Re: GList empty after iteration?

[Andrey Maklakov <anmaklakov gmail com>]

Hello Craig,
  I think this is because after first loop, variable "events" is NULL,
and you cant get first element of GList from it:

g_list_next()  --- Returns : the next element, or NULL if there are no
more elements.

> Hi All,
>
> I am confused about GList. My application is parsing a file and creating
> midi data with it. I am using GList to store the midi data.  I have
> created a GtkListStore to view the parsed data (to insure I am parsing
> the data properly).  So, below I iterate through the GList and "copy"
> the data into a tree view.  But, I am shocked to see that after I
> iterate through the GList, I cannot iterate through the list again.  I
> have debugged the list after the iteration with g_list_length(events)
> which shows the list length at 0.  What is up with this?  The first
> while loop has data, the second while loop has not data. The code is
> below-->
>
>        GtkTreeIter tree_iter;
>        events = g_list_reverse(events);
>        events = g_list_first(events);
>        while(events)
>        {
>                gtk_list_store_append (list_store, &tree_iter);
>                struct midi_event *me = events->data;
>                gtk_list_store_set(list_store, &tree_iter,
>                                   0, me->time_stamp,
>                                   1, me->event_type,
>                                   2, me->message1,
>                                   3, me->message2,
>                                  -1);
>                events = g_list_next(events);
>        }
>        /// this is where the list appears to be empty!!!!
>        events = g_list_first(events);
>        while(events)
>        {
>                g_print("midi event \n");
>                events = g_list_next(events);
>        }
>
> Thanks for any help!