Bug 468026 - ClassCastException when opening a diagram

 - patch exception when opening a diagram
(Exception comming from an edge between a Model and a Class) 

Change-Id: If9547f2f89ed79e3d57d46e14b320278f0d2da60
Signed-off-by: Benoit Maggi <benoit.maggi@cea.fr>
Reviewed-on: https://git.eclipse.org/r/48468
Tested-by: Hudson CI
Reviewed-by: Camille Letavernier <camille.letavernier@cea.fr>

3 files changed, 356 insertions, 343 deletions

diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.clazz/custom-src/org/eclipse/papyrus/uml/diagram/clazz/custom/edit/part/AbstractAssociationEditPart.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.clazz/custom-src/org/eclipse/papyrus/uml/diagram/clazz/custom/edit/part/AbstractAssociationEditPart.java
index 8ac8c8f1f08..0ffc4d324d8 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.clazz/custom-src/org/eclipse/papyrus/uml/diagram/clazz/custom/edit/part/AbstractAssociationEditPart.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.clazz/custom-src/org/eclipse/papyrus/uml/diagram/clazz/custom/edit/part/AbstractAssociationEditPart.java
@@ -1,172 +1,175 @@
-/*****************************************************************************

- * Copyright (c) 2009 CEA LIST.

- *

- *

- * All rights reserved. This program and the accompanying materials

- * are made available under the terms of the Eclipse Public License v1.0

- * which accompanies this distribution, and is available at

- * http://www.eclipse.org/legal/epl-v10.html

- *

- * Contributors:

- *  Patrick Tessier (CEA LIST) Patrick.tessier@cea.fr - Initial API and implementation

- *

- *****************************************************************************/

-package org.eclipse.papyrus.uml.diagram.clazz.custom.edit.part;

-

-import org.eclipse.emf.common.notify.Notification;

-import org.eclipse.emf.ecore.EObject;

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

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

-import org.eclipse.papyrus.uml.diagram.clazz.custom.figure.AssociationFigure;

-import org.eclipse.papyrus.uml.diagram.common.editparts.UMLConnectionNodeEditPart;

-import org.eclipse.uml2.uml.AggregationKind;

-import org.eclipse.uml2.uml.Association;

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

-import org.eclipse.uml2.uml.Property;

-

-/**

- * this a abstract editpart use to add listeners

- */

-public abstract class AbstractAssociationEditPart extends UMLConnectionNodeEditPart {

-

-	protected static final String ASSOCIATION_END_LISTENERS_SOURCE = "AssociationEndListenersSource";

-

-	protected static final String ASSOCIATION_END_LISTENERS_TARGET = "AssociationEndListenersTarget";

-

-	public AbstractAssociationEditPart(View view) {

-		super(view);

-	}

-

-	/**

-	 *

-	 * {@inheritDoc}

-	 */

-	@Override

-	public void activate() {

-		super.activate();

-		addAssociationEndListeners();

-	}

-

-	/**

-	 * this methods add listeners on targets and sources

-	 */

-	protected void addAssociationEndListeners() {

-		EObject semanticElement = resolveSemanticElement();

-		if (semanticElement instanceof Association) {

-			Association association = (Association) semanticElement;

-			if (association.getMemberEnds().size() >= 2) {

-				EObject sourceEnd = association.getMemberEnds().get(0);

-				EObject targetEnd = association.getMemberEnds().get(1);

-				addListenerFilter(ASSOCIATION_END_LISTENERS_SOURCE, this, sourceEnd);

-				addListenerFilter(ASSOCIATION_END_LISTENERS_TARGET, this, targetEnd);

-			}

-		}

-	}

-

-	/**

-	 *

-	 * {@inheritDoc}

-	 */

-	@Override

-	public void deactivate() {

-		removeAssociationEndListeners();

-		super.deactivate();

