Initial revision
[emacs.git] / lisp / double.el
blob0a422bedbf145368f5033f6d2f81d762f0038643
1 ;;; double.el --- Support for keyboard remapping with double clicking
3 ;; Copyright (C) 1994 Free Software Foundation, Inc.
5 ;; Author: Per Abrahamsen <abraham@iesd.auc.dk>
6 ;; Keywords: i18n
8 ;; This file is part of GNU Emacs.
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.
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.
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 the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
25 ;;; Commentary:
27 ;; This mode is intended for use with languages that adds a small
28 ;; number of extra letters not available on the keyboard.
29 ;;
30 ;; Examples includes Scandinavian and German with an US keyboard.
32 ;; The idea is that certain keys are overloaded. When you press it
33 ;; once it will insert one string, and when you press it twice the
34 ;; string will be replaced by another. This can be used for mapping
35 ;; keys on a US keyboard to generate characters according to the local
36 ;; keyboard convention when pressed once, and according to US keyboard
37 ;; convention when pressed twice.
39 ;; To use this mode, you must define the variable `double-map' and
40 ;; then enable double mode with `M-x double-mode'. Read the
41 ;; documentation for both of them.
43 ;; The default mapping is for getting Danish/Norwegian keyboard layout
44 ;; using ISO Latin 1 on a US keyboard.
46 ;; Important node: While I would like to hear comments, bug reports,
47 ;; suggestions, please do @strong{not} expect me to put other mappings
48 ;; than the default into this file. There are billions and billions
49 ;; of such mappings, and just supporting the most common would
50 ;; increase the size of this nice small file manyfold.
52 ;;; ChangeLog:
54 ;; * 1994-06-21 Per Abrahamsen
55 ;; Added `double-prefix-only'.
56 ;; * 1994-02-28 Per Abrahamsen
57 ;; Use 127 instead of 'delete to delete a character.
58 ;; * 1994-02-03 Per Abrahamsen
59 ;; Created.
61 ;;; Code:
63 (defvar double-map
64 '((?\; "\346" ";")
65 (?\' "\370" "'")
66 (?\[ "\345" "[")
67 (?\: "\306" ":")
68 (?\" "\330" "\"")
69 (?\{ "\305" "{"))
70 "Alist of key translations activated by double mode.
72 Each entry is a list with three elements:
73 1. The key activating the translation.
74 2. The string to be inserted when the key is pressed once.
75 3. The string to be inserted when the key is pressed twice.")
77 (defvar double-prefix-only t
78 "*Non-nil means that Double mode mapping only works for prefix keys.
79 That is, for any key `X' in `double-map', `X' alone will be mapped
80 but not `C-u X' or `ESC X' since the X is not the prefix key.")
82 ;;; Read Event
84 (defvar double-last-event nil)
85 ;; The last key that generated a double key event.
87 (defun double-read-event (prompt)
88 ;; Read an event
89 (if isearch-mode (isearch-update))
90 (if prompt
91 (prog2 (message "%s%c" prompt double-last-event)
92 (read-event)
93 (message ""))
94 (read-event)))
96 (global-set-key [ignore] '(lambda () (interactive)))
98 (or (boundp 'isearch-mode-map)
99 (load-library "isearch"))
101 (define-key isearch-mode-map [ignore]
102 (function (lambda () (interactive) (isearch-update))))
104 (defun double-translate-key (prompt)
105 ;; Translate input events using double map.
106 (let ((key last-input-char))
107 (cond (unread-command-events
108 ;; Artificial event, ignore it.
109 (vector key))
110 ((and double-prefix-only
111 (> (length (this-command-keys)) 1))
112 ;; This is not a prefix key, ignore it.
113 (vector key))
114 ((eq key 'magic-start)
115 ;; End of generated event. See if he will repeat it...
116 (let ((new (double-read-event prompt))
117 (entry (assoc double-last-event double-map)))
118 (if (eq new double-last-event)
119 (progn
120 (setq unread-command-events
121 (append (make-list (1- (length (nth 1 entry)))
122 127)
123 (nth 2 entry)
124 '(magic-end)))
125 (vector 127))
126 (setq unread-command-events (list new))
127 [ignore])))
128 ((eq key 'magic-end)
129 ;; End of double event. Ignore.
130 [ignore])
132 ;; New key.
133 (let ((exp (nth 1 (assoc key double-map))))
134 (setq double-last-event key)
135 (setq unread-command-events
136 (append (substring exp 1) '(magic-start)))
137 (vector (aref exp 0)))))))
139 ;;; Key Translation Map
141 (defvar default-key-translation-map
142 (or key-translation-map (make-sparse-keymap))
143 "Key translation you want to have effect, regardless of Double mode.
144 This defaults to the value of `key-translation-map' when double was
145 first loaded.")
147 (make-variable-buffer-local 'key-translation-map)
149 (defun double-setup ()
150 ;; Setup key-translation-map as indicated by `double-map'.
151 (setq key-translation-map (copy-keymap default-key-translation-map))
152 (mapcar (function (lambda (entry)
153 (define-key key-translation-map (vector (nth 0 entry))
154 'double-translate-key)))
155 (append double-map '((magic-start) (magic-end)))))
157 ;;; Mode
159 (defvar double-mode nil)
160 ;; Indicator for the double mode.
161 (make-variable-buffer-local 'double-mode)
163 (or (assq 'double-mode minor-mode-alist)
164 (setq minor-mode-alist
165 (cons '(double-mode " Double") minor-mode-alist)))
167 ;; This feature seemed useless and it confused describe-mode,
168 ;; so I deleted it.
169 ;;;(defvar double-mode-name "Double")
170 ;;;;; Name of current double mode.
171 ;;; (make-variable-buffer-local 'double-mode-name)
173 ;;;###autoload
174 (defun double-mode (arg)
175 "Toggle Double mode.
176 With prefix arg, turn Double mode on iff arg is positive.
178 When Double mode is on, some keys will insert different strings
179 when pressed twice. See variable `double-map' for details."
180 (interactive "P")
181 (if (or (and (null arg) double-mode)
182 (<= (prefix-numeric-value arg) 0))
183 ;; Turn it off
184 (if double-mode
185 (progn
186 (let ((double-map))
187 (double-setup))
188 (setq double-mode nil)
189 (force-mode-line-update)))
190 ;;Turn it on
191 (if double-mode
193 (double-setup)
194 (setq double-mode t)
195 (force-mode-line-update))))
197 (provide 'double)
199 ;;; double.el ends here