Bug 537724: [Sequence Diagram] Support ReconnectRequests for

GeneralOrdering

Change-Id: I7199af44fec105e54d7b9e1fc295a5198e686b76
Signed-off-by: Camille Letavernier <cletavernier@eclipsesource.com>

7 files changed, 231 insertions, 88 deletions

diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractExecutionSpecificationEditPart.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractExecutionSpecificationEditPart.java
index 1bccffeb26f..f2c32ec6a46 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractExecutionSpecificationEditPart.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractExecutionSpecificationEditPart.java
@@ -336,6 +336,8 @@ public abstract class AbstractExecutionSpecificationEditPart extends RoundedComp
 			if (connectionEditPart instanceof MessageSyncEditPart) {
 				// Sync Message
 				return new AnchorHelper.FixedAnchorEx(getFigure(), PositionConstants.TOP);
+			} else if (DurationLinkUtil.isDurationLink(reconnectRequest) || GeneralOrderingUtil.isGeneralOrderingLink(reconnectRequest)) {
+				return OccurrenceSpecificationUtil.isStart(getFigure(), reconnectRequest.getLocation()) ? new NodeTopAnchor(getFigure()) : new NodeBottomAnchor(getFigure());
 			}
 		}
 		// Fixed bug about computing target anchor when creating message sync.
@@ -422,6 +424,8 @@ public abstract class AbstractExecutionSpecificationEditPart extends RoundedComp
 			if (connectionEditPart instanceof MessageReplyEditPart) {
 				// Reply Message
 				return new AnchorHelper.FixedAnchorEx(getFigure(), PositionConstants.BOTTOM);
+			} else if (DurationLinkUtil.isDurationLink(reconnectRequest) || GeneralOrderingUtil.isGeneralOrderingLink(reconnectRequest)) {
+				return OccurrenceSpecificationUtil.isStart(getFigure(), reconnectRequest.getLocation()) ? new NodeTopAnchor(getFigure()) : new NodeBottomAnchor(getFigure());
 			}
 		} else if (request instanceof CreateConnectionViewRequest) {
 			CreateConnectionViewRequest createRequest = (CreateConnectionViewRequest) request;
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractMessageEditPart.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractMessageEditPart.java
index 33e5891bb1a..2d82fef3fdd 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractMessageEditPart.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/AbstractMessageEditPart.java
@@ -419,6 +419,11 @@ public abstract class AbstractMessageEditPart extends UMLConnectionNodeEditPart
 			if (DurationLinkUtil.isDurationLink(createRequest) || GeneralOrderingUtil.isGeneralOrderingLink(createRequest)) {
 				return OccurrenceSpecificationUtil.isSource(getConnectionFigure(), createRequest) ? new ConnectionSourceAnchor(getPrimaryShape()) : new ConnectionTargetAnchor(getPrimaryShape());
 			}
+		} else if (request instanceof ReconnectRequest) {
+			ReconnectRequest reconnectRequest = (ReconnectRequest) request;
+			if (DurationLinkUtil.isDurationLink(reconnectRequest) || GeneralOrderingUtil.isGeneralOrderingLink(reconnectRequest)) {
+				return OccurrenceSpecificationUtil.isSource(getConnectionFigure(), reconnectRequest.getLocation()) ? new ConnectionSourceAnchor(getPrimaryShape()) : new ConnectionTargetAnchor(getPrimaryShape());
+			}
 		}
 		return super.getSourceConnectionAnchor(request);
 	}
@@ -438,6 +443,11 @@ public abstract class AbstractMessageEditPart extends UMLConnectionNodeEditPart
 			if (DurationLinkUtil.isDurationLink(createRequest) || GeneralOrderingUtil.isGeneralOrderingLink(createRequest)) {
 				return OccurrenceSpecificationUtil.isSource(getConnectionFigure(), createRequest) ? new ConnectionSourceAnchor(getPrimaryShape()) : new ConnectionTargetAnchor(getPrimaryShape());
 			}
+		} else if (request instanceof ReconnectRequest) {
+			ReconnectRequest reconnectRequest = (ReconnectRequest) request;
+			if (DurationLinkUtil.isDurationLink(reconnectRequest) || GeneralOrderingUtil.isGeneralOrderingLink(reconnectRequest)) {
+				return OccurrenceSpecificationUtil.isSource(getConnectionFigure(), reconnectRequest.getLocation()) ? new ConnectionSourceAnchor(getPrimaryShape()) : new ConnectionTargetAnchor(getPrimaryShape());
+			}
 		}
 		return super.getTargetConnectionAnchor(request);
