newVal)

Fire a PropertyChangeEvent containing the old and new values of the property to all the global listeners, and to all the listeners for the specified property name. This does nothing if old and new are equal.

Parameters:


firePropertyChange

public void firePropertyChange(java.lang.String propertyName, java.lang.Object oldVal, java.lang.Object newVal)

Fire a PropertyChangeEvent containing the old and new values of the property to all the global listeners, and to all the listeners for the specified property name. This does nothing if old and new are non-null and equal.

Parameters:


getPropertyChangeListeners

public synchronized PropertyChangeListener[] getPropertyChangeListeners()

Returns an array of all registered property change listeners. Those that were registered under a name will be wrapped in a PropertyChangeListenerProxy, so you must check whether the listener is an instance of the proxy class in order to see what name the real listener is registered under. If there are no registered listeners, this returns an empty array.

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getPropertyChangeListeners

public synchronized PropertyChangeListener[] getPropertyChangeListeners(java.lang.String propertyName)

Returns an array of all property change listeners registered under the given property name. If there are no registered listeners, this returns an empty array.

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hasListeners

public synchronized boolean hasListeners(java.lang.String propertyName)

Tell whether the specified property is being listened on or not. This will only return true if there are listeners on all properties or if there is a listener specifically on this property.

Parameters:

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removePropertyChangeListener

public synchronized void removePropertyChangeListener(java.beans.PropertyChangeListener l)

Removes a PropertyChangeListener from the list of global listeners. If any specific properties are being listened on, they must be deregistered by themselves; this will only remove the general listener to all properties. If add() has been called multiple times for a particular listener, remove() will have to be called the same number of times to deregister it. This method will unwrap a PropertyChangeListenerProxy, removing the underlying delegate from the named property list.

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removePropertyChangeListener

public synchronized void removePropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener l)

Removes a PropertyChangeListener from listening to a specific property. If add() has been called multiple times for a particular listener on a property, remove() will have to be called the same number of times to deregister it. This method will unwrap a PropertyChangeListenerProxy, removing the underlying delegate from the named property list if the names match.

Parameters:

Throws: