Re: [gtk-list] Re: question about resizing & combos

[Gustavo Joćo Alves Marques Carneiro <ee96090 fe up pt>]

	Ok. I think I found another problem. You have created a glist that
contains a list of 'static' strings. Those strings are embedded in the
program code by the compiler and can't be freed. Each item of glist->data
is a pointer to one of those static strings. It's not dynamic memory
allocation, so you don't have to bother releasing it -- it will be done
automatically. Just remove the g_free. 


On Wed, 27 Oct 1999, Giaslas Georgios wrote:

> Thank you Gustavo for replying so quick 
> 
> i tried to put g_free(l->data) before g_list_remove
> but i get a segmentation fault when the program tries to execute g_free
> 
> i also checked with gdb that 'while' doesn't ever result 
> in an endless loop.
> 
> So, there must be another problem
> 
> Thanx anyway
> -----------------------------------------
> > 2) i have a combo box and when the user selects
> >    a string i want all the strings before this to be removed.
> >    i've done it and when i change the comboentry using
> >    arrow keys it's ok. but when it's changed using the
> >    mouse i get a segmentation fault.
> >    Is it a bug or it's my fault?
> >    please try the following little program to see what
> >    i mean exactly.
> >
> > (I use gtk+ version 1.2.6)
> >
> > Please reply this time...
> >
> > Thank you all
> >
> > -----------------------------
> > #include <gtk/gtk.h>
> >
> > GList *glist=NULL;
> >    gint active=0;
> >    GtkWidget *combo;
> >    GtkWidget *window;
> >
> >    static gint delete_callback(GtkWidget *widget, gpointer data)
> >    {
> >        gtk_main_quit();
> >        return(FALSE);
> >    }
> >
> >    void callback(GtkEntry *comboentry, gpointer data)
> >    {
> >        GList *l;
> >        gint cnt=0;
> >        if (active)
> >        {
> >            l=g_list_first(glist);
> >            while (g_strcasecmp(l->data, gtk_entry_get_text(comboentry)))
> >            {
> >                g_print("data %s deleted\n", (gchar *) l->data);
> >                glist=g_list_remove(glist, l->data);
> >                g_free(l->data);
> 
> >        g_free(l->data) should come before g_list_remove because it is
> >not guaranteed that the location pointed by 'l' is valid after you remove
> 
> >it from the list.
> 
> >                cnt++;
> >                l=g_list_first(glist);
> >            }
> >        Also, you should take care that this previous 'while' doesn't
> ever
> >result in an endless loop.
> 
> >            gtk_combo_set_popdown_strings(GTK_COMBO(combo), glist);
> >        }
> >    }
> >
> >    int main (int argc, char *argv[])
> >    {
> >        gtk_init(&argc, &argv);
> >        window=gtk_window_new(GTK_WINDOW_TOPLEVEL);
> >        gtk_signal_connect(GTK_OBJECT(window), "delete_event",
> >                            GTK_SIGNAL_FUNC(delete_callback), NULL);
> >        combo=gtk_combo_new();
> >        glist = g_list_append(glist, "String 1");
> >        glist = g_list_append(glist, "String 2");
> >        glist = g_list_append(glist, "String 3");
> >        glist = g_list_append(glist, "String 4");
> >        gtk_signal_connect(GTK_OBJECT(GTK_COMBO(combo)->entry),
> "changed",
> >  GTK_SIGNAL_FUNC(callback), NULL);
> >
> >        gtk_combo_set_popdown_strings( GTK_COMBO(combo), glist);
> >        gtk_container_add(GTK_CONTAINER(window), combo);
> >        gtk_widget_show_all(window);
> >        active=1;
> >        gtk_main();
> >        return 0;
> >    }
> > --------------------------
> >
> 
> 
> 

-- 
Gustavo J.A.M. Carneiro
World::Portugal::FEUP::DEEC::LEEC::TEC
[reinolinux.fe.up.pt/~ee96090]