User Menu Item Show Predicate
Predicate User Function which is invoked each time a User Menu Item is about to displayed to evaluate whether it should be visible.
important
This is used for both Column Menus and Context Menus.
The handler
recieves a Menu Info object which provides full information of the column / cell where the menu is being displayed and returns true or false whether the Menu Item should show.
handler: (menuInfo: MenuInfo) => boolean;