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1 | (* Keyboard.mod provides compatibility with Logitech 3.0 Keyboard module. | |
2 | ||
3 | Copyright (C) 2004-2024 Free Software Foundation, Inc. | |
4 | Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>. | |
5 | ||
6 | This file is part of GNU Modula-2. | |
7 | ||
8 | GNU Modula-2 is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3, or (at your option) | |
11 | any later version. | |
12 | ||
13 | GNU Modula-2 is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | General Public License for more details. | |
17 | ||
18 | Under Section 7 of GPL version 3, you are granted additional | |
19 | permissions described in the GCC Runtime Library Exception, version | |
20 | 3.1, as published by the Free Software Foundation. | |
21 | ||
22 | You should have received a copy of the GNU General Public License and | |
23 | a copy of the GCC Runtime Library Exception along with this program; | |
24 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
25 | <http://www.gnu.org/licenses/>. *) | |
26 | ||
27 | IMPLEMENTATION MODULE Keyboard ; | |
28 | ||
29 | FROM Selective IMPORT SetOfFd, InitSet, KillSet, MaxFdsPlusOne, ReadCharRaw, | |
30 | Timeval, InitTime, KillTime, FdIsSet, FdZero, FdSet, | |
31 | Select ; | |
32 | ||
33 | ||
34 | CONST | |
35 | stdin = 0 ; | |
36 | ||
37 | ||
38 | (* | |
39 | Read - reads a character from StdIn. If necessary it will wait | |
40 | for a key to become present on StdIn. | |
41 | *) | |
42 | ||
43 | PROCEDURE Read (VAR ch: CHAR) ; | |
44 | BEGIN | |
45 | ch := ReadCharRaw(stdin) | |
46 | END Read ; | |
47 | ||
48 | ||
49 | (* | |
50 | KeyPressed - returns TRUE if a character can be read from StdIn | |
51 | without blocking the caller. | |
52 | *) | |
53 | ||
54 | PROCEDURE KeyPressed () : BOOLEAN ; | |
55 | VAR | |
56 | s : SetOfFd ; | |
57 | t : Timeval ; | |
58 | r : INTEGER ; | |
59 | Pressed: BOOLEAN ; | |
60 | BEGIN | |
61 | t := InitTime(0, 0) ; | |
62 | s := InitSet() ; | |
63 | FdZero(s) ; | |
64 | FdSet(stdin, s) ; | |
65 | r := Select(MaxFdsPlusOne(stdin, stdin), | |
66 | s, NIL, NIL, t) ; | |
67 | Pressed := FdIsSet(stdin, s) ; | |
68 | s := KillSet(s) ; | |
69 | t := KillTime(t) ; | |
70 | RETURN( Pressed ) | |
71 | END KeyPressed ; | |
72 | ||
73 | ||
74 | END Keyboard. |