-	}

-

-	/**

-	 *

-	 * {@inheritDoc}

-	 */

-	@Override

-	protected void handleNotificationEvent(Notification event) {

-		super.handleNotificationEvent(event);

-		// set the good ends for the association figure

-		if (resolveSemanticElement() != null) {

-			refreshVisuals();

-		}

-	}

-

-	/**

-	 *

-	 * {@inheritDoc}

-	 */

-	@Override

-	protected void refreshVisuals() {

-		if (resolveSemanticElement() != null) {

-			if (getSource() == null || getTarget() == null) {

-				return;

-			}

-			if (!(getSource() instanceof GraphicalEditPart && getTarget() instanceof GraphicalEditPart)) {

-				return;

-			}

-			// FIXME: This is a quick fix to avoid model corruption when an associationClass is drawn between an association and a Class.

-			// A better solution would probably be to forbid this behavior. Currently, it is not possible to draw directly an Association Class between

-			// an association and a class, but it is possible to retarget an AssociationClass' end to an Association (Which would lead to a diagram corruption)

-			if (((GraphicalEditPart) getSource()).resolveSemanticElement() == null || ((GraphicalEditPart) getTarget()).resolveSemanticElement() == null) {

-				return;

-			}

-			Property source = null;

-			Property target = null;

-			// Get the association

-			Element umlElement = getUMLElement();

-			if (umlElement instanceof Association) {

-				Association association = (Association) getUMLElement();

-				assert (association.getMemberEnds().size() >= 2);

-				if (association.getMemberEnds() != null && association.getMemberEnds().size() >= 2) {

-					if ((association.getMemberEnds().get(0)).getType().equals(((GraphicalEditPart) getSource()).resolveSemanticElement())) {

-						source = ((association.getMemberEnds().get(0)));

-						target = ((association.getMemberEnds().get(1)));

-					} else {

-						source = ((association.getMemberEnds().get(1)));

-						target = ((association.getMemberEnds().get(0)));

-					}

-					int sourceType = 0;

-					int targetType = 0;

-					// to display the dot.

-					// owned?

-					if (!source.getOwner().equals(resolveSemanticElement())) {

-						sourceType += AssociationFigure.owned;

-						sourceType += AssociationFigure.navigable;

-					}

-					if (!target.getOwner().equals(resolveSemanticElement())) {

-						targetType += AssociationFigure.owned;

-						targetType += AssociationFigure.navigable;

-					}

-					// aggregation? for it the opposite is changed

-					if (source.getAggregation() == AggregationKind.SHARED_LITERAL) {

-						targetType += AssociationFigure.aggregation;

-					}

-					if (target.getAggregation() == AggregationKind.SHARED_LITERAL) {

-						sourceType += AssociationFigure.aggregation;

-					}

-					// composite? for it the opposite is changed

-					if (source.getAggregation() == AggregationKind.COMPOSITE_LITERAL) {

-						targetType += AssociationFigure.composition;

-					}

-					if (target.getAggregation() == AggregationKind.COMPOSITE_LITERAL) {

-						sourceType += AssociationFigure.composition;

-					}

-					// navigable?

-					if (association.getNavigableOwnedEnds().contains(source)) {

-						sourceType += AssociationFigure.navigable;

-					}

-					if (association.getNavigableOwnedEnds().contains(target)) {

-						targetType += AssociationFigure.navigable;

-					}

-					if (getPrimaryShape() instanceof AssociationFigure) {

-						((AssociationFigure) getPrimaryShape()).setEnd(sourceType, targetType);

-					}

-				}

-			}

-		}

-		super.refreshVisuals();

-	}

-

-	/**

-	 * this method is used to remove listener on ends

-	 */

-	protected void removeAssociationEndListeners() {

-		removeListenerFilter(ASSOCIATION_END_LISTENERS_SOURCE);

-		removeListenerFilter(ASSOCIATION_END_LISTENERS_TARGET);

