Merge from emacs--rel--22
[bpt/emacs.git] / lisp / vt100-led.el
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55535639 1;;; vt100-led.el --- functions for LED control on VT-100 terminals & clones
76d7458e 2
c90f2757 3;; Copyright (C) 1988, 2001, 2002, 2003, 2004, 2005,
409cc4a3 4;; 2006, 2007, 2008 Free Software Foundation, Inc.
58142744 5
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6;; Author: Howard Gayle
7;; Maintainer: FSF
6251ee24 8;; Keywords: hardware
e5167999 9
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10;; This file is part of GNU Emacs.
11
eb3fa2cf 12;; GNU Emacs is free software: you can redistribute it and/or modify
3b4a6e27 13;; it under the terms of the GNU General Public License as published by
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14;; the Free Software Foundation, either version 3 of the License, or
15;; (at your option) any later version.
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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
eb3fa2cf 23;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
3b4a6e27 24
55535639
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25;;; Commentary:
26
e5167999 27;;; Code:
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28
29(defvar led-state (make-vector 5 nil)
9fa04a08 30 "The internal state of the LEDs. Choices are nil, t, `flash'.
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31Element 0 is not used.")
32
33(defun led-flash (l)
34 "Flash LED l."
35 (aset led-state l 'flash)
36 (led-update))
37
38(defun led-off (&optional l)
39 "Turn off vt100 led number L. With no argument, turn them all off."
40 (interactive "P")
41 (if l
42 (aset led-state (prefix-numeric-value l) nil)
43 (fillarray led-state nil))
44 (led-update))
45
46(defun led-on (l)
e4e0a304 47 "Turn on LED L."
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48 (aset led-state l t)
49 (led-update))
50
51(defun led-update ()
52 "Update the terminal's LEDs to reflect the internal state."
53 (let ((f "\e[?0") ; String to flash.
54 (o "\e[0") ; String for steady on.
55 (l 1)) ; Current LED number.
56 (while (/= l 5)
57 (let ((s (aref led-state l)))
58 (cond
59 ((eq s 'flash)
60 (setq f (concat f ";" (int-to-string l))))
61 (s
62 (setq o (concat o ";" (int-to-string l))))))
63 (setq l (1+ l)))
64 (setq o (concat o "q" f "t"))
65 (send-string-to-terminal o)))
66
67(provide 'vt100-led)
76d7458e 68
cbee283d 69;; arch-tag: 346e6480-5e31-4234-aafe-257cea4a36d1
76d7458e 70;;; vt100-led.el ends here