- All Implemented Interfaces:
Serializable
public class VetoableChangeSupport 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 VetoableChangeListener
can be registered for all properties
or for a property specified by name.
Here is an example of VetoableChangeSupport
usage that follows
the rules and recommendations laid out in the JavaBeans specification:
public class MyBean {
private final VetoableChangeSupport vcs = new VetoableChangeSupport(this);
public void addVetoableChangeListener(VetoableChangeListener listener) {
this.vcs.addVetoableChangeListener(listener);
}
public void removeVetoableChangeListener(VetoableChangeListener listener) {
this.vcs.removeVetoableChangeListener(listener);
}
private String value;
public String getValue() {
return this.value;
}
public void setValue(String newValue) throws PropertyVetoException {
String oldValue = this.value;
this.vcs.fireVetoableChange("value", oldValue, newValue);
this.value = newValue;
}
[...]
}
A VetoableChangeSupport
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:
PropertyChangeSupport
, Serialized Form
-
Constructor Summary
Constructors Constructor Description VetoableChangeSupport(Object sourceBean)
Constructs aVetoableChangeSupport
object. -
Method Summary
Modifier and Type Method Description void
addVetoableChangeListener(VetoableChangeListener listener)
Add a VetoableChangeListener to the listener list.void
addVetoableChangeListener(String propertyName, VetoableChangeListener listener)
Add a VetoableChangeListener for a specific property.void
fireVetoableChange(PropertyChangeEvent event)
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
fireVetoableChange(String propertyName, boolean oldValue, boolean newValue)
Reports a boolean constrained property update to listeners that have been registered to track updates of all properties or a property with the specified name.void
fireVetoableChange(String propertyName, int oldValue, int newValue)
Reports an integer constrained property update to listeners that have been registered to track updates of all properties or a property with the specified name.void
fireVetoableChange(String propertyName, Object oldValue, Object newValue)
Reports a constrained property update to listeners that have been registered to track updates of all properties or a property with the specified name.VetoableChangeListener[]
getVetoableChangeListeners()
Returns an array of all the listeners that were added to the VetoableChangeSupport object with addVetoableChangeListener().VetoableChangeListener[]
getVetoableChangeListeners(String propertyName)
Returns an array of all the listeners which have been associated with the named property.boolean
hasListeners(String propertyName)
Check if there are any listeners for a specific property, including those registered on all properties.void
removeVetoableChangeListener(VetoableChangeListener listener)
Remove a VetoableChangeListener from the listener list.void
removeVetoableChangeListener(String propertyName, VetoableChangeListener listener)
Remove a VetoableChangeListener for a specific property.
-
Constructor Details
-
VetoableChangeSupport
Constructs aVetoableChangeSupport
object.- Parameters:
sourceBean
- The bean to be given as the source for any events.
-
-
Method Details
-
addVetoableChangeListener
Add a VetoableChangeListener to the listener list. The listener is registered for all properties. The same listener object may be added more than once, and will be called as many times as it is added. Iflistener
is null, no exception is thrown and no action is taken.- Parameters:
listener
- The VetoableChangeListener to be added
-
removeVetoableChangeListener
Remove a VetoableChangeListener from the listener list. This removes a VetoableChangeListener that was registered for all properties. Iflistener
was added more than once to the same event source, it will be notified one less time after being removed. Iflistener
is null, or was never added, no exception is thrown and no action is taken.- Parameters:
listener
- The VetoableChangeListener to be removed
-
getVetoableChangeListeners
Returns an array of all the listeners that were added to the VetoableChangeSupport object with addVetoableChangeListener().If some listeners have been added with a named property, then the returned array will be a mixture of VetoableChangeListeners and
VetoableChangeListenerProxy
s. If the calling method is interested in distinguishing the listeners then it must test each element to see if it's aVetoableChangeListenerProxy
, perform the cast, and examine the parameter.VetoableChangeListener[] listeners = bean.getVetoableChangeListeners(); for (int i = 0; i < listeners.length; i++) { if (listeners[i] instanceof VetoableChangeListenerProxy) { VetoableChangeListenerProxy proxy = (VetoableChangeListenerProxy)listeners[i]; if (proxy.getPropertyName().equals("foo")) { // proxy is a VetoableChangeListener which was associated // with the property named "foo" } } }
- Returns:
- all of the
VetoableChangeListeners
added or an empty array if no listeners have been added - Since:
- 1.4
- See Also:
VetoableChangeListenerProxy
-
addVetoableChangeListener
