Making custom class objects viewable via TreeView

[Adrian Zgorzalek <a zgorzalek gmail com>]

Hello,

I got a bunch of questions connected with TreeView, making data viewable
via TreeView and some design issues.

Firstly, I'll state a problem. I would like to have a collection of Foo objects.
They have their methods, store some data. I want the collection to supply
me, besides collection interface, some methods to call on stored data.
I also want to expose objects stored in the collection to user, allow they
to modify them, add, delete and reorder.

Obvious idea is to use TreeView, but I met some serious problems.

First, how to make Foo objects viewable? Deriving from Gtk::TreeModelColumnRecord
leads me to nowhere, since then I have no access to data stored inside Foo,
Gtk::TreeModelColumn<T> seems to be just a meta-data for a model to create View and
Store. More clearly, I want to e.g. have object representing triple on plain (int, int, int),
and got some methods like symmetry along a given line etc. Implemeting it inside
TreeModelColumnRecord is impossible - no access to stored data. Making a class Foo
that got 3 private ints leads me to no idea how to make this object viewable through
view.

Ideally, I look for something like as follows:
I have a Store that has Foo objects. Then to a View I add columns like (x), (y), (z),
corresponding to example above, and specify accessors methods inside Foo object, so that
View can correctly save and show data to/from a Foo.

One more problem connected with deriving from Gtk::TreeModelColumnRecord is that in my
opinion it brakes OOP rule: its not Foo business to take care of being viewable,
it exposes methods to modify itself and get stored data, but how it is done is just a matter of somebody
writing class responsible for showing data to a user. Also storing everything in one place:
data and display issues, is making code messy.

I suppose that deriving my collection from ListStore or TreeStore will solve a problem
of adding some methods to call on stored data.

So far, after investigating materials I've found and after some talks on IRC channel
the only idea I have is to keep data in two places and try to sync them, but it seems
to be a pain in the neck, it also makes my memory usage twice as more... so its not
a solution at all.

I would appreciate any help with this problem, I am not looking for easy solutions,
rather elegant.
If elegant solution does not exist, then please point me the least awful way
to do what I want.

Looking forward to hearing from you,

Regards,
Adrian