Bug 436921 - [IBD] can not drag&drop connector in ibd when corresponding

ports are hidden

Change-Id: I4c76c6cd0a34c04bb7e7036ed6b18dd7c329a2c5
Signed-off-by: ashatilov <montages.as@gmail.com>

4 files changed, 226 insertions, 47 deletions

diff --git a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.common/src-common-gmf/org/eclipse/papyrus/gmf/diagram/common/edit/policy/CommonDiagramDragDropEditPolicy.java b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.common/src-common-gmf/org/eclipse/papyrus/gmf/diagram/common/edit/policy/CommonDiagramDragDropEditPolicy.java
index c7ef4c55813..6eb9309e52f 100644
--- a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.common/src-common-gmf/org/eclipse/papyrus/gmf/diagram/common/edit/policy/CommonDiagramDragDropEditPolicy.java
+++ b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.common/src-common-gmf/org/eclipse/papyrus/gmf/diagram/common/edit/policy/CommonDiagramDragDropEditPolicy.java
@@ -60,6 +60,7 @@ import org.eclipse.papyrus.uml.diagram.common.commands.CommonDeferredCreateConne
 import org.eclipse.papyrus.uml.diagram.common.commands.SemanticAdapter;
 import org.eclipse.papyrus.uml.diagram.common.edit.part.AbstractElementBorderEditPart;
 import org.eclipse.papyrus.uml.diagram.common.edit.part.AbstractElementLabelEditPart;
+import org.eclipse.papyrus.uml.diagram.common.helper.Element2IAdaptableRegistryHelper;
 import org.eclipse.papyrus.uml.diagram.common.util.CrossReferencerUtil;
 import org.eclipse.uml2.uml.Classifier;
 import org.eclipse.uml2.uml.Element;
@@ -70,6 +71,8 @@ import org.eclipse.uml2.uml.Element;
  */
 public abstract class CommonDiagramDragDropEditPolicy extends DiagramDragDropEditPolicy {
 
+	private Element2IAdaptableRegistryHelper myElement2IAdaptableRegistryHelper;
+
 	/** The graphical type registry. */
 	protected IGraphicalTypeRegistry registry;
 
@@ -91,6 +94,16 @@ public abstract class CommonDiagramDragDropEditPolicy extends DiagramDragDropEdi
 		return specificDropList;
 	}
 
+	/**
+	 * Gets composite command adapters
+	 */
+	protected Element2IAdaptableRegistryHelper getElement2IAdaptableRegistryHelper() {
+		if (myElement2IAdaptableRegistryHelper == null) {
+			myElement2IAdaptableRegistryHelper = new Element2IAdaptableRegistryHelper();
+		}
+		return myElement2IAdaptableRegistryHelper;
+	}
+
 	protected abstract Set<String> getSpecificDropBehaviorTypes();
 
 	/**
diff --git a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomBlockPropertyCompositeDropEditPolicy.java b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomBlockPropertyCompositeDropEditPolicy.java
index 21e16a34700..c701ee1e58b 100644
--- a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomBlockPropertyCompositeDropEditPolicy.java
+++ b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomBlockPropertyCompositeDropEditPolicy.java
@@ -22,7 +22,6 @@ import org.eclipse.emf.transaction.RunnableWithResult;
 import org.eclipse.gef.commands.Command;

 import org.eclipse.gef.commands.UnexecutableCommand;

 import org.eclipse.gmf.runtime.common.core.command.ICommand;

-import org.eclipse.gmf.runtime.diagram.ui.commands.CommandProxy;

 import org.eclipse.gmf.runtime.diagram.ui.commands.ICommandProxy;

 import org.eclipse.gmf.runtime.diagram.ui.editparts.GraphicalEditPart;

 import org.eclipse.gmf.runtime.diagram.ui.requests.DropObjectsRequest;

