easy-menu-define): Use ` and , read-macros

instead of (` and (,.  Implement :filter.  Doc fix.
(easy-menu-do-define): Call `easy-menu-create-menu' instead of
`easy-menu-create-keymaps'.
(easy-menu-create-keymaps): Replaced by `easy-menu-create-menu'.
(easy-menu-create-menu): New public function.  Replaces
`easy-menu-create-keymaps', but with large changes.
(easy-menu-button-prefix): New constant.
(easy-menu-do-add-item, easy-menu-make-symbol): New functions.
(easy-menu-update-button): Doc fix.
(easy-menu-change): New optional argument BEFORE.
Now just a call to `easy-menu-add-item'.
(easy-menu-add-item, easy-menu-item-present-p)
(easy-menu-remove-item): New public functions.
(easy-menu-get-map, easy-menu-is-button-p, easy-menu-have-button-p)
(easy-menu-real-binding, easy-menu-change-prefix, easy-menu-filter):
New functions.

1 files changed, 302 insertions, 108 deletions

diff --git a/lisp/emacs-lisp/easymenu.el b/lisp/emacs-lisp/easymenu.el
index 4988d0e1d14..5abda172c1e 100644
--- a/lisp/emacs-lisp/easymenu.el
+++ b/lisp/emacs-lisp/easymenu.el
@@ -1,6 +1,6 @@
 ;;; easymenu.el --- support the easymenu interface for defining a menu.
 
-;; Copyright (C) 1994, 1996 Free Software Foundation, Inc.
+;; Copyright (C) 1994, 1996, 1998 Free Software Foundation, Inc.
 
 ;; Keywords: emulations
 ;; Author: rms
@@ -37,6 +37,11 @@ The menu keymap is stored in symbol SYMBOL, both as its value
 and as its function definition.   DOC is used as the doc string for SYMBOL.
 
 The first element of MENU must be a string.  It is the menu bar item name.
+It may be followed by the keyword argument pair
+   :filter FUNCTION
+FUNCTION is a function with one argument, the menu.  It returns the actual
+menu displayed.
+
 The rest of the elements are menu items.
 
 A menu item is usually a vector of three elements:  [NAME CALLBACK ENABLE]
@@ -53,7 +58,7 @@ Alternatively, a menu item may have the form:
 
    [ NAME CALLBACK [ KEYWORD ARG ] ... ]
 
-Where KEYWORD is one of the symbol defined below.
+Where KEYWORD is one of the symbols defined below.
 
    :keys KEYS
 
@@ -92,11 +97,12 @@ as a solid horizontal line.
 
 A menu item can be a list.  It is treated as a submenu.
 The first element should be the submenu name.  That's used as the
-menu item in the top-level menu.  The cdr of the submenu list
-is a list of menu items, as above."
-  (` (progn
-       (defvar (, symbol) nil (, doc))
-       (easy-menu-do-define (quote (, symbol)) (, maps) (, doc) (, menu)))))
+menu item name in the top-level menu.  It may be followed by the :filter
+FUNCTION keyword argument pair.  The rest of the submenu list are menu items,
+as above."
+  `(progn
+     (defvar ,symbol nil ,doc)
+     (easy-menu-do-define (quote ,symbol) ,maps ,doc ,menu)))
 
 ;;;###autoload
 (defun easy-menu-do-define (symbol maps doc menu)
@@ -104,7 +110,7 @@ is a list of menu items, as above."
   ;; `easy-menu-define' in order to make byte compiled files
   ;; compatible.  Therefore everything interesting is done in this
   ;; function. 
-  (set symbol (easy-menu-create-keymaps (car menu) (cdr menu)))
+  (set symbol (easy-menu-create-menu (car menu) (cdr menu)))
   (fset symbol (` (lambda (event) (, doc) (interactive "@e")
 		    (x-popup-menu event (, symbol)))))
   (mapcar (function (lambda (map) 
@@ -112,110 +118,169 @@ is a list of menu items, as above."
 	      (cons (car menu) (symbol-value symbol)))))
 	  (if (keymapp maps) (list maps) maps)))
 
