lisp/options.el

   1 ;;; options.el --- edit Options command for Emacs.
   2
   3 ;; Maintainer: FSF
   4 ;; Last-Modified: 10 Apr 1991
   5
   6 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Code:
  25
  26 ;;;###autoload
  27 (defun list-options ()
  28   "Display a list of Emacs user options, with values and documentation."
  29   (interactive)
  30   (save-excursion
  31     (set-buffer (get-buffer-create "*List Options*"))
  32     (Edit-options-mode))
  33   (with-output-to-temp-buffer "*List Options*"
  34     (let (vars)
  35       (mapatoms (function (lambda (sym)
  36                             (if (user-variable-p sym)
  37                                 (setq vars (cons sym vars))))))
  38       (setq vars (sort vars 'string-lessp))
  39       (while vars
  40         (let ((sym (car vars)))
  41           (princ ";; ")
  42           (prin1 sym)
  43           (princ ":\n\t")
  44           (prin1 (symbol-value sym))
  45           (terpri)
  46           (princ (substitute-command-keys
  47                   (documentation-property sym 'variable-documentation)))
  48           (princ "\n;;\n"))
  49         (setq vars (cdr vars))))))
  50
  51 ;;;###autoload
  52 (defun edit-options ()
  53   "Edit a list of Emacs user option values.
  54 Selects a buffer containing such a list,
  55 in which there are commands to set the option values.
  56 Type \\[describe-mode] in that buffer for a list of commands."
  57   (interactive)
  58   (list-options)
  59   (pop-to-buffer "*List Options*"))
  60
  61 (defvar Edit-options-mode-map
  62   (let ((map (make-keymap)))
  63     (define-key map "s" 'Edit-options-set)
  64     (define-key map "x" 'Edit-options-toggle)
  65     (define-key map "1" 'Edit-options-t)
  66     (define-key map "0" 'Edit-options-nil)
  67     (define-key map "p" 'backward-paragraph)
  68     (define-key map " " 'forward-paragraph)
  69     (define-key map "n" 'forward-paragraph)
  70     map)
  71   "")
  72
  73 ;; Edit Options mode is suitable only for specially formatted data.
  74 (put 'Edit-options-mode 'mode-class 'special)
  75
  76 (defun Edit-options-mode ()
  77   "\\<Edit-options-mode-map>\
  78 Major mode for editing Emacs user option settings.
  79 Special commands are:
  80 \\[Edit-options-set] -- set variable point points at.  New value read using minibuffer.
  81 \\[Edit-options-toggle] -- toggle variable, t -> nil, nil -> t.
  82 \\[Edit-options-t] -- set variable to t.
  83 \\[Edit-options-nil] -- set variable to nil.
  84 Changed values made by these commands take effect immediately.
  85
  86 Each variable description is a paragraph.
  87 For convenience, the characters \\[backward-paragraph] and \\[forward-paragraph] move back and forward by paragraphs."
  88   (kill-all-local-variables)
  89   (set-syntax-table emacs-lisp-mode-syntax-table)
  90   (use-local-map Edit-options-mode-map)
  91   (make-local-variable 'paragraph-separate)
  92   (setq paragraph-separate "[^\^@-\^?]")
  93   (make-local-variable 'paragraph-start)
  94   (setq paragraph-start "^\t")
  95   (setq truncate-lines t)
  96   (setq major-mode 'Edit-options-mode)
  97   (setq mode-name "Options")
  98   (run-hooks 'Edit-options-mode-hook))
  99
 100 (defun Edit-options-set () (interactive)
 101   (Edit-options-modify
 102    '(lambda (var) (eval-minibuffer (concat "New " (symbol-name var) ": ")))))
 103
 104 (defun Edit-options-toggle () (interactive)
 105   (Edit-options-modify '(lambda (var) (not (symbol-value var)))))
 106
 107 (defun Edit-options-t () (interactive)
 108   (Edit-options-modify '(lambda (var) t)))
 109
 110 (defun Edit-options-nil () (interactive)
 111   (Edit-options-modify '(lambda (var) nil)))
 112
 113 (defun Edit-options-modify (modfun)
 114   (save-excursion
 115    (let (var pos)
 116      (re-search-backward "^;; \\|\\`")
 117      (forward-char 3)
 118      (setq pos (point))
 119      (save-restriction
 120        (narrow-to-region pos (progn (end-of-line) (1- (point))))
 121        (goto-char pos)
 122        (setq var (read (current-buffer))))
 123      (goto-char pos)
 124      (forward-line 1)
 125      (forward-char 1)
 126      (save-excursion
 127        (set var (funcall modfun var)))
 128      (kill-sexp 1)
 129      (prin1 (symbol-value var) (current-buffer)))))
 130
 131 ;;; options.el ends here