Bug 536638: [Sequence Diagram] Provide OccurrenceSpecification Anchors

for Durations
https://bugs.eclipse.org/bugs/show_bug.cgi?id=536638

- Add anchors for ExecutionSpecifications and Messages

Change-Id: I99ebf56afa8ca4d433c18e7ba7d4dfc9b406c180
Signed-off-by: Camille Letavernier <cletavernier@eclipsesource.com>

11 files changed, 312 insertions, 3 deletions

diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/FixAnchorHelper.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/FixAnchorHelper.java
index 0b61105bbcc..e2ab8201b1d 100755
--- a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/FixAnchorHelper.java
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/FixAnchorHelper.java
@@ -19,6 +19,7 @@ import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.draw2d.AbstractPointListShape;
+import org.eclipse.draw2d.Connection;
 import org.eclipse.draw2d.ConnectionAnchor;
 import org.eclipse.draw2d.IFigure;
 import org.eclipse.draw2d.PositionConstants;
@@ -36,6 +37,7 @@ import org.eclipse.gmf.runtime.common.core.command.CommandResult;
 import org.eclipse.gmf.runtime.common.core.command.ICommand;
 import org.eclipse.gmf.runtime.diagram.ui.commands.ICommandProxy;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.INodeEditPart;
+import org.eclipse.gmf.runtime.draw2d.ui.figures.BaseSlidableAnchor;
 import org.eclipse.gmf.runtime.draw2d.ui.figures.PolylineConnectionEx;
 import org.eclipse.gmf.runtime.emf.commands.core.command.AbstractTransactionalCommand;
 import org.eclipse.gmf.runtime.gef.ui.figures.NodeFigure;
@@ -139,6 +141,22 @@ public class FixAnchorHelper {
 	protected Point getRealAnchorPoint(final AbstractConnectionEditPart edgeEP, final boolean sourcePoint) {
 		final IFigure figure = edgeEP.getFigure();
 		Point point = null;
+		if (figure instanceof Connection) {
+			// Bug 536638: We now have specific Anchors that are dynamically computed, and not based on a X/Y Ratio
+			// We *don't* want to "fix" these!
+			Connection connection = (Connection) figure;
+			if (sourcePoint && connection.getSourceAnchor() != null) {
+				ConnectionAnchor sourceAnchor = connection.getSourceAnchor();
+				if (false == sourceAnchor instanceof BaseSlidableAnchor) {
+					return null;
+				}
+			} else if (!sourcePoint && connection.getTargetAnchor() != null) {
+				ConnectionAnchor targetAnchor = connection.getTargetAnchor();
+				if (false == targetAnchor instanceof BaseSlidableAnchor) {
+					return null;
+				}
+			}
+		}
 		if (figure instanceof AbstractPointListShape) {
 			if (sourcePoint) {
 				point = ((AbstractPointListShape) figure).getStart().getCopy();
@@ -343,12 +361,12 @@ public class FixAnchorHelper {
 
