freepascal.compiler/rtl/os2/tests/basicpm.pas

program BasicPM;

uses
 Os2Def, PMWin;

function ClientWindowProc (Window, Msg: cardinal; MP1, MP2: pointer): pointer;
                                                                 cdecl; export;
var
 Li: longint;
 Ps: cardinal;
 R: TRectL;
 P: TPointL;
 Rgn: cardinal;
begin
 ClientWindowProc := nil;
 case Msg of
  wm_Paint: begin
             PS := WinBeginPaint(Window, 0, nil);
{            GpiErase(PS);}
             WinEndPaint(PS);
            end;
  else ClientWindowProc := WinDefWindowProc (Window, Msg, MP1, MP2);
 end;
end;

const
 idClientWindow = 11000;
 WinFlags: cardinal = fcf_TitleBar + fcf_SysMenu + fcf_SizeBorder +
                                   fcf_MinMax + fcf_TaskList + fcf_NoByteAlign;
 ClassName = 'MYVIEW';

var
 Anchor, MsgQue: cardinal;
 Message: TQMsg;
 Frame, Client: cardinal;
begin
 Anchor := WinInitialize(0);
 { It might be beneficial to set the second parameter of the following }
 { call to something large, such as 1000.  The OS/2 documentation does }
 { not recommend this, however } MsgQue := WinCreateMsgQueue(Anchor, 0);
 if MsgQue = 0 then Halt (254);
 WinRegisterClass (Anchor, ClassName, proc (ClientWindowProc), cs_SizeRedraw,
                                                             SizeOf (pointer));
 Frame := WinCreateStdWindow (hwnd_Desktop, 0, WinFlags, ClassName,
                                       'BASIC', 0, 0, idClientWindow, Client);
 if (Frame <> 0) then
 begin
  WinSetWindowPos (Frame, 0, 0, WinQuerySysValue (hwnd_Desktop,
         sv_CyScreen) - 200, 200, 200, swp_Move + swp_Size + swp_Activate +
                                                                     swp_Show);
  while WinGetMsg (Anchor, Message, 0, 0, 0) do
                                              WinDispatchMsg (Anchor, Message);

  WinDestroyWindow (Frame);
 end;
 WinDestroyMsgQueue (MsgQue);
 WinTerminate (Anchor);
end.