lisp/vt-control.el

   1 ;;; vt-control.el --- Common VTxxx control functions
   2
   3 ;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.
   4
   5 ;; Author: Rob Riepel <riepel@networking.stanford.edu>
   6 ;; Maintainer: Rob Riepel <riepel@networking.stanford.edu>
   7 ;; Keywords: terminals
   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 the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;;  The functions contained in this file send various VT control codes
  29 ;;  to the terminal where emacs is running.  The following functions are
  30 ;;  available.
  31
  32 ;;    Function           Action
  33
  34 ;;    vt-wide            set wide screen (132 characters)
  35 ;;    vt-narrow          set narrow screen (80 characters)
  36 ;;    vt-toggle-screen   toggle wide/narrow screen
  37 ;;    vt-keypad-on       set applications keypad on
  38 ;;    vt-keypad-off      set applications keypad off
  39 ;;    vt-numlock         toggle applications keypad on/off
  40
  41 ;;; Usage:
  42
  43 ;;  To use enable these functions, simply load this file.
  44
  45 ;;  Note: vt-control makes no effort to determine how the terminal is
  46 ;;        initially set.  It assumes the terminal starts with a width
  47 ;;        of 80 characters and the applications keypad enabled.  Nor
  48 ;;        does vt-control try to restore the terminal when emacs is
  49 ;;        killed or suspended.
  50
  51 ;;; Code:
  52
  53
  54 ;;;  Global variables
  55
  56 (defvar vt-applications-keypad-p t
  57   "If non-nil, keypad is in applications mode.")
  58
  59 (defvar vt-wide-p nil
  60   "If non-nil, the screen is 132 characters wide.")
  61
  62
  63 ;;;  Screen width functions.
  64
  65 (defun vt-wide nil
  66   "Set the screen 132 characters wide."
  67   (interactive)
  68   (send-string-to-terminal "\e[?3h")
  69   (set-screen-width 132)
  70   (setq vt-wide-p t))
  71
  72 (defun vt-narrow nil
  73   "Set the screen 80 characters wide."
  74   (interactive)
  75   (send-string-to-terminal "\e[?3l")
  76   (set-screen-width 80)
  77   (setq vt-wide-p nil))
  78
  79 (defun vt-toggle-screen nil
  80   "Toggle between 80 and 132 character screen width."
  81   (interactive)
  82   (if vt-wide-p (vt-narrow) (vt-wide)))
  83
  84
  85 ;;;  Applications keypad functions.
  86
  87 (defun vt-keypad-on (&optional tell)
  88   "Turn on the VT applications keypad."
  89   (interactive)
  90   (send-string-to-terminal "\e=")
  91   (setq vt-applications-keypad-p t)
  92   (if (or tell (interactive-p)) (message "Applications keypad enabled.")))
  93
  94 (defun vt-keypad-off (&optional tell)
  95   "Turn off the VT applications keypad."
  96   (interactive "p")
  97   (send-string-to-terminal "\e>")
  98   (setq vt-applications-keypad-p nil)
  99   (if (or tell (interactive-p)) (message "Applications keypad disabled.")))
 100
 101 (defun vt-numlock nil
 102   "Toggle VT application keypad on and off."
 103   (interactive)
 104   (if vt-applications-keypad-p (vt-keypad-off (interactive-p))
 105     (vt-keypad-on (interactive-p))))
 106
 107 (provide 'vt-control)
 108
 109 ;;; vt-control.el ends here