-(defvar easy-menu-item-count 0)
+(defun easy-menu-filter-return (menu)
+ "Convert MENU to the right thing to return from a menu filter.
+MENU is a menu as computed by `easy-menu-define' or `easy-menu-create-menu' or
+a symbol whose value is such a menu.
+In Emacs a menu filter must return a menu (a keymap), in XEmacs a filter must
+return a menu items list (without menu name and keywords). This function
+returns the right thing in the two cases."
+ (easy-menu-get-map menu nil))		; Get past indirections.
 
-;; Return a menu keymap corresponding to a Lucid-style menu list
-;; MENU-ITEMS, and with name MENU-NAME.
 ;;;###autoload
-(defun easy-menu-create-keymaps (menu-name menu-items)
-  (let ((menu (make-sparse-keymap menu-name)) old-items have-buttons)
+(defun easy-menu-create-menu (menu-name menu-items)
+  "Create a menu called MENU-NAME with items described in MENU-ITEMS.
+MENU-NAME is a string, the name of the menu.  MENU-ITEMS is a list of items
+possibly preceded by keyword pairs as described in `easy-menu-define'."
+  (let ((menu (make-sparse-keymap menu-name))
+	keyword filter have-buttons)
+    ;; Look for keywords.
+    (while (and menu-items (cdr menu-items)
+		(symbolp (setq keyword (car menu-items)))
+		(= ?: (aref (symbol-name keyword) 0)))
+      (if (eq keyword ':filter) (setq filter (cadr menu-items)))
+      (setq menu-items (cddr menu-items)))
     ;; Process items in reverse order,
     ;; since the define-key loop reverses them again.
     (setq menu-items (reverse menu-items))
     (while menu-items
-      (let* ((item (car menu-items))
-	     (callback (if (vectorp item) (aref item 1)))
-	     (not-button t)
-	     command enabler item-string name)
-	(cond ((stringp item)
-	       (setq command nil)
-	       (setq item-string (if (string-match "^-+$" item) "" item)))
-	      ((consp item)
-	       (setq command (easy-menu-create-keymaps (car item) (cdr item)))
-	       (setq name (setq item-string (car item))))
-	      ((vectorp item)
-	       (setq command (make-symbol (format "menu-function-%d"
-						  easy-menu-item-count)))
-	       (setq easy-menu-item-count (1+ easy-menu-item-count))
-	       (setq name (setq item-string (aref item 0)))
-	       (let ((keyword (aref item 2)))
-		 (if (and (symbolp keyword)
-			  (= ?: (aref (symbol-name keyword) 0)))
-		     (let ((count 2)
-			   style selected active keys active-specified
-			   arg)
-		       (while (> (length item) count)
-			 (setq keyword (aref item count))
-			 (setq arg (aref item (1+ count)))
-			 (setq count (+ 2 count))
-			 (cond ((eq keyword ':keys)
-				(setq keys arg))
-			       ((eq keyword ':active)
-				(setq active (or arg ''nil)
-				      active-specified t))
-			       ((eq keyword ':suffix)
-				(setq item-string
-				      (concat item-string " " arg)))
-			       ((eq keyword ':style)
-				(setq style arg))
-			       ((eq keyword ':selected)
-				(setq selected arg))))
-		       (if keys
-			   (setq item-string
-				 (concat item-string "  (" keys ")")))
-		       (if (and selected
-				(or (eq style 'radio) (eq style 'toggle)))
-			   ;; Simulate checkboxes and radio buttons.
-			   (progn
-			     (setq item-string
-				   (concat
-				    (if (eval selected)
-					(if (eq style 'radio) "(*) " "[X] ")
-				      (if (eq style 'radio) "( ) " "[ ] "))
-				    item-string))
-			     (put command 'menu-enable
-				  (list 'easy-menu-update-button
-					item-string
-					(if (eq style 'radio) ?* ?X)
-					selected
-					(or active t)))
-			     (setq not-button nil
-				   active     nil
-				   have-buttons t)
-			     (while old-items ; Fix items aleady defined.
-			       (setcar (car old-items)
-				       (concat "    " (car (car old-items))))
-			       (setq old-items (cdr old-items)))))
-		       (if active-specified (put command 'menu-enable active)))
-		   ;; If the third element is nil,
-		   ;; make this command always disabled.
-		   (put command 'menu-enable (or keyword ''nil))))
-	       (if (symbolp callback)
-		   (fset command callback)
-		 (fset command (list 'lambda () '(interactive) callback)))
-	       (put command 'menu-alias t)))
-	(if (null command)
-	    ;; Handle inactive strings specially--allow any number
-	    ;; of identical ones.
-	    (setcdr menu (cons (list nil item-string) (cdr menu)))
-	  (if (and not-button have-buttons)
-	      (setq item-string (concat "    " item-string)))
-	  (setq command (cons item-string command))
-	  (if (not have-buttons)	; Save all items so that we can fix
-	      (setq old-items (cons command old-items))) ; if we have buttons.
-	  (when name
-	    (let ((key (vector (intern name))))
-	      (if (lookup-key menu key)
-		  (setq key (vector (intern (concat name "*")))))
-	      (define-key menu key command)))))
+      (setq have-buttons
+	    (easy-menu-do-add-item menu (car menu-items) have-buttons))
       (setq menu-items (cdr menu-items)))
+    (when filter
+      (setq menu (easy-menu-make-symbol menu nil))
+      (put menu 'menu-enable
+	   `(easy-menu-filter (quote ,menu) (quote ,filter))))
     menu))
 
