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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
21 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23 ;;; Code:
25 ;;;###autoload
26 (defun list-options ()
27 "Display a list of Emacs user options, with values and documentation."
28 (interactive)
29 (save-excursion
30 (set-buffer (get-buffer-create "*List Options*"))
31 (Edit-options-mode))
32 (with-output-to-temp-buffer "*List Options*"
33 (let (vars)
34 (mapatoms (function (lambda (sym)
35 (if (user-variable-p sym)
36 (setq vars (cons sym vars))))))
37 (setq vars (sort vars 'string-lessp))
38 (while vars
39 (let ((sym (car vars)))
40 (princ ";; ")
41 (prin1 sym)
42 (princ ":\n\t")
43 (prin1 (symbol-value sym))
44 (terpri)
45 (princ (substitute-command-keys
46 (documentation-property sym 'variable-documentation)))
47 (princ "\n;;\n"))
48 (setq vars (cdr vars))))))
50 ;;;###autoload
51 (defun edit-options ()
52 "Edit a list of Emacs user option values.
53 Selects a buffer containing such a list,
54 in which there are commands to set the option values.
55 Type \\[describe-mode] in that buffer for a list of commands."
56 (interactive)
57 (list-options)
58 (pop-to-buffer "*List Options*"))
60 (defvar Edit-options-mode-map
61 (let ((map (make-keymap)))
62 (define-key map "s" 'Edit-options-set)
63 (define-key map "x" 'Edit-options-toggle)
64 (define-key map "1" 'Edit-options-t)
65 (define-key map "0" 'Edit-options-nil)
66 (define-key map "p" 'backward-paragraph)
67 (define-key map " " 'forward-paragraph)
68 (define-key map "n" 'forward-paragraph)
69 map)
70 "")
72 ;; Edit Options mode is suitable only for specially formatted data.
73 (put 'Edit-options-mode 'mode-class 'special)
75 (defun Edit-options-mode ()
76 "\\<Edit-options-mode-map>\
77 Major mode for editing Emacs user option settings.
78 Special commands are:
79 \\[Edit-options-set] -- set variable point points at. New value read using minibuffer.
80 \\[Edit-options-toggle] -- toggle variable, t -> nil, nil -> t.
81 \\[Edit-options-t] -- set variable to t.
82 \\[Edit-options-nil] -- set variable to nil.
83 Changed values made by these commands take effect immediately.
85 Each variable description is a paragraph.
86 For convenience, the characters \\[backward-paragraph] and \\[forward-paragraph] move back and forward by paragraphs."
87 (kill-all-local-variables)
88 (set-syntax-table emacs-lisp-mode-syntax-table)
89 (use-local-map Edit-options-mode-map)
90 (make-local-variable 'paragraph-separate)
91 (setq paragraph-separate "[^\^@-\^?]")
92 (make-local-variable 'paragraph-start)
93 (setq paragraph-start "^\t")
94 (setq truncate-lines t)
95 (setq major-mode 'Edit-options-mode)
96 (setq mode-name "Options")
97 (run-hooks 'Edit-options-mode-hook))
99 (defun Edit-options-set () (interactive)
100 (Edit-options-modify
101 '(lambda (var) (eval-minibuffer (concat "New " (symbol-name var) ": ")))))
103 (defun Edit-options-toggle () (interactive)
104 (Edit-options-modify '(lambda (var) (not (symbol-value var)))))
106 (defun Edit-options-t () (interactive)
107 (Edit-options-modify '(lambda (var) t)))
109 (defun Edit-options-nil () (interactive)
110 (Edit-options-modify '(lambda (var) nil)))
112 (defun Edit-options-modify (modfun)
113 (save-excursion
114 (let (var pos)
115 (re-search-backward "^;; \\|\\`")
116 (forward-char 3)
117 (setq pos (point))
118 (save-restriction
119 (narrow-to-region pos (progn (end-of-line) (1- (point))))
120 (goto-char pos)
121 (setq var (read (current-buffer))))
122 (goto-char pos)
123 (forward-line 1)
124 (forward-char 1)
125 (save-excursion
126 (set var (funcall modfun var)))
127 (kill-sexp 1)
128 (prin1 (symbol-value var) (current-buffer)))))
130 ;;; options.el ends here