@@ -69,8 +68,7 @@ public class CustomBlockPropertyCompositeDropEditPolicy extends CustomDragDropEd
 	protected ICommand getSpecificDropCommand(DropObjectsRequest dropRequest, EObject droppedEObject, String nodeType, String edgeType) {

 		if ((UMLGraphicalTypes.SHAPE_UML_PORT_AS_AFFIXED_ID.equals(nodeType)) || (SysMLGraphicalTypes.SHAPE_SYSML_FLOWPORT_AS_AFFIXED_ID.equals(nodeType))) {

 			PortDropHelper portDropHelper = new PortDropHelper(getEditingDomain());

-			Command portDropCommand = portDropHelper.getDropPortOnPart((Port) droppedEObject, dropRequest.getLocation().getCopy(), (GraphicalEditPart) getHost());

-			return new CommandProxy(portDropCommand);

+			return portDropHelper.getDropPortOnPart((Port) droppedEObject, dropRequest.getLocation().getCopy(), (GraphicalEditPart) getHost());

 		}

 

 		return super.getSpecificDropCommand(dropRequest, droppedEObject, nodeType, edgeType);

diff --git a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomDragDropEditPolicy.java b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomDragDropEditPolicy.java
index fe139c19fa8..a8e2388952b 100644
--- a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomDragDropEditPolicy.java
+++ b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/edit/policy/CustomDragDropEditPolicy.java
@@ -20,10 +20,19 @@ import java.util.List;
 import java.util.Set;

 

 import org.eclipse.core.runtime.IAdaptable;

+import org.eclipse.draw2d.geometry.Point;

+import org.eclipse.emf.ecore.EClass;

 import org.eclipse.emf.ecore.EObject;

 import org.eclipse.emf.ecore.EReference;

+import org.eclipse.gef.EditPart;

+import org.eclipse.gef.commands.UnexecutableCommand;

+import org.eclipse.gmf.runtime.common.core.command.CompositeCommand;

 import org.eclipse.gmf.runtime.common.core.command.ICommand;

 import org.eclipse.gmf.runtime.diagram.core.util.ViewUtil;

+import org.eclipse.gmf.runtime.diagram.ui.commands.CommandProxy;

+import org.eclipse.gmf.runtime.diagram.ui.editparts.CompartmentEditPart;

+import org.eclipse.gmf.runtime.diagram.ui.editparts.DiagramEditPart;

+import org.eclipse.gmf.runtime.diagram.ui.editparts.GraphicalEditPart;

 import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;

 import org.eclipse.gmf.runtime.diagram.ui.requests.CreateConnectionViewRequest;

 import org.eclipse.gmf.runtime.diagram.ui.requests.DropObjectsRequest;

@@ -32,18 +41,22 @@ import org.eclipse.gmf.runtime.notation.Diagram;
 import org.eclipse.gmf.runtime.notation.NotationPackage;

 import org.eclipse.gmf.runtime.notation.View;

 import org.eclipse.papyrus.gmf.diagram.common.edit.policy.CommonDiagramDragDropEditPolicy;

+import org.eclipse.papyrus.infra.gmfdiag.common.adapter.SemanticAdapter;

+import org.eclipse.papyrus.infra.gmfdiag.common.commands.CommonDeferredCreateConnectionViewCommand;

 import org.eclipse.papyrus.sysml.blocks.NestedConnectorEnd;

 import org.eclipse.papyrus.sysml.diagram.internalblock.dnd.helper.CustomLinkMappingHelper;

 import org.eclipse.papyrus.sysml.diagram.internalblock.provider.CustomGraphicalTypeRegistry;

+import org.eclipse.papyrus.sysml.diagram.internalblock.utils.PortDropHelper;

 import org.eclipse.papyrus.sysml.service.types.utils.ConnectorUtils;

-import org.eclipse.papyrus.uml.diagram.common.commands.CommonDeferredCreateConnectionViewCommand;

-import org.eclipse.papyrus.uml.diagram.common.commands.SemanticAdapter;