-	}

-}

+/*****************************************************************************
+ * Copyright (c) 2009 CEA LIST.
+ *
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *  Patrick Tessier (CEA LIST) Patrick.tessier@cea.fr - Initial API and implementation
+ *  Benoit Maggi (CEA LIST) - Bug 468026
+ *****************************************************************************/
+package org.eclipse.papyrus.uml.diagram.clazz.custom.edit.part;
+
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.gmf.runtime.diagram.ui.editparts.GraphicalEditPart;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.uml.diagram.clazz.custom.figure.AssociationFigure;
+import org.eclipse.papyrus.uml.diagram.common.editparts.UMLConnectionNodeEditPart;
+import org.eclipse.uml2.uml.AggregationKind;
+import org.eclipse.uml2.uml.Association;
+import org.eclipse.uml2.uml.Element;
+import org.eclipse.uml2.uml.Property;
+import org.eclipse.uml2.uml.Type;
+
+/**
+ * this abstract editpart is used to add listeners
+ */
+public abstract class AbstractAssociationEditPart extends UMLConnectionNodeEditPart {
+
+	protected static final String ASSOCIATION_END_LISTENERS_SOURCE = "AssociationEndListenersSource"; //$NON-NLS-1$
+
+	protected static final String ASSOCIATION_END_LISTENERS_TARGET = "AssociationEndListenersTarget"; //$NON-NLS-1$
+
+	public AbstractAssociationEditPart(View view) {
+		super(view);
+	}
+
+	/**
+	 *
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void activate() {
+		super.activate();
+		addAssociationEndListeners();
+	}
+
+	/**
+	 * this methods add listeners on targets and sources
+	 */
+	protected void addAssociationEndListeners() {
+		EObject semanticElement = resolveSemanticElement();
+		if (semanticElement instanceof Association) {
+			Association association = (Association) semanticElement;
+			if (association.getMemberEnds().size() >= 2) {
+				EObject sourceEnd = association.getMemberEnds().get(0);
+				EObject targetEnd = association.getMemberEnds().get(1);
+				addListenerFilter(ASSOCIATION_END_LISTENERS_SOURCE, this, sourceEnd);
+				addListenerFilter(ASSOCIATION_END_LISTENERS_TARGET, this, targetEnd);
+			}
+		}
+	}
+
+	/**
+	 *
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void deactivate() {
+		removeAssociationEndListeners();
+		super.deactivate();
+	}
+
+	/**
+	 *
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void handleNotificationEvent(Notification event) {
+		super.handleNotificationEvent(event);
+		// set the good ends for the association figure
+		if (resolveSemanticElement() != null) {
+			refreshVisuals();
+		}
+	}
+
+	/**
+	 *
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void refreshVisuals() {
+		if (resolveSemanticElement() != null) {
+			if (getSource() == null || getTarget() == null) {
+				return;
+			}
+			if (!(getSource() instanceof GraphicalEditPart && getTarget() instanceof GraphicalEditPart)) {
+				return;
+			}
+			// FIXME: This is a quick fix to avoid model corruption when an associationClass is drawn between an association and a Class.
+			// A better solution would probably be to forbid this behavior. Currently, it is not possible to draw directly an Association Class between
+			// an association and a class, but it is possible to retarget an AssociationClass' end to an Association (Which would lead to a diagram corruption)
+			if (((GraphicalEditPart) getSource()).resolveSemanticElement() == null || ((GraphicalEditPart) getTarget()).resolveSemanticElement() == null) {
+				return;
+			}
+			Property source = null;
+			Property target = null;
+			// Get the association
+			Element umlElement = getUMLElement();
+			if (umlElement instanceof Association) {
+				Association association = (Association) getUMLElement();
+				assert (association.getMemberEnds().size() >= 2);
+				if (association.getMemberEnds() != null && association.getMemberEnds().size() >= 2) {
+					Property firstProperty = association.getMemberEnds().get(0);
+					Type firstPropertyType = firstProperty.getType();
+					if (firstPropertyType!= null && firstPropertyType.equals(((GraphicalEditPart) getSource()).resolveSemanticElement())) {
+						source = (firstProperty);
+						target = ((association.getMemberEnds().get(1)));
+					} else {
+						source = ((association.getMemberEnds().get(1)));
+						target = (firstProperty);
+					}
+					int sourceType = 0;
+					int targetType = 0;
+					// to display the dot.
+					// owned?
+					if (!source.getOwner().equals(resolveSemanticElement())) {
+						sourceType += AssociationFigure.owned;
+						sourceType += AssociationFigure.navigable;
+					}
+					if (!target.getOwner().equals(resolveSemanticElement())) {
+						targetType += AssociationFigure.owned;
+						targetType += AssociationFigure.navigable;
+					}
+					// aggregation? for it the opposite is changed
+					if (source.getAggregation() == AggregationKind.SHARED_LITERAL) {
+						targetType += AssociationFigure.aggregation;
+					}
+					if (target.getAggregation() == AggregationKind.SHARED_LITERAL) {
+						sourceType += AssociationFigure.aggregation;
+					}
+					// composite? for it the opposite is changed
+					if (source.getAggregation() == AggregationKind.COMPOSITE_LITERAL) {
+						targetType += AssociationFigure.composition;
+					}
+					if (target.getAggregation() == AggregationKind.COMPOSITE_LITERAL) {
+						sourceType += AssociationFigure.composition;
+					}
+					// navigable?
+					if (association.getNavigableOwnedEnds().contains(source)) {
+						sourceType += AssociationFigure.navigable;
+					}
+					if (association.getNavigableOwnedEnds().contains(target)) {
+						targetType += AssociationFigure.navigable;
+					}
+					if (getPrimaryShape() instanceof AssociationFigure) {
+						((AssociationFigure) getPrimaryShape()).setEnd(sourceType, targetType);
+					}
+				}
+			}
+		}
+		super.refreshVisuals();
+	}
+
+	/**
+	 * this method is used to remove listener on ends
+	 */
+	protected void removeAssociationEndListeners() {
+		removeListenerFilter(ASSOCIATION_END_LISTENERS_SOURCE);
+		removeListenerFilter(ASSOCIATION_END_LISTENERS_TARGET);
+	}
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndSourceLabelHelper.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndSourceLabelHelper.java
index d9a994074c8..dd3045d0d61 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndSourceLabelHelper.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndSourceLabelHelper.java
@@ -1,83 +1,88 @@
-/*****************************************************************************

