[cleanup] Avoid NPE during platform shutdownv1.0.0rc1

Change-Id: Idee97760ce975d69b4362f70a2263cb1b7bb7b07
Signed-off-by: Maxime PORHEL <maxime.porhel@obeo.fr>

1 files changed, 15 insertions, 2 deletions

diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/editor/tabbar/TabbarToolBarManager.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/editor/tabbar/TabbarToolBarManager.java
index ccd3408c1a..7edb2d4180 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/editor/tabbar/TabbarToolBarManager.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/editor/tabbar/TabbarToolBarManager.java
@@ -26,6 +26,7 @@ import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.ToolBar;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchPart;
+import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.actions.ActionFactory.IWorkbenchAction;
 import org.eclipse.ui.forms.FormColors;
@@ -81,17 +82,29 @@ public class TabbarToolBarManager extends ToolBarManager {
 
     @Override
     public void update(boolean force) {
-        IWorkbenchPage activePage = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
-        if (activePage != null && tabbarPart instanceof DDiagramEditor && activePage.getActivePart() != tabbarPart) {
+        IWorkbenchPage activePage = getSafeActivePage();
+        if (activePage == null) {
+            // No active page -> return.
+            return;
+        } else if (tabbarPart instanceof DDiagramEditor && activePage.getActivePart() != tabbarPart) {
             if (getControl().getItems().length > 0) {
                 // part is not focused -> return.
                 return;
             }
         }
+
         super.update(force);
         updateGradientBackground();
     }
 
+    private IWorkbenchPage getSafeActivePage() {
+        IWorkbenchWindow activeWorkbenchWindow = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
+        if (activeWorkbenchWindow != null) {
+            return activeWorkbenchWindow.getActivePage();
+        }
+        return null;
+    }
+
     /**
      * Update the gradient background if needed:
      * <UL>