| 12
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 
 | ;;; vt100-led.el --- functions for LED control on VT-100 terminals & clones.
;; Copyright (C) 1988 Free Software Foundation, Inc.
;; Author: Howard Gayle
;; Maintainer: FSF
;; Keywords: hardware
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Code:
(defvar led-state (make-vector 5 nil)
   "The internal state of the LEDs.  Choices are nil, t, `flash.
Element 0 is not used.")
(defun led-flash (l)
  "Flash LED l."
  (aset led-state l 'flash)
  (led-update))
(defun led-off (&optional l)
  "Turn off vt100 led number L.  With no argument, turn them all off."
  (interactive "P")
  (if l
      (aset led-state (prefix-numeric-value l) nil)
    (fillarray led-state nil))
  (led-update))
(defun led-on (l)
  "Turn on LED l."
  (aset led-state l t)
  (led-update))
(defun led-update ()
  "Update the terminal's LEDs to reflect the internal state."
  (let ((f "\e[?0")			; String to flash.
	(o "\e[0")			; String for steady on.
	(l 1))				; Current LED number.
    (while (/= l 5)
      (let ((s (aref led-state l)))
	(cond
	 ((eq s 'flash)
	  (setq f (concat f ";" (int-to-string l))))
	 (s
	  (setq o (concat o ";" (int-to-string l))))))
      (setq l (1+ l)))
    (setq o (concat o "q" f "t"))
    (send-string-to-terminal o)))
(provide 'vt100-led)
;;; vt100-led.el ends here
 |