add: extern GtkWidget * main_statusbar;
context: gboolean division_node_maybe_expand ( GtkTreeModel *model, GtkTreePath *path, 				      GtkTreeIter *iter, gpointer data ){    GtkTreeView * tree_view = g_object_get_data ( G_OBJECT(model), "tree-view" );    if ( tree_view )    {	if ( (gint) data == gtk_tree_path_get_depth ( path ) )	    gtk_tree_view_expand_to_path ( tree_view, path );    }    return FALSE;}