lisp/disp-table.el

   1 ;;; disp-table.el --- functions for dealing with char tables
   2
   3 ;; Copyright (C) 1987, 1994, 1995, 1999, 2002, 2003, 2004,
   4 ;;   2005, 2006 Free Software Foundation, Inc.
   5
   6 ;; Author: Erik Naggum <erik@naggum.no>
   7 ;; Based on a previous version by Howard Gayle
   8 ;; Maintainer: FSF
   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 2, or (at your option)
  16 ;; 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; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 ;; Boston, MA 02110-1301, USA.
  27
  28 ;;; Commentary:
  29
  30 ;;; Code:
  31
  32 (put 'display-table 'char-table-extra-slots 6)
  33
  34 ;;;###autoload
  35 (defun make-display-table ()
  36   "Return a new, empty display table."
  37   (make-char-table 'display-table nil))
  38
  39 (or standard-display-table
  40     (setq standard-display-table (make-display-table)))
  41
  42 ;;; Display-table slot names.  The property value says which slot.
  43
  44 (put 'truncation 'display-table-slot 0)
  45 (put 'wrap 'display-table-slot 1)
  46 (put 'escape 'display-table-slot 2)
  47 (put 'control 'display-table-slot 3)
  48 (put 'selective-display 'display-table-slot 4)
  49 (put 'vertical-border 'display-table-slot 5)
  50
  51 ;;;###autoload
  52 (defun display-table-slot (display-table slot)
  53   "Return the value of the extra slot in DISPLAY-TABLE named SLOT.
  54 SLOT may be a number from 0 to 5 inclusive, or a slot name (symbol).
  55 Valid symbols are `truncation', `wrap', `escape', `control',
  56 `selective-display', and `vertical-border'."
  57   (let ((slot-number
  58          (if (numberp slot) slot
  59            (or (get slot 'display-table-slot)
  60                (error "Invalid display-table slot name: %s" slot)))))
  61     (char-table-extra-slot display-table slot-number)))
  62
  63 ;;;###autoload
  64 (defun set-display-table-slot (display-table slot value)
  65   "Set the value of the extra slot in DISPLAY-TABLE named SLOT to VALUE.
  66 SLOT may be a number from 0 to 5 inclusive, or a name (symbol).
  67 Valid symbols are `truncation', `wrap', `escape', `control',
  68 `selective-display', and `vertical-border'."
  69   (let ((slot-number
  70          (if (numberp slot) slot
  71            (or (get slot 'display-table-slot)
  72                (error "Invalid display-table slot name: %s" slot)))))
  73     (set-char-table-extra-slot display-table slot-number value)))
  74
  75 ;;;###autoload
  76 (defun describe-display-table (dt)
  77   "Describe the display table DT in a help buffer."
  78   (with-output-to-temp-buffer "*Help*"
  79     (princ "\nTruncation glyph: ")
  80     (prin1 (display-table-slot dt 'truncation))
  81     (princ "\nWrap glyph: ")
  82     (prin1 (display-table-slot dt 'wrap))
  83     (princ "\nEscape glyph: ")
  84     (prin1 (display-table-slot dt 'escape))
  85     (princ "\nCtrl glyph: ")
  86     (prin1 (display-table-slot dt 'control))
  87     (princ "\nSelective display glyph sequence: ")
  88     (prin1 (display-table-slot dt 'selective-display))
  89     (princ "\nVertical window border glyph: ")
  90     (prin1 (display-table-slot dt 'vertical-border))
  91     (princ "\nCharacter display glyph sequences:\n")
  92     (save-excursion
  93       (set-buffer standard-output)
  94       (let ((vector (make-vector 256 nil))
  95             (i 0))
  96         (while (< i 256)
  97           (aset vector i (aref dt i))
  98           (setq i (1+ i)))
  99         (describe-vector vector))
 100       (help-mode))
 101     (print-help-return-message)))
 102
 103 ;;;###autoload
 104 (defun describe-current-display-table ()
 105   "Describe the display table in use in the selected window and buffer."
 106   (interactive)
 107   (let ((disptab (or (window-display-table (selected-window))
 108                      buffer-display-table
 109                      standard-display-table)))
 110     (if disptab
 111         (describe-display-table disptab)
 112       (message "No display table"))))
 113
 114 ;;;###autoload
 115 (defun standard-display-8bit (l h)
 116   "Display characters in the range L to H literally."
 117   (or standard-display-table
 118       (setq standard-display-table (make-display-table)))
 119   (while (<= l h)
 120     (aset standard-display-table l (if (or (< l ?\ ) (>= l 127)) (vector l)))
 121     (setq l (1+ l))))
 122
 123 ;;;###autoload
 124 (defun standard-display-default (l h)
 125   "Display characters in the range L to H using the default notation."
 126   (or standard-display-table
 127       (setq standard-display-table (make-display-table)))
 128   (while (<= l h)
 129     (if (and (>= l ?\ ) (char-valid-p l))
 130         (aset standard-display-table l nil))
 131     (setq l (1+ l))))
 132
 133 ;; This function does NOT take terminal-dependent escape sequences.
