GtkTreeModelSort + GtkTreeModelFilter

[Patrick Fritzsch <lugpaj anet ne jp>]

Hallo,
i am starting to learn gtk2 and i am somehow understaning now the basics 
of the complex treeview idea of gtk2 (at least i hope so ;) ).

i understand that the GtkTreeModelSort and GtkTreeModelFilter Interfaces 
are just a
GtkTreeModel with more functionality. Actually for the programm i want 
to code those functionalities would be prefect. But not GtkTreeModelSort 
or GtkTreeModelFilter, i would like to use both.
But well, i cannot use both, i can use one or the other i think.
Otherwise i think i would have to code my own Model interface, where i 
looked a bit into it, but is at the moment totally too much code and 
work for this problem.

I am wondering, is there any cheap solution for combining those two 
Model interfaces?

greetings,
Patrick