+import org.eclipse.papyrus.uml.diagram.common.edit.part.AbstractElementNodeLabelEditPart;

 import org.eclipse.papyrus.uml.diagram.common.utils.UMLGraphicalTypes;

 import org.eclipse.uml2.uml.Connector;

 import org.eclipse.uml2.uml.ConnectorEnd;

+import org.eclipse.uml2.uml.Element;

 import org.eclipse.uml2.uml.EncapsulatedClassifier;

 import org.eclipse.uml2.uml.Port;

 import org.eclipse.uml2.uml.Property;

+import org.eclipse.uml2.uml.TypedElement;

 import org.eclipse.uml2.uml.util.UMLUtil;

 

 /** Customization of the DND edit policy for the Internal Block Diagram */

@@ -91,54 +104,206 @@ public class CustomDragDropEditPolicy extends CommonDiagramDragDropEditPolicy {
 		ConnectorEnd source = droppedEObject.getEnds().get(0);

 		ConnectorEnd target = droppedEObject.getEnds().get(1);

 

-		// Find views in current diagram representing source and target

-		Collection<View> sourceViews = getViewsForConnectorEnd(source);

-		Collection<View> targetViews = getViewsForConnectorEnd(target);

+		return dropBinaryLink(new CompositeCommand("drop Connector"), source.getRole(), target.getRole(), edgeType, dropRequest.getLocation(), droppedEObject);

+	}

 

-		IAdaptable sourceViewAdapter = null;

-		IAdaptable targetViewAdapter = null;

+	/**

+	 * the method provides command to create the binary link into the diagram.

+	 * If the source and the target views do not exist, these views will be

+	 * created.

+	 *

+	 * @param cc

+	 *            the composite command that will contain the set of command to

+	 *            create the binary link

+	 * @param source

+	 *            the source the element source of the link

+	 * @param target

+	 *            the target the element target of the link

+	 * @param linkVISUALID

+	 *            the link VISUALID used to create the view

+	 * @param location

+	 *            the location the location where the view will be be created

+	 * @param semanticLink

+	 *            the semantic link that will be attached to the view

+	 *

+	 * @return the composite command

+	 */

+	protected CompositeCommand dropBinaryLink(CompositeCommand cc, Element source, Element target, String edgeType, Point absoluteLocation, Element semanticLink) {

+		IAdaptable sourceViewAdapter = findAdapter(cc, source, getLinkSourceDropLocation(absoluteLocation, source, target), edgeType);

+		IAdaptable targetViewAdapter = findAdapter(cc, target, getLinkTargetDropLocation(absoluteLocation, source, target), edgeType);

+		IAdaptable droppedViewAdapter = new SemanticAdapter(semanticLink, null);

 

-		// If either a source or target lacks create view for these elements, abort...

-		if (sourceViews.isEmpty() || targetViews.isEmpty()) {

-			return org.eclipse.gmf.runtime.common.core.command.UnexecutableCommand.INSTANCE;

+		CreateConnectionViewRequest.ConnectionViewDescriptor linkdescriptor = new CreateConnectionViewRequest.ConnectionViewDescriptor(droppedViewAdapter, edgeType, getDiagramPreferencesHint());

+		CommonDeferredCreateConnectionViewCommand createConnectionViewCommand = new CommonDeferredCreateConnectionViewCommand(getEditingDomain(), edgeType, sourceViewAdapter, targetViewAdapter, getViewer(), getDiagramPreferencesHint(), linkdescriptor, null);

+		createConnectionViewCommand.setElement(semanticLink);

+		cc.compose(createConnectionViewCommand);

+		return cc;

+	}

+

+	/**

+	 * This method allows to specify a location for the creation of a node at

+	 * the source of a dropped link. Overriding implementations must not modify

+	 * the absoluteLocation parameter (use {@link Point#getCopy()})

+	 *

+	 * @param absoluteLocation

+	 *            the request's drop location

+	 * @param source

+	 *            the source of the dropped link

+	 * @param target

+	 *            the target of the dropped link

+	 * @return the new location for the node

+	 */

+	protected Point getLinkSourceDropLocation(Point absoluteLocation, Element source, Element target) {

