Function useIntersectionObserver

packages/solid-router/src/utils.ts:48–76

(
  ref: Solid.Accessor<T | null>,
  callback: (entry: IntersectionObserverEntry | undefined) => void,
  intersectionObserverOptions: IntersectionObserverInit = {},
  options: { disabled?: boolean } = {},
)

 * ```
 */
export function useIntersectionObserver<T extends Element>(
  ref: Solid.Accessor<T | null>,
  callback: (entry: IntersectionObserverEntry | undefined) => void,
  intersectionObserverOptions: IntersectionObserverInit = {},
  options: { disabled?: boolean } = {},
): Solid.Accessor<IntersectionObserver | null> {
  const isIntersectionObserverAvailable =
    typeof IntersectionObserver === 'function'
  let observerRef: IntersectionObserver | null = null

  Solid.createEffect(() => {
    const r = ref()
    if (!r || !isIntersectionObserverAvailable || options.disabled) {
      return
    }

    observerRef = new IntersectionObserver(([entry]) => {
      callback(entry)
    }, intersectionObserverOptions)

    observerRef.observe(r)

    Solid.onCleanup(() => {
      observerRef?.disconnect()
    })
  })

  return () => observerRef
}