From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Mon, 11 Oct 2021 11:15:41 +0000 (+0200)
Subject: Allow :keys in menus to be computed dynamically
X-Git-Tag: emacs-29.0.90~3671^2~619
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=74d3a1e7d6450f226d2f942d0c0e3410eea87dfc;p=emacs.git

Allow :keys in menus to be computed dynamically

* doc/lispref/keymaps.texi (Extended Menu Items): Document it
(bug#28930).

* src/keyboard.c (parse_menu_item): Allow :keys to be a function.
---

diff --git a/doc/lispref/keymaps.texi b/doc/lispref/keymaps.texi
index 407bdca5ed4..066d8b3693a 100644
--- a/doc/lispref/keymaps.texi
+++ b/doc/lispref/keymaps.texi
@@ -2319,6 +2319,12 @@ This property specifies that @var{string} is the string to display
 as the keyboard equivalent for this menu item.  You can use
 the @samp{\\[...]} documentation construct in @var{string}.
 
+This property can also be a function (which will be called with no
+arguments).  This function should return a string.  This function will
+be called every time the menu is computed, so using a function that
+takes a lot of time to compute is not a good idea, and it should
+expect to be called from any context.
+
 @item :filter @var{filter-fn}
 This property provides a way to compute the menu item dynamically.
 The property value @var{filter-fn} should be a function of one argument;
diff --git a/etc/NEWS b/etc/NEWS
index b91a5cbb721..010a6e51e3b 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -134,6 +134,11 @@ with recent versions of Firefox.
 
 * Lisp Changes in Emacs 29.1
 
++++
+** :keys in 'menu-item' can now be a function.
+If so, it is called whenever the menu is computed, and can be used to
+calculate the keys dynamically.
+
 +++
 ** New major mode 'clean-mode'.
 This is a new major mode meant for debugging.  It kills absolutely all
diff --git a/src/keyboard.c b/src/keyboard.c
index 9a50a5e5eb7..7184b1509b1 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -7841,7 +7841,9 @@ parse_menu_item (Lisp_Object item, int inmenubar)
 	      else if (EQ (tem, QCkeys))
 		{
 		  tem = XCAR (item);
-		  if (CONSP (tem) || STRINGP (tem))
+		  if (FUNCTIONP (tem))
+		    ASET (item_properties, ITEM_PROPERTY_KEYEQ, call0 (tem));
+		  else if (CONSP (tem) || STRINGP (tem))
 		    ASET (item_properties, ITEM_PROPERTY_KEYEQ, tem);
 		}
 	      else if (EQ (tem, QCbutton) && CONSP (XCAR (item)))