Gui: fix regression that NaviCube cannot be switched off any more

src/Gui/DlgSettingsNavigation.cpp

@@ -123,8 +123,7 @@ void DlgSettingsNavigation::recreateNaviCubes()
     for (auto view : views) {
         if (auto view3d = qobject_cast<View3DInventor*>(view)) {
             auto viewer = view3d->getViewer();
-            viewer->deleteNavigationCube();
-            viewer->createNavigationCube();
+            viewer->updateNavigationCube();
         }
     }
 }

src/Gui/View3DInventorViewer.cpp

@@ -1176,20 +1176,11 @@ NaviCube* View3DInventorViewer::getNavigationCube() const
     return naviCube;
 }
 
-void View3DInventorViewer::createNavigationCube()
-{
-    if (!naviCube) {
-        naviCube = new NaviCube(this);
-        naviCubeEnabled = true;
-    }
-}
-
-void View3DInventorViewer::deleteNavigationCube()
+void View3DInventorViewer::updateNavigationCube()
 {
     if (naviCube) {
         delete naviCube;
-        naviCube = nullptr;
-        naviCubeEnabled = false;
+        naviCube = new NaviCube(this);
     }
 }
 

src/Gui/View3DInventorViewer.h

@@ -387,8 +387,7 @@ public:
     bool isEnabledNaviCube() const;
     void setNaviCubeCorner(int);
     NaviCube* getNavigationCube() const;
-    void createNavigationCube();
-    void deleteNavigationCube();
+    void updateNavigationCube();
     void setEnabledVBO(bool b);
     bool isEnabledVBO() const;
     void setRenderCache(int);