lisp/vt-control.el

   1 ;;; vt-control.el --- Common VTxxx control functions
   2
   3 ;; Copyright (C) 1993-1994, 2001-2017 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 3 of the License, or
  14 ;; (at your option) 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.  If not, see <https://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;;  The functions contained in this file send various VT control codes
  27 ;;  to the terminal where emacs is running.  The following functions are
  28 ;;  available.
  29
  30 ;;    Function           Action
  31
  32 ;;    vt-wide            set wide screen (132 characters)
  33 ;;    vt-narrow          set narrow screen (80 characters)
  34 ;;    vt-toggle-screen   toggle wide/narrow screen
  35 ;;    vt-keypad-on       set applications keypad on
  36 ;;    vt-keypad-off      set applications keypad off
  37 ;;    vt-numlock         toggle applications keypad on/off
  38
  39 ;;; Usage:
  40
  41 ;;  To use enable these functions, simply load this file.
  42
  43 ;;  Note: vt-control makes no effort to determine how the terminal is
  44 ;;        initially set.  It assumes the terminal starts with a width
  45 ;;        of 80 characters and the applications keypad enabled.  Nor
  46 ;;        does vt-control try to restore the terminal when emacs is
  47 ;;        killed or suspended.
  48
  49 ;;; Code:
  50
  51
  52 ;;;  Global variables
  53
  54 (defvar vt-applications-keypad-p t
  55   "If non-nil, keypad is in applications mode.")
  56
  57 (defvar vt-wide-p nil
  58   "If non-nil, the screen is 132 characters wide.")
  59
  60
  61 ;;;  Screen width functions.
  62
  63 (defun vt-wide nil
  64   "Set the screen 132 characters wide."
  65   (interactive)
  66   (send-string-to-terminal "\e[?3h")
  67   (set-frame-width (selected-frame) 132)
  68   (setq vt-wide-p t))
  69
  70 (defun vt-narrow nil
  71   "Set the screen 80 characters wide."
  72   (interactive)
  73   (send-string-to-terminal "\e[?3l")
  74   (set-frame-width (selected-frame) 80)
  75   (setq vt-wide-p nil))
  76
  77 (defun vt-toggle-screen nil
  78   "Toggle between 80 and 132 character screen width."
  79   (interactive)
  80   (if vt-wide-p (vt-narrow) (vt-wide)))
  81
  82
  83 ;;;  Applications keypad functions.
  84
  85 (defun vt-keypad-on (&optional tell)
  86   "Turn on the VT applications keypad."
  87   (interactive)
  88   (send-string-to-terminal "\e=")
  89   (setq vt-applications-keypad-p t)
  90   (if (or tell (called-interactively-p 'interactive))
  91       (message "Applications keypad enabled.")))
  92
  93 (defun vt-keypad-off (&optional tell)
  94   "Turn off the VT applications keypad."
  95   (interactive "p")
  96   (send-string-to-terminal "\e>")
  97   (setq vt-applications-keypad-p nil)
  98   (if (or tell (called-interactively-p 'interactive))
  99       (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
 105       (vt-keypad-off (called-interactively-p 'interactive))
 106     (vt-keypad-on (called-interactively-p 'interactive))))
 107
 108 (provide 'vt-control)
 109
 110 ;;; vt-control.el ends here