https://invisible-island.net/ncurses/man/
mitem_visible(3x) Library calls mitem_visible(3x)
item_visible - check visibility of a menu item
#include <menu.h> bool item_visible(const ITEM *item);
A menu item is visible when it is in the portion of a posted menu that is mapped onto the screen (if the menu is scrollable, in particular, this portion will be smaller than the whole menu).
These routines emulate the System V menu library. They were not supported on Version 7 or BSD versions.
Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond.
curses(3x), menu(3x) ncurses 6.5 2024-03-16 mitem_visible(3x)