+		return absoluteLocation;

+	}

+

+	/**

+	 * This method allows to specify a location for the creation of a node at

+	 * the target of a dropped link. Overriding implementations must not modify

+	 * the absoluteLocation parameter (use {@link Point#getCopy()})

+	 *

+	 * @param absoluteLocation

+	 *            the request's drop location

+	 * @param source

+	 *            the source of the dropped link

+	 * @param target

+	 *            the target of the dropped link

+	 * @return the new location for the node

+	 */

+	protected Point getLinkTargetDropLocation(Point absoluteLocation, Element source, Element target) {

+		if (lookForEditPart(source) == null && lookForEditPart(target) == null) {

+			return absoluteLocation.getTranslated(100, 0);

 		}

+		return absoluteLocation;

+	}

 

-		View selectedSourceView = null;

-		View selectedTargetView = null;

-		// until a correct one is found, check that source and target views selected are correct given the current path for the connector...

-		for (View sourceView : sourceViews) {

-			View targetView = getFirstValidTargetViewForSource(sourceView, targetViews, droppedEObject);

-			if (targetView != null) {

-				selectedSourceView = sourceView;

-				selectedTargetView = targetView;

-				break;

-			}

+	/**

+	 * the method provides command to create the binary link into the diagram.

+	 * Find source/target adapter

+	 * If the source and the target views do not exist, these views will be

+	 * created.

+	 * 

+	 * @see dropBinaryLink(CompositeCommand cc, Element source, Element target, int linkVISUALID

+	 *      , Point absoluteLocation, Element semanticLink)

+	 *

+	 * @param cc

+	 *            the composite command that will contain the set of command to

+	 *            create the binary link

+	 * @param source

+	 *            source/target link node

+	 * @param point

+	 *            source/target node location

+	 */

+	private IAdaptable findAdapter(CompositeCommand cc, Element source, Point dropLocation, String edgeType) {

+		IAdaptable result = getElement2IAdaptableRegistryHelper().findAdapter(source);

+		if (result != null) {

+			return result;

+		}

+		GraphicalEditPart editPart = (GraphicalEditPart) lookForEditPart(source);

+		if (editPart != null) {

+			return new SemanticAdapter(null, editPart.getModel());

 		}

+		if (isPortSource(source)) {

+			ICommand createPortCommand = createPortViewCommand(source, dropLocation);

+			cc.add(createPortCommand);

+			return (IAdaptable) createPortCommand.getCommandResult().getReturnValue();

+		}

+		ICommand createCommand = getDefaultDropNodeCommand(edgeType, dropLocation, source);

+		cc.add(createCommand);

+		return (IAdaptable) createCommand.getCommandResult().getReturnValue();

+	}

 

+	protected boolean isPortSource(Element source) {

+		return source instanceof Port;

+	}

 

-		// Create source adapter

-		if (selectedSourceView != null) { // sourceViewAdapter should still be null in this case

-			sourceViewAdapter = new SemanticAdapter(null, selectedSourceView);

-		} else {

-			return org.eclipse.gmf.runtime.common.core.command.UnexecutableCommand.INSTANCE;

+	private ICommand createPortViewCommand(Element source, Point dropLocation) {

+		if (false == source instanceof Port) {

+			return new CommandProxy(UnexecutableCommand.INSTANCE);

 		}

-

-		// Create target adapter

-		if (selectedTargetView != null) { // targetViewAdapter should still be null in this case

-			targetViewAdapter = new SemanticAdapter(null, selectedTargetView);

-		} else {

-			return org.eclipse.gmf.runtime.common.core.command.UnexecutableCommand.INSTANCE;

+		EditPart portContainer = lookForEditPart(source.eContainer(), true);

+		if (portContainer == null) {

+			return new CommandProxy(UnexecutableCommand.INSTANCE);

 		}

+		PortDropHelper portDropHelper = new PortDropHelper(getEditingDomain());

