One of the mechanism that Sphinx uses to get notified about changes in your Sphinx-based models is registering Listeners when the editingDomain for your model is being created. This mechanism can also be used for your own listeners.
Sphinx defines the extension point org.eclipse.sphinx.emf.editingDomainFactoryListeners and in org.eclipse.sphinx.emf it registers a number of its own listeners:
The registry entries for that extension point are processed in EditingDomainFactoryListenerRegistry.readContributedEditingDomainFactoryListeners(). It creates an EditingDomainFactoryListenerRegistry.ListenerDescriptor which stores the class name and registers it internally for the meta-models that are specified in the extension. The ListenerDescriptor also contains code to actually load the specified class and instantiate it (base type is ITransactionalEditingDomainFactoryListener).
The method EditingDomainFactoryListenerRegistry.getListeners(IMetaModelDescriptor) can be used to get all the ITransactionalEditingDomainFactoryListener that are registered for a given IMetaModelDescriptor.
These are in turn invoked from ExtendedWorkspaceEditingDomainFactory.firePostCreateEditingDomain(Collection, TransactionalEditingDomain). ExtendedWorkspaceEditingDomainFactory is responsible for creating the editing domain and through this feature we have a nice mechanism to register custom listeners each time an editing domain is created by Sphinx (e.g., after models are being loaded).