(*
* Svgalib-Gpc - Pascal porting of Svgalib header files.
* Copyright 1999, 2000 (C) Nicola Girardi <girardi@vicenza.linux.it>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*)
unit VgaNormalKeyboard;
interface
uses GPC; (* Gnu Pascal unit, for AssignTFDD and such stuff *)
var KeyboardFile: Text; (* this can be accessed by user programs
* to wait for keyboard events
*)
procedure KeyboardInit; (* initializing procedure *)
procedure KeyboardFlush;
procedure KeyboardClose; (* close keyboard files *)
function AnyKeyPressed : Boolean; (* useful function like KeyPressed (CRT) *)
function KeyPressed (Key: Integer) : Boolean; (* tells if Key is pressed *)
function WaitKey : Integer; (*waits for a key to be pressed and return its ASCII value *)
function GetKey : Integer; (*asmname 'vga_getkey';*)
(*
* Read a character from the keyboard without waiting;
* returns zero if no key pressed and the ASCII value other
* wise. It uses AnyKeyPressed (see below)
*)
implementation
var
KeyboardFD : asmname '__svgalib_tty_fd' Integer;
buffered : Integer;
function GetCh : Integer; asmname 'vga_getch'; (* only internally used *)
function KeyboardSelectFunc (var PrivateData; Writing: Boolean) : Integer;
begin
if Writing then KeyboardSelectFunc:= -1
else KeyboardSelectFunc:= KeyboardFD;
end;
(* actually does nothing, because the keyboard in normal mode is
* already set up so this just clears the buffered
*)
procedure KeyboardOpenProc (var PrivateData; Mode: TOpenMode);
begin buffered:= 0 end;
procedure KeyboardInit;
begin
AssignTFDD(KeyboardFile, KeyboardOpenProc, KeyboardSelectFunc,
TSelectProc(nil), TReadFunc(nil), TWriteFunc(nil),
TFlushProc(nil), TCloseProc(nil), TDoneProc(nil),
Pointer(nil));
Reset(KeyboardFile);
end;
procedure KeyboardClose;
begin Close(KeyboardFile) end;
function AnyKeyPressed : Boolean; (* tells if any key is pressed *)
var
SelectInput : array [ 1 .. 1 ] of IOSelectType;
SelectRv : Integer;
begin
if (KeyboardFD = -1) (* keyboard uninitialized *)
then AnyKeyPressed:= false;
SelectInput[1].f := @KeyboardFile;
SelectInput[1].Wanted:= [ SelectReadOrEOF ];
SelectRv:= IOSelect(SelectInput, 0);
if SelectRv = 1 then
begin
buffered:= GetCh;
AnyKeyPressed:= true;
end
else AnyKeyPressed:= ( buffered <> 0 );
end;
function KeyPressed (Key: Integer) : Boolean; (* tells if Key is pressed *)
var
Dummy: Boolean;
begin
if (KeyboardFD = -1) (* keyboard uninitialized *)
then KeyPressed:= false;
Dummy:= AnyKeyPressed; (* treated as a procedure to manage a key in the buffer *)
KeyPressed:= ( buffered = Key );
end;
function GetKey : Integer; (*asmname 'vga_getkey';*)
begin
if not AnyKeyPressed
then GetKey:= 0
else
begin
GetKey:= buffered;
buffered:= 0;
end;
end;
function WaitKey : Integer;
begin
WaitKey:= 0; (* initial value *)
repeat until AnyKeyPressed;
WaitKey:= buffered;
buffered:= 0;
end;
end.
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