public class ConnectionLayout extends DelegatingLayout {
            public void layout(IFigure parent) {
            ...
            Connection conn = (Connection)parent;
            points = new PointList();
            while(條件成立){
            Point p[i] = //計算第i個節(jié)點坐標
            Points.add(p[i]);
            }
            ...
            conn.setPoints(points);
            }
            }
            

            public class RelationshipConnection extends PolylineConnectionEx {
            public RelationshipConnection() {
            setLayoutManager(new ConnectionLayout());
            }
            }
            

            public void paintFigure(Graphics g) {
            super.paintFigure(g);
            Color oldForeground = g.getForegroundColor();
            Color oldBackground = g.getBackgroundColor();
            g.setForegroundColor(FlowUtil.FORE_COLOR);
            g.setBackgroundColor(FlowUtil.TASK_BG_COLOR);
            g.fillGradient(bounds, true);
            g.setForegroundColor(oldForeground);
            g.setBackgroundColor(oldBackground);
            }
            

            protected void setLabelTextHelper(IFigure figure, String text) {
            if (figure instanceof WrapLabel) {
            WrapLabel l = (WrapLabel)figure;
            l.setText(text);
            l.setTextPlacement(PositionConstants.SOUTH);
            l.setTextWrap(true);
            } else {
            ((Label) figure).setText(text);
            }
            }
            protected void setLabelIconHelper(IFigure figure, Image icon) {
            if (figure instanceof WrapLabel) {
            WrapLabel l = (WrapLabel)figure;
            l.setIcon(icon);
            l.setIconAlignment(PositionConstants.TOP);
            } else {
            ((Label) figure).setIcon(icon);
            }
            }
            

            installEditPolicy(EditPolicyRoles.CREATION_ROLE,	new XXXCreationEditPolicy());
            

            protected Command getCreateCommand(CreateViewRequest request) {
            TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
            .getEditingDomain();
            CompositeTransactionalCommand cc = //Create Process command
            ...
            Command cmd = new ICommandProxy(cc.reduce());
            CompoundCommand cm = new CompoundCommand();
            cm.add(cmd);
            // add Create Connection command
            if(request instanceof CreateViewAndElementRequest){
            CreateElementRequestAdapter requestAdapter =
            ((CreateViewAndElementRequest)request)
            .getViewAndElementDescriptor().getCreateElementRequestAdapter();
            if(CBSDiagramUtil.getInstance().getSourceEP() instanceof DANode2EditPart){
            CreateChildrenRelation4ProcessCommand cmd1 = createRalationCommand(
            editingDomain,
            (CreateViewAndElementRequest)request,
            requestAdapter);
            Command cmd2 = new ICommandProxy(cmd1);
            cm.add(cmd2);
            }
            }
            return new ICommandProxy(new CommandProxy(cm.unwrap()));
            }
            private CreateChildrenRelation4ProcessCommand createRelationCommand(
            TransactionalEditingDomain editingDomain, CreateViewAndElementRequest request,
            CreateElementRequestAdapter requestAdapter) {
            Diagram diagramView = (View)getHost().getModel()).getDiagram();
            IElementType type = ProcessElementTypes.Relation_3001;
            CreateConnectionViewAndElementRequest req =
            New CreateConnectionViewAndElementRequest(type,
            ((IHintedType) type).getSemanticHint(),
            request.getViewAndElementDescriptor().getPreferencesHint());
            CreateChildrenRelation4ProcessCommand cmd =
            new CreateChildrenRelation4ProcessCommand(editingDomain,requestAdapter,req,
            diagramView.getDiagram());
            return cmd ;
            }
            