 	/**
 	 * Return the side of the point on the included Rectangle
-	 * 
+	 *
 	 * @since 3.1
 	 * @param pt
 	 *            Point with absolute position
 	 * @return integer representing the position from PositionConstants.
-	 * 
+	 *
 	 */
 	protected int getSideFromRectangle(Point pt) {
 		while (getIncludedRect().contains(pt)) {
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/AnchorConstants.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/AnchorConstants.java
new file mode 100644
index 00000000000..fe9339c31b0
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/AnchorConstants.java
@@ -0,0 +1,72 @@
+/*****************************************************************************
+ * 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.anchors;
+
+import org.eclipse.draw2d.IFigure;
+import org.eclipse.uml2.uml.DestructionOccurrenceSpecification;
+import org.eclipse.uml2.uml.ExecutionSpecification;
+import org.eclipse.uml2.uml.Message;
+
+/**
+ * Constants class for Anchors
+ */
+public final class AnchorConstants {
+	private AnchorConstants() {
+		// Constants class; no instance
+	}
+
+	/**
+	 * <p>
+	 * The Anchor Terminal for an Anchor at the start/beginning of an element.
+	 * </p>
+	 *
+	 * <p>
+	 * This anchor represents a single point (Which depends on the anchorage {@link IFigure}), without any parameter.
+	 * </p>
+	 *
+	 * <p>
+	 * This anchor may represent, for example, the start of an {@link ExecutionSpecification}, or the source Send Event of a {@link Message}
+	 * </p>
+	 */
+	public static final String START_TERMINAL = "start";
+
+	/**
+	 * <p>
+	 * The Anchor Terminal for an Anchor at the finish/end of an element.
+	 * </p>
+	 *
+	 * <p>
+	 * This anchor represents a single point (Which depends on the anchorage {@link IFigure}), without any parameter.
+	 * </p>
+	 *
+	 * <p>
+	 * This anchor may represent, for example, the finish of an {@link ExecutionSpecification}, or the target Receive Event of a {@link Message}
+	 * </p>
+	 */
+	public static final String END_TERMINAL = "end";
+
+	/**
+	 * <p>
+	 * The Anchor Terminal for an Anchor at the center of an element.
+	 * </p>
+	 *
+	 * <p>
+	 * This anchor represents a single point (Which depends on the anchorage {@link IFigure}), without any parameter.
+	 * </p>
+	 *
+	 * <p>
+	 * This anchor typically represents the center of the X in a {@link DestructionOccurrenceSpecification}
+	 * </p>
+	 */
+	public static final String CENTER_TERMINAL = "center";
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/CenterAnchor.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/CenterAnchor.java
new file mode 100644
index 00000000000..be94663a889
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/CenterAnchor.java
@@ -0,0 +1,36 @@
+/*****************************************************************************
+ * 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.anchors;
+
+import org.eclipse.draw2d.AbstractConnectionAnchor;
+import org.eclipse.draw2d.IFigure;
+import org.eclipse.draw2d.geometry.Point;
+import org.eclipse.uml2.uml.DestructionOccurrenceSpecification;
+
+/**
+ * An anchor to the center of an element (Typically a {@link DestructionOccurrenceSpecification})
+ */
+public class CenterAnchor extends AbstractConnectionAnchor {
+
+	public CenterAnchor(IFigure anchorage) {
+		super(anchorage);
+	}
+
+	@Override
+	public Point getLocation(Point reference) {
+		Point center = getOwner().getBounds().getCenter().getCopy();
+		getOwner().translateToAbsolute(center);
+		return center;
+	}
+
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/ConnectionSourceAnchor.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/ConnectionSourceAnchor.java
new file mode 100644
index 00000000000..6da15ce29b3
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/ConnectionSourceAnchor.java
@@ -0,0 +1,38 @@
+/*****************************************************************************
+ * 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.anchors;
+
+import org.eclipse.draw2d.AbstractConnectionAnchor;
+import org.eclipse.draw2d.PolylineConnection;
+import org.eclipse.draw2d.geometry.Point;
+
+/**
+ * Anchors a Connection to the source of a {@link PolylineConnection} (Typically the sendEvent of a Message)
+ */
+public class ConnectionSourceAnchor extends AbstractConnectionAnchor {
+
+	private final PolylineConnection anchorage;
+
+	public ConnectionSourceAnchor(PolylineConnection anchorage) {
+		super(anchorage);
+		this.anchorage = anchorage;
+	}
+
+	@Override
+	public Point getLocation(Point reference) {
+		Point source = anchorage.getStart().getCopy();
+		anchorage.translateToAbsolute(source);
+		return source;
+	}
+
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/ConnectionTargetAnchor.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/ConnectionTargetAnchor.java
new file mode 100644
index 00000000000..eeea63e49b6
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/ConnectionTargetAnchor.java
@@ -0,0 +1,39 @@
+/*****************************************************************************
+ * 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.anchors;
+
+import org.eclipse.draw2d.AbstractConnectionAnchor;
+import org.eclipse.draw2d.PolylineConnection;
+import org.eclipse.draw2d.geometry.Point;
+
+
+/**
+ * Anchors a Connection to the target of a {@link PolylineConnection} (Typically the receiveEvent of a Message)
+ */
+public class ConnectionTargetAnchor extends AbstractConnectionAnchor {
+
+	private final PolylineConnection anchorage;
+
+	public ConnectionTargetAnchor(PolylineConnection anchorage) {
+		super(anchorage);
+		this.anchorage = anchorage;
+	}
+
+	@Override
+	public Point getLocation(Point reference) {
+		Point target = anchorage.getEnd().getCopy();
+		anchorage.translateToAbsolute(target);
+		return target;
+	}
+
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/NodeBottomAnchor.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/NodeBottomAnchor.java
new file mode 100644
index 00000000000..efd72365047
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/NodeBottomAnchor.java
@@ -0,0 +1,36 @@
+/*****************************************************************************
+ * 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.anchors;
+
+import org.eclipse.draw2d.AbstractConnectionAnchor;
+import org.eclipse.draw2d.IFigure;
+import org.eclipse.draw2d.geometry.Point;
+
+/**
+ * Anchors a Connection to the Bottom-Center point of a Node (Typically the finish of an Execution Specification)
+ */
+public class NodeBottomAnchor extends AbstractConnectionAnchor {
+
+	public NodeBottomAnchor(IFigure anchorage) {
+		super(anchorage);
+	}
+
+	@Override
+	public Point getLocation(Point reference) {
+		IFigure owner = getOwner();
+		Point bottom = owner.getBounds().getBottom().getCopy();
+		owner.translateToAbsolute(bottom);
+		return bottom;
+	}
+
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/NodeTopAnchor.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/NodeTopAnchor.java
new file mode 100644
index 00000000000..f11b1fdc436
--- /dev/null
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/anchors/NodeTopAnchor.java
@@ -0,0 +1,36 @@
+/*****************************************************************************
+ * 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.anchors;
+
+import org.eclipse.draw2d.AbstractConnectionAnchor;
+import org.eclipse.draw2d.IFigure;
+import org.eclipse.draw2d.geometry.Point;
+
+/**
+ * Anchors a Connection to the Top-Center point of a Node (Typically the start of an Execution Specification)
+ */
+public class NodeTopAnchor extends AbstractConnectionAnchor {
+
+	public NodeTopAnchor(IFigure anchorage) {
+		super(anchorage);
+	}
+
+	@Override
+	public Point getLocation(Point reference) {
+		IFigure owner = getOwner();
+		Point top = owner.getBounds().getTop().getCopy();
+		owner.translateToAbsolute(top);
+		return top;
+	}
+
+}
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/DurationLinkFigure.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/DurationLinkFigure.java
index babfbb5dfd0..d3063197edd 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/DurationLinkFigure.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/DurationLinkFigure.java
@@ -14,6 +14,7 @@
 package org.eclipse.papyrus.uml.diagram.sequence.figures;
 
