[527109] Fix potential class cast exception and test failure

Bug: 527109
Change-Id: I16fd40d4b0b44df86d298b23d8fd3bdbddbe4a90
Signed-off-by: Pierre Guilet <pierre.guilet@obeo.fr>

1 files changed, 12 insertions, 10 deletions

diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/ui/NoCopyDragEditPartsTrackerEx.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/ui/NoCopyDragEditPartsTrackerEx.java
index 9e2bcc6d2f..422b0c8bee 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/ui/NoCopyDragEditPartsTrackerEx.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/ui/NoCopyDragEditPartsTrackerEx.java
@@ -93,16 +93,18 @@ public class NoCopyDragEditPartsTrackerEx extends SnapToAllDragEditPartsTracker
     private boolean isAuthorized() {
         boolean isAuthorized = true;
         EditPart movedEditPart = getSourceEditPart();
-        EditPartQuery editPartQuery = new EditPartQuery((AbstractBorderedDiagramElementEditPart) movedEditPart);
-        if (movedEditPart instanceof AbstractBorderedDiagramElementEditPart && (editPartQuery.isInShowingMode() || editPartQuery.isInLayoutingMode())) {
-            // We are in layouting mode
-            EditPart targetEditPart = getTargetEditPart();
-            // Check if the target container is not the same as before move
-            boolean notSameContainer = targetEditPart != null
-                    && !(movedEditPart.getParent() == targetEditPart || targetEditPart instanceof CompartmentEditPart && targetEditPart.getParent() == movedEditPart.getParent());
-            notSameContainer = notSameContainer && (targetEditPart instanceof IGraphicalEditPart && ((IGraphicalEditPart) targetEditPart).resolveSemanticElement() instanceof DSemanticDecorator);
-            if (notSameContainer) {
-                isAuthorized = false;
+        if (movedEditPart instanceof AbstractBorderedDiagramElementEditPart) {
+            EditPartQuery editPartQuery = new EditPartQuery((IGraphicalEditPart) movedEditPart);
+            if (editPartQuery.isInShowingMode() || editPartQuery.isInLayoutingMode()) {
+                // We are in layouting mode
+                EditPart targetEditPart = getTargetEditPart();
+                // Check if the target container is not the same as before move
+                boolean notSameContainer = targetEditPart != null
+                        && !(movedEditPart.getParent() == targetEditPart || targetEditPart instanceof CompartmentEditPart && targetEditPart.getParent() == movedEditPart.getParent());
+                notSameContainer = notSameContainer && (targetEditPart instanceof IGraphicalEditPart && ((IGraphicalEditPart) targetEditPart).resolveSemanticElement() instanceof DSemanticDecorator);
+                if (notSameContainer) {
+                    isAuthorized = false;
+                }
             }
         }
         return isAuthorized;