+		return portDropHelper.getDropPortOnPart((Port) source, dropLocation.getCopy(), (GraphicalEditPart) portContainer);

+	}

 

-		// Create a view for the dropped link between the source and target view adapters

-		IAdaptable droppedObjectAdapter = new SemanticAdapter(droppedEObject, null);

+	protected EditPart lookForEditPart(EObject semantic) {

+		return lookForEditPart(semantic, false);

+	}

 

-		CreateConnectionViewRequest.ConnectionViewDescriptor linkdescriptor = new CreateConnectionViewRequest.ConnectionViewDescriptor(droppedObjectAdapter, edgeType, getDiagramPreferencesHint());

+	/**

+	 * Look for editPart from his semantic.

+	 *

+	 * @param semantic

+	 *            the semantic

+	 *

+	 * @return the edits the part or null if not found

+	 */

+	protected EditPart lookForEditPart(EObject semantic, boolean byType) {

+		Collection<EditPart> editPartSet = getHost().getViewer().getEditPartRegistry().values();

+		Iterator<EditPart> editPartIterator = editPartSet.iterator();

+		while (editPartIterator.hasNext()) {

+			EditPart nextEditPart = editPartIterator.next();

+			if (!isEditPartTypeAdapted(nextEditPart.getClass(), semantic.eClass())) {

+				continue;

+			}

+			EObject nextSemantic = ((GraphicalEditPart) nextEditPart).resolveSemanticElement();

+			if (semantic.equals(nextSemantic)) {

+				return nextEditPart;

+			}

+			if (byType && nextSemantic instanceof TypedElement && ((TypedElement) nextSemantic).getType() != null) {

+				EObject nextSemanticType = ((TypedElement) nextSemantic).getType();

+				if (semantic.equals(nextSemanticType)) {

+					return nextEditPart;

+				}

+			}

+		}

+		return null;

+	}

 

-		CommonDeferredCreateConnectionViewCommand createConnectionViewCommand = new CommonDeferredCreateConnectionViewCommand(getEditingDomain(), edgeType, sourceViewAdapter, targetViewAdapter, getViewer(), getDiagramPreferencesHint(), linkdescriptor, null);

-		createConnectionViewCommand.setElement(droppedEObject);

+	/**

+	 * Check if the edit part type is the best one to represent an object of the

+	 * given EClass type

+	 *

+	 * @param editPartClass

+	 *            the type of EditPart which may represent a semantic element

+	 * @param eClass

+	 *            the EClass type of the represented semantic element

+	 * @return true if an edit part of this type should be selected

+	 */

+	private boolean isEditPartTypeAdapted(Class<? extends EditPart> editPartClass, EClass eClass) {

+		if (DiagramEditPart.class.isAssignableFrom(editPartClass) || CompartmentEditPart.class.isAssignableFrom(editPartClass)) {

+			// the edit part is disqualified, as a compartment or a diagram can not be dropped

+			return false;

+		} else if (AbstractElementNodeLabelEditPart.class.isAssignableFrom(editPartClass)) {

+			return false;

+		} else if (GraphicalEditPart.class.isAssignableFrom(editPartClass)) {

+			// check the edit part type against advised ones

+			return isEditPartTypeSuitableForEClass(editPartClass.asSubclass(GraphicalEditPart.class), eClass);

+		}

+		return false;

+	}

 

-		return createConnectionViewCommand;

+	/**

+	 * Check if an edit part type correctly represent a semantic element of the

+	 * given EClass. Subclasses should implement this method to restrict the

+	 * possibilities during drop of a link. If an edit part is not of a suitable

+	 * type, returning false will eliminate it to represent the element as a

+	 * source or target edit part. This can be used for example to disable label

+	 * edit parts, which may represent the same model element as the main node.

