constructor TDTCalendarForm.CreateNewDTCalendarForm(AOwner: TComponent;
  ADTPicker: TCustomDateTimePicker);
var
  P: TPoint;
  CalClass: TCalendarControlWrapperClass;
  CalControl: TControl;
begin
  inherited CreateNew(AOwner);

  ADTPicker.FAllowDroppingCalendar := False;
  FClosing := False;

  DTPicker := ADTPicker;
  BiDiMode := DTPicker.BiDiMode;
  DTPickersParentForm := GetParentForm(DTPicker);
  if Assigned(DTPickersParentForm) then begin
    DTPickersParentForm.AddHandlerOnVisibleChanged(@VisibleOfParentChanged);
    DTPickersParentForm.FreeNotification(Self);
    PopupParent := DTPickersParentForm;
    {$IFDEF LINUX}
    PopupMode := pmNone;  // <---Use None to avoid focus issues on Linux.
    {$ELSE}
    PopupMode := pmExplicit;
    {$ENDIF}
  end else
    PopupMode := pmAuto;