+
+;; Button prefixes.
+(defvar easy-menu-button-prefix
+  '((radio ?* . "( ) ") (toggle ?X . "[ ] ")))
+
+(defun easy-menu-do-add-item (menu item have-buttons &optional prev top)
+  ;; Parse an item description and add the item to a keymap.  This is
+  ;; the function that is used for item definition by the other easy-menu
+  ;; functions.
+  ;; MENU is a sparse keymap.
+  ;; ITEM defines an item as in `easy-menu-define'.
+  ;; HAVE-BUTTONS is a string or nil.  If not nil, use as item prefix for
+  ;; items that are not toggle or radio buttons to compensate for the
+  ;; button prefix.
+  ;; PREV is nil or a tail in MENU.  If PREV is not nil put item after
+  ;; PREV in MENU, otherwise put it first in MENU.
+  ;; If TOP is true, this is an item in the menu bar itself so
+  ;; don't use prefix.  In this case HAVE-BUTTONS will be nil.
+  (let (command name item-string is-button)
+    (cond
+     ((stringp item)
+      (setq item
+	    (if (string-match	; If an XEmacs separator
+		 "^\\(-+\\|\
+--:\\(\\(no\\|\\(sing\\|doub\\)le\\(Dashed\\)?\\)Line\\|\
+shadow\\(Double\\)?Etched\\(In\\|Out\\)\\(Dash\\)?\\)\\)$"
+		 item) ""		; use a single line separator.
+	      (concat have-buttons item)))
+      ;; Handle inactive strings specially,
+      ;; allow any number of identical ones.
+      (cond
+       (prev (setq menu prev))
+       ((and (consp (cdr menu)) (stringp (cadr menu))) (setq menu (cdr menu))))
+      (setcdr menu (cons (list nil item) (cdr menu))))
+     ((consp item)
+      (setq name (setq item-string (car item)))
+      (setq command (if (keymapp (setq item (cdr item))) item
+		      (easy-menu-create-menu name item))))
+     ((vectorp item)
+      (setq name (setq item-string (aref item 0)))
+      (setq command (easy-menu-make-symbol (aref item 1) t))
+      (let ((active (aref item 2))
+	    (count 2)
+	    style selected)
+	(if (and (symbolp active) (= ?: (aref (symbol-name active) 0)))
+	    (let ((count 2) keyword arg suffix keys)
+	      (setq active nil)
+	      (while (> (length item) count)
+		(setq keyword (aref item count))
+		(setq arg (aref item (1+ count)))
+		(setq count (+ 2 count))
+		(cond
+		 ((eq keyword ':keys) (setq keys arg))
+		 ((eq keyword ':active) (setq active arg))
+		 ((eq keyword ':suffix) (setq suffix arg))
+		 ((eq keyword ':style) (setq style arg))
+		 ((eq keyword ':selected) (setq selected arg))))
+	      (if suffix (setq item-string (concat item-string " " suffix)))
+	      (if keys
+		  (setq item-string (concat item-string "  (" keys ")")))
+	      (when (and selected
+			 (setq style (assq style easy-menu-button-prefix)))
+		;; Simulate checkboxes and radio buttons.
+		(setq item-string (concat (cddr style) item-string))
+		(put command 'menu-enable
+		     `(easy-menu-update-button ,item-string
+					       ,(cadr style)
+					       ,selected
+					       ,(or active t)))
