lisp/options.el

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