Package org.apache.wicket.util.listener

Class ListenerCollection<T>

java.lang.Object

org.apache.wicket.util.listener.ListenerCollection<T>

Type Parameters:

T - type of listeners

All Implemented Interfaces:

Serializable, Iterable<T>

Direct Known Subclasses:

AjaxRequestTargetListenerCollection, ApplicationListenerCollection, BehaviorInstantiationListenerCollection, ChangeListenerSet, ComponentInitializationListenerCollection, ComponentInstantiationListenerCollection, ComponentOnAfterRenderListenerCollection, ComponentOnBeforeRenderListenerCollection, ComponentOnConfigureListenerCollection, HeaderContributorListenerCollection, OnComponentTagListenerCollection, RequestCycleListenerCollection, SessionListenerCollection

public abstract class ListenerCollection<T>
extends Object
implements Serializable, Iterable<T>

Represents a collection of listeners. Facilitates invocation of events on each listener.

Listeners will be invoked in the order added to the collection when using notify(INotifier) or in reversed order when using reversedNotify(INotifier).

Author:

ivaynberg (Igor Vaynberg), Jonathan Locke

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static interface	ListenerCollection.INotifier<T>	Used to notify a listener.

Constructor Summary

Constructors

Constructor	Description
ListenerCollection()

Method Summary

Modifier and Type	Method	Description
boolean	add(T listener)	Adds a listener to this set of listeners.
protected boolean	isAllowingDuplicates()	Whether or not added listeners should be checked for duplicates.
protected boolean	isAllowingNulls()	Whether or not to allow nulls in listener collection.
Iterator<T>	iterator()	Returns an iterator that can iterate the listeners.
protected void	notify(ListenerCollection.INotifier<T> notifier)	Notifies each listener in this
protected void	notifyIgnoringExceptions(ListenerCollection.INotifier<T> notifier)	Notifies each listener in this set ignoring exceptions.
void	remove(T listener)	Removes a listener from this set.
protected void	reversedNotify(ListenerCollection.INotifier<T> notifier)	Notifies each listener in this in reversed order
protected void	reversedNotifyIgnoringExceptions(ListenerCollection.INotifier<T> notifier)	Notifies each listener in this set in reverse order ignoring exceptions

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

ListenerCollection

public ListenerCollection()

Method Details

add

public boolean add(T listener)

Adds a listener to this set of listeners.

Parameters:

listener - The listener to add

Returns:

true if the listener was added

notify

protected void notify(ListenerCollection.INotifier<T> notifier)

Notifies each listener in this

Parameters:

notifier - notifier used to notify each listener

notifyIgnoringExceptions

protected void notifyIgnoringExceptions(ListenerCollection.INotifier<T> notifier)

Notifies each listener in this set ignoring exceptions. Exceptions will be logged.

Parameters:

notifier - notifier used to notify each listener

reversedNotifyIgnoringExceptions

protected void reversedNotifyIgnoringExceptions(ListenerCollection.INotifier<T> notifier)

Notifies each listener in this set in reverse order ignoring exceptions

Parameters:

notifier - notifier used to notify each listener

reversedNotify

protected void reversedNotify(ListenerCollection.INotifier<T> notifier)

Notifies each listener in this in reversed order

Parameters:

notifier - notifier used to notify each listener

remove

public void remove(T listener)

Removes a listener from this set.

Parameters:

listener - The listener to remove

isAllowingDuplicates

protected boolean isAllowingDuplicates()

Whether or not added listeners should be checked for duplicates.

Returns:

true to ignore duplicates

isAllowingNulls

protected boolean isAllowingNulls()

Whether or not to allow nulls in listener collection.

Returns:

true to allow nulls to be added to the collection

iterator

public Iterator<T> iterator()

Returns an iterator that can iterate the listeners.

Specified by:

iterator in interface Iterable<T>

Returns:

an iterator that can iterate the listeners.