22.12.7 Modifying Menus

When you insert a new item in an existing menu, you probably want to put it in a particular place among the menu's existing items. If you use define-key to add the item, it normally goes at the front of the menu. To put it elsewhere in the menu, use define-key-after:

Function: define-key-after map key binding &optional after

Define a binding in map for key, with value binding, just like define-key, but position the binding in map after the binding for the event after. The argument key should be of length one--a vector or string with just one element. But after should be a single event type--a symbol or a character, not a sequence. The new binding goes after the binding for after. If after is t or is omitted, then the new binding goes last, at the end of the keymap. However, new bindings are added before any inherited keymap.

Here is an example:

(define-key-after my-menu [drink] '("Drink" . drink-command) 'eat)

makes a binding for the fake function key DRINK and puts it right after the binding for EAT.

Here is how to insert an item called `Work' in the `Signals' menu of Shell mode, after the item break:

(define-key-after (lookup-key shell-mode-map [menu-bar signals]) [work] '("Work" . work-command) 'break)