 	}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/CDestructionOccurrenceSpecificationEditPart.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/CDestructionOccurrenceSpecificationEditPart.java
index fe1368e481f..05cbf46e2fc 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/CDestructionOccurrenceSpecificationEditPart.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/parts/CDestructionOccurrenceSpecificationEditPart.java
@@ -17,6 +17,7 @@ import java.util.List;
 import org.eclipse.draw2d.ConnectionAnchor;
 import org.eclipse.gef.EditPolicy;
 import org.eclipse.gef.Request;
+import org.eclipse.gef.requests.ReconnectRequest;
 import org.eclipse.gmf.runtime.diagram.ui.requests.CreateConnectionViewRequest;
 import org.eclipse.gmf.runtime.diagram.ui.requests.CreateUnspecifiedTypeConnectionRequest;
 import org.eclipse.gmf.runtime.gef.ui.figures.NodeFigure;
@@ -55,6 +56,11 @@ public class CDestructionOccurrenceSpecificationEditPart extends DestructionOccu
 			if (DurationLinkUtil.isDurationLink(createRequest) || GeneralOrderingUtil.isGeneralOrderingLink(createRequest)) {
 				return new CenterAnchor(getFigure());
 			}
+		} else if (request instanceof ReconnectRequest) {
+			ReconnectRequest reconnectRequest = (ReconnectRequest) request;
+			if (DurationLinkUtil.isDurationLink(reconnectRequest) || GeneralOrderingUtil.isGeneralOrderingLink(reconnectRequest)) {
+				return new CenterAnchor(getFigure());
+			}
 		}
 		return super.getTargetConnectionAnchor(request);
 	}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/policies/OccurenceSemanticEditPolicy.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/policies/OccurenceSemanticEditPolicy.java
new file mode 100644
index 00000000000..d66ae19ab8e
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/policies/OccurenceSemanticEditPolicy.java
@@ -0,0 +1,179 @@
+/*****************************************************************************
+ * Copyright (c) 2018 CEA LIST, EclipseSource and others.
+ *
+ * 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:
+ *   EclipseSource - Initial API and implementation
+ *
+ *****************************************************************************/
+
+package org.eclipse.papyrus.uml.diagram.sequence.edit.policies;
+
+import org.eclipse.draw2d.IFigure;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.transaction.TransactionalEditingDomain;
+import org.eclipse.gef.EditPart;
+import org.eclipse.gef.Request;
+import org.eclipse.gef.commands.Command;
+import org.eclipse.gef.requests.ReconnectRequest;
+import org.eclipse.gmf.runtime.diagram.core.util.ViewUtil;
+import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
+import org.eclipse.gmf.runtime.diagram.ui.editpolicies.SemanticEditPolicy;
+import org.eclipse.gmf.runtime.emf.type.core.requests.ReorientRelationshipRequest;
+import org.eclipse.gmf.runtime.notation.Anchor;
+import org.eclipse.gmf.runtime.notation.Edge;
+import org.eclipse.gmf.runtime.notation.IdentityAnchor;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.infra.emf.utils.EMFHelper;
+import org.eclipse.papyrus.infra.gmfdiag.common.editpolicies.DefaultSemanticEditPolicy;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.AnchorConstants;
+import org.eclipse.papyrus.uml.diagram.sequence.util.GeneralOrderingUtil;
+import org.eclipse.papyrus.uml.diagram.sequence.util.OccurrenceSpecificationUtil;
+import org.eclipse.uml2.uml.ExecutionSpecification;
+import org.eclipse.uml2.uml.Message;
+import org.eclipse.uml2.uml.OccurrenceSpecification;
+
+/**
+ * A {@link SemanticEditPolicy} that is able to target specific {@link OccurrenceSpecification}s
+ * from a request (Typically for {@link Message#getSendEvent()},{@link Message#getReceiveEvent()},
+ * {@link ExecutionSpecification#getStart()} and {@link ExecutionSpecification#getFinish()})
+ */
+public class OccurenceSemanticEditPolicy extends DefaultSemanticEditPolicy {
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * <p>
+	 * Overridden to support {@link ReconnectRequest}, when only the anchor changes, referencing
+	 * a different {@link OccurrenceSpecification} on the same edit part.
