com.tplan.robot.util

Class GenericListenerSupport<T>

java.lang.Object

com.tplan.robot.util.GenericListenerSupport<T>

Direct Known Subclasses:

ChangeListenerSupport, CommandListenerSupport, PropertyChangeListenerSupport

public class GenericListenerSupport<T>
extends Object

Generic listener support. Compared to the classic java.awt listener system it features:

• Memory leak preventing - listeners may be stored through weak or soft references.
• No duplicates in the list are allowed - one object may be present in the list of listeners just once regardless of whether it registers directly or through a reference.
• The listener support is coupled with the GenericListener interface which allows to implement a type specific listener support similar to the PropertyChangeSupport one for virtually any custom or Java native listener.
• The support allows to push a listener to the first place in the list.

T-Plan Robot Enterprise, (C) 2009-2022 T-Plan Limited. All rights reserved.

Constructor Summary

Constructors

Constructor and Description
GenericListenerSupport()

Method Summary

Modifier and Type	Method and Description
boolean	addListener(Reference<T> listener)
boolean	addListener(T listener)
Object	findListener(T listener)
void	fireEvent(GenericListener<T> gl, EventObject event, Object userObject) Fire an event.
List<T>	getListeners() Get the list of all current listeners as direct references.
boolean	pushListener(Reference<T> listener)
boolean	pushListener(T listener)
void	removeAllListeners()
Object	removeListener(T listener) Remove a listener.

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericListenerSupport

public GenericListenerSupport()

Method Detail

addListener

public boolean addListener(T listener)

addListener

public boolean addListener(Reference<T> listener)

pushListener

public boolean pushListener(T listener)

pushListener

public boolean pushListener(Reference<T> listener)

findListener

public Object findListener(T listener)

removeListener

public Object removeListener(T listener)

Remove a listener.

Parameters:

listener - a listener of the given generic type.

Returns:

the removed object which is either null (when the object is not there) or the argument (if it was added through addListener(java.lang.Object)) or a reference to the argument (when it was added through addListener(java.lang.ref.Reference)).

getListeners

public List<T> getListeners()

Get the list of all current listeners as direct references.

Returns:

a list of all valid listeners. As this is a copy of the current list the calling object may modify it. The method never returns null.

fireEvent

public void fireEvent(GenericListener<T> gl,
                      EventObject event,
                      Object userObject)

Fire an event.

Parameters:

gl - an object that wishes to fire the event and knows how to do it for the given listener type.

event - an event to fire.

userObject - a user object to be passed in the event.

removeAllListeners

public void removeAllListeners()