gtktreeview and gtkscrolledwindow

[eric jrdn2 <eric_jrdn2 yahoo fr>]

Hello, I'm new on this list, and I would like to ask a question. I'm 
using gtk+ by means of the gtkmm wrapper.

I have a treeview in a scrolledwindow. Is there a good reason for the 
treeview to ask values to the model for treeviewcolumns which are 
outside the screen?

Let me be clearer.
When adding treeviewcolumns to the treeview, there are two distincts 
behaviours.
- Rows which are outside the screen (that is, one must scroll to see 
them) are not queried to the treemodel
- Columns which are outside the screen are queried.

This behaviour is a problem for me.
For simplicity, let me tell you that I have a Treeview with 170 columns 
of 100 pixels width.

You understand of course that I encounter a dramatic performance loss if 
I query each 170 columns values.
Using some get_path_at_pos method, I know if a column is on the screen 
or not, and save (double->string->treeview display) time.

Now the problem:
170 columns of 100 pixels gives 17000 pixels.
In gdkgeometry-x11.c, there is a 16384 cutoff value. The bad thing is 
that columns after this value are not well displayed when I scroll the 
scrolledwindow.

So my question was:
Is there a good reason for the treeview to ask values to the model for 
treeviewcolumns which are outside the screen?

Thank You.