title: Get Item from QStandardItemModel for QTableView
body: <p>I have a <code>QTreeView</code> in which each node represents a data object. I managed to pack a pointer to this data objects into a <code>QVariant</code> so that I know which is selected in the Tree. I can access the nodes by the <code>currentIndex()</code> function.</p>
  
  <p>The root of the Tree is at <code>QStandardItemModel::invisibleRootItem()</code>. Other nodes are added by the parent nodes <code>appendRow</code> function. So the Items have no <code>row</code> and <code>column</code> that I can use in <code>QStandardItemModel::item()</code>.</p>
  
  <p>Is there a way to give the nodes valid coordinates or to retrieve the items without coordinates.</p>