Re: [gtkmm] Storing Glib::RefPtrs in treemodels

[Matthew Walton <matthew alledora co uk>]

Problem solved. Somehow I managed to forget adding the data column to
the TreeModelColumnRecord; this is certainly not the error I would have
expected from that, but at least I've tracked it down.

On Fri, 2003-07-11 at 21:52, joey yandle wrote:
> > I have a Gtk::TreeStore subclass which has as one of its columns a
> > Glib::TreeModelColumn<Glib::RefPtr<Towel::TrackStore> > where
> > Towel::TrackStore is a subclass of Gtk::ListStore. When a row is added
> > to this TreeStore, the relevant column is populated with
> > Towel::TrackStore::create(), which returns a RefPtr with a TrackStore
> > inside it as one might expect.
> > 
> 
> What are you trying to do here?  Why do you want to display a Gtk::ListStore
> in a Gtk::TreeView?  
> 
> > The trouble is, every time the program tries to access the column, Glib
> > claims
> > 
> > (towel:9825): GLib-GObject-CRITICAL **: file gobject.c: line 1583
> > (g_value_get_object): assertion `G_VALUE_HOLDS_OBJECT (value)' failed
> > 
> 
> That's probably because there is no CellRenderer that can display 
> such a column.  
> 
> > And I have no idea why this might be, because I am sure that
> > everything's being created properly. Do I perhaps not understand how
> > RefPtrs work properly? Should I perhaps be doing this in a completely
> > different manner? I suppose I could store straight pointers instead, but
> > that would increase the complexity of the memory management code, which
> > I'm trying not to do because it's a horrible source of nasty bugs.
> > 
> 
> It looks like you want to store this as data in the model.  That's fine;
> as long as you don't add that column to the view, you won't have any 
> problem.  But if you're trying to display this, you're doing the wrong
> thing.
> 
> cheers,
> --
> joey yandle
-- 
Matthew Walton <matthew alledora co uk>