lisp/disp-table.el

   1 ;;; disp-table.el --- functions for dealing with char tables.
   2
   3 ;; Copyright (C) 1987, 1994 Free Software Foundation, Inc.
   4
   5 ;; Author: Howard Gayle
   6 ;; Maintainer: FSF
   7 ;; Keywords: i18n
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Code:
  26
  27 (defconst display-table-len 262
  28   "The proper length of a display table.")
  29
  30 (defun describe-display-table (dt)
  31   "Describe the display table DT in a help buffer."
  32   (with-output-to-temp-buffer "*Help*"
  33     (princ "\nTruncation glyph: ")
  34     (prin1 (aref dt 256))
  35     (princ "\nWrap glyph: ")
  36     (prin1 (aref dt 257))
  37     (princ "\nEscape glyph: ")
  38     (prin1 (aref dt 258))
  39     (princ "\nCtrl glyph: ")
  40     (prin1 (aref dt 259))
  41     (princ "\nSelective display glyph sequence: ")
  42     (prin1 (aref dt 260))
  43     (princ "\nVertical window border glyph: ")
  44     (prin1 (aref dt 261))
  45     (princ "\nCharacter display glyph sequences:\n")
  46     (save-excursion
  47       (set-buffer standard-output)
  48       (let ((vector (make-vector 256 nil))
  49             (i 0))
  50         (while (< i 256)
  51           (aset vector i (aref dt i))
  52           (setq i (1+ i)))
  53         (describe-vector vector))
  54       (help-mode))
  55     (print-help-return-message)))
  56
  57 ;;;###autoload
  58 (defun describe-current-display-table ()
  59   "Describe the display table in use in the selected window and buffer."
  60   (interactive)
  61   (let ((disptab
  62          (or (window-display-table (selected-window))
  63              buffer-display-table
  64              standard-display-table)))
  65     (if disptab
  66         (describe-display-table disptab)
  67       (message "No display table"))))
  68
  69 ;;;###autoload
  70 (defun make-display-table ()
  71   "Return a new, empty display table."
  72   (make-vector display-table-len nil))
  73
  74 ;;;###autoload
  75 (defun standard-display-8bit (l h)
  76   "Display characters in the range L to H literally."
  77   (while (<= l h)
  78     (if (and (>= l ?\ ) (< l 127))
  79         (if standard-display-table (aset standard-display-table l nil))
  80       (or standard-display-table
  81           (setq standard-display-table (make-vector display-table-len nil)))
  82       (aset standard-display-table l (vector l)))
  83     (setq l (1+ l))))
  84
  85 ;;;###autoload
  86 (defun standard-display-default (l h)
  87   "Display characters in the range L to H using the default notation."
  88   (while (<= l h)
  89     (if (and (>= l ?\ ) (< l 127))
  90         (if standard-display-table (aset standard-display-table l nil))
  91       (or standard-display-table
  92           (setq standard-display-table (make-vector display-table-len nil)))
  93       (aset standard-display-table l nil))
  94     (setq l (1+ l))))
  95
  96 ;;;###autoload
  97 (defun standard-display-ascii (c s)
  98   "Display character C using string S.
  99 S is usually a terminal-dependent escape sequence.
 100 This function is meaningless for an X frame."
 101   (if window-system
 102       (error "Cannot use string glyphs in a windowing system"))
 103   (or standard-display-table
 104       (setq standard-display-table (make-vector display-table-len nil)))
 105   (aset standard-display-table c (apply 'vector (append s nil))))
 106
 107 ;;;###autoload
 108 (defun standard-display-g1 (c sc)
 109   "Display character C as character SC in the g1 character set.
 110 This function assumes that your terminal uses the SO/SI characters;
 111 it is meaningless for an X frame."
 112   (if window-system
 113       (error "Cannot use string glyphs in a windowing system"))
 114   (or standard-display-table
 115       (setq standard-display-table (make-vector display-table-len nil)))
 116   (aset standard-display-table c
 117         (vector (create-glyph (concat "\016" (char-to-string sc) "\017")))))
 118
 119 ;;;###autoload
 120 (defun standard-display-graphic (c gc)
 121   "Display character C as character GC in graphics character set.
 122 This function assumes VT100-compatible escapes; it is meaningless for an
 123 X frame."
 124   (if window-system
 125       (error "Cannot use string glyphs in a windowing system"))
 126   (or standard-display-table
 127       (setq standard-display-table (make-vector display-table-len nil)))
 128   (aset standard-display-table c
 129         (vector (create-glyph (concat "\e(0" (char-to-string gc) "\e(B")))))
 130
 131 ;;;###autoload
 132 (defun standard-display-underline (c uc)
 133   "Display character C as character UC plus underlining."
 134   (if window-system (require 'faces))
 135   (or standard-display-table
 136       (setq standard-display-table (make-vector display-table-len nil)))
 137   (aset standard-display-table c
 138         (vector
 139          (if window-system
 140              (logior uc (lsh (face-id (internal-find-face 'underline)) 8))
 141            (create-glyph (concat "\e[4m" (char-to-string uc) "\e[m"))))))
 142
 143 ;; Allocate a glyph code to display by sending STRING to the terminal.
 144 ;;;###autoload
 145 (defun create-glyph (string)
 146   (if (= (length glyph-table) 65536)
 147       (error "No free glyph codes remain"))
 148   ;; Don't use slots that correspond to ASCII characters.
 149   (if (= (length glyph-table) 32)
 150       (setq glyph-table (vconcat glyph-table (make-vector 224 nil))))
 151   (setq glyph-table (vconcat glyph-table (list string)))
 152   (1- (length glyph-table)))
 153
 154 ;;;###autoload
 155 (defun standard-display-european (arg)
 156   "Toggle display of European characters encoded with ISO 8859.
 157 When enabled, characters in the range of 160 to 255 display not
 158 as octal escapes, but as accented characters.
 159 With prefix argument, enable European character display iff arg is positive."
 160   (interactive "P")
 161   (if (or (<= (prefix-numeric-value arg) 0)
 162           (and (null arg)
 163                (vectorp standard-display-table)
 164                (>= (length standard-display-table) 161)
 165                (equal (aref standard-display-table 160) [160])))
 166       (standard-display-default 160 255)
 167     (standard-display-8bit 160 255)))
 168
 169 (provide 'disp-table)
 170
 171 ;;; disp-table.el ends here