--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/prim/options.el	Mon Aug 13 08:45:50 2007 +0200
@@ -0,0 +1,145 @@
+;;; options.el --- edit Options command for XEmacs.
+
+;; Copyright (C) 1985, 1993 Free Software Foundation, Inc.
+
+;; Maintainer: FSF
+
+;; This file is part of XEmacs.
+
+;; XEmacs is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; XEmacs is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with XEmacs; see the file COPYING.  If not, write to the Free
+;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;; Synched up with: FSF 19.30.
+
+;;; Commentary:
+
+;; This code provides functions to list and edit the values of all global
+;; option variables known to loaded Emacs Lisp code.  There are two entry
+;; points, `list-options' and `edit' options'.  The latter enters a major
+;; mode specifically for editing option values.  Do `M-x describe-mode' in
+;; that context for more details.
+
+;;; Code:
+
+;;;###autoload
+(defun list-options ()
+  "Display a list of XEmacs user options, with values and documentation."
+  (interactive)
+  (save-excursion
+    (set-buffer (get-buffer-create "*List Options*"))
+    (Edit-options-mode))
+  (with-output-to-temp-buffer "*List Options*"
+    (let (vars)
+      (mapatoms #'(lambda (sym)
+		    (if (user-variable-p sym)
+			(setq vars (cons sym vars)))))
+      (setq vars (sort vars 'string-lessp))
+      (while vars
+	(let ((sym (car vars)))
+	  (princ ";; ")
+	  (prin1 sym)
+	  (princ ":\n\t")
+	  (if (boundp sym)
+	      (prin1 (symbol-value sym))
+              (princ "#<unbound>"))
+	  (terpri)
+	  (princ (substitute-command-keys 
+		  (documentation-property sym 'variable-documentation)))
+	  (princ "\n;;\n"))
+	(setq vars (cdr vars)))))
+  (save-excursion
+    (set-buffer "*List Options*")
+    (setq buffer-read-only t)))
+
+;;;###autoload
+(defun edit-options ()
+  "Edit a list of XEmacs user option values.
+Selects a buffer containing such a list,
+in which there are commands to set the option values.
+Type \\[describe-mode] in that buffer for a list of commands."
+  (interactive)
+  (list-options)
+  (pop-to-buffer "*List Options*"))
+
+(defvar Edit-options-mode-map
+  (let ((map (make-keymap)))
+    (define-key map "s" 'Edit-options-set)
+    (define-key map "x" 'Edit-options-toggle)
+    (define-key map "1" 'Edit-options-t)
+    (define-key map "0" 'Edit-options-nil)
+    (define-key map "p" 'backward-paragraph)
+    (define-key map " " 'forward-paragraph)
+    (define-key map "n" 'forward-paragraph)
+    map)
+  "")
+
+;; Edit Options mode is suitable only for specially formatted data.
+(put 'Edit-options-mode 'mode-class 'special)
+
+(defun Edit-options-mode ()
+  "\\<Edit-options-mode-map>\
+Major mode for editing XEmacs user option settings.
+Special commands are:
+\\[Edit-options-set] -- set variable point points at.  New value read using minibuffer.
+\\[Edit-options-toggle] -- toggle variable, t -> nil, nil -> t.
+\\[Edit-options-t] -- set variable to t.
+\\[Edit-options-nil] -- set variable to nil.
+Changed values made by these commands take effect immediately.
+
+Each variable description is a paragraph.
+For convenience, the characters \\[backward-paragraph] and \\[forward-paragraph] move back and forward by paragraphs."
+  (kill-all-local-variables)
+  (set-syntax-table emacs-lisp-mode-syntax-table)
+  (use-local-map Edit-options-mode-map)
+  (make-local-variable 'paragraph-separate)
+  (setq paragraph-separate "[^\^@-\^?]")
+  (make-local-variable 'paragraph-start)
+  (setq paragraph-start "\t")
+  (setq truncate-lines t)
+  (setq major-mode 'Edit-options-mode)
+  (setq mode-name (gettext "Options"))
+  (run-hooks 'Edit-options-mode-hook))
+
+(defun Edit-options-set () (interactive)
+  (Edit-options-modify
+   '(lambda (var) (eval-minibuffer (format "New %s:" (symbol-name var))))))
+
+(defun Edit-options-toggle () (interactive)
+  (Edit-options-modify '(lambda (var) (not (symbol-value var)))))
+
+(defun Edit-options-t () (interactive)
+  (Edit-options-modify '(lambda (var) t)))
+
+(defun Edit-options-nil () (interactive)
+  (Edit-options-modify '(lambda (var) nil)))
+
+(defun Edit-options-modify (modfun)
+  (save-excursion
+   (let ((buffer-read-only nil) var pos)
+     (re-search-backward "^;; \\|\\`")
+     (forward-char 3)
+     (setq pos (point))
+     (save-restriction
+      (narrow-to-region pos (progn (end-of-line) (1- (point))))
+      (goto-char pos)
+      (setq var (read (current-buffer))))
+     (goto-char pos)
+     (forward-line 1)
+     (forward-char 1)
+     (save-excursion
+      (set var (funcall modfun var)))
+     (kill-sexp 1)
+     (prin1 (symbol-value var) (current-buffer)))))
+
+;;; options.el ends here