Re: GtkListStore: forcing a sort

[Owen Taylor <otaylor redhat com>]

On Sun, 2003-04-13 at 17:46, Mattperry wrote:
> Thus spake Owen Taylor (otaylor redhat com):
>
> > On Sat, 2003-04-12 at 04:32, Mattperry wrote:
> > > I have looked through the API reference and mailing lists, and I can't
> > > seem to find an answer to this somewhat simple question.  I have a
> > > GtkTreeView which uses a GtkListStore model.  The list store is
> > > populated with a struct (ie, store = gtk_list_store_new(1, G_TYPE_POINTER);
> > > I add many columns and use gtk_tree_view_column_set_cell_data_func() to
> > > display various records of my structure in the columns in different
> > > ways.  Now, this works very well, as I only have one copy of the data,
> > > and any change takes effect immediately.  However, I would like to sort
> > > the list after any change has been made to the data.
> > >
> > > I have found the automatic sorting features unsatisfactory for two
> > > reasons.  First, I need to sort based on 2 columns simultaneously (one
> > > has priority), and it doesn't seem like I can do this.  Second, I want
> > > to be able to issue a sort command whenever I want, rather than wait for
> > > the user to click on the title of one of the columns.  It seems like
> > > such a sort function would be fairly standard.  Where can I find this
> > > functionality?
> >
> > Note that, if a list store has a sort function, it's _always_ sorted;
> > there is no concept of sorting it.
> >
> > gtk_tree_sortable_set_sort_func() and
> > gtk_tree_sortable_set_default_sort_func() let you sort with whatever
> > functions you want.
> >
> > Regards,
> >                                         Owen
>
> I'm using gtk_tree_sortable_set_default_sort_func(), but I notice my
> sort function is never called.  My sort function looks like this:
>
> gint list_cmp(GtkTreeModel *model, GtkTreeIter *a, GtkTreeIter *b, gpointer d)
> {
>     struct sound_entry *entry1, *entry2;
>
>     gtk_tree_model_get(model, a, DATA_COL, &entry1, -1);
>     gtk_tree_model_get(model, b, DATA_COL, &entry2, -1);
>
>     g_warning("sort");
>
>     return sound_cmp(entry1, entry2);
> }
>
> "sort" never gets printed, and my list never gets sorted.  Also, I don't
> see how it's possible that the list store is always sorted if my data
> changes independently of my list store.  I have a function like this:
>     gtk_list_store_set(store, iter, DATA_COL, entry, -1);
> and then function renderers to render the different columns of this
> entry.  If I change entry->name, for example, how is the list store to
> notice this?  How can I tell it that it needs to be sorted? 

Well, you have to be able to tell the GtkTreeView that the row
changed so that it gets rerendered and resize-computed. So, this
isn't very different. I think setting your pointer back with the
same value should work.

> As it stands, using ..._set_default_sort_func() results in my sort function
> never being called (regardles of whether I set the sort_column_id to the
> DEFAULT_SORT_COLUMN_ID).  Is this a bug?

Yes, almost certainly in your code. If you provide a small standalone
test case, it might be easier to see what's going wrong.

Regards,
                                               Owen