 import org.eclipse.draw2d.ColorConstants;
+import org.eclipse.draw2d.ConnectionRouter;
 import org.eclipse.draw2d.Graphics;
 import org.eclipse.draw2d.PolylineConnection;
 import org.eclipse.draw2d.PolylineDecoration;
@@ -189,7 +190,7 @@ public class DurationLinkFigure extends UMLEdgeFigure {
 	public boolean containsPoint(int x, int y) {
 		Rectangle topLine = new Rectangle(getStart(), getTopLineEnd());
 		topLine.expand(SELECTION_TOLERANCE, SELECTION_TOLERANCE);
-		if (topLine.contains(x, y)){
+		if (topLine.contains(x, y)) {
 			return true;
 		}
 
@@ -233,6 +234,11 @@ public class DurationLinkFigure extends UMLEdgeFigure {
 		return bounds;
 	}
 
+	@Override
+	public void setConnectionRouter(ConnectionRouter cr) {
+		// Skip; this figure doesn't support routers/bendpoints
+	}
+
 	/**
 	 * <p>
 	 * Set the orientation of the arrow (Orientation#VERTICAL or Orientation#HORIZONTAL).
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/ExecutionSpecificationNodePlate.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/ExecutionSpecificationNodePlate.java
index 48d512dc7b6..3a6c01fd127 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/ExecutionSpecificationNodePlate.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/ExecutionSpecificationNodePlate.java
@@ -18,6 +18,9 @@ import org.eclipse.draw2d.PositionConstants;
 import org.eclipse.draw2d.geometry.PrecisionPoint;
 import org.eclipse.gef.GraphicalEditPart;
 import org.eclipse.papyrus.infra.gmfdiag.common.figure.node.LinkLFSVGNodePlateFigure;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.AnchorConstants;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.NodeBottomAnchor;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.NodeTopAnchor;
 import org.eclipse.papyrus.uml.diagram.sequence.edit.helpers.AnchorHelper;
 
