Class PropertyChangeSupport
- All Implemented Interfaces:
Serializable
- Direct Known Subclasses:
SwingPropertyChangeSupport
public class PropertyChangeSupport extends Object implements Serializable
PropertyChangeEvent
s to them. You can use an instance of this class as a member field of your bean and delegate these types of work to it. The PropertyChangeListener
can be registered for all properties or for a property specified by name. Here is an example of PropertyChangeSupport
usage that follows the rules and recommendations laid out in the JavaBeans specification:
public class MyBean { private final PropertyChangeSupport pcs = new PropertyChangeSupport(this); public void addPropertyChangeListener(PropertyChangeListener listener) { this.pcs.addPropertyChangeListener(listener); } public void removePropertyChangeListener(PropertyChangeListener listener) { this.pcs.removePropertyChangeListener(listener); } private String value; public String getValue() { return this.value; } public void setValue(String newValue) { String oldValue = this.value; this.value = newValue; this.pcs.firePropertyChange("value", oldValue, newValue); } [...] }
A PropertyChangeSupport
instance is thread-safe.
This class is serializable. When it is serialized it will save (and restore) any listeners that are themselves serializable. Any non-serializable listeners will be skipped during serialization.
- Since:
- 1.1
- See Also:
Constructor Summary
Constructor | Description |
---|---|
PropertyChangeSupport |
Constructs a PropertyChangeSupport object. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
void |
addPropertyChangeListener |
Add a PropertyChangeListener to the listener list. |
void |
addPropertyChangeListener |
Add a PropertyChangeListener for a specific property. |
void |
fireIndexedPropertyChange |
Reports a boolean bound indexed property update to listeners that have been registered to track updates of all properties or a property with the specified name. |
void |
fireIndexedPropertyChange |
Reports an integer bound indexed property update to listeners that have been registered to track updates of all properties or a property with the specified name. |
void |
fireIndexedPropertyChange |
Reports a bound indexed property update to listeners that have been registered to track updates of all properties or a property with the specified name. |
void |
firePropertyChange |
Fires a property change event to listeners that have been registered to track updates of all properties or a property with the specified name. |
void |
firePropertyChange |
Reports a boolean bound property update to listeners that have been registered to track updates of all properties or a property with the specified name. |
void |
firePropertyChange |
Reports an integer bound property update to listeners that have been registered to track updates of all properties or a property with the specified name. |
void |
firePropertyChange |
Reports a bound property update to listeners that have been registered to track updates of all properties or a property with the specified name. |
PropertyChangeListener[] |
getPropertyChangeListeners() |
Returns an array of all the listeners that were added to the PropertyChangeSupport object with addPropertyChangeListener(). |
PropertyChangeListener[] |
getPropertyChangeListeners |
Returns an array of all the listeners which have been associated with the named property. |
boolean |
hasListeners |
Check if there are any listeners for a specific property, including those registered on all properties. |
void |
removePropertyChangeListener |
Remove a PropertyChangeListener from the listener list. |
void |
removePropertyChangeListener |
Remove a PropertyChangeListener for a specific property. |
Constructor Details
PropertyChangeSupport
public PropertyChangeSupport(Object sourceBean)
PropertyChangeSupport
object.- Parameters:
-
sourceBean
- The bean to be given as the source for any events.
Method Details
addPropertyChangeListener
public void addPropertyChangeListener(PropertyChangeListener listener)
listener
is null, no exception is thrown and no action is taken.- Parameters:
-
listener
- The PropertyChangeListener to be added
removePropertyChangeListener
public void removePropertyChangeListener(PropertyChangeListener listener)
listener
was added more than once to the same event source, it will be notified one less time after being removed. If listener
is null, or was never added, no exception is thrown and no action is taken.- Parameters:
-
listener
- The PropertyChangeListener to be removed
getPropertyChangeListeners
public PropertyChangeListener[] getPropertyChangeListeners()
If some listeners have been added with a named property, then the returned array will be a mixture of PropertyChangeListeners and PropertyChangeListenerProxy
s. If the calling method is interested in distinguishing the listeners then it must test each element to see if it's a PropertyChangeListenerProxy
, perform the cast, and examine the parameter.