- * Copyright (c) 2008 CEA LIST.

- *

- *

- * All rights reserved. This program and the accompanying materials

- * are made available under the terms of the Eclipse Public License v1.0

- * which accompanies this distribution, and is available at

- * http://www.eclipse.org/legal/epl-v10.html

- *

- * Contributors:

- *  Patrick Tessier (CEA LIST) - Initial API and implementation

- *

- *****************************************************************************/

-package org.eclipse.papyrus.uml.diagram.common.helper;

-

-import java.util.Iterator;

-

-import org.eclipse.emf.ecore.util.EcoreUtil;

-import org.eclipse.gef.GraphicalEditPart;

-import org.eclipse.gmf.runtime.notation.Edge;

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

-import org.eclipse.uml2.uml.Association;

-import org.eclipse.uml2.uml.Classifier;

-import org.eclipse.uml2.uml.Property;

-

-/**

- * Helper for labels displaying {@link Property}

- */

-public class AssociationEndSourceLabelHelper extends AssociationEndPropertyLabelHelper {

-

-	private static AssociationEndSourceLabelHelper labelHelper;

-

-	public static AssociationEndSourceLabelHelper getInstance() {

-		if (labelHelper == null) {

-			labelHelper = new AssociationEndSourceLabelHelper();

-		}

-		return labelHelper;