+	 * </p>
+	 *
+	 * @param request
+	 * @return
+	 */
+	@Override
+	public Command getCommand(Request request) {
+		if (REQ_RECONNECT_SOURCE.equals(request.getType())
+				&& relationshipSourceHasChanged((ReconnectRequest) request)) {
+			EditPart connectionEP = ((ReconnectRequest) request)
+					.getConnectionEditPart();
+			if (ViewUtil.resolveSemanticElement((View) connectionEP.getModel()) == null) {
+				return getReorientRefRelationshipSourceCommand((ReconnectRequest) request);
+			} else {
+				return getReorientRelationshipSourceCommand((ReconnectRequest) request);
+			}
+		} else if (REQ_RECONNECT_TARGET.equals(request.getType())
+				&& relationshipTargetHasChanged((ReconnectRequest) request)) {
+			EditPart connectionEP = ((ReconnectRequest) request)
+					.getConnectionEditPart();
+			if (ViewUtil.resolveSemanticElement((View) connectionEP.getModel()) == null) {
+				return getReorientRefRelationshipTargetCommand((ReconnectRequest) request);
+			} else {
+				return getReorientRelationshipTargetCommand((ReconnectRequest) request);
+			}
+		}
+		return super.getCommand(request);
+	}
+
+	protected boolean relationshipSourceHasChanged(ReconnectRequest request) {
+		return getSourceOccurrence((Edge) request.getConnectionEditPart().getModel()) != getOccurrence(request);
+	}
+
+	protected boolean relationshipTargetHasChanged(ReconnectRequest request) {
+		return getTargetOccurrence((Edge) request.getConnectionEditPart().getModel()) != getOccurrence(request);
+	}
+
+	@Override
+	protected Command getReorientRelationshipSourceCommand(ReconnectRequest request) {
+		if (GeneralOrderingUtil.isGeneralOrderingLink(request)) {
+			EObject connectionSemElement = ViewUtil.resolveSemanticElement(((View) request.getConnectionEditPart()
+					.getModel()));
+			EObject targetSemElement = getOccurrence(request);
+			EObject oldSemElement = getSourceOccurrence((Edge) request.getConnectionEditPart().getModel());
+
+			TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
+					.getEditingDomain();
+			ReorientRelationshipRequest semRequest = new ReorientRelationshipRequest(
+					editingDomain, connectionSemElement, targetSemElement,
+					oldSemElement, ReorientRelationshipRequest.REORIENT_SOURCE);
+
+			semRequest.addParameters(request.getExtendedData());
+
+			return getSemanticCommand(semRequest);
+		}
+
+		return super.getReorientRefRelationshipSourceCommand(request);
+	}
+
+	@Override
+	protected Command getReorientRelationshipTargetCommand(ReconnectRequest request) {
+		if (GeneralOrderingUtil.isGeneralOrderingLink(request)) {
+			EObject connectionSemElement = ViewUtil.resolveSemanticElement((View) request.getConnectionEditPart().getModel());
+			EObject targetSemElement = getOccurrence(request);
+			EObject oldSemElement = getTargetOccurrence((Edge) request.getConnectionEditPart().getModel());
+
+			TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
+					.getEditingDomain();
+			ReorientRelationshipRequest semRequest = new ReorientRelationshipRequest(
+					editingDomain, connectionSemElement, targetSemElement,
+					oldSemElement, ReorientRelationshipRequest.REORIENT_TARGET);
+
+			semRequest.addParameters(request.getExtendedData());
+
+			return getSemanticCommand(semRequest);
+		}
+
+		return super.getReorientRelationshipTargetCommand(request);
+	}
+
+	private EObject getOccurrence(ReconnectRequest request) {
+		EObject element = EMFHelper.getEObject(request.getTarget());
+		IFigure targetFigure = ((IGraphicalEditPart) request.getTarget()).getFigure();
+		if (element instanceof Message) {
+			if (OccurrenceSpecificationUtil.isSource(targetFigure, request.getLocation())) {
+				return ((Message) element).getSendEvent();
+			} else {