Add a VetoableChangeListener for a specific property. The listener will be invoked only when a call on fireVetoableChange names that specific property. The same listener object may be added more than once. For each property, the listener will be invoked the number of times it was added for that property. IfpropertyName
orlistener
is null, no exception is thrown and no action is taken.- Parameters:
propertyName
- The name of the property to listen on.listener
- The VetoableChangeListener to be added- Since:
- 1.2
-
removeVetoableChangeListener
Remove a VetoableChangeListener for a specific property. Iflistener
was added more than once to the same event source for the specified property, it will be notified one less time after being removed. IfpropertyName
is null, no exception is thrown and no action is taken. Iflistener
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 VetoableChangeListener to be removed- Since:
- 1.2
-
getVetoableChangeListeners
Returns an array of all the listeners which have been associated with the named property.- Parameters:
propertyName
- The name of the property being listened to- Returns:
- all the
VetoableChangeListeners
associated with the named property. If no such listeners have been added, or ifpropertyName
is null, an empty array is returned. - Since:
- 1.4
-
fireVetoableChange
public void fireVetoableChange(String propertyName, Object oldValue, Object newValue) throws PropertyVetoExceptionReports a constrained property update to listeners that have been registered to track updates of all properties or a property with the specified name.Any listener can throw a
PropertyVetoException
to veto the update. If one of the listeners vetoes the update, this method passes a new "undo"PropertyChangeEvent
that reverts to the old value to all listeners that already confirmed this update and throws thePropertyVetoException
again.No event is fired if old and new values are equal and non-null.
This is merely a convenience wrapper around the more general
fireVetoableChange(PropertyChangeEvent)
method.- Parameters:
propertyName
- the programmatic name of the property that is about to changeoldValue
- the old value of the propertynewValue
- the new value of the property- Throws:
PropertyVetoException
- if one of listeners vetoes the property update
-
fireVetoableChange
public void fireVetoableChange(String propertyName, int oldValue, int newValue) throws PropertyVetoExceptionReports an integer constrained property update to listeners that have been registered to track updates of all properties or a property with the specified name.Any listener can throw a
PropertyVetoException
to veto the update. If one of the listeners vetoes the update, this method passes a new "undo"PropertyChangeEvent
that reverts to the old value to all listeners that already confirmed this update and throws thePropertyVetoException
again.No event is fired if old and new values are equal.
This is merely a convenience wrapper around the more general
fireVetoableChange(String, Object, Object)
method.- Parameters:
propertyName
- the programmatic name of the property that is about to changeoldValue
- the old value of the propertynewValue
- the new value of the property- Throws:
PropertyVetoException
- if one of listeners vetoes the property update- Since:
- 1.2
-
fireVetoableChange
public void fireVetoableChange(String propertyName, boolean oldValue, boolean newValue) throws PropertyVetoExceptionReports a boolean constrained property update to listeners that have been registered to track updates of all properties or a property with the specified name.Any listener can throw a
PropertyVetoException
to veto the update. If one of the listeners vetoes the update, this method passes a new "undo"PropertyChangeEvent
that reverts to the old value to all listeners that already confirmed this update and throws thePropertyVetoException
again.No event is fired if old and new values are equal.
This is merely a convenience wrapper around the more general
fireVetoableChange(String, Object, Object)
method.- Parameters:
propertyName
- the programmatic name of the property that is about to changeoldValue
- the old value of the propertynewValue
- the new value of the property- Throws:
PropertyVetoException
- if one of listeners vetoes the property update- Since:
- 1.2
-
fireVetoableChange
Fires a property change event to listeners that have been registered to track updates of all properties or a property with the specified name.Any listener can throw a
PropertyVetoException
to veto the update. If one of the listeners vetoes the update, this method passes a new "undo"PropertyChangeEvent
that reverts to the old value to all listeners that already confirmed this update and throws thePropertyVetoException
again.No event is fired if the given event's old and new values are equal and non-null.
- Parameters:
event
- thePropertyChangeEvent
to be fired- Throws:
PropertyVetoException
- if one of listeners vetoes the property update- Since:
- 1.2
-
hasListeners
Check if there are any listeners for a specific property, including those registered on all properties. IfpropertyName
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
-