rem: gtk_tree_model_iter_parent ( model, &parent, &iter );  if ( gtk_tree_model_iter_children (model, &child, &parent) ) { do { gtk_tree_store_set (GTK_TREE_STORE (model), &child, PAYMENT_METHODS_DEFAULT_COLUMN, FALSE, -1); } while ( gtk_tree_model_iter_next (model, &child) ); } else {  dialogue ( _("Serious brain damage expected.") );
add: gtk_tree_store_set (GTK_TREE_STORE (model), &iter, PAYMENT_METHODS_DEFAULT_COLUMN, 1, -1);
context: item_toggled (GtkCellRendererToggle *cell,	      gchar                 *path_str,	      gpointer               data){  GtkTreePath *path = gtk_tree_path_new_from_string (path_str);  GtkTreeIter iter, parent, child;  gboolean toggle_item;  struct struct_type_ope * type_ope;  /* get toggled iter */  gtk_tree_model_get_iter (model, &iter, path);  gtk_tree_model_get (model, &iter, 		      PAYMENT_METHODS_DEFAULT_COLUMN, &toggle_item, 		      PAYMENT_METHODS_POINTER_COLUMN, &type_ope,		      -1);  p_tab_nom_de_compte_variable = p_tab_nom_de_compte + type_ope -> no_compte;    if (type_ope -> signe_type == 1) /* Dbit */    TYPE_DEFAUT_DEBIT = type_ope -> no_type;  else if  (type_ope -> signe_type == 2) /* Crdit */    TYPE_DEFAUT_CREDIT = type_ope -> no_type;  /* do something with the value */  toggle_item ^= 1;  gtk_tree_model_iter_parent ( model, &parent, &iter );    if ( gtk_tree_model_iter_children (model, &child, &parent) )    {      do 	{	  gtk_tree_store_set (GTK_TREE_STORE (model), &child, 			      PAYMENT_METHODS_DEFAULT_COLUMN, FALSE, 			      -1);	}      while ( gtk_tree_model_iter_next (model, &child) );    }   else    {      /* Should not happen theorically */      dialogue ( _("Serious brain damage expected.") );    }  /* set new value */  gtk_tree_store_set (GTK_TREE_STORE (model), &iter, 		      PAYMENT_METHODS_DEFAULT_COLUMN, toggle_item, 		      -1);  /* clean up */  gtk_tree_path_free (path);}