lisp/disp-table.el

   1 ;;; disp-table.el --- functions for dealing with char tables.
   2
   3 ;; Copyright (C) 1987, 1994, 1995 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)) 8))
 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)
 180   "Toggle display of European characters encoded with ISO 8859.
 181 When enabled, characters in the range of 160 to 255 display not
 182 as octal escapes, but as accented characters.
 183 With prefix argument, enable European character display iff arg is positive."
 184   (interactive "P")
 185   (if (or (<= (prefix-numeric-value arg) 0)
 186           (and (null arg)
 187                (char-table-p standard-display-table)
 188                ;; Test 161, because 160 displays as a space.
 189                (equal (aref standard-display-table 161) [161])))
 190       (standard-display-default 160 255)
 191     (standard-display-8bit 160 255)
 192     ;; Make non-line-break space display as a plain space.
 193     ;; Most X fonts do the wrong thing for code 160.
 194     (aset standard-display-table 160 [32])))
 195
 196 (provide 'disp-table)
 197
 198 ;;; disp-table.el ends here