Sets @iter to point to the first child of @parent.
If @parent has no children, %FALSE is returned and @iter is set to be invalid. @parent will remain a valid node after this function has been called.
If @parent is %NULL returns the first node, equivalent to gtk_tree_model_get_iter_first (tree_model, iter);
the new #GtkTreeIter-struct to be set to the child
the #GtkTreeIter-struct, or %NULL
Return: %TRUE, if @iter has been set to the first child
See Implementation
Sets @iter to point to the first child of @parent.
If @parent has no children, %FALSE is returned and @iter is set to be invalid. @parent will remain a valid node after this function has been called.
If @parent is %NULL returns the first node, equivalent to gtk_tree_model_get_iter_first (tree_model, iter);