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