get-shortcut-prefix in selectable-menu-item<%>

Returns a list of symbols that indicates the keyboard prefix used for the menu item's keyboard shortcut. The allowed symbols for the list are the following:

• 'alt -- Meta (Windows and X only)

• 'cmd -- Command (Mac OS X only)

• 'meta -- Meta (X only)

• 'ctl -- Control

• 'shift -- Shift

• 'opt -- Option (Mac OS X only)

Under X, at most one of 'alt and 'meta can be supplied; the only difference between 'alt and 'meta is the key combination's display in a menu.

The default shortcut prefix is available from get-default-shortcut-prefix .

The shortcut key, as determined by get-shortcut, matches a key event using either the normally reported key code or the other-Shift/AltGr key code (as produced by get-other-shift-key-code in key-event%, etc.). When the shortcut key is a key-code symbol or an ASCII letter or digit, then the shortcut matches only the exact combination of modifier keys listed in the prefix. For character shortcuts other than ASCII letters and digits, however, then the shortcut prefix merely determines a minimum set of modifier keys, because additional modifiers may be needed to access the character; an exception is that, under Windows or X, the Alt/Meta key press must match the prefix exactly (i.e., included or not). In all cases, the most precise match takes precedence; see map-function in keymap% for more information on match ranking.

An empty list can be used for a shortcut prefix. However, the default on-menu-char in frame% method checks for menu shortcuts only when the key event includes either a non-Shift modifer or a Function key. Thus, an empty shortcut prefix is normally useful only if the shortcut key is a Function key.

• (send a-selectable-menu-item get-shortcut-prefix) -> list of symbols in '(alt cmd meta ctl shift option)