code: public void ensureVisible(CmsSitemapTreeItem item) {
  
          // open the tree
          CmsTreeItem ti = item.getParentItem();
          while (ti != null) {
              ti.setOpen(true);
              ti = ti.getParentItem();
          }
          // scroll
          CmsDomUtil.ensureVisible(RootPanel.getBodyElement(), item.getElement(), 200);
      }
docs: Ensures the given item is visible in the viewport.<p>
  
  @param item the item to see