Re: New list/tree model questions

[Archit Baweja <bighead users sourceforge net>]

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Hi

Now thats exactly what I was looking for! Thanks.

Archit Baweja

Havoc Pennington <hp@redhat.com> writes:

> Maxim Koshelev <max@krascoal.ru> writes:
> > gtk_tree_model_get needs a iterator as parameter. So as far as I can
> > understand there is no
> > function to get  row by data (like gtk_clist_find_row_from_data) in
> > new tree model.
> > Or I'm wrong?
> > 
> 
> No you're right about that, I just wasn't sure what you were asking.
> 
> Look at how find_row_from_data works:
> 
> gint
> gtk_clist_find_row_from_data (GtkCList *clist,
>                               gpointer  data)
> {
>   GList *list;
>   gint n;
> 
>   g_return_val_if_fail (GTK_IS_CLIST (clist), -1);
> 
>   for (n = 0, list = clist->row_list; list; n++, list = list->next)
>     if (GTK_CLIST_ROW (list)->data == data)
>       return n;
> 
>   return -1;
> }
> 
> You can write exactly the same thing for tree view (this assumes a
> list rather than a tree):
> 
> gboolean
> find_row_from_data (GtkTreeModel *model,
>                     GtkTreeIter  *iter,
>                     int           column,
>                     void         *data)
> {
>   GtkTreeIter tmp;
>   void *this_data;
> 
>   if (!gtk_tree_model_get_iter_first (model, &tmp))
>      return FALSE;
> 
>   do
>   {
>      gtk_tree_model_get (model, &tmp, column, &this_data, -1);
>      if (this_data == data)
>        {
>            *iter = tmp;
>            return TRUE;
>        }
>    } while (gtk_tree_model_iter_next (model, &tmp));
> 
>    return FALSE; /* FALSE return means not found */
> }
> 
> 
> Note that in both cases, this is a linear search and thus best
> avoided. The tree model case only works for columns that contain
> pointers, clearly, some columns can contain ints or strings or 
> whatever. The returned data from gtk_tree_model_get() will need
> to be freed if it's a string or boxed type rather than 
> G_TYPE_POINTER.
> 
> To handle a tree in addition to a list, you need to recurse into the
> model instead of just walking over it linearly.
> 
> Havoc
> _______________________________________________
> gtk-app-devel-list mailing list
> gtk-app-devel-list@gnome.org
> http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
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