Well, you're passing something that isn't a GtkWidget to sig_con1. The type of the pointer should not matter as long as it points to a GtkWidget (some secret sauce under the hood is used to know whether it's a valid pointer or not). We would need to see what calls sig_con1 to debug further, but look there. On Sun, Jul 19, 2015 at 12:15 PM, Patrick <patrick@xxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi Everyone > > I am doing something strange. I am mixing C GTK and COBOL. It's GnuCOBOL and > it compiles to intermediate C. > > I can create widgets by creating pointers in COBOL and passing them to C GTK > functions and such but I can't seem to connect signals. > > This code: > > int sig_con1( GtkWidget * widget_id ) { > g_signal_connect(G_OBJECT(widget_id),"clicked", > G_CALLBACK(handler1_to_handler2),NULL); > ..... > > > compiles but when it runs I get : > > (anak:18978): GLib-GObject-WARNING **: invalid unclassed pointer in cast to > 'GObject' > > (anak:18978): GLib-GObject-WARNING **: instance with invalid (NULL) class > pointer > > > COBOL is actually passing in a void pointer so widget_id is actually type > void. I can't seem to cast it to a pointer to a G_OBJECT. Changing the > functions prototype to void * widget_id did not help. > > Could anyone give me a tip or two of how to cast ? > > Thanks-Patrick > > > > > > > _______________________________________________ > gtk-list mailing list > gtk-list@xxxxxxxxx > https://mail.gnome.org/mailman/listinfo/gtk-list -- Jasper _______________________________________________ gtk-list mailing list gtk-list@xxxxxxxxx https://mail.gnome.org/mailman/listinfo/gtk-list