Let SessionController emit signalUndoStackChanged only via explicit helper method

Author: Friedrich W. H. Kossebau

webodf/lib/gui/SessionController.js

@@ -304,7 +304,7 @@ gui.SessionControllerOptions = function () {
          * @return {undefined}
          */
         function forwardUndoStackChange(e) {
-            odtDocument.emit(ops.OdtDocument.signalUndoStackChanged, e);
+            odtDocument.emitSignalUndoStackChanged(e);
         }
 
         /**

webodf/lib/ops/OdtDocument.js

@@ -984,6 +984,15 @@ ops.OdtDocument = function OdtDocument(odfCanvas) {
         eventNotifier.emit(ops.Document.signalCursorMoved, cursor);
     };
 
+    /**
+     * Emit the signal that the passed cursor moved.
+     * @param {?Event} e
+     * @return {undefined}
+     */
+    this.emitSignalUndoStackChanged = function(e) {
+        eventNotifier.emit(ops.OdtDocument.signalUndoStackChanged, e);
+    };
+
     /**
      * @return {undefined}
      */