gdk_window_add_filter(widget->window, widget_window_filter, mozarea);
gtk_mozarea_realize (GtkWidget *widget){  GtkMozArea *mozarea;    g_return_if_fail (GTK_IS_MOZAREA (widget));  GTK_WIDGET_SET_FLAGS (widget, GTK_REALIZED);  mozarea = GTK_MOZAREA (widget);  mozarea->superwin = gdk_superwin_new (gtk_widget_get_parent_window (widget),                                        widget->allocation.x,                                        widget->allocation.y,                                        widget->allocation.width,                                        widget->allocation.height);  gdk_window_set_user_data (mozarea->superwin->shell_window, mozarea);  widget->window = mozarea->superwin->shell_window;  widget->style = gtk_style_attach (widget->style, widget->window);  /* make sure that we add a reference to this window.     if we don't then it will be destroyed by both the superwin     destroy method and the widget class destructor */  gdk_window_ref(widget->window);  /* attach the toplevel X listener */  attach_toplevel_listener(mozarea);}