org.jutil.event
Class TypeApplicabilityNotifier

java.lang.Object
  |
  +--org.jutil.event.TypeApplicabilityNotifier

All Implemented Interfaces:

ApplicabilityNotifier, Notifier

public abstract class TypeApplicabilityNotifier

extends java.lang.Object

implements ApplicabilityNotifier

A support class for optional notifiers that depend on the type of the listener and the event to be processed.

Most often a ChainNotifier will be used in the case where the EventSourceSupport contains listeners of different types, or when different call-back methods of the listeners need to be called depending on the type of the event fired. This class implements the ApplicabilityNotifier.isApplicable(EventListener, EventObject) method to check whether the type of the listener and the event is compatible with a given listener type and event type.

Note that we do not demand this type to be pure (see JML), although all the methods we offer are.

Version:

$Revision: 1.3 $

Author:

Jan Dockx

Field Summary

static java.lang.String

CVS_REVISION

Constructor Summary

TypeApplicabilityNotifier(java.lang.Class listenerType)
public behavior
pre listenerType != null;
pre Class.forName("java.util.EventListener").isAssignableFrom(listenerType);
assignable listenerType, eventType;
post this.listenerType == listenerType;
post this.eventType == Class.forName("java.util.EventObject");

TypeApplicabilityNotifier(java.lang.Class listenerType, java.lang.Class eventType)
public behavior
pre listenerType != null;
pre Class.forName("java.util.EventListener").isAssignableFrom(listenerType);
pre eventType != null;
pre Class.forName("java.util.EventObject").isAssignableFrom(eventType);
assignable listenerType, eventType;
post this.listenerType == listenerType;
post this.eventType == eventType;

Method Summary

java.lang.Class	getEventType() public behavior post \result == eventType;
java.lang.Class	getListenerType() public behavior post \result == listenerType;
boolean	isApplicable(java.util.EventListener listener, java.util.EventObject event) also public behavior pre listener != null; post \result ==> (listenerType.isInstance(listener) && ((event == null) || eventType.isInstance(event))); // remember that isInstance would be false when event == null

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jutil.event.Notifier

notifyEventListener

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

Constructor Detail

TypeApplicabilityNotifier

public TypeApplicabilityNotifier(java.lang.Class listenerType,
                                 java.lang.Class eventType)

public behavior
pre listenerType != null;
pre Class.forName("java.util.EventListener").isAssignableFrom(listenerType);
pre eventType != null;
pre Class.forName("java.util.EventObject").isAssignableFrom(eventType);
assignable listenerType, eventType;
post this.listenerType == listenerType;
post this.eventType == eventType;

TypeApplicabilityNotifier

public TypeApplicabilityNotifier(java.lang.Class listenerType)

public behavior
pre listenerType != null;
pre Class.forName("java.util.EventListener").isAssignableFrom(listenerType);
assignable listenerType, eventType;
post this.listenerType == listenerType;
post this.eventType == Class.forName("java.util.EventObject");

Method Detail

isApplicable

public boolean isApplicable(java.util.EventListener listener,
                            java.util.EventObject event)

also
public behavior
pre listener != null;
post \result ==>
(listenerType.isInstance(listener) &&
((event == null) || eventType.isInstance(event)));
// remember that isInstance would be false when event == null

Specified by:

isApplicable in interface ApplicabilityNotifier

getListenerType

public final java.lang.Class getListenerType()

public behavior
post \result == listenerType;

getEventType

public final java.lang.Class getEventType()

public behavior
post \result == eventType;