+		(setq is-button t)
+		(setq active nil)	; Already taken care of active.
+		(when (not (or have-buttons top))
+		  (setq have-buttons "    ")
+		  ;; Add prefix to menu items defined so far.
+		  (easy-menu-change-prefix menu t)))))
+	(if active (put command 'menu-enable active)))))
+    (when name
+      (and (not is-button) have-buttons
+	   (setq item-string (concat have-buttons item-string)))
+      (setq item (cons item-string command))
+      (setq name (vector (intern name)))
+      (if prev (define-key-after menu name item (vector (caar prev)))
+	(define-key menu name item)))
+    have-buttons))
+
+(defvar easy-menu-item-count 0)
+
+(defun easy-menu-make-symbol (callback call)
+  ;; Return a unique symbol with CALLBACK as function value.
+  ;; If CALL is false then this is a keymap, not a function.
+  ;; Else if CALLBACK is a symbol, avoid the indirection when looking for
+  ;; key-bindings in menu.
+  ;; Else make a lambda expression of CALLBACK.
+  (let ((command
+	 (make-symbol (format "menu-function-%d" easy-menu-item-count))))
+    (setq easy-menu-item-count (1+ easy-menu-item-count))
+    (fset command
+	  (cond
+	   ((not call) callback)
+	   ((symbolp callback)
+	    ;; Try find key-bindings for callback instead of for command
+	    (put command 'menu-alias t) ; when displaying menu.
+	    callback)
+	   (t `(lambda () (interactive) ,callback))))
+    command))
+
+(defun easy-menu-filter (name filter)
+  "Used as menu-enable property to filter menus.
+A call to this function is used as the menu-enable property for a menu with
+a filter function.
+NAME is a symbol with a keymap as function value.  Call the function FILTER
+with this keymap as argument.  FILTER must return a keymap which becomes the
+new function value for NAME.  Use `easy-menu-filter-return' to return the
+correct value in a way portable to XEmacs. If the new keymap is `eq' the old,
+then the menu is not updated."
+  (let* ((old (symbol-function name))
+	 (new (funcall filter old)))
+    (or (eq old new)			; No change
+	(and (fset name new)
+	     ;; Make sure the menu gets updated by returning a
+	     ;; different value than last time to cheat the cache. 
+	     (random)))))
+
 (defun easy-menu-update-button (item ch selected active)
   "Used as menu-enable property to update buttons.
 A call to this function is used as the menu-enable property for buttons.
-ITEM is the item-string into wich CH or ` ' is inserted depending on if
-SELECTED is true or not. The menu entry in enabled iff ACTIVE is true."
+ITEM is the item-string into which CH or ` ' is inserted depending on if
+SELECTED is true or not.  The menu entry in enabled iff ACTIVE is true."
   (let ((new (if selected ch ? ))
 	(old (aref item 1)))
     (if (eq new old)
@@ -228,24 +293,153 @@ SELECTED is true or not. The menu entry in enabled iff ACTIVE is true."
       (and active
 	   (random)))))
 
