| 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 | |
| } | |
| } | |