-	}

-

-	/**

-	 * {@inheritDoc}

-	 */

-	@Override

-	public Property getUMLElement(GraphicalEditPart editPart) {

-		if ((View) editPart.getModel() != null && ((View) editPart.getModel()).eContainer() != null) {

-			if (((Edge) ((View) editPart.getModel()).eContainer()).getSource() == null) {

-				return null;

-			}

-			Classifier source = (Classifier) ((Edge) ((View) editPart.getModel()).eContainer()).getSource().getElement();

-			Property propertyToDisplay = null;

-			if (((View) editPart.getModel()) != null && (((View) editPart.getModel()).getElement() instanceof Association)) {

-				// look for the property that is typed by the classifier

-				Iterator<Property> propertiesIterator = ((Association) ((View) editPart.getModel()).getElement()).getMemberEnds().iterator();

-				// find the first

-				while (propertiesIterator.hasNext() && propertyToDisplay == null) {

-					Property currentProperty = propertiesIterator.next();

-					if (EcoreUtil.equals(currentProperty.getType(), source)) {

-						propertyToDisplay = currentProperty;

-					}

-				}

-			}

-			if (propertyToDisplay != null) {

-				return propertyToDisplay;

-			}

-			// /in the case of reorient the property must be not found,

-			// so we have to find the property that is different from the source.

-			Classifier target = (Classifier) ((Edge) ((View) editPart.getModel()).eContainer()).getSource().getElement();

-			if (((View) editPart.getModel()) != null && (((View) editPart.getModel()).getElement() instanceof Association)) {

-				// look for the property that is typed by the classifier

-				Iterator<Property> propertiesIterator = ((Association) ((View) editPart.getModel()).getElement()).getMemberEnds().iterator();

-				// find the last

-				while (propertiesIterator.hasNext()) {

-					Property currentProperty = propertiesIterator.next();

-					if (!EcoreUtil.equals(currentProperty.getType(), target)) {

-						propertyToDisplay = currentProperty;

-					}

-				}

-			}

-			return propertyToDisplay;

-		}

-		return null;

-	}

-}

+/*****************************************************************************
+ * Copyright (c) 2008 CEA LIST.
+ *
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *  Patrick Tessier (CEA LIST) - Initial API and implementation
+ *  Benoit Maggi (CEA LIST)    - Bug 468026
+ *****************************************************************************/
+package org.eclipse.papyrus.uml.diagram.common.helper;
+
+import java.util.Iterator;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.gef.GraphicalEditPart;
+import org.eclipse.gmf.runtime.notation.Edge;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.uml2.uml.Association;
+import org.eclipse.uml2.uml.Property;
+
+/**
+ * Helper for labels displaying {@link Property}
+ */
+public class AssociationEndSourceLabelHelper extends AssociationEndPropertyLabelHelper {
+
+	private static AssociationEndSourceLabelHelper labelHelper;
+
+	public static AssociationEndSourceLabelHelper getInstance() {
+		if (labelHelper == null) {
+			labelHelper = new AssociationEndSourceLabelHelper();
+		}
+		return labelHelper;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Property getUMLElement(GraphicalEditPart editPart) {
+		View model = (View) editPart.getModel();
+		if (model != null && model.eContainer() != null) {
+			Edge eContainer = (Edge) model.eContainer();
+			View sourceContainer = eContainer.getSource();
+			if (sourceContainer == null) {
+				return null;
+			}
+			
+			Property propertyToDisplay = null;
+			if (model != null && (model.getElement() instanceof Association)) {
+				// look for the property that is typed by the classifier
+				Iterator<Property> propertiesIterator = ((Association) model.getElement()).getMemberEnds().iterator();
+				// find the first
+				EObject source = sourceContainer.getElement();
+				while (propertiesIterator.hasNext() && propertyToDisplay == null) {
+					Property currentProperty = propertiesIterator.next();
+					if (EcoreUtil.equals(currentProperty.getType(), source)) {
+						propertyToDisplay = currentProperty;
+					}
+				}
+			}
+			if (propertyToDisplay != null) {
+				return propertyToDisplay;
+			}
+			// /in the case of reorient the property must be not found,
+			// so we have to find the property that is different from the source.
+			
+			if (model != null && (model.getElement() instanceof Association)) {
+				// look for the property that is typed by the classifier
+				Iterator<Property> propertiesIterator = ((Association) model.getElement()).getMemberEnds().iterator();
+				// find the last
+				EObject target = sourceContainer.getElement();
+				while (propertiesIterator.hasNext()) {
+					Property currentProperty = propertiesIterator.next();
+					if (!EcoreUtil.equals(currentProperty.getType(), target)) {
+						propertyToDisplay = currentProperty;
+					}
+				}
+			}
+			return propertyToDisplay;
+		}
+		return null;
+	}
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndTargetLabelHelper.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndTargetLabelHelper.java
index e8cc9d6f0f3..7b5452f6848 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndTargetLabelHelper.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.common/src/org/eclipse/papyrus/uml/diagram/common/helper/AssociationEndTargetLabelHelper.java
@@ -1,88 +1,93 @@
-/*****************************************************************************