-(defun easy-menu-change (path name items)
+(defun easy-menu-change (path name items &optional before)
   "Change menu found at PATH as item NAME to contain ITEMS.
 PATH is a list of strings for locating the menu containing NAME in the
 menu bar.  ITEMS is a list of menu items, as in `easy-menu-define'.
 These items entirely replace the previous items in that map.
+If NAME is not present in the menu located by PATH, then add item NAME to
+that menu. If the optional argument BEFORE is present add NAME in menu
+just before BEFORE, otherwise add at end of menu.
 
-Call this from `menu-bar-update-hook' to implement dynamic menus."
-  (let ((map (key-binding (apply 'vector
-				 'menu-bar
-				 (mapcar 'intern (append path (list name)))))))
-    (if (keymapp map)
-	(setcdr map (cdr (easy-menu-create-keymaps name items)))
-      (error "Malformed menu in `easy-menu-change'"))))
+Either call this from `menu-bar-update-hook' or use a menu filter,
+to implement dynamic menus."
+  (easy-menu-add-item nil path (cons name items) before))
 
+;; XEmacs needs the following two functions to add and remove menus.
+;; In Emacs this is done automatically when switching keymaps, so
+;; here these functions are noops.
 (defun easy-menu-remove (menu))
 
 (defun easy-menu-add (menu &optional map))
 
