export function scrollIntoView( container: HTMLElement, selected: HTMLElement, scrollPadding: number = 0, ): void { if (!selected) { container.scrollTop = 0 return } const offsetParents: HTMLElement[] = [] let pointer = selected.offsetParent while ( pointer !== null && container !== pointer && container.contains(pointer) ) { offsetParents.push(pointer as HTMLElement) pointer = (pointer as HTMLElement).offsetParent } const top = selected.offsetTop + offsetParents.reduce((prev, curr) => prev + curr.offsetTop, 0) const bottom = top + selected.offsetHeight const viewRectTop = container.scrollTop + scrollPadding const viewRectBottom = container.scrollTop + container.clientHeight - scrollPadding if (top < viewRectTop) { container.scrollTop = top - scrollPadding } else if (bottom > viewRectBottom) { container.scrollTop = bottom - container.clientHeight + scrollPadding } }