- * Copyright (c) 2008 CEA LIST.

- *

- *

- * All rights reserved. This program and the accompanying materials

- * are made available under the terms of the Eclipse Public License v1.0

- * which accompanies this distribution, and is available at

- * http://www.eclipse.org/legal/epl-v10.html

- *

- * Contributors:

- *  Patrick Tessier (CEA LIST) - Initial API and implementation

- *

- *****************************************************************************/

-package org.eclipse.papyrus.uml.diagram.common.helper;

-

-import java.util.Iterator;

-

-import org.eclipse.emf.ecore.EObject;

-import org.eclipse.emf.ecore.util.EcoreUtil;

-import org.eclipse.gef.GraphicalEditPart;

-import org.eclipse.gmf.runtime.notation.Edge;

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

-import org.eclipse.uml2.uml.Association;

-import org.eclipse.uml2.uml.Classifier;

-import org.eclipse.uml2.uml.Property;

-

-/**

- * Helper for labels displaying {@link Property}

- */

-public class AssociationEndTargetLabelHelper extends AssociationEndPropertyLabelHelper {

-

-	private static AssociationEndTargetLabelHelper labelHelper;

-

-	public static AssociationEndTargetLabelHelper getInstance() {

-		if (labelHelper == null) {

-			labelHelper = new AssociationEndTargetLabelHelper();

-		}

-		return labelHelper;

-	}

-

-	/**

-	 * {@inheritDoc}

-	 */

-	@Override

-	public Property getUMLElement(GraphicalEditPart editPart) {

-		if ((View) editPart.getModel() != null && ((View) editPart.getModel()).eContainer() != null) {

-			EObject container = ((View) editPart.getModel()).eContainer();

-			if (!(container instanceof Edge)) {

-				return null; // Happens e.g. when redoing the suppression of an association's end. The association is contained in a ChangeDescription

-			}

-			if (((Edge) ((View) editPart.getModel()).eContainer()).getTarget() == null) {

-				return null;

-			}

-			Classifier target = (Classifier) ((Edge) ((View) editPart.getModel()).eContainer()).getTarget().getElement();

-			Property propertyToDisplay = null;

-			if (((View) editPart.getModel()) != null && (((View) editPart.getModel()).getElement() instanceof Association)) {

-				// look for the property that is typed by the classifier

-				Iterator<Property> propertiesIterator = ((Association) ((View) editPart.getModel()).getElement()).getMemberEnds().iterator();

-				// find the last

-				while (propertiesIterator.hasNext()) {

-					Property currentProperty = propertiesIterator.next();

-					if (EcoreUtil.equals(currentProperty.getType(), target)) {

-						propertyToDisplay = currentProperty;

-					}

-				}

-			}

-			if (propertyToDisplay != null) {

-				return propertyToDisplay;

-			}

-			// /in the case of reorient the property must be not found,

-			// so we have to find the property that is different from the source.