            private void createRelationView() {
            DARelationViewFactory drvf = new DARelationViewFactory();
            final int index = -1 ;
            boolean persisted = true ;
            final String semanticHint = connReq.getConnectionViewAndElementDescriptor()
            .getSemanticHint();
            ConnectionViewAndElementDescriptor ccd =
            connReq.getConnectionViewAndElementDescriptor();
            final CreateElementRequestAdapter rAdapter = ccd.getCreateElementRequestAdapter();
            PreferencesHint preferencesHint = ccd.getPreferencesHint();
            Node srcNode = getSrcView();
            Node tgtNode = getTgtView();
            if(srcNode == null || tgtNode == null){
            return ;
            }
            View view = drvf.createView(rAdapter, containerView, semanticHint,
            index, persisted, preferencesHint);
            Edge edge = (Edge)view;
            edge.setSource(srcNode);
            edge.setTarget(tgtNode);
            }
            

            public class CustomizeDestroyElementCommand extends DestroyElementCommand {
            …
            @Override
            protected CommandResult doExecuteWithResult(IProgressMonitor monitor, IAdaptable info)
            throws ExecutionException {
            ProcessEditPart editpart = (ProcessEditPart)getHost();
            if(root == null) {
            root = (ProcessEditPart)editpart.getParent();
            }
            // delete all descents and their relative process flow
            List children = editpart.getSourceConnections();
            int size = children.size();
            for(int i=0; i<size; i++) {
            delete((ProcessEditPart)((RelationshipsEditPart)children.get(i)).getTarget());
            }
            // update parent's process flow
            List targetConns = editpart.getTargetConnections();
            if(targetConns.size() != 0) {
            ProcessEditPart parent =
            (ProcessEditPart)((RelationshipsEditPart)targetConns.get(0)).getSource();
            Diagram flowDiagram = getOrDeleteProcessFlowDiagram(parent, false);
            if(flowDiagram != null) {
            deleteFlow(flowDiagram, ((Node)editpart.getModel()).getElement());
            }
            }
            // delete self process flow and close flow editor if acitved
            Diagram flowDiagram  = getOrDeleteProcessFlowDiagram(editpart, true);
            if(flowDiagram != null) {
            closeEditor(flowDiagram);
            }
            return super.doExecuteWithResult(monitor, info);
            }
            }
            

            protected Command getDestroyElementCommand(DestroyElementRequest req) {
            CompoundCommand cc = getDestroyEdgesCommand();
            addDestroyShortcutsCommand(cc);
            View view = (View) getHost().getModel();
            if (view.getEAnnotation("Shortcut") != null) { //$NON-NLS-1$
            req.setElementToDestroy(view);
            }
            cc.add(getGEFWrapper(new CustomizeDestroyElementCommand(req)));
            return cc.unwrap();
            }
            

            public class EditingDomainManager {
            public TransactionalEditingDomain getCurrentEditingDomain(final String id){
            ...
            return editingDomain ;
            }
            public Diagram getDiagramOfElement(Resource gmfRes, String editorID, Process element) {
            ...
            return  getDiagram(gmfRes, kind,element);
            }
            }
            

            private void openFlowEditor() {
            ...
            IWorkbenchPage page = PlatformUI.getWorkbench()
            .getActiveWorkbenchWindow().getActivePage();
            if(!isFlowDiagramExisted(node)){
            initialFlowDiagram(node);
            }
            Diagram diagram = getProcessNodeDiagram(node);
            DiagramEditorInput input = new DiagramEditorInput(diagram);
            try {
            IEditorPart ep = page.openEditor(input, editorId, true);
            } catch (PartInitException e) {
            e.printStackTrace();
            }
            }
            

            @Override
            public Diagram getDiagram() {
            IEditorInput input = getEditorInput();
            if(input instanceof DiagramEditorInput){
            DiagramEditorInput dinput = (DiagramEditorInput)input;
            return dinput.getDiagram();
            }
            return super.getDiagram();
            }
            

            @Override
            public IEditorInput createInputWithEditingDomain(IEditorInput editorInput,
            TransactionalEditingDomain domain) {
            return editorInput;
            }
            @Override
            public IStatus getStatus(Object element) {
            return STATUS_OK;
            }
            @Override
            public boolean isModifiable(Object element) {
            if(element instanceof DiagramEditorInput){
            return true;
            }
            return super.isModifiable(element);
            }