PropertyChangeListener[] listeners = bean.getPropertyChangeListeners();
for (int i = 0; i < listeners.length; i++) {
if (listeners[i] instanceof PropertyChangeListenerProxy) {
PropertyChangeListenerProxy proxy =
(PropertyChangeListenerProxy)listeners[i];
if (proxy.getPropertyName().equals("foo")) {
// proxy is a PropertyChangeListener which was associated
// with the property named "foo"
}
}
}
- Returns:
- all of the
PropertyChangeListeners
added or an empty array if no listeners have been added - Since:
- 1.4
- See Also:
addPropertyChangeListener
public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener)
propertyName
or listener
is null, no exception is thrown and no action is taken.- Parameters:
-
propertyName
- The name of the property to listen on. -
listener
- The PropertyChangeListener to be added - Since:
- 1.2
removePropertyChangeListener
public void removePropertyChangeListener(String propertyName, PropertyChangeListener listener)
listener
was added more than once to the same event source for the specified property, it will be notified one less time after being removed. If propertyName
is null, no exception is thrown and no action is taken. If listener
is null, or was never added for the specified property, no exception is thrown and no action is taken.- Parameters:
-
propertyName
- The name of the property that was listened on. -
listener
- The PropertyChangeListener to be removed - Since:
- 1.2
getPropertyChangeListeners
public PropertyChangeListener[] getPropertyChangeListeners(String propertyName)
- Parameters:
-
propertyName
- The name of the property being listened to - Returns:
- all of the
PropertyChangeListeners
associated with the named property. If no such listeners have been added, or ifpropertyName
is null, an empty array is returned. - Since:
- 1.4
firePropertyChange
public void firePropertyChange(String propertyName, Object oldValue, Object newValue)
No event is fired if old and new values are equal and non-null.
This is merely a convenience wrapper around the more general firePropertyChange(PropertyChangeEvent)
method.
- Parameters:
-
propertyName
- the programmatic name of the property that was changed -
oldValue
- the old value of the property -
newValue
- the new value of the property
firePropertyChange
public void firePropertyChange(String propertyName, int oldValue, int newValue)
No event is fired if old and new values are equal.
This is merely a convenience wrapper around the more general firePropertyChange(String, Object, Object)
method.
- Parameters:
-
propertyName
- the programmatic name of the property that was changed -
oldValue
- the old value of the property -
newValue
- the new value of the property - Since:
- 1.2
firePropertyChange
public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue)
No event is fired if old and new values are equal.
This is merely a convenience wrapper around the more general firePropertyChange(String, Object, Object)
method.
- Parameters:
-
propertyName
- the programmatic name of the property that was changed -
oldValue
- the old value of the property -
newValue
- the new value of the property - Since:
- 1.2
firePropertyChange
public void firePropertyChange(PropertyChangeEvent event)
No event is fired if the given event's old and new values are equal and non-null.
- Parameters:
-
event
- thePropertyChangeEvent
to be fired - Since:
- 1.2
fireIndexedPropertyChange
public void fireIndexedPropertyChange(String propertyName, int index, Object oldValue, Object newValue)
No event is fired if old and new values are equal and non-null.
This is merely a convenience wrapper around the more general firePropertyChange(PropertyChangeEvent)
method.
- Parameters:
-
propertyName
- the programmatic name of the property that was changed -
index
- the index of the property element that was changed -
oldValue
- the old value of the property -
newValue
- the new value of the property - Since:
- 1.5
fireIndexedPropertyChange
public void fireIndexedPropertyChange(String propertyName, int index, int oldValue, int newValue)
No event is fired if old and new values are equal.
This is merely a convenience wrapper around the more general fireIndexedPropertyChange(String, int, Object, Object)
method.
- Parameters:
-
propertyName
- the programmatic name of the property that was changed -
index
- the index of the property element that was changed -
oldValue
- the old value of the property -
newValue
- the new value of the property - Since:
- 1.5
fireIndexedPropertyChange
public void fireIndexedPropertyChange(String propertyName, int index, boolean oldValue, boolean newValue)
No event is fired if old and new values are equal.
This is merely a convenience wrapper around the more general fireIndexedPropertyChange(String, int, Object, Object)
method.
- Parameters:
-
propertyName
- the programmatic name of the property that was changed -
index
- the index of the property element that was changed -
oldValue
- the old value of the property -
newValue
- the new value of the property - Since:
- 1.5
hasListeners
public boolean hasListeners(String propertyName)
propertyName
is null, only check for listeners registered on all properties.- Parameters:
-
propertyName
- the property name. - Returns:
- true if there are one or more listeners for the given property
- Since:
- 1.2
© 1993, 2021, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/17/docs/api/java.desktop/java/beans/PropertyChangeSupport.html