-			Classifier source = (Classifier) ((Edge) ((View) editPart.getModel()).eContainer()).getSource().getElement();

-			if (((View) editPart.getModel()) != null && (((View) editPart.getModel()).getElement() instanceof Association)) {

-				// look for the property that is typed by the classifier

-				Iterator<Property> propertiesIterator = ((Association) ((View) editPart.getModel()).getElement()).getMemberEnds().iterator();

-				// find the last

-				while (propertiesIterator.hasNext()) {

-					Property currentProperty = propertiesIterator.next();

-					if (!EcoreUtil.equals(currentProperty.getType(), source)) {

-						propertyToDisplay = currentProperty;

-					}

-				}

-			}

-			return propertyToDisplay;

-		}

-		return null;

-	}

-}

+/*****************************************************************************
+ * Copyright (c) 2008 CEA LIST.
+ *
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *  Patrick Tessier (CEA LIST) - Initial API and implementation
+ *  Benoit Maggi (CEA LIST)    - Bug 468026
+ *****************************************************************************/
+package org.eclipse.papyrus.uml.diagram.common.helper;
+
+import java.util.Iterator;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.gef.GraphicalEditPart;
+import org.eclipse.gmf.runtime.notation.Edge;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.uml2.uml.Association;
+import org.eclipse.uml2.uml.Property;
+
+/**
+ * Helper for labels displaying {@link Property}
+ */
+public class AssociationEndTargetLabelHelper extends AssociationEndPropertyLabelHelper {
+
+	private static AssociationEndTargetLabelHelper labelHelper;
+
+	public static AssociationEndTargetLabelHelper getInstance() {
+		if (labelHelper == null) {
+			labelHelper = new AssociationEndTargetLabelHelper();
+		}
+		return labelHelper;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Property getUMLElement(GraphicalEditPart editPart) {
+		View model = (View) editPart.getModel();
+		if (model != null && model.eContainer() != null) {
+			EObject container = model.eContainer();
+			if (!(container instanceof Edge)) {
+				return null; // Happens e.g. when redoing the suppression of an association's end. The association is contained in a ChangeDescription
+			}
+			Edge eContainer = (Edge) model.eContainer();
+			View targetContainer = eContainer.getTarget();
+			if (targetContainer == null) {
+				return null;
+			}
+			
+			Property propertyToDisplay = null;
+			if (model != null && (model.getElement() instanceof Association)) {
+				// look for the property that is typed by the classifier
+				Iterator<Property> propertiesIterator = ((Association) model.getElement()).getMemberEnds().iterator();
+				// find the last
+				EObject element = targetContainer.getElement();
+				while (propertiesIterator.hasNext()) {
+					Property currentProperty = propertiesIterator.next();
+					if (EcoreUtil.equals(currentProperty.getType(), element)) {
+						propertyToDisplay = currentProperty;
+					}
+				}
+			}
+			if (propertyToDisplay != null) {
+				return propertyToDisplay;
+			}
+			// in the case of reorient the property must be not found,
+			// so we have to find the property that is different from the source.
+			
+			if (model != null && (model.getElement() instanceof Association)) {
+				// look for the property that is typed by the classifier
+				Iterator<Property> propertiesIterator = ((Association) model.getElement()).getMemberEnds().iterator();
+				// find the last
+				View sourceContainer = eContainer.getSource();
+				EObject element = sourceContainer.getElement();
+				while (propertiesIterator.hasNext()) {
+					Property currentProperty = propertiesIterator.next();
+					if (!EcoreUtil.equals(currentProperty.getType(), element)) {
+						propertyToDisplay = currentProperty;
+					}
+				}
+			}
+			return propertyToDisplay;
+		}
+		return null;
+	}
+}