leim/quail/uni-input.el

   1 ;;; uni-input.el --- Hex Unicode input method
   2
   3 ;; Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   4 ;;   Free Software Foundation, Inc.
   5 ;; Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
   6 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   7 ;;   Registration Number H14PRO021
   8
   9 ;; Author: Dave Love <fx@gnu.org>
  10 ;; Keywords: i18n
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software: you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation, either version 3 of the License, or
  17 ;; (at your option) any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  26
  27 ;;; Commentary:
  28
  29 ;; Provides an input method for entering characters by hex unicode in
  30 ;; the form `uxxxx', similarly to the Yudit editor.
  31
  32 ;; This is not really a Quail method, but uses some Quail functions.
  33 ;; There is probably A Better Way.
  34
  35 ;; You can get a similar effect by using C-q with
  36 ;; `read-quoted-char-radix' set to 16.
  37
  38 ;; Note that this only allows you to enter BMP values unless someone
  39 ;; extends it to use variable numbers of digits.
  40
  41 ;;; Code:
  42
  43 (require 'quail)
  44
  45 (defun ucs-input-insert-char (char)
  46   (insert char)
  47   (move-overlay quail-overlay (overlay-start quail-overlay) (point)))
  48
  49 (defun ucs-input-method (key)
  50   (if (or buffer-read-only
  51           (and (/= key ?U) (/= key ?u)))
  52       (list key)
  53     (quail-setup-overlays nil)
  54     (ucs-input-insert-char key)
  55     (let ((modified-p (buffer-modified-p))
  56           (buffer-undo-list t)
  57           (input-method-function nil)
  58           (echo-keystrokes 0)
  59           (help-char nil)
  60           (events (list key))
  61           (str "    "))
  62       (unwind-protect
  63           (catch 'non-digit
  64             (progn
  65               (dotimes (i 4)
  66                 (let ((seq (read-key-sequence nil))
  67                       key)
  68                   (if (and (stringp seq)
  69                            (= 1 (length seq))
  70                            (setq key (aref seq 0))
  71                            (memq key '(?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9 ?a
  72                                           ?b ?c ?d ?e ?f ?A ?B ?C ?D ?E ?F)))
  73                       (progn
  74                         (push key events)
  75                         (ucs-input-insert-char key))
  76                     (quail-delete-region)
  77                     (throw 'non-digit (append (reverse events)
  78                                               (listify-key-sequence seq))))))
  79               (quail-delete-region)
  80               (let ((n (string-to-number (apply 'string
  81                                             (cdr (nreverse events)))
  82                                      16)))
  83                 (if (characterp n)
  84                     (list n)))))
  85         (quail-delete-overlays)
  86         (set-buffer-modified-p modified-p)
  87         (run-hooks 'input-method-after-insert-chunk-hook)))))
  88
  89 (defun ucs-input-activate (&optional arg)
  90   "Activate UCS input method.
  91 With arg, activate UCS input method if and only if arg is positive.
  92
  93 While this input method is active, the variable
  94 `input-method-function' is bound to the function `ucs-input-method'."
  95   (if (and arg
  96           (< (prefix-numeric-value arg) 0))
  97       (unwind-protect
  98           (progn
  99             (quail-hide-guidance)
 100             (quail-delete-overlays)
 101             (setq describe-current-input-method-function nil))
 102         (kill-local-variable 'input-method-function))
 103     (setq inactivate-current-input-method-function 'ucs-input-inactivate)
 104     (setq describe-current-input-method-function 'ucs-input-help)
 105     (quail-delete-overlays)
 106     (if (eq (selected-window) (minibuffer-window))
 107         (add-hook 'minibuffer-exit-hook 'quail-exit-from-minibuffer))
 108     (set (make-local-variable 'input-method-function)
 109          'ucs-input-method)))
 110
 111 (defun ucs-input-inactivate ()
 112   "Inactivate UCS input method."
 113   (interactive)
 114   (ucs-input-activate -1))
 115
 116 (defun ucs-input-help ()
 117   (interactive)
 118   (with-output-to-temp-buffer "*Help*"
 119     (princ "\
 120 Input method: ucs (mode line indicator:U+)
 121
 122 Input as Unicode: U<hex> or u<hex>, where <hex> is a four-digit hex number.")))
 123
 124 ;; The file ../leim-ext.el contains the following call.
 125 ;; (register-input-method "ucs" "UTF-8" 'ucs-input-activate "U+"
 126 ;;                     "Unicode input as hex in the form Uxxxx.")
 127
 128 (provide 'uni-input)
 129
 130 ;; arch-tag: e0d91c7c-19a1-43d3-8f2b-28c0e031efaa
 131 ;;; uni-input.el ends here