org.apache.jena.graph

Interface GraphEventManager

All Superinterfaces:

GraphListener

All Known Implementing Classes:

SimpleEventManager

public interface GraphEventManager
extends GraphListener

The component of a graph responsible for managing events and listeners. The interface extends GraphListener because most of the notificiations are the same; the special case to note is that an event manager expects to be handed iterator events as lists, not as iterators.

Method Summary

Modifier and Type	Method and Description
boolean	listening() Answer true iff there is at least one attached listener.
void	notifyAddIterator(Graph g, List<Triple> triples) Notify all attached listeners that an iterator [of triples] has been added to the graph; its content has been captured in the list triples.
void	notifyDeleteIterator(Graph g, List<Triple> triples) Notify all attached listeners that an iterator [of triples] has been removed from the graph; its content has been captured in the list triples.
GraphEventManager	register(GraphListener listener) Attached listener to this manager; notification events sent to the manager are sent to all registered listeners.
GraphEventManager	unregister(GraphListener listener) If listener is attached to this manager, detach it, otherwise do nothing.

Methods inherited from interface org.apache.jena.graph.GraphListener

notifyAddArray, notifyAddGraph, notifyAddIterator, notifyAddList, notifyAddTriple, notifyDeleteArray, notifyDeleteGraph, notifyDeleteIterator, notifyDeleteList, notifyDeleteTriple, notifyEvent

Method Detail

register

GraphEventManager register(GraphListener listener)

Attached listener to this manager; notification events sent to the manager are sent to all registered listeners. A listener may be registered multiple times, in which case it's called multiple times per event. A listener will be notified of an event if it is registered before the Graph method call that initiated the event, and was not unregistered before that method call returned. In addition, a listener may (or may not) be notified of an event if it is registered before such a method returns or is unregistered after such a method is called. For example, it may unregister itself in response to the event. If the registration and/or unregistration occur on different threads the usual thread uncertainties in such statements apply.

Parameters:

listener - a listener to be fed events

Returns:

this manager, for cascading

unregister

GraphEventManager unregister(GraphListener listener)

If listener is attached to this manager, detach it, otherwise do nothing. Only a single registration is removed.

Parameters:

listener - the listener to be detached from the graph

Returns:

this manager, for cascading

listening

boolean listening()

Answer true iff there is at least one attached listener.

Returns:

true iff there is at least one attached listener

notifyAddIterator

void notifyAddIterator(Graph g,
                       List<Triple> triples)

Notify all attached listeners that an iterator [of triples] has been added to the graph; its content has been captured in the list triples.

notifyDeleteIterator

void notifyDeleteIterator(Graph g,
                          List<Triple> triples)

Notify all attached listeners that an iterator [of triples] has been removed from the graph; its content has been captured in the list triples.