{

   System independent system interface for go32v2

   Copyright (c) 2000 by Pierre Muller

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
}

Const
  SystemEventActive : Boolean = false;


procedure InitSystemMsg;
var
  res : word;
begin
  if SystemEventActive then
    exit;
  { enable close }
  asm
    movl $0x168f,%eax
    movl $1,%edx
    int $0x2f
    movw %ax,Res
  end;
  SystemEventActive:=(Res=0);
end;


procedure DoneSystemMsg;
begin
  if not SystemEventActive then
    exit;
  { disable close }
  asm
    movl $0x168f,%eax
    movl $0,%edx
    int $0x2f
  end;
  SystemEventActive:=false;
end;

procedure GetSystemEvent(var SystemEvent: TSystemEvent);
begin
  PollSystemEvent(SystemEvent);
end;

function PollSystemEvent(var SystemEvent: TSystemEvent):boolean;
var
  CloseState : word;
begin
  SystemEvent.typ:=SysNothing;
  if not SystemEventActive then
    exit(false);
  { Query close }
  asm
    movl $0x168f,%eax
    movl $100,%edx
    int $0x2f
    movw %ax,CloseState
  end;
  if (CloseState = 0) then
    begin
      { acknowledge Close }
      asm
        movl $0x168f,%eax
        movl $200,%edx
        int $0x2f
        movw %ax,CloseState
      end;
      { non zero means error ! }
      if CloseState=0 then
        begin
          PollSystemEvent:=true;
          SystemEvent.typ:=SysClose;
        end;
    end;
end;