Remove waitForScrollDestinationItemsMeasured from store

src/core/scroller.ts

@@ -6,8 +6,9 @@ import {
  VirtualStