lisp/vt-control.el

   1 ;;; vt-control.el --- Common VTxxx control functions
   2
   3 ;; Copyright (C) 1993 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
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Commentary:
  26
  27 ;;  The functions contained in this file send various VT control codes
  28 ;;  to the terminal where emacs is running.  The following functions are
  29 ;;  available.
  30
  31 ;;    Function           Action
  32
  33 ;;    vt-wide            set wide screen (132 characters)
  34 ;;    vt-narrow          set narrow screen (80 characters)
  35 ;;    vt-toggle-screen   toggle wide/narrow screen
  36 ;;    vt-keypad-on       set applications keypad on
  37 ;;    vt-keypad-off      set applications keypad off
  38 ;;    vt-numlock         toggle applications keypad on/off
  39
  40 ;;; Usage:
  41
  42 ;;  To use enable these functions, simply load this file.
  43
  44 ;;  Note: vt-control makes no effort to determine how the terminal is
  45 ;;        initially set.  It assumes the terminal starts with a width
  46 ;;        of 80 characters and the applications keypad enabled.  Nor
  47 ;;        does vt-control try to restore the terminal when emacs is
  48 ;;        killed or suspended.
  49
  50 ;;; Code:
  51
  52
  53 ;;;  Revision Information
  54
  55 (defconst vt-revision "$Revision: 1.3 $"
  56   "Revision number of vt-control.")
  57
  58
  59 ;;;  Global variables
  60
  61 (defvar vt-applications-keypad-p t
  62   "If non-nil, keypad is in applications mode.")
  63
  64 (defvar vt-wide-p nil
  65   "If non-nil, the screen is 132 characters wide.")
  66
  67
  68 ;;;  Screen width functions.
  69
  70 (defun vt-wide nil
  71   "Set the screen 132 characters wide."
  72   (interactive)
  73   (send-string-to-terminal "\e[?3h")
  74   (set-screen-width 132)
  75   (setq vt-wide-p t))
  76
  77 (defun vt-narrow nil
  78   "Set the screen 80 characters wide."
  79   (interactive)
  80   (send-string-to-terminal "\e[?3l")
  81   (set-screen-width 80)
  82   (setq vt-wide-p nil))
  83
  84 (defun vt-toggle-screen nil
  85   "Toggle between 80 and 132 character screen width."
  86   (interactive)
  87   (if vt-wide-p (vt-narrow) (vt-wide)))
  88
  89
  90 ;;;  Applications keypad functions.
  91
  92 (defun vt-keypad-on (&optional tell)
  93   "Turn on the VT applications keypad."
  94   (interactive)
  95   (send-string-to-terminal "\e[\e=")
  96   (setq vt-applications-keypad-p t)
  97   (if (or tell (interactive-p)) (message "Applications keypad enabled.")))
  98
  99 (defun vt-keypad-off (&optional tell)
 100   "Turn off the VT applications keypad."
 101   (interactive "p")
 102   (send-string-to-terminal "\e[\e>")
 103   (setq vt-applications-keypad-p nil)
 104   (if (or tell (interactive-p)) (message "Applications keypad disabled.")))
 105
 106 (defun vt-numlock nil
 107   "Toggle VT application keypad on and off."
 108   (interactive)
 109   (if vt-applications-keypad-p (vt-keypad-off (interactive-p))
 110     (vt-keypad-on (interactive-p))))
 111
 112 ;;; vt-control.el ends here