Re: GtkTreeModelSort

[Jonathan Blandford <jrb redhat com>]

Stuart Jansen <smj8 email byu edu> writes:

> I've been fairly impressed with the new tree CMV design so far. However,
> I'm having a hard time using the GtkTreeModelSort and modifying the
> data.
>
> Let me see if I've got this right:
> Because there is no way to access the data once it is put into a
> GtkListStore or GtkTreeStore, a seperate copy must be maintained. Like
> in gtk-demo were editable values are stored ina a GArray. (Can I just
> say that not being able to read the stored values is a _real_ pain?)

No.  You can certainly access the data once it's in a List/Tree store.
The whole purpose of the design is to avoid duplicating data when
possible.

To get values, just use:
gtk_tree_model_get (model,
                    iter,
                    COL_1, &val1,
                    COL_2, &val2,
                    -1);
etc.

> To avoid changing the order of the rows in the GtkListStore, I can't
> just sort the GtkTreeModel (actually GtkListStore) but must wrap it in a
> GtkTreeModelSort. (With the advantage that I can define sort functions
> for individual columns.)

You can define sort functions for individual columns with the
GtkListStore as well.  It also implements the GtkTreeSortable interface.

> I'm doing that and can edit/add rows without a problem. I'm having real
> trouble removing rows, however. Could someone give at least a generally
> description or better (bless your heart) example code describing the
> correct way to use a GtkTreeModelSort?

GtkTreeModelSort is just a wrapper model and cannot be modified
directly.  You simply have to add/remove rows to the model being mapped
(ie, gtk_list_store_append, gtk_list_store_remove).

Hope that helped,
-Jonathan