 /**
@@ -46,6 +49,12 @@ public class ExecutionSpecificationNodePlate extends LinkLFSVGNodePlateFigure im
 
 	@Override
 	public ConnectionAnchor getConnectionAnchor(String terminal) {
+		if (AnchorConstants.START_TERMINAL.equals(terminal)) {
+			return new NodeTopAnchor(this);
+		} else if (AnchorConstants.END_TERMINAL.equals(terminal)) {
+			return new NodeBottomAnchor(this);
+		}
+
 		// Use FixedAnchorEx for MessageSync, this will be invoked by mapConnectionAnchor(termial) operation.
 		if (terminal != null && terminal.indexOf("{") != -1 && terminal.indexOf("}") != -1) {
 			int position = AnchorHelper.FixedAnchorEx.parsePosition(terminal);
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/MessageFigure.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/MessageFigure.java
index 41a0026f7f1..f4754c4d938 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/MessageFigure.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/figures/MessageFigure.java
@@ -14,6 +14,7 @@
 package org.eclipse.papyrus.uml.diagram.sequence.figures;
 
 import org.eclipse.draw2d.ColorConstants;
+import org.eclipse.draw2d.ConnectionAnchor;
 import org.eclipse.draw2d.RotatableDecoration;
 import org.eclipse.draw2d.Shape;
 import org.eclipse.gmf.runtime.draw2d.ui.figures.WrappingLabel;
@@ -21,6 +22,9 @@ import org.eclipse.gmf.runtime.draw2d.ui.mapmode.IMapMode;
 import org.eclipse.gmf.runtime.draw2d.ui.mapmode.MapModeUtil;
 import org.eclipse.papyrus.infra.gmfdiag.common.figure.node.PapyrusWrappingLabel;
 import org.eclipse.papyrus.uml.diagram.common.figure.edge.UMLEdgeFigure;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.AnchorConstants;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.ConnectionSourceAnchor;
+import org.eclipse.papyrus.uml.diagram.sequence.anchors.ConnectionTargetAnchor;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Cursor;
@@ -178,4 +182,15 @@ public abstract class MessageFigure extends UMLEdgeFigure {
 	public void setMapMode(IMapMode mapMode) {
 		this.mapMode = mapMode;
 	}
+
+
+	@Override
+	public ConnectionAnchor getConnectionAnchor(String terminal) {
+		if (AnchorConstants.START_TERMINAL.equals(terminal)) {
+			return new ConnectionSourceAnchor(this);
+		} else if (AnchorConstants.END_TERMINAL.equals(terminal)) {
+			return new ConnectionTargetAnchor(this);
+		}
+		return super.getConnectionAnchor(terminal);
+	}
 }
diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/SequenceUtil.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/SequenceUtil.java
index b83f8c5bfc7..079c6f0707f 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/SequenceUtil.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/util/SequenceUtil.java
@@ -531,6 +531,10 @@ public class SequenceUtil {
 				// get position from anchor id
 				String oldTerminal = ((IdentityAnchor) idAnchor).getId();
 				PrecisionPoint pp = BaseSlidableAnchor.parseTerminalString(oldTerminal);
+				if (pp == null) {
+					// Not a BaseSlidableAnchor
+					return null;
+				}
 				if (pp.preciseX() <= 1 && pp.preciseX() >= 0 && pp.preciseY() >= 0 && pp.preciseY() <= 1) {
 					int xPos = linkedPartBounds.x + delta.width + (int) Math.round(anchorOwningFigure.getBounds().width * pp.preciseX());
 					int yPos = linkedPartBounds.y + delta.height + (int) Math.round(anchorOwningFigure.getBounds().height * pp.preciseY());