This is a first cut at making FltkListResource work properly. The resource maintains a hash of its items' selected status, the MultiBrowser widget gets a callback that updates the hash and isSelected() looks up the hash for the answer. It's the same technique I used for FltkOptionMenuResource , where the FLTK widgets are linked to their resources by user_data() and callback arguments. I added equals() and hashValue() methods to Items so they could be hash keys, and implemented an object::Object wrapper class for boolean values to be the hash values. The wrapper class is inside FltkListResource , though it could easily move to lout::object IMHO. The patch also enables the ListResource widget in test/dw-ui-test . Unfortunately it's still a little buggy. Specifying multiple selected items initially doesn't work right: they are all selected in the resource but only one is selected on the FLTK widget. Things also go out of sync when you select a group item: any previously selected item is unselected in the widget but not in the resource. I'll look into these further. Comments are welcome! Regards, Jeremy Henty