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[emacs.git] / lisp / options.el
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1 ;;; options.el --- edit Options command for Emacs.
3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
5 ;; Maintainer: FSF
7 ;; This file is part of GNU Emacs.
9 ;; GNU Emacs is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation; either version 2, or (at your option)
12 ;; any later version.
14 ;; GNU Emacs is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
24 ;;; Commentary:
26 ;; This code provides functions to list and edit the values of all global
27 ;; option variables known to loaded Emacs Lisp code. There are two entry
28 ;; points, `list-options' and `edit' options'. The latter enters a major
29 ;; mode specifically for editing option values. Do `M-x describe-mode' in
30 ;; that context for more details.
32 ;;; Code:
34 ;;;###autoload
35 (defun list-options ()
36 "Display a list of Emacs user options, with values and documentation."
37 (interactive)
38 (save-excursion
39 (set-buffer (get-buffer-create "*List Options*"))
40 (Edit-options-mode))
41 (with-output-to-temp-buffer "*List Options*"
42 (let (vars)
43 (mapatoms (function (lambda (sym)
44 (if (user-variable-p sym)
45 (setq vars (cons sym vars))))))
46 (setq vars (sort vars 'string-lessp))
47 (while vars
48 (let ((sym (car vars)))
49 (princ ";; ")
50 (prin1 sym)
51 (princ ":\n\t")
52 (prin1 (symbol-value sym))
53 (terpri)
54 (princ (substitute-command-keys
55 (documentation-property sym 'variable-documentation)))
56 (princ "\n;;\n"))
57 (setq vars (cdr vars)))))
58 (save-excursion
59 (set-buffer "*List Options*")
60 (setq buffer-read-only t)))
62 ;;;###autoload
63 (defun edit-options ()
64 "Edit a list of Emacs user option values.
65 Selects a buffer containing such a list,
66 in which there are commands to set the option values.
67 Type \\[describe-mode] in that buffer for a list of commands."
68 (interactive)
69 (list-options)
70 (pop-to-buffer "*List Options*"))
72 (defvar Edit-options-mode-map
73 (let ((map (make-keymap)))
74 (define-key map "s" 'Edit-options-set)
75 (define-key map "x" 'Edit-options-toggle)
76 (define-key map "1" 'Edit-options-t)
77 (define-key map "0" 'Edit-options-nil)
78 (define-key map "p" 'backward-paragraph)
79 (define-key map " " 'forward-paragraph)
80 (define-key map "n" 'forward-paragraph)
81 map)
82 "")
84 ;; Edit Options mode is suitable only for specially formatted data.
85 (put 'Edit-options-mode 'mode-class 'special)
87 (defun Edit-options-mode ()
88 "\\<Edit-options-mode-map>\
89 Major mode for editing Emacs user option settings.
90 Special commands are:
91 \\[Edit-options-set] -- set variable point points at. New value read using minibuffer.
92 \\[Edit-options-toggle] -- toggle variable, t -> nil, nil -> t.
93 \\[Edit-options-t] -- set variable to t.
94 \\[Edit-options-nil] -- set variable to nil.
95 Changed values made by these commands take effect immediately.
97 Each variable description is a paragraph.
98 For convenience, the characters \\[backward-paragraph] and \\[forward-paragraph] move back and forward by paragraphs."
99 (kill-all-local-variables)
100 (set-syntax-table emacs-lisp-mode-syntax-table)
101 (use-local-map Edit-options-mode-map)
102 (make-local-variable 'paragraph-separate)
103 (setq paragraph-separate "[^\^@-\^?]")
104 (make-local-variable 'paragraph-start)
105 (setq paragraph-start "\t")
106 (setq truncate-lines t)
107 (setq major-mode 'Edit-options-mode)
108 (setq mode-name "Options")
109 (run-hooks 'Edit-options-mode-hook))
111 (defun Edit-options-set () (interactive)
112 (Edit-options-modify
113 '(lambda (var) (eval-minibuffer (concat "New " (symbol-name var) ": ")))))
115 (defun Edit-options-toggle () (interactive)
116 (Edit-options-modify '(lambda (var) (not (symbol-value var)))))
118 (defun Edit-options-t () (interactive)
119 (Edit-options-modify '(lambda (var) t)))
121 (defun Edit-options-nil () (interactive)
122 (Edit-options-modify '(lambda (var) nil)))
124 (defun Edit-options-modify (modfun)
125 (save-excursion
126 (let ((buffer-read-only nil) var pos)
127 (re-search-backward "^;; \\|\\`")
128 (forward-char 3)
129 (setq pos (point))
130 (save-restriction
131 (narrow-to-region pos (progn (end-of-line) (1- (point))))
132 (goto-char pos)
133 (setq var (read (current-buffer))))
134 (goto-char pos)
135 (forward-line 1)
136 (forward-char 1)
137 (save-excursion
138 (set var (funcall modfun var)))
139 (kill-sexp 1)
140 (prin1 (symbol-value var) (current-buffer)))))
142 ;;; options.el ends here