lisp/disp-table.el

   1 ;;; disp-table.el --- functions for dealing with char tables.
   2
   3 ;; Copyright (C) 1987, 1994, 1995, 1999 Free Software Foundation, Inc.
   4
   5 ;; Author: Erik Naggum <erik@naggum.no>
   6 ;; Based on a previous version by Howard Gayle
   7 ;; Maintainer: FSF
   8 ;; Keywords: i18n
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Code:
  28
  29 (put 'display-table 'char-table-extra-slots 6)
  30
  31 ;;;###autoload
  32 (defun make-display-table ()
  33   "Return a new, empty display table."
  34   (make-char-table 'display-table nil))
  35
  36 (or standard-display-table
  37     (setq standard-display-table (make-display-table)))
  38
  39 ;;; Display-table slot names.  The property value says which slot.
  40
  41 (put 'truncation 'display-table-slot 0)
  42 (put 'wrap 'display-table-slot 1)
  43 (put 'escape 'display-table-slot 2)
  44 (put 'control 'display-table-slot 3)
  45 (put 'selective-display 'display-table-slot 4)
  46 (put 'vertical-border 'display-table-slot 5)
  47
  48 ;;;###autoload
  49 (defun display-table-slot (display-table slot)
  50   "Return the value of the extra slot in DISPLAY-TABLE named SLOT.
  51 SLOT may be a number from 0 to 5 inclusive, or a slot name (symbol).
  52 Valid symbols are `truncation', `wrap', `escape', `control',
  53 `selective-display', and `vertical-border'."
  54   (let ((slot-number
  55          (if (numberp slot) slot
  56            (or (get slot 'display-table-slot)
  57                (error "Invalid display-table slot name: %s" slot)))))
  58     (char-table-extra-slot display-table slot-number)))
  59
  60 ;;;###autoload
  61 (defun set-display-table-slot (display-table slot value)
  62   "Set the value of the extra slot in DISPLAY-TABLE named SLOT to VALUE.
  63 SLOT may be a number from 0 to 5 inclusive, or a name (symbol).
  64 Valid symbols are `truncation', `wrap', `escape', `control',
  65 `selective-display', and `vertical-border'."
  66   (let ((slot-number
  67          (if (numberp slot) slot
  68            (or (get slot 'display-table-slot)
  69                (error "Invalid display-table slot name: %s" slot)))))
  70     (set-char-table-extra-slot display-table slot-number value)))
  71
  72 ;;;###autoload
  73 (defun describe-display-table (dt)
  74   "Describe the display table DT in a help buffer."
  75   (with-output-to-temp-buffer "*Help*"
  76     (princ "\nTruncation glyph: ")
  77     (prin1 (display-table-slot dt 'truncation))
  78     (princ "\nWrap glyph: ")
  79     (prin1 (display-table-slot dt 'wrap))
  80     (princ "\nEscape glyph: ")
  81     (prin1 (display-table-slot dt 'escape))
  82     (princ "\nCtrl glyph: ")
  83     (prin1 (display-table-slot dt 'control))
  84     (princ "\nSelective display glyph sequence: ")
  85     (prin1 (display-table-slot dt 'selective-display))
  86     (princ "\nVertical window border glyph: ")
  87     (prin1 (display-table-slot dt 'vertical-border))
  88     (princ "\nCharacter display glyph sequences:\n")
  89     (save-excursion
  90       (set-buffer standard-output)
  91       (let ((vector (make-vector 256 nil))
  92             (i 0))
  93         (while (< i 256)
  94           (aset vector i (aref dt i))
  95           (setq i (1+ i)))
  96         (describe-vector vector))
  97       (help-mode))
  98     (print-help-return-message)))
  99
 100 ;;;###autoload
 101 (defun describe-current-display-table ()
 102   "Describe the display table in use in the selected window and buffer."
 103   (interactive)
 104   (let ((disptab (or (window-display-table (selected-window))
 105                      buffer-display-table
 106                      standard-display-table)))
 107     (if disptab
 108         (describe-display-table disptab)
 109       (message "No display table"))))
 110
 111 ;;;###autoload
 112 (defun standard-display-8bit (l h)
 113   "Display characters in the range L to H literally."
 114   (while (<= l h)
 115     (if (and (>= l ?\ ) (< l 127))
 116         (aset standard-display-table l nil)
 117       (aset standard-display-table l (vector l)))
 118     (setq l (1+ l))))
 119
 120 ;;;###autoload
 121 (defun standard-display-default (l h)
 122   "Display characters in the range L to H using the default notation."
 123   (while (<= l h)
 124     (if (and (>= l ?\ ) (< l 127))
 125         (aset standard-display-table l nil)
 126       (aset standard-display-table l nil))
 127     (setq l (1+ l))))
 128
 129 ;; This function does NOT take terminal-dependent escape sequences.
 130 ;; For that, you need to go through create-glyph.  Use one of the
 131 ;; other functions below, or roll your own.