+(defun easy-menu-add-item (menu path item &optional before)
+  "At the end of the submenu of MENU with path PATH add ITEM.
+If ITEM is already present in this submenu, then this item will be changed.
+otherwise ITEM will be added at the end of the submenu, unless the optional
+argument BEFORE is present, in which case ITEM will instead be added
+before the item named BEFORE.
+MENU is either a symbol, which have earlier been used as the first
+argument in a call to `easy-menu-define', or the value of such a symbol
+i.e. a menu, or nil which stands for the menu-bar itself.
+PATH is a list of strings for locating the submenu where ITEM is to be
+added.  If PATH is nil, MENU itself is used.  Otherwise, the first
+element should be the name of a submenu directly under MENU.  This
+submenu is then traversed recursively with the remaining elements of PATH.
+ITEM is either defined as in `easy-menu-define' or a menu defined earlier
+by `easy-menu-define' or `easy-menu-create-menu'."
+  (let ((top (not (or menu path)))
+	tmp prev next)
+    (setq menu (easy-menu-get-map menu path))
+    (or (lookup-key menu (vector (intern (elt item 0))))
+	(and menu (keymapp (cdr menu)))
+	(setq tmp (cdr menu)))
+    (while (and tmp (not (keymapp tmp))
+		(not (and (consp (car tmp)) (symbolp (caar tmp)))))
+      (setq tmp (cdr tmp)))
+    (and before (setq before (intern before)))
+    (if (or (null tmp) (keymapp tmp) (eq (setq prev (caar tmp)) before))
+	(setq prev nil)
+      (while (and tmp (not (keymapp tmp))
+		  (not (and (consp (car tmp))
+			    (eq (caar (setq next tmp)) before))))
+	(if next (setq prev next))
+	(setq next nil)
+	(setq tmp (cdr tmp))))
+    (when (or (keymapp item)
+	      (and (symbolp item) (keymapp (symbol-value item))))
+      ;; Item is a keymap, find the prompt string and use as item name.
+      (setq next (easy-menu-get-map item nil))
+      (if (not (keymapp item)) (setq item next))
+      (setq tmp nil)			; No item name yet.
+      (while (and (null tmp) (consp (setq next (cdr next)))
+		  (not (keymapp next)))
+	(if (stringp (car next)) (setq tmp (car next)) ; Got a name.
+	  (setq next (cdr next))))
+      (setq item (cons tmp item)))
+    (easy-menu-do-add-item menu item
+			   (and (not top) (easy-menu-have-button menu) "    ")
+			   prev top)))
+
+(defun easy-menu-item-present-p (menu path name)
+  "In submenu of MENU with path PATH, return true iff item NAME is present.
+MENU and PATH are defined as in `easy-menu-add-item'.
+NAME should be a string, the name of the element to be looked for."
+  (lookup-key (easy-menu-get-map menu path) (vector (intern name))))
+
+(defun easy-menu-remove-item (menu path name)
+  "From submenu of MENU with path PATH remove item NAME.
+MENU and PATH are defined as in `easy-menu-add-item'.
+NAME should be a string, the name of the element to be removed."
+  (let ((item (vector (intern name)))
+	(top (not (or menu path)))
+	tmp)
+    (setq menu (easy-menu-get-map menu path))
+    (when (setq tmp (lookup-key menu item))
+      (define-key menu item nil)
+      (and (not top)
+	   (easy-menu-is-button tmp)	; Removed item was a button and
+	   (not (easy-menu-have-button menu)) ; no buttons left then
+	   ;; remove prefix from items in menu
+	   (easy-menu-change-prefix menu nil)))))
+
+(defun easy-menu-get-map (menu path)
+  ;; Return a sparse keymap in which to add or remove an item.
+  ;; MENU and PATH are as defined in `easy-menu-remove-item'.
+  (if (null menu)
+      (setq menu (key-binding (vconcat '(menu-bar) (mapcar 'intern path))))
+    (if (and (symbolp menu) (not (keymapp menu)))
+	(setq menu (symbol-value menu)))
+    (if path (setq menu (lookup-key menu (vconcat (mapcar 'intern path))))))
+  (while (and (symbolp menu) (keymapp menu))
+    (setq menu (symbol-function menu)))
+  (or (keymapp menu) (error "Malformed menu in easy-menu: (%s)" menu))
+  menu)
+
+(defun easy-menu-is-button (val)
+  ;; VAL is a real menu binding.  Return true iff it is a toggle or
+  ;; radio button.
+  (and (symbolp val)
+       (consp (setq val (get val 'menu-enable)))
+       (eq (car val) 'easy-menu-update-button)))
+
+(defun easy-menu-have-button (map)
+  ;; MAP is a sparse keymap.  Return true iff there is any toggle or radio
+  ;; button in MAP.
+  (let ((have nil) tmp)
+    (while (and (consp map) (not have))
+      (and (consp (setq tmp (car map)))
+	   (consp (setq tmp (cdr tmp)))
+	   (stringp (car tmp))
+	   (setq have (easy-menu-is-button (easy-menu-real-binding tmp))))
+      (setq map (cdr map)))
+    have))
+
+(defun easy-menu-real-binding (val)
+  ;; Val is a menu keymap binding.  Skip item string.
+  ;; Also skip a possible help string and/or key-binding cache.
+  (if (and (consp (setq val (cdr val))) (stringp (car val)))
+      (setq val (cdr val)))		; Skip help string.
+  (if (and (consp val) (consp (car val))
+	   (or (null (caar val)) (vectorp (caar val))))
+      (setq val (cdr val)))		; Skip key-binding cache.
+  val)
+
+(defun easy-menu-change-prefix (map add)
+  ;; MAP is a sparse keymap.
+  ;; If ADD is true add a button compensating prefix to each menu item in MAP.
+  ;; Else remove prefix instead.
+  (let (tmp val)
+    (while (consp map)
+      (when (and (consp (setq tmp (car map)))
+		 (consp (setq tmp (cdr tmp)))
+		 (stringp (car tmp)))
+	(cond
+	 (add (setcar tmp (concat "    " (car tmp))))
+	 ((string-match "$    " (car tmp))
+	  (setcar tmp (substring (car tmp) (match-end 0))))))
+      (setq map (cdr map)))))
+
 (provide 'easymenu)
 
 ;;; easymenu.el ends here