+				return ((Message) element).getReceiveEvent();
+			}
+		} else if (element instanceof ExecutionSpecification) {
+			if (OccurrenceSpecificationUtil.isStart(targetFigure, request.getLocation())) {
+				return ((ExecutionSpecification) element).getStart();
+			} else {
+				return ((ExecutionSpecification) element).getFinish();
+			}
+		}
+		return element;
+	}
+
+	private EObject getTargetOccurrence(Edge connection) {
+		return getOccurrence(connection.getTargetAnchor(), connection.getTarget());
+	}
+
+	private EObject getSourceOccurrence(Edge connection) {
+		return getOccurrence(connection.getSourceAnchor(), connection.getSource());
+	}
+
+	private EObject getOccurrence(Anchor anchor, View targetElement) {
+		String anchorId = ((IdentityAnchor) anchor).getId();
+		EObject element = targetElement.getElement();
+		if (AnchorConstants.END_TERMINAL.equals(anchorId)) {
+			if (element instanceof Message) {
+				return ((Message) element).getReceiveEvent();
+			} else if (element instanceof ExecutionSpecification) {
+				return ((ExecutionSpecification) element).getFinish();
+			}
+		} else if (AnchorConstants.START_TERMINAL.equals(anchorId)) {
+			if (element instanceof Message) {
+				return ((Message) element).getSendEvent();
+			} else if (element instanceof ExecutionSpecification) {
+				return ((ExecutionSpecification) element).getStart();
+			}
+		}
+		return null;
+	}
+
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/referencialgrilling/LifeLineGraphicalNodeEditPolicy.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/referencialgrilling/LifeLineGraphicalNodeEditPolicy.java
index 35c932164d8..40a47ae6d23 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/referencialgrilling/LifeLineGraphicalNodeEditPolicy.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/referencialgrilling/LifeLineGraphicalNodeEditPolicy.java
@@ -701,7 +701,7 @@ public class LifeLineGraphicalNodeEditPolicy extends DefaultGraphicalNodeEditPol
 
 		// Check if the target is lower than the source
 		Point sourceLocation = SequenceUtil.getAbsoluteEdgeExtremity((ConnectionNodeEditPart) request.getConnectionEditPart(), true);
-		if (!isTargetLowerThanSource(sourceLocation, request.getLocation().getCopy())) {
+		if (sourceLocation != null && !isTargetLowerThanSource(sourceLocation, request.getLocation().getCopy())) {
 			Object object = request.getExtendedData().get(SequenceUtil.DO_NOT_CHECK_HORIZONTALITY);
 			if (!(object instanceof Boolean) || ((object instanceof Boolean) && !((Boolean) object))) {// If not HorizontalMove parameter true
 				return UnexecutableCommand.INSTANCE;
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationMoveHelper.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationMoveHelper.java
index 064a0d2dacc..2fd7d82d01b 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationMoveHelper.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationMoveHelper.java
@@ -129,17 +129,6 @@ public class OccurrenceSpecificationMoveHelper {
 		if (command != null) {
 			globalCmd.add(command);
 		}
-		// reconnect the corresponding general ordering(s) if necessary
-		command = getReconnectGeneralOrderingCommand(movedOccurrenceSpecification1, yLocation1, lifelinePart, notToMoveEditParts);
-		if (command != null) {
-			globalCmd.add(command);
-		}
-		if (movedOccurrenceSpecification2 != null) {
-			command = getReconnectGeneralOrderingCommand(movedOccurrenceSpecification2, yLocation2, lifelinePart, notToMoveEditParts);
-			if (command != null) {
-				globalCmd.add(command);
-			}
-		}
 		// return null rather than an empty non executable command
 		if (globalCmd.isEmpty()) {
 			return null;
@@ -148,75 +137,6 @@ public class OccurrenceSpecificationMoveHelper {
