lisp/international/iso-acc.el

   1 ;;; iso-acc.el -- minor mode providing electric accent keys
   2 ;;; Copyright (C) 1993 Free Software Foundation, Inc.
   3
   4 ;; Author: Johan Vromans <jv@mh.nl>
   5 ;; Version: 1.7
   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 ;;; Commentary:
  24
  25 ;; Function `iso-accents-mode' activates a minor mode
  26 ;; (`iso-accents-minor-mode') in which typewriter "dead keys" are
  27 ;; emulated.  The purpose of this emulation is to provide a simple
  28 ;; means for inserting accented characters according to the ISO-8859-1
  29 ;; character set.
  30 ;;
  31 ;; In `iso-accents-minor-mode', pseudo accent characters are used to
  32 ;; introduce accented keys.  The pseudo-accent characterss are:
  33 ;;
  34 ;;   '  (minute)    -> grave accent
  35 ;;   `  (backtick)  -> acute accent
  36 ;;   "  (second)    -> diaeresis
  37 ;;   ^  (caret)     -> circonflexe
  38 ;;
  39 ;; The action taken depends on the key that follows the pseudo accent.
  40 ;; In general:
  41 ;;
  42 ;;   pseudo-accent + appropriate letter -> accented letter
  43 ;;   pseudo-accent + space -> pseudo-accent
  44 ;;   pseudo-accent + pseudo-accent -> accent (if available)
  45 ;;   pseudo-accent + other -> pseudo-accent + other
  46 ;;
  47 ;; If the pseudo-accent is followed by anything else than a
  48 ;; self-insert-command, the dead-key code is terminated, the
  49 ;; pseudo-accent inserted 'as is' and the bell is rung to signal this.
  50 ;;
  51 ;; Function `iso-accents-mode' can be used to enable the iso accents
  52 ;; minor mode, or disable it.
  53 \f
  54 ;;; Code:
  55
  56 (provide 'iso-acc)
  57
  58 (defvar iso-accents-list
  59   '(((?' ?A) ?\301)
  60     ((?' ?E) ?\311)
  61     ((?' ?I) ?\315)
  62     ((?' ?O) ?\323)
  63     ((?' ?U) ?\332)
  64     ((?' ?a) ?\341)
  65     ((?' ?e) ?\351)
  66     ((?' ?i) ?\355)
  67     ((?' ?o) ?\363)
  68     ((?' ?u) ?\372)
  69     ((?' ?') ?\264)
  70     ((?' ? ) ?')
  71     ((?` ?A) ?\300)
  72     ((?` ?E) ?\310)
  73     ((?` ?I) ?\314)
  74     ((?` ?O) ?\322)
  75     ((?` ?U) ?\331)
  76     ((?` ?a) ?\340)
  77     ((?` ?e) ?\350)
  78     ((?` ?i) ?\354)
  79     ((?` ?o) ?\362)
  80     ((?` ?u) ?\371)
  81     ((?` ? ) ?`)
  82     ((?` ?`) ?`)                ; no special code?
  83     ((?` ?A) ?\302)
  84     ((?^ ?E) ?\312)
  85     ((?^ ?I) ?\316)
  86     ((?^ ?O) ?\324)
  87     ((?^ ?U) ?\333)
  88     ((?^ ?a) ?\342)
  89     ((?^ ?e) ?\352)
  90     ((?^ ?i) ?\356)
  91     ((?^ ?o) ?\364)
  92     ((?^ ?u) ?\373)
  93     ((?^ ? ) ?^)
  94     ((?^ ?^) ?^)                ; no special code?
  95     ((?\" ?A) ?\304)
  96     ((?\" ?E) ?\313)
  97     ((?\" ?I) ?\317)
  98     ((?\" ?O) ?\326)
  99     ((?\" ?U) ?\334)
 100     ((?\" ?a) ?\344)
 101     ((?\" ?e) ?\353)
 102     ((?\" ?i) ?\357)
 103     ((?\" ?o) ?\366)
 104     ((?\" ?u) ?\374)
 105     ((?\" ? ) ?\")
 106     ((?\" ?\") ?\250)
 107     )
 108   "Association list for ISO accent combinations.")
