leim/quail/uni-input.el

   1 ;;; uni-input.el --- Hex Unicode input method
   2
   3 ;; Copyright (C) 2001-2012  Free Software Foundation, Inc.
   4 ;; Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
   5 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   6 ;;   Registration Number H14PRO021
   7
   8 ;; Author: Dave Love <fx@gnu.org>
   9 ;; Keywords: i18n
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software: you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation, either version 3 of the License, or
  16 ;; (at your option) any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  25
  26 ;;; Commentary:
  27
  28 ;; Provides an input method for entering characters by hex unicode in
  29 ;; the form `uxxxx', similarly to the Yudit editor.
  30
  31 ;; This is not really a Quail method, but uses some Quail functions.
  32 ;; There is probably A Better Way.
  33
  34 ;; You can get a similar effect by using C-q with
  35 ;; `read-quoted-char-radix' set to 16.
  36
  37 ;; Note that this only allows you to enter BMP values unless someone
  38 ;; extends it to use variable numbers of digits.
  39
  40 ;;; Code:
  41
  42 (require 'quail)
  43
  44 (defun ucs-input-insert-char (char)
  45   (insert char)
  46   (move-overlay quail-overlay (overlay-start quail-overlay) (point)))
  47
  48 (defun ucs-input-method (key)
  49   (if (or buffer-read-only
  50           (and (/= key ?U) (/= key ?u)))
  51       (list key)
  52     (quail-setup-overlays nil)
  53     (ucs-input-insert-char key)
  54     (let ((modified-p (buffer-modified-p))
  55           (buffer-undo-list t)
  56           (input-method-function nil)
  57           (echo-keystrokes 0)
  58           (help-char nil)
  59           (events (list key))
  60           (str "    "))
  61       (unwind-protect
  62           (catch 'non-digit
  63             (progn
  64               (dotimes (i 4)
  65                 (let ((seq (read-key-sequence nil))
  66                       key)
  67                   (if (and (stringp seq)
  68                            (= 1 (length seq))
  69                            (setq key (aref seq 0))
  70                            (memq key '(?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9 ?a
  71                                           ?b ?c ?d ?e ?f ?A ?B ?C ?D ?E ?F)))
  72                       (progn
  73                         (push key events)
  74                         (ucs-input-insert-char key))
  75                     (quail-delete-region)
  76                     (throw 'non-digit (append (reverse events)
  77                                               (listify-key-sequence seq))))))
  78               (quail-delete-region)
  79               (let ((n (string-to-number (apply 'string
  80                                             (cdr (nreverse events)))
  81                                      16)))
  82                 (if (characterp n)
  83                     (list n)))))
  84         (quail-delete-overlays)
  85         (set-buffer-modified-p modified-p)
  86         (run-hooks 'input-method-after-insert-chunk-hook)))))
  87
  88 (defun ucs-input-activate (&optional arg)
  89   "Activate UCS input method.
  90 With arg, activate UCS input method if and only if arg is positive.
  91
  92 While this input method is active, the variable
  93 `input-method-function' is bound to the function `ucs-input-method'."
  94   (if (and arg
  95           (< (prefix-numeric-value arg) 0))
  96       (unwind-protect
  97           (progn
  98             (quail-hide-guidance)
  99             (quail-delete-overlays)
 100             (setq describe-current-input-method-function nil))
 101         (kill-local-variable 'input-method-function))
 102     (setq deactivate-current-input-method-function 'ucs-input-deactivate)
 103     (setq describe-current-input-method-function 'ucs-input-help)
 104     (quail-delete-overlays)
 105     (if (eq (selected-window) (minibuffer-window))
 106         (add-hook 'minibuffer-exit-hook 'quail-exit-from-minibuffer))
 107     (set (make-local-variable 'input-method-function)
 108          'ucs-input-method)))
 109
 110 (defun ucs-input-deactivate ()
 111   "Deactivate UCS input method."
 112   (interactive)
 113   (ucs-input-activate -1))
 114
 115 (define-obsolete-function-alias
 116   'ucs-input-inactivate
 117   'ucs-input-deactivate "24.3")
 118
 119 (defun ucs-input-help ()
 120   (interactive)
 121   (with-output-to-temp-buffer "*Help*"
 122     (princ "\
 123 Input method: ucs (mode line indicator:U+)
 124
 125 Input as Unicode: U<hex> or u<hex>, where <hex> is a four-digit hex number.")))
 126
 127 ;; The file ../leim-ext.el contains the following call.
 128 ;; (register-input-method "ucs" "UTF-8" 'ucs-input-activate "U+"
 129 ;;                     "Unicode input as hex in the form Uxxxx.")
 130
 131 (provide 'uni-input)
 132
 133 ;;; uni-input.el ends here