How private is "internal" data supposed to be

["Brian J. Murrell" <gtk-list-in interlinx bc ca>]

I am in the process of learing C++.  I have the syntax and concepts down
and am just working on wrapping my mind around class design.  One of the
neatest things I thought about C++ was the concept of "abstract data". 
That being a data item that has behaviours and traits and hides
implementation.  C++ does a very good job of not letting you access
implementation details.

The same abstract data concepts can be done in C but you cannot protect
the user of your data item from accessing implementation details.  So on
to my question:

How abstract are the data items (i.e. widgets) in GTK+ supposed to be? 
Take for instance a CList.  Am I supposed to dive in and grab the
"selection" GList?  My C++ experience tells me no.  But there is no
accessor function to get a list of the currently selected items from a
CList (that I can see anyway).

Thots?
b.


--
Brian J. Murrell                              InterLinx Support Services, Inc.
North Vancouver, B.C.                                             604 983 UNIX
        Platform and Brand Independent UNIX Support - R3.2 - R4 - BSD