SessionRecorder.java

public class SessionRecorder extends OWLEditorKitHook {
	
    public static String SRID = "org.protege.editor.owl.client.SessionRecorder";

    private Logger logger = LoggerFactory.getLogger(HistoryManager.class);

    private OWLOntologyManager manager;
    private Map<OWLOntologyID, Stack<List<OWLOntologyChange>>> stash = new HashMap<>();
    private boolean enabled = true;

    private OWLOntologyChangeListener ontologyChangeListener = changes -> {
        if (enabled) {
            OWLOntologyID ontologyId = getEditorKit().getOWLModelManager().getActiveOntology().getOntologyID();
            stash.get(ontologyId).add(changes);
        }
    };

    public static SessionRecorder getInstance(OWLEditorKit editorKit) {
        return (SessionRecorder) editorKit.get(SRID);
    }
    
    @Override
    public void initialise() throws Exception {
        getEditorKit().getOWLModelManager().addOntologyChangeListener(ontologyChangeListener);
    }

    /**
     * Call this method to clear the change history.
     */
    public void clear() {
        OWLOntologyID ontologyId = getEditorKit().getOWLModelManager().getActiveOntology().getOntologyID();
    	stash.get(ontologyId).clear();
    }

    /**
     * Call this method to stop listening to changes that are being applied to the current ontology.
     * For example:
     *   (1) Open remote project:
     *        ...
     *       Client client = clientSession.getActiveClient();
     *       ServerDocument serverDocument = client.openProject(pid);
     *       sessionRecoder.stopRecording(); // STOP
     *       VersionedOWLOntology vont = ((LocalHttpClient) client).buildVersionedOntology(serverDocument, owlManager, pid);
     *       sessionRecoder.startRecording(); //START
     *       clientSession.setActiveProject(pid, vont);
     *
     *   (2) Update project
     *        ...
     *       List<OWLOntologyChange> remoteChanges = ChangeHistoryUtils.getOntologyChanges(remoteChangeHistory, ontology);
     *       List<OWLOntologyChange> conflictChanges = getConflicts(localChanges, remoteChanges);
     *       if (conflictChanges.isEmpty()) {
     *           sessionRecorder.stopRecording(); // STOP
     *           performUpdate(remoteChanges);
     *           incomingChanges = remoteChanges;
     *           vont.update(remoteChangeHistory);
     *           sessionRecoder.startRecording(); // START
     *        }
     */
    public void stopRecording() {
        enabled = false;
    }

    /**
     * Call this method to start listening to changes that are being applied to the current ontology
     */
    public void startRecording() {
        enabled = true;
    }
  
    public List<OWLOntologyChange> getUncommittedChanges() {
        OWLOntologyID ontologyId = getEditorKit().getOWLModelManager().getActiveOntology().getOntologyID();
        Stack<List<OWLOntologyChange>> stashStack = stash.get(ontologyId);

        // Flatten the stack
        List<OWLOntologyChange> toReturn = new ArrayList<>();
        for (List<OWLOntologyChange> changes : stashStack) {
            toReturn.addAll(changes);
        }
        return ChangeListMinimizer.collapse(toReturn); // a new util code from Matthew to collapse changes (not yet public)
    }

	@Override
	public void dispose() throws Exception {
		getEditorKit().getOWLModelManager().removeOntologyChangeListener(ontologyChangeListener);
	}
}