Method set_scroll_handler

dlib/gui_widgets/base_widgets.h:1043–1046

            typename T
            >
        void set_scroll_handler (
            T& object,
            void (T::*eh)()
        ) { auto_mutex M(m); scroll_handler = make_mfp(object,eh); }

        void set_scroll_handler (
            const any_function<void()>& eh