+	 *

+	 * @param editPartClass

+	 *            the type of EditPart which must be checked

+	 * @param eClass

+	 *            the EClass type of the element which the edit part must

+	 *            represent

+	 * @return the only edit part type which can be selected (return a common

+	 *         super type if several edit parts can be chosen)

+	 */

+	protected boolean isEditPartTypeSuitableForEClass(Class<? extends GraphicalEditPart> editPartClass, EClass eClass) {

+		return true;

 	}

 

 	/**

diff --git a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/utils/PortDropHelper.java b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/utils/PortDropHelper.java
index 152f25adce9..558ddbd4789 100644
--- a/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/utils/PortDropHelper.java
+++ b/plugins/sysml/diagram/org.eclipse.papyrus.sysml.diagram.internalblock/src/org/eclipse/papyrus/sysml/diagram/internalblock/utils/PortDropHelper.java
@@ -18,15 +18,18 @@ import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.transaction.TransactionalEditingDomain;
 import org.eclipse.gef.commands.Command;
 import org.eclipse.gef.commands.UnexecutableCommand;
+import org.eclipse.gmf.runtime.common.core.command.ICommand;
 import org.eclipse.gmf.runtime.diagram.core.util.ViewUtil;
+import org.eclipse.gmf.runtime.diagram.ui.commands.CommandProxy;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.GraphicalEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.requests.CreateViewRequest;
 import org.eclipse.gmf.runtime.diagram.ui.requests.CreateViewRequest.ViewDescriptor;
 import org.eclipse.gmf.runtime.diagram.ui.requests.DropObjectsRequest;
+import org.eclipse.gmf.runtime.emf.core.util.EObjectAdapter;
 import org.eclipse.gmf.runtime.notation.Node;
 import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.commands.wrappers.CommandProxyWithResult;
 import org.eclipse.papyrus.infra.gmfdiag.common.utils.ViewDescriptorUtil;
-import org.eclipse.papyrus.uml.diagram.common.commands.SemanticAdapter;
 import org.eclipse.papyrus.uml.diagram.common.helper.ElementHelper;
 import org.eclipse.uml2.uml.Classifier;
 import org.eclipse.uml2.uml.Port;
@@ -42,29 +45,29 @@ public class PortDropHelper extends ElementHelper {
 		this.editDomain = editDomain;
 	}
 
-	public Command getDropPortOnPart(DropObjectsRequest request, GraphicalEditPart host) {
+	public ICommand getDropPortOnPart(DropObjectsRequest request, GraphicalEditPart host) {
 
 		Object droppedEObject = request.getObjects().get(0);
 		if (!isValidPort(droppedEObject, getHostEObject(host))) {
-			return UnexecutableCommand.INSTANCE;
+			return new CommandProxy(UnexecutableCommand.INSTANCE);
 		}
 
 		return getDropPortOnPart((Port) droppedEObject, request.getLocation().getCopy(), host);
 	}
 
-	public Command getDropPortOnPart(Port droppedPort, Point location, GraphicalEditPart host) {
+	public ICommand getDropPortOnPart(Port droppedPort, Point location, GraphicalEditPart host) {
 
 		if (!isValidPort(droppedPort, getHostEObject(host))) {
-			return UnexecutableCommand.INSTANCE;
+			return new CommandProxy(UnexecutableCommand.INSTANCE);
 		}
 
 		// Prepare the view creation command
-		ViewDescriptor descriptor = new ViewDescriptor(new SemanticAdapter(droppedPort, null), Node.class, /* explicit semantic hint is mandatory */null, ViewDescriptorUtil.PERSISTED, host.getDiagramPreferencesHint());
+		ViewDescriptor descriptor = new ViewDescriptor(new EObjectAdapter(droppedPort), Node.class, /* explicit semantic hint is mandatory */null, ViewDescriptorUtil.PERSISTED, host.getDiagramPreferencesHint());
 		CreateViewRequest createViewRequest = new CreateViewRequest(descriptor);
 		createViewRequest.setLocation(location);
 		Command viewCreateCommand = host.getCommand(createViewRequest);
 
-		return viewCreateCommand;
+		return new CommandProxyWithResult(viewCreateCommand, descriptor);
 	}
 
 	private boolean isValidPort(Object object, EObject dropTarget) {