org.eclipse.emf.ecp.changebroker.spi

Interface ChangeBroker

All Known Implementing Classes:

ChangeBrokerImpl

public interface ChangeBroker

A Change Broker maintains sets of observers. Based on incoming notifications it forwards the notification to the observers based on strategies.

There are two kinds of observers: regular EMFObservers and ReadOnlyEMFObservers.

EMFObservers may change the EMF model and therefore trigger further notifications. To prevent circular updates between EMFObservers, notifications that arrive while the handleNotification method is called, will not be forwarded to non ReadOnlyEMFObservers.

ReadOnlyEMFObservers are not allowed to change the EMF model. They will receive all notifications at any time.

Author:

Jonas, jfaltermeier

Method Summary

Modifier and Type	Method and Description
void	continueNotification() Notifying the ChangeObserver is started again if stopNotification() was called beforehand.
void	continueNotification(Object blocker) Removes a blocker.
void	stopNotification() Stops notifying all ChangeObserver.
void	stopNotification(Object blocker) Stops notifying all ChangeObserver.
void	subscribe(EMFObserver observer) Adds an ChangeObserver that will receive all notifications.
void	subscribeToEClass(ChangeObserver observer, org.eclipse.emf.ecore.EClass eClass) Adds an ChangeObserver that will receive notifications of notifiers with the given EClass.
void	subscribeToFeature(ChangeObserver observer, org.eclipse.emf.ecore.EStructuralFeature feature) Adds an ChangeObserver that will receive notifications when the given EStructuralFeautre is effected.
void	subscribeToTree(ChangeObserver observer, org.eclipse.emf.ecore.EClass eClass) Adds an ChangeObserver that will receive notifications of notifiers with the given EClass or which are contained (either direct or indirect) in an EObject of the given EClass.
void	unsubsribe(EMFObserver observer) Removes an observer.

Method Detail

subscribe

void subscribe(EMFObserver observer)

Adds an ChangeObserver that will receive all notifications. Does nothing if already registered.

Parameters:

observer - the observer

Since:

1.7

subscribeToEClass

void subscribeToEClass(ChangeObserver observer,
                       org.eclipse.emf.ecore.EClass eClass)

Adds an ChangeObserver that will receive notifications of notifiers with the given EClass. Does nothing if already registered.

Parameters:

observer - the observer

eClass - the required EClass of the notifier

Since:

1.7

subscribeToTree

void subscribeToTree(ChangeObserver observer,
                     org.eclipse.emf.ecore.EClass eClass)

Adds an ChangeObserver that will receive notifications of notifiers with the given EClass or which are contained (either direct or indirect) in an EObject of the given EClass. Does nothing if already registered.

Parameters:

observer - the observer

eClass - the required EClass of the notifier or of one of its parents

subscribeToFeature

void subscribeToFeature(ChangeObserver observer,
                        org.eclipse.emf.ecore.EStructuralFeature feature)

Adds an ChangeObserver that will receive notifications when the given EStructuralFeautre is effected. Does nothing if already registered.

Parameters:

observer - the observer

feature - the feature to receive changes for

Since:

1.7

unsubsribe

void unsubsribe(EMFObserver observer)

Removes an observer. Does nothing if receiver is not registered.

Parameters:

observer - the receiver

Since:

1.7

stopNotification

void stopNotification()

Stops notifying all ChangeObserver. ReadOnlyEMFObservers will still be notified.

continueNotification

void continueNotification()

Notifying the ChangeObserver is started again if stopNotification() was called beforehand. Has no effect if the notification process has been blocked or if stopNotification() wasn't called before.

stopNotification

void stopNotification(Object blocker)

Stops notifying all ChangeObserver. ReadOnlyEMFObservers will still be notified. The notifications will we blocked until continueNotification(Object) has been called with all blocking elements. Using the same blocker multiple times has no effect.

Parameters:

blocker - the key object used to block all notifications

continueNotification

void continueNotification(Object blocker)

Removes a blocker. When all blockers have been removed the notification process will continue. This method calls continueNotification() internally in all cases, even if the given blocker object was not used as a blocker beforehand.

Parameters:

blocker - the blocker object to remove.