org.hypergraphdb.event

Interface HGEventManager

All Superinterfaces:

HGGraphHolder

All Known Implementing Classes:

HGDefaultEventManager

public interface HGEventManager
extends HGGraphHolder

A HGEventManager is bound to a single HyperGraph instance. It is responsible for holding all event listeners and it performs event handling via its dispatch method. Concrete implementations can be configured with the HGConfiguration object when the database is opened.

Event types are simply identified by their Java class objects.

Author:

Borislav Iordanov

Method Summary

Methods

Modifier and Type	Method and Description
<T extends HGEvent> void	addListener(Class<T> eventType, HGListener listener) Register a new listener for a given event type.
void	clear() Removal all event listeners for all event types.
HGListener.Result	dispatch(HyperGraph graph, HGEvent event) Dispatch an event to all listeners registered for its type.
<T extends HGEvent> void	removeListener(Class<T> eventType, HGListener listener) Remove a listener registered for the particular type.

Methods inherited from interface org.hypergraphdb.HGGraphHolder

setHyperGraph

Method Detail

addListener

<T extends HGEvent> void addListener(Class<T> eventType,
                                   HGListener listener)

Register a new listener for a given event type.

Type Parameters:

T -

Parameters:

eventType -

listener -

removeListener

<T extends HGEvent> void removeListener(Class<T> eventType,
                                      HGListener listener)

Remove a listener registered for the particular type.

Type Parameters:

T -

Parameters:

eventType -

listener -

clear

void clear()

Removal all event listeners for all event types.

dispatch

HGListener.Result dispatch(HyperGraph graph,
                         HGEvent event)

Dispatch an event to all listeners registered for its type. All listeners are invoked in the order in which they were registered. If a listener returns a HGListener.Result.cancel event, the dispatch process is interrupted and the cancellation is passed on to the caller of the dispatch method without invoking any further listeners.

Because event types can be organized in hierarchy, rooted at HGEvent, a dispatcher must call listener registered for the particular event class and also all its superclasses up to the HGEvent type itself.

Parameters:

graph -

event -

Returns: