append
Appends a new row to @tree_store.
If @parent is non-null, then it will append the new row after the last child of @parent, otherwise it will append a row to the top level.
The @iter parameter will be changed to point to this new row. The row will be empty after this function is called. To fill in values, you need to call gtk_tree_store_set() or gtk_tree_store_set_value().
Parameters
iter
An unset GtkTreeIter
to set to the appended row
parent
A valid GtkTreeIter