MQL5 ReferenceStandard LibraryPanels and DialogsCCheckGroupOnVScrollHide CreateOnEventAddItemValueCreateButtonOnVScrollShowOnVScrollHideOnScrollLineDownOnScrollLineUpOnChangeItemRedrawRowState OnVScrollHide The virtual handler of the dependent VScroll (vertical scroll) control "Hide" internal event. virtual bool OnVScrollHide() Return Value true - event processed, otherwise - false. OnVScrollShow OnScrollLineDown