org.modeshape.graph.observe
Class LocalObservationBus

java.lang.Object
  org.modeshape.graph.observe.LocalObservationBus

All Implemented Interfaces:

Observable, ObservationBus, Observer

@ThreadSafe
public class LocalObservationBus
extends Object
implements ObservationBus

A simple Observer that is itself Observable. This class essentially multiplexes the events from a single Observable to disseminate each event to multiple Observers.

Constructor Summary

LocalObservationBus()

Method Summary

boolean	hasObservers() Determine whether this particular bus currently has any observers.
void	notify(Changes changes) Method that is called for each set of changes from the Observable instance(s) with which this observer is registered.
boolean	register(Observer observer) Register the supplied observer.
void	shutdown() Unregister all registered observers, and mark this as no longer accepting new registered observers.
void	start() Prepare this bus for operation by starting any resources.
boolean	unregister(Observer observer) Unregister the supplied observer.

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalObservationBus

public LocalObservationBus()

Method Detail

start

public void start()

Prepare this bus for operation by starting any resources.

Specified by:

start in interface ObservationBus

See Also:

ObservationBus.start()

register

public boolean register(Observer observer)

Register the supplied observer. This method does nothing if the observer reference is null.

Specified by:

register in interface Observable

Parameters:

observer - the observer to be added; may be null

Returns:

true if the observer was added, or false if the observer was null, if the observer was already registered, or if the observer could not be added

See Also:

Observable.register(org.modeshape.graph.observe.Observer)

unregister

public boolean unregister(Observer observer)

Unregister the supplied observer. This method does nothing if the observer reference is null.

Specified by:

unregister in interface Observable

Parameters:

observer - the observer to be removed; may not be null

Returns:

true if the observer was removed, or false if the observer was null or if the observer was not registered on this source

See Also:

Observable.unregister(org.modeshape.graph.observe.Observer)

notify

public void notify(Changes changes)

Method that is called for each set of changes from the Observable instance(s) with which this observer is registered.

Specified by:

notify in interface Observer

Parameters:

changes - the changes that are being published

See Also:

Observer.notify(org.modeshape.graph.observe.Changes)

hasObservers

public boolean hasObservers()

Determine whether this particular bus currently has any observers.

Specified by:

hasObservers in interface ObservationBus

Returns:

true if there is at least one observer, or false otherwise

See Also:

ObservationBus.hasObservers()

shutdown

public void shutdown()

Unregister all registered observers, and mark this as no longer accepting new registered observers.

Specified by:

shutdown in interface ObservationBus

See Also:

ObservationBus.shutdown()