[475580] Avoid CCE in interpreted expression completion

Use IStructuredSelected instead of the overly specific TreeSelection,
and actually check the runtime instance before casting.

Bug: 475580
Change-Id: I45e0f26977231cb7a3dd622da0fffce86ea676c2
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>

1 files changed, 3 insertions, 3 deletions

diff --git a/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/tools/api/assist/TextContentProposalProvider.java b/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/tools/api/assist/TextContentProposalProvider.java
index 49065da436..5845c690d8 100644
--- a/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/tools/api/assist/TextContentProposalProvider.java
+++ b/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/tools/api/assist/TextContentProposalProvider.java
@@ -18,7 +18,7 @@ import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.jface.fieldassist.ContentProposalAdapter;
 import org.eclipse.jface.fieldassist.IContentProposal;
-import org.eclipse.jface.viewers.TreeSelection;
+import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.sirius.common.tools.api.contentassist.ContentContext;
 import org.eclipse.sirius.common.tools.api.contentassist.ContentProposal;
 import org.eclipse.sirius.common.tools.api.interpreter.CompoundInterpreter;
@@ -105,8 +105,8 @@ public class TextContentProposalProvider implements IAssistContentProvider {
     }
 
     private Object getSelectedElement() {
-        if (element == null && view != null) {
-            return ((TreeSelection) view.getSelection()).getFirstElement();
+        if (element == null && view != null && view.getSelection() instanceof IStructuredSelection) {
+            return ((IStructuredSelection) view.getSelection()).getFirstElement();
         } else {
             return element;
         }