Package jasima.core.util.observer

Class NotifierImpl<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

java.lang.Object

jasima.core.util.observer.NotifierImpl<SUBJECT,MESSAGE>

All Implemented Interfaces:

Notifier<SUBJECT,MESSAGE>

public class NotifierImpl<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>
extends Object
implements Notifier<SUBJECT,MESSAGE>

Example implementation of Notifier functionality. A NotifierImpl handles notifier functionality for some real Notifier (subject).

It is safe to fire new events while a current one is executing. In that case the new message will be processed after processing the current one finished.

Listeners can also be removed while a message is send/processed.

As an example of how to use this class, have a look at ExperimentListener used by Experiments.

Author:

Torsten Hildebrandt

See Also:

Notifier, NotifierListener

Field Summary

Fields inherited from interface jasima.core.util.observer.Notifier

adapters

Constructor Summary

Constructors

Constructor	Description
NotifierImpl(SUBJECT subject)

Method Summary

Modifier and Type	Method	Description
<T extends NotifierListener<SUBJECT,MESSAGE>> void	addListener(TypeHint<T> listenerType, T eventHandler)	Adds a new listener.
<T extends NotifierListener<SUBJECT,MESSAGE>> void	addListener(Class<T> listenerType, T eventHandler)	Adds a new listener.
<T extends NotifierListener<SUBJECT,MESSAGE>> T	addListener(T l)	Adds a new listener.
void	fire(MESSAGE msg)	Send a message to all registered listeners.
NotifierListener<SUBJECT,MESSAGE>	getListener(int idx)	Returns the listener with the given index (0-based).
Notifier<SUBJECT,MESSAGE>	notifierImpl()
int	numListener()	Returns the number of currently registered listeners.
void	removeCurrentListener()	This method can be used to unregister the currently active listener while firing.
boolean	removeListener(NotifierListener<SUBJECT,MESSAGE> l)	Removes the listener given as a parameter.

Methods inherited from class java.lang.Object

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

Methods inherited from interface jasima.core.util.observer.Notifier

fire

Constructor Detail

NotifierImpl

public NotifierImpl(SUBJECT subject)

Method Detail

notifierImpl

public Notifier<SUBJECT,MESSAGE> notifierImpl()

Specified by:

notifierImpl in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

numListener

public int numListener()

Returns the number of currently registered listeners.

Specified by:

numListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

addListener

public <T extends NotifierListener<SUBJECT,MESSAGE>> T addListener(T l)

Adds a new listener.

Specified by:

addListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

addListener

public <T extends NotifierListener<SUBJECT,MESSAGE>> void addListener(Class<T> listenerType,
                                                                            T eventHandler)

Adds a new listener. In contrast to addListener(NotifierListener) this method has an additional type parameter, usually representing a functional interface. Using this approach eventHandler can be a lambda expression or method reference.

Specified by:

addListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

addListener

public <T extends NotifierListener<SUBJECT,MESSAGE>> void addListener(TypeHint<T> listenerType,
                                                                            T eventHandler)

Adds a new listener. This is the same as addListener(Class, NotifierListener), only adding TypeRef as a super type token. This can be used when the listener is a parameterized type.

Specified by:

addListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

removeListener

public boolean removeListener(NotifierListener<SUBJECT,MESSAGE> l)

Removes the listener given as a parameter. This method returns true on success and false when the listener could not be found.

Specified by:

removeListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

removeCurrentListener

public void removeCurrentListener()

This method can be used to unregister the currently active listener while firing. This is particularly useful when using lambda's as listeners (see addListener(Class, NotifierListener)), as their reference is otherwise hard to find (not accessible using this).

Specified by:

removeCurrentListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

Throws:

NullPointerException - If called while not firing.

getListener

public NotifierListener<SUBJECT,MESSAGE> getListener(int idx)

Returns the listener with the given index (0-based).

Specified by:

getListener in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>

See Also:

numListener()

fire

public void fire(MESSAGE msg)

Send a message to all registered listeners.

Specified by:

fire in interface Notifier<SUBJECT extends Notifier<SUBJECT,MESSAGE>,MESSAGE>