code: def draw_widget(self, item):
          
          if item:
              self.filter_remove(remember=True)
              selected_id = self.treedata[item]['id']
              item = self.get_toplevel_parent(item)
              widget_id = self.treedata[item]['id']
              wclass = self.treedata[item]['class']
              xmlnode = self.tree_node_to_xml('', item)
              self.previewer.draw(item, widget_id, xmlnode, wclass)
              self.previewer.show_selected(item, selected_id)
              self.filter_restore()
docs: Create a preview of the selected treeview item