 132 ;;;###autoload
 133 (defun standard-display-ascii (c s)
 134   "Display character C using printable string S."
 135   (aset standard-display-table c (vconcat s)))
 136
 137 ;;;###autoload
 138 (defun standard-display-g1 (c sc)
 139   "Display character C as character SC in the g1 character set.
 140 This function assumes that your terminal uses the SO/SI characters;
 141 it is meaningless for an X frame."
 142   (if window-system
 143       (error "Cannot use string glyphs in a windowing system"))
 144   (aset standard-display-table c
 145         (vector (create-glyph (concat "\016" (char-to-string sc) "\017")))))
 146
 147 ;;;###autoload
 148 (defun standard-display-graphic (c gc)
 149   "Display character C as character GC in graphics character set.
 150 This function assumes VT100-compatible escapes; it is meaningless for an
 151 X frame."
 152   (if window-system
 153       (error "Cannot use string glyphs in a windowing system"))
 154   (aset standard-display-table c
 155         (vector (create-glyph (concat "\e(0" (char-to-string gc) "\e(B")))))
 156
 157 ;;;###autoload
 158 (defun standard-display-underline (c uc)
 159   "Display character C as character UC plus underlining."
 160   (if window-system (require 'faces))
 161   (aset standard-display-table c
 162         (vector
 163          (if window-system
 164              (logior uc (lsh (face-id (internal-find-face 'underline)) 19))
 165            (create-glyph (concat "\e[4m" (char-to-string uc) "\e[m"))))))
 166
 167 ;; Allocate a glyph code to display by sending STRING to the terminal.
 168 ;;;###autoload
 169 (defun create-glyph (string)
 170   (if (= (length glyph-table) 65536)
 171       (error "No free glyph codes remain"))
 172   ;; Don't use slots that correspond to ASCII characters.
 173   (if (= (length glyph-table) 32)
 174       (setq glyph-table (vconcat glyph-table (make-vector 224 nil))))
 175   (setq glyph-table (vconcat glyph-table (list string)))
 176   (1- (length glyph-table)))
 177
 178 ;;;###autoload
 179 (defun standard-display-european (arg &optional auto)
 180   "Toggle display of European characters encoded with ISO 8859.
 181
 182 This function is semi-obsolete; you can use `set-language-environment'
 183 coupled with either the `--unibyte' option, the EMACS_UNIBYTE
 184 environment variable or customizing `enable-multibyte-characters' if
 185 you prefer to use unibyte characters.
 186
 187 When enabled, characters in the range of 160 to 255 display not
 188 as octal escapes, but as accented characters.  Codes 146 and 160
 189 display as apostrophe and space, even though they are not the ASCII
 190 codes for apostrophe and space.
 191
 192 With prefix argument, enable European character display iff arg is positive.
 193
 194 Normally, this function turns off `enable-multibyte-characters' for
 195 existing and subsequently created Emacs buffers.  This is because
 196 users who call this function probably want to edit European characters
 197 in single-byte mode."
 198
 199   ;; If the optional argument AUTO is non-nil, this function
 200   ;; does not alter `enable-multibyte-characters'.
 201   ;; AUTO also specifies, in this case, the coding system for terminal output.
 202   ;; The AUTO argument is meant for use by startup.el only.
 203   ;; which is why it is not in the doc string.
 204   (interactive "P")
 205   (if (or (<= (prefix-numeric-value arg) 0)
 206           (and (null arg)
 207                (char-table-p standard-display-table)
 208                ;; Test 161, because 160 displays as a space.
 209                (equal (aref standard-display-table 161) [161])))
 210       (progn
 211         (standard-display-default 160 255)
 212         (unless (memq window-system '(x w32))
 213           (set-terminal-coding-system nil)))
 214     ;; If the user does this explicitly,
 215     ;; turn off multibyte chars for more compatibility.
 216     (unless auto
 217       (setq-default enable-multibyte-characters nil)
 218       (mapcar (lambda (buffer)
 219                 (with-current-buffer buffer
 220                   (if enable-multibyte-characters
 221                       (set-buffer-multibyte nil))))
 222               (buffer-list)))
 223     ;; If the user does this explicitly,
 224     ;; switch to Latin-1 language environment
 225     ;; unless some other has been specified.
 226     (unless auto
 227       (if (equal current-language-environment "English")
 228           (set-language-environment "latin-1")))
 229     (unless (or noninteractive (memq window-system '(x w32)))
 230       ;; Send those codes literally to a non-X terminal.
 231       ;; If AUTO is nil, we are using single-byte characters,
 232       ;; so it doesn't matter which one we use.
 233       (set-terminal-coding-system
 234        (cond ((not (equal current-language-environment "English"))
 235               (intern (downcase current-language-environment)))
 236              ((eq auto t) 'latin-1)
 237              ((symbolp auto) (or auto 'latin-1))
 238              ((stringp auto) (intern auto)))))
 239     (standard-display-european-internal)))
 240
 241 (provide 'disp-table)
 242
 243 ;;; disp-table.el ends here