 	}
 
 	/**
-	 * Get the command to reconnect general ordering attached to a moved occurrence specification
-	 *
-	 * @param movedOccurrenceSpecification
-	 *            moving occurrence specification
-	 * @param yLocation
-	 *            y location where occurrence specification is moved
-	 * @param lifelinePart
-	 *            lifeline edit part containing the moved element
-	 * @param notToMoveEditParts
-	 *            list of edit parts which must not be moved in the created command
-	 * @return command to reconnect general ordering edit parts linked to the occurrence specification or null
-	 */
-	private static Command getReconnectGeneralOrderingCommand(OccurrenceSpecification movedOccurrenceSpecification, int yLocation, LifelineEditPart lifelinePart, List<EditPart> notToMoveEditParts) {
-		// the global command which shall be completed and returned
-		CompoundCommand command = new CompoundCommand();
-		Point referencePoint = getReferencePoint(lifelinePart, movedOccurrenceSpecification, yLocation);
-		EditPart childToReconnectTo = SequenceUtil.findPartToReconnectTo(lifelinePart, referencePoint);
-		// if referencePoint is on a moved part, it must be translated with the location delta of this part
-		if (!notToMoveEditParts.isEmpty() && childToReconnectTo != lifelinePart) {
-			Point oldLoc = SequenceUtil.findLocationOfEvent(lifelinePart, movedOccurrenceSpecification);
-			if (oldLoc == null) {
-				return null;
-			}
-			referencePoint.y = oldLoc.y;
-		}
-		// reconnect general ordering from the event
-		for (GeneralOrdering go : movedOccurrenceSpecification.getToAfters()) {
-			Collection<Setting> settings = CacheAdapter.getInstance().getNonNavigableInverseReferences(go);
-			for (Setting ref : settings) {
-				if (NotationPackage.eINSTANCE.getView_Element().equals(ref.getEStructuralFeature())) {
-					View view = (View) ref.getEObject();
-					EditPart part = DiagramEditPartsUtil.getEditPartFromView(view, lifelinePart);
-					// the general ordering part must start or finish on the lifeline (with the event)
-					if (part instanceof ConnectionEditPart && !notToMoveEditParts.contains(part)) {
-						Request reconnectRequest = makeReconnectRequest((ConnectionEditPart) part, true, referencePoint, childToReconnectTo);
-						Command reconnect = childToReconnectTo.getCommand(reconnectRequest);
-						if (reconnect.canExecute()) {
-							command.add(reconnect);
-						}
-					}
-				}
-			}
-		}
-		// reconnect general ordering to the event
-		for (GeneralOrdering go : movedOccurrenceSpecification.getToBefores()) {
-			Collection<Setting> settings = CacheAdapter.getInstance().getNonNavigableInverseReferences(go);
-			for (Setting ref : settings) {
-				if (NotationPackage.eINSTANCE.getView_Element().equals(ref.getEStructuralFeature())) {
-					View view = (View) ref.getEObject();
-					EditPart part = DiagramEditPartsUtil.getEditPartFromView(view, lifelinePart);
-					// the general ordering part must start or finish on the lifeline (with the event)
-					if (part instanceof ConnectionEditPart && !notToMoveEditParts.contains(part)) {
-						Request reconnectRequest = makeReconnectRequest((ConnectionEditPart) part, false, referencePoint, childToReconnectTo);
-						Command reconnect = childToReconnectTo.getCommand(reconnectRequest);
-						if (reconnect.canExecute()) {
-							command.add(reconnect);
-						}
-					}
-				}
-			}
-		}
-		// return null rather than an empty non executable command
-		if (command.isEmpty()) {
-			return null;
-		}
-		return command;
-	}
-
-	/**
 	 * Get the command to reconnect message attached to a moved occurrence specification
 	 *
 	 * @param movedOccurrenceSpecification
