(make-menuitem label action #&optional extra-label picture-above picture-left hover-action unhover-action hotkey-prefs submenu?)
Return a newly created menuitem object using the given arguments. label is a string giving the main text label of the menu item; action is a procedure or menu object -- if it is a procedure, it gets invoked when the menuitem is selected, if it is a menu object, that menu is attached as a submenu from the enclosing menu that the created menuitem is put in. You can also force action to be treated as a submenu by setting submenu? to #t. extra-label is extra text describing the menu item -- often this contains a shortcut key description, or some other descriptive text. picture-above and picture-left are picture objects which correspond to images to display within the bounding region of the menuitem. hover-action and unhover-action are procedures to be invoked when the mouse pointer hovers over the item and is moved away after hovering over the item, respectively. hotkey-prefs is a string listing preferred alphanumeric shortcut-keys for the given menu-item; the menu creation routine uses these as hints for assigning shortcut keys to the various menuitems. For a higher-level interface to this function, see menuitem.