 134 ;; For that, you need to go through create-glyph.  Use one of the
 135 ;; other functions below, or roll your own.
 136 ;;;###autoload
 137 (defun standard-display-ascii (c s)
 138   "Display character C using printable string S."
 139   (or standard-display-table
 140       (setq standard-display-table (make-display-table)))
 141   (aset standard-display-table c (vconcat s)))
 142
 143 ;;;###autoload
 144 (defun standard-display-g1 (c sc)
 145   "Display character C as character SC in the g1 character set.
 146 This function assumes that your terminal uses the SO/SI characters;
 147 it is meaningless for an X frame."
 148   (if (memq window-system '(x w32 mac))
 149       (error "Cannot use string glyphs in a windowing system"))
 150   (or standard-display-table
 151       (setq standard-display-table (make-display-table)))
 152   (aset standard-display-table c
 153         (vector (create-glyph (concat "\016" (char-to-string sc) "\017")))))
 154
 155 ;;;###autoload
 156 (defun standard-display-graphic (c gc)
 157   "Display character C as character GC in graphics character set.
 158 This function assumes VT100-compatible escapes; it is meaningless for an
 159 X frame."
 160   (if (memq window-system '(x w32 mac))
 161       (error "Cannot use string glyphs in a windowing system"))
 162   (or standard-display-table
 163       (setq standard-display-table (make-display-table)))
 164   (aset standard-display-table c
 165         (vector (create-glyph (concat "\e(0" (char-to-string gc) "\e(B")))))
 166
 167 ;;;###autoload
 168 (defun standard-display-underline (c uc)
 169   "Display character C as character UC plus underlining."
 170   (or standard-display-table
 171       (setq standard-display-table (make-display-table)))
 172   (aset standard-display-table c
 173         (vector
 174          (if window-system
 175              (logior uc (lsh (face-id 'underline) 19))
 176            (create-glyph (concat "\e[4m" (char-to-string uc) "\e[m"))))))
 177
 178 ;;;###autoload
 179 (defun create-glyph (string)
 180   "Allocate a glyph code to display by sending STRING to the terminal."
 181   (if (= (length glyph-table) 65536)
 182       (error "No free glyph codes remain"))
 183   ;; Don't use slots that correspond to ASCII characters.
 184   (if (= (length glyph-table) 32)
 185       (setq glyph-table (vconcat glyph-table (make-vector 224 nil))))
 186   (setq glyph-table (vconcat glyph-table (list string)))
 187   (1- (length glyph-table)))
 188
 189 ;;;###autoload
 190 (defun standard-display-european (arg)
 191   "Semi-obsolete way to toggle display of ISO 8859 European characters.
 192
 193 This function is semi-obsolete; if you want to do your editing with
 194 unibyte characters, it is better to `set-language-environment' coupled
 195 with either the `--unibyte' option or the EMACS_UNIBYTE environment
 196 variable, or else customize `enable-multibyte-characters'.
 197
 198 With prefix argument, this command enables European character display
 199 if arg is positive, disables it otherwise.  Otherwise, it toggles
 200 European character display.
 201
 202 When this mode is enabled, characters in the range of 160 to 255
 203 display not as octal escapes, but as accented characters.  Codes 146
 204 and 160 display as apostrophe and space, even though they are not the
 205 ASCII codes for apostrophe and space.
 206
 207 Enabling European character display with this command noninteractively
 208 from Lisp code also selects Latin-1 as the language environment, and
 209 selects unibyte mode for all Emacs buffers \(both existing buffers and
 210 those created subsequently).  This provides increased compatibility
 211 for users who call this function in `.emacs'."
 212
 213   (if (or (<= (prefix-numeric-value arg) 0)
 214           (and (null arg)
 215                (char-table-p standard-display-table)
 216                ;; Test 161, because 160 displays as a space.
 217                (equal (aref standard-display-table 161) [161])))
 218       (progn
 219         (standard-display-default 160 255)
 220         (unless (or (memq window-system '(x w32 mac)))
 221           (and (terminal-coding-system)
 222                (set-terminal-coding-system nil))))
 223
 224     (display-warning 'i18n
 225                      "`standard-display-european' is semi-obsolete; see its doc string for details"
 226                      :warning)
 227
 228     ;; Switch to Latin-1 language environment
 229     ;; unless some other has been specified.
 230     (if (equal current-language-environment "English")
 231         (set-language-environment "latin-1"))
 232     (unless (or noninteractive (memq window-system '(x w32 mac)))
 233       ;; Send those codes literally to a character-based terminal.
 234       ;; If we are using single-byte characters,
 235       ;; it doesn't matter which coding system we use.
 236       (set-terminal-coding-system
 237        (let ((c (intern (downcase current-language-environment))))
 238          (if (coding-system-p c) c 'latin-1))))
 239     (standard-display-european-internal)))
 240
 241 (provide 'disp-table)
 242
 243 ;;; arch-tag: ffe4c28c-960c-47aa-b8a8-ae89d371ffc7
 244 ;;; disp-table.el ends here