- Since partClosed() is triggered when any IWorkBenchPart is closed, the...

- Since partClosed() is triggered when any IWorkBenchPart is closed, the current implementation erroneously removes the EditorActivationListener even if any other view but the "Model Elements" view is closed.
- Hence, use a different approach and in partActivated() check, if the LibraryView's TreeViewer control is disposed

org.fortiss.tooling.kernel.ui/trunk/src/org/fortiss/tooling/kernel/ui/internal/views/LibraryView.java

@@ -35,6 +35,7 @@ import org.eclipse.swt.SWT;
 import org.eclipse.swt.dnd.Transfer;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Control;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IWorkbenchPart;
 import org.eclipse.ui.dialogs.FilteredTree;
@@ -58,7 +59,7 @@ import org.fortiss.tooling.kernel.ui.service.IModelElementHandlerService;
  * @author eder
  * @author $Author: hoelzl $
  * @version $Rev: 18709 $
- * @ConQAT.Rating YELLOW Hash: BE8E3D97227DDE47F53B4B956DD07B7E
+ * @ConQAT.Rating YELLOW Hash: 32812CD7C455CF4BD58FB5653785E326
  */
 public class LibraryView extends ViewPart {
 
@@ -262,16 +263,14 @@ public class LibraryView extends ViewPart {
 				return;
 			}
 
+			Control control = viewer.getControl();
+			if(control == null || control.isDisposed()) {
+				return;
+			}
+
 			IEditorPart part = (IEditorPart)workbenchPart;
 			viewer.setInput(IPrototypeService.INSTANCE.getAllTopLevelPrototypesCategories());
 			switchWorkbenchEditor(part);
 		}
-
-		/** {@inheritDoc} */
-		@Override
-		public void partClosed(IWorkbenchPart part) {
-			getSite().getWorkbenchWindow().getPartService()
-					.removePartListener(editorActivationListener);
-		}
 	}
 }