Gtk.ComboBox:active
"active" Number : Read / Write
The item which is currently active. If the model is a non-flat treemodel, and the active item is not an immediate child of the root of the tree, this property has the value <literal>gtk_tree_path_get_indices (path)[0]</literal>, where <literal>path</literal> is the Gtk.TreePath of the active item.
Since 2.4