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationUtil.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationUtil.java
index 46c9bb2f8fb..64e288b16e5 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationUtil.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/OccurrenceSpecificationUtil.java
@@ -20,6 +20,7 @@ import org.eclipse.draw2d.geometry.PointList;
 import org.eclipse.draw2d.geometry.Rectangle;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.gef.EditPart;
+import org.eclipse.gef.Request;
 import org.eclipse.gef.requests.CreateConnectionRequest;
 import org.eclipse.gef.requests.CreateRequest;
 import org.eclipse.gmf.runtime.diagram.core.edithelpers.CreateElementRequestAdapter;
@@ -73,12 +74,23 @@ public class OccurrenceSpecificationUtil {
 	 * 		<code>true</code> if the given request is closer to the top of the figure; false if it is closer to the bottom
 	 */
 	public static boolean isStart(IFigure targetFigure, CreateRequest createRequest) {
-		Point location = createRequest.getLocation();
+		return isStart(targetFigure, createRequest.getLocation());
+	}
+
+	/**
+	 * Test whether the given request is closer to the start (top) or to the finish (bottom) point of the execution specification
+	 *
+	 * @param Point
+	 *            The current request location
+	 * @return
+	 * 		<code>true</code> if the given request is closer to the top of the figure; false if it is closer to the bottom
+	 */
+	public static boolean isStart(IFigure targetFigure, Point requestLocation) {
 		Rectangle bounds = targetFigure.getBounds().getCopy();
 		targetFigure.translateToAbsolute(bounds);
 
-		double distanceToTop = location.getDistance(bounds.getTop());
-		double distanceToBottom = location.getDistance(bounds.getBottom());
+		double distanceToTop = requestLocation.getDistance(bounds.getTop());
+		double distanceToBottom = requestLocation.getDistance(bounds.getBottom());
 		return distanceToTop < distanceToBottom;
 	}
 
@@ -93,15 +105,28 @@ public class OccurrenceSpecificationUtil {
 	 * 		<code>true</code> if the given request is closer to the source of the connection; false if it is closer to the target
 	 */
 	public static boolean isSource(IFigure targetFigure, CreateRequest createRequest) {
-		Point location = createRequest.getLocation();
+		return isSource(targetFigure, createRequest.getLocation());
+	}
+
+	/**
+	 * Test whether the given request is closer to the source or to the target point of the message
+	 *
+	 * @param targetFigure
+	 *            The connection figure representing the message
+	 * @param requestLocation
+	 *            The mouse location for the current {@link Request}
+	 * @return
+	 * 		<code>true</code> if the given request is closer to the source of the connection; false if it is closer to the target
+	 */
+	public static boolean isSource(IFigure targetFigure, Point requestLocation) {
 		IFigure connection = targetFigure;
 		if (connection instanceof Connection) {
 			PointList points = ((Connection) connection).getPoints();
 			if (points.size() >= 2) {
 				Point source = points.getFirstPoint();
 				Point target = points.getLastPoint();
-				double distanceToSource = location.getDistance(source);
-				double distanceToTarget = location.getDistance(target);
+				double distanceToSource = requestLocation.getDistance(source);
+				double distanceToTarget = requestLocation.getDistance(target);
 				return distanceToSource < distanceToTarget;
 			}
 		}
@@ -112,7 +137,6 @@ public class OccurrenceSpecificationUtil {
 	}
 
 
-
 	/**
 	 * Find the semantic {@link OccurrenceSpecification} represented by the given <code>connectorEnd</code>.
 	 * The connector should be the source or target of a DurationLink connector.