| import { observeElementOffset, type Virtualizer } from "@tanstack/solid-virtual" |
|
|
| export function observeElementOffsetReconnectAware<TScrollElement extends Element, TItemElement extends Element>( |
| instance: Virtualizer<TScrollElement, TItemElement>, |
| callback: (offset: number, isScrolling: boolean) => void, |
| ) { |
| let active = true |
| const deliver = (offset: number, isScrolling: boolean) => { |
| if (!active) return |
| callback(offset, isScrolling) |
| } |
| const cleanupOffset = observeElementOffset(instance, deliver) |
| const element = instance.scrollElement |
| const targetWindow = instance.targetWindow |
| const root = element?.closest("main") ?? element?.ownerDocument.body |
| if (!element || !targetWindow || !root) |
| return () => { |
| active = false |
| cleanupOffset?.() |
| } |
|
|
| let removed = false |
| let frame: number | undefined |
| const clearCheck = () => { |
| if (frame === undefined) return |
| targetWindow.cancelAnimationFrame(frame) |
| frame = undefined |
| } |
| const startCheck = () => { |
| clearCheck() |
| const deadline = targetWindow.performance.now() + instance.options.isScrollingResetDelay |
| let framesAfterDeadline = 0 |
| const check = (time: number) => { |
| frame = undefined |
| if (element.isConnected) { |
| const offset = instance.options.horizontal |
| ? element.scrollLeft * (instance.options.isRtl ? -1 : 1) |
| : element.scrollTop |
| if (instance.scrollOffset === null || Math.abs(offset - instance.scrollOffset) > 1) deliver(offset, false) |
| } |
| if (time >= deadline) framesAfterDeadline += 1 |
| if (framesAfterDeadline >= 2) return |
| frame = targetWindow.requestAnimationFrame(check) |
| } |
| frame = targetWindow.requestAnimationFrame(check) |
| } |
| const observer = new targetWindow.MutationObserver((records) => { |
| if (!active) return |
| records.forEach((record) => { |
| if (record.target === element || element.contains(record.target)) return |
| if (mutationNodesContainElement(record.removedNodes, element)) { |
| removed = true |
| clearCheck() |
| } |
| if (!removed || !element.isConnected || !mutationNodesContainElement(record.addedNodes, element)) return |
| removed = false |
| startCheck() |
| }) |
| }) |
| |
| observer.observe(root, { childList: true, subtree: true }) |
|
|
| return () => { |
| active = false |
| observer.disconnect() |
| clearCheck() |
| cleanupOffset?.() |
| } |
| } |
|
|
| export function mutationNodesContainElement(nodes: Iterable<Node>, element: Element) { |
| return [...nodes].some((node) => node === element || node.contains(element)) |
| } |
|
|
