program HelloGUI;

uses
  KolibriOS;

var
  WndLeft, WndTop, WndWidth, WndHeight: Integer;

begin
  with GetScreenSize do
  begin
    WndWidth := Width div 4;
    WndHeight := Height div 4;
    WndLeft := (Width - WndWidth) div 2;
    WndTop := (Height - WndHeight) div 2;
  end;

  while True do
    case WaitEvent of
      REDRAW_EVENT:
        begin
          BeginDraw;
          DrawWindow(WndLeft, WndTop, WndWidth, WndHeight, 'Hello!', $00FFFFFF,
            WS_SKINNED_FIXED + WS_CLIENT_COORDS + WS_CAPTION, CAPTION_MOVABLE);
          EndDraw;
        end;
      KEY_EVENT:
        GetKey;
      BUTTON_EVENT:
        if GetButton.ID = 1 then
          TerminateThread;
    end;
end.