| 1 | ;;; vt100-led.el --- functions for LED control on VT-100 terminals & clones |
| 2 | |
| 3 | ;; Copyright (C) 1988, 2002, 2003, 2004, 2005, |
| 4 | ;; 2006 Free Software Foundation, Inc. |
| 5 | |
| 6 | ;; Author: Howard Gayle |
| 7 | ;; Maintainer: FSF |
| 8 | ;; Keywords: hardware |
| 9 | |
| 10 | ;; This file is part of GNU Emacs. |
| 11 | |
| 12 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
| 13 | ;; it under the terms of the GNU General Public License as published by |
| 14 | ;; the Free Software Foundation; either version 2, or (at your option) |
| 15 | ;; any later version. |
| 16 | |
| 17 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | ;; GNU General Public License for more details. |
| 21 | |
| 22 | ;; You should have received a copy of the GNU General Public License |
| 23 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
| 24 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 25 | ;; Boston, MA 02110-1301, USA. |
| 26 | |
| 27 | ;;; Commentary: |
| 28 | |
| 29 | ;;; Code: |
| 30 | |
| 31 | (defvar led-state (make-vector 5 nil) |
| 32 | "The internal state of the LEDs. Choices are nil, t, `flash. |
| 33 | Element 0 is not used.") |
| 34 | |
| 35 | (defun led-flash (l) |
| 36 | "Flash LED l." |
| 37 | (aset led-state l 'flash) |
| 38 | (led-update)) |
| 39 | |
| 40 | (defun led-off (&optional l) |
| 41 | "Turn off vt100 led number L. With no argument, turn them all off." |
| 42 | (interactive "P") |
| 43 | (if l |
| 44 | (aset led-state (prefix-numeric-value l) nil) |
| 45 | (fillarray led-state nil)) |
| 46 | (led-update)) |
| 47 | |
| 48 | (defun led-on (l) |
| 49 | "Turn on LED l." |
| 50 | (aset led-state l t) |
| 51 | (led-update)) |
| 52 | |
| 53 | (defun led-update () |
| 54 | "Update the terminal's LEDs to reflect the internal state." |
| 55 | (let ((f "\e[?0") ; String to flash. |
| 56 | (o "\e[0") ; String for steady on. |
| 57 | (l 1)) ; Current LED number. |
| 58 | (while (/= l 5) |
| 59 | (let ((s (aref led-state l))) |
| 60 | (cond |
| 61 | ((eq s 'flash) |
| 62 | (setq f (concat f ";" (int-to-string l)))) |
| 63 | (s |
| 64 | (setq o (concat o ";" (int-to-string l)))))) |
| 65 | (setq l (1+ l))) |
| 66 | (setq o (concat o "q" f "t")) |
| 67 | (send-string-to-terminal o))) |
| 68 | |
| 69 | (provide 'vt100-led) |
| 70 | |
| 71 | ;;; arch-tag: 346e6480-5e31-4234-aafe-257cea4a36d1 |
| 72 | ;;; vt100-led.el ends here |