how to make a hook function and call from C?

[joakim]

I want to call lisp inside a gtk widget signal handler:

------------------------------------------------
      xw->widget=GTK_WIDGET(gtk_button_new_with_label (    xw->title));
      g_signal_connect (G_OBJECT (xw->widget), "clicked", G_CALLBACK (hello), 
xw);
...
      
static void hello( GtkWidget *widget,
                   gpointer   data )
{
  printf ("button clicked %d\n",data);
  Lisp_Object args[2];
  struct xwidget* xw=(  struct xwidget*)data;
  
  /* FIXME i have no particular idea how to call lisp yet
  args[0] = data->message_hook;
  args[1] = arg;
  Ffuncall (2, args);
  */
  //  call0(intern("xwidget-dummy-hook")); //crashes even if fn exists
  //  call0(intern("beep")); //"beep" seems to not crash and not do anything 
but "info" crashes
                  
}
-----------------------------------------------
When I click the button, the "hello" function is reached, but
I cant figure out how to call a lisp function.

- Are there any similar examples in the codebase somewhere?

- I would like xw->message_hook to contain a lisp hook, settable from the
lisp level. How do I set this up at the C level?

- Should I use Ffuncall to call my new hook or what?


-- 
Joakim Verona