public PreviewUIControllerImpl() {
previewController = Lookup.getDefault().lookup(PreviewController.class);
listeners = new ArrayList<PropertyChangeListener>();
ProjectController pc = Lookup.getDefault().lookup(ProjectController.class);
graphController = Lookup.getDefault().lookup(GraphController.class);
pc.addWorkspaceListener(new WorkspaceListener() {
@Override
public void initialize(Workspace workspace) {
workspace.add(new PreviewUIModelImpl());
enableRefresh();
}