lisp/options.el

   1 ;;; options.el --- edit Options command for Emacs.
   2
   3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6
   7 ;; This file is part of GNU Emacs.
   8
   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.
  13
  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.
  18
  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.
  22
  23 ;;; Code:
  24
  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))))))
  49
  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*"))
  59
  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   "")
  71
  72 ;; Edit Options mode is suitable only for specially formatted data.
  73 (put 'Edit-options-mode 'mode-class 'special)
  74
  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.
  84
  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))
  98
  99 (defun Edit-options-set () (interactive)
 100   (Edit-options-modify
 101    '(lambda (var) (eval-minibuffer (concat "New " (symbol-name var) ": ")))))
 102
 103 (defun Edit-options-toggle () (interactive)
 104   (Edit-options-modify '(lambda (var) (not (symbol-value var)))))
 105
 106 (defun Edit-options-t () (interactive)
 107   (Edit-options-modify '(lambda (var) t)))
 108
 109 (defun Edit-options-nil () (interactive)
 110   (Edit-options-modify '(lambda (var) nil)))
 111
 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)))))
 129
 130 ;;; options.el ends here