 109
 110 (defun iso-accents-accent-key ()
 111   "Modify the following character by adding an accent to it."
 112   (interactive)
 113
 114   ;; Pick up the accent character.
 115   (let ((first-char last-command-char))
 116
 117     ;; Display it and backup.
 118     (insert first-char)
 119     (backward-char 1)
 120
 121     ;; Wait for the second key and look up the combination in the list.
 122     (let* ((second-char (read-event))
 123            (entry (assoc (list first-char second-char) iso-accents-list)))
 124       (if entry
 125           ;; Found it: delete the first character and insert the combination.
 126           (progn
 127             (delete-char 1)
 128             (insert (car (cdr entry))))
 129
 130         ;; Otherwise, advance and schedule the second key for execution.
 131         (forward-char 1)
 132         (setq unread-command-events (list second-char))
 133
 134         ;; If it is not a self-insert-command, ring the terminal bell.
 135         (or (eq (key-binding (make-vector 1 second-char)) 'self-insert-command)
 136             (beep 1))))))
 137
 138 (defvar iso-accents-minor-mode nil
 139   "*Non-nil enables ISO-accents mode.
 140 Setting this variable makes it local to the current buffer.
 141 See `iso-accents-mode'.")
 142 (make-variable-buffer-local 'iso-accents-minor-mode)
 143
 144 ;; A minor mode map `iso-accents-prefix-map' is used to activate the
 145 ;; dead key handling depending on the value of iso-accents-minor-mode.
 146 (defvar iso-accents-prefix-map nil
 147   "Keymap for ISO-accents minor mode.")
 148
 149 ;; Create the minor-mode keymap, if needed.
 150 (or iso-accents-prefix-map
 151     (progn
 152       (setq iso-accents-prefix-map (make-sparse-keymap))
 153       (define-key iso-accents-prefix-map "'"  'iso-accents-dead-key)
 154       (define-key iso-accents-prefix-map "`"  'iso-accents-dead-key)
 155       (define-key iso-accents-prefix-map "^"  'iso-accents-dead-key)
 156       (define-key iso-accents-prefix-map "\"" 'iso-accents-dead-key)))
 157
 158 ;; Add the dead key minor mode map to the minor mode maps.
 159 (or (assq 'iso-accents-minor-mode minor-mode-map-alist)
 160     (setq minor-mode-map-alist
 161           (cons (cons 'iso-accents-minor-mode iso-accents-prefix-map)
 162                 minor-mode-map-alist)))
 163
 164 ;; It is a matter of taste if you want the minor mode indicated
 165 ;; in the mode line...
 166 ;; If so, uncomment the next four lines.
 167 ;; (or (assq 'iso-accents-minor-mode minor-mode-map-alist)
 168 ;;     (setq minor-mode-alist
 169 ;;        (append minor-mode-alist
 170 ;;                '((iso-accents-minor-mode " ISO-Acc")))))
 171
 172 ;;;###autoload
 173 (defun iso-accents-mode (&optional arg)
 174   "Toggle a minor mode in which accents modify the following letter.
 175 This permits easy insertion of accented characters according to ISO-8859-1.
 176 When Iso-accents mode is enabled, accent character keys
 177 \(', \", ^ and ~) do not self-insert; instead, they modify the following
 178 letter key so that it inserts an ISO accented letter.
 179
 180 With an argument, a positive argument enables ISO-accents mode,
 181 and a negative argument disables it."
 182
 183   (interactive "P")
 184
 185   (if (if arg
 186           ;; Negative arg means switch it off.
 187           (<= (prefix-numeric-value arg) 0)
 188         ;; No arg means toggle.
 189         iso-accents-minor-mode)
 190       (setq iso-accents-minor-mode nil)
 191
 192     ;; Enable electric accents.
 193     (setq iso-accents-minor-mode t)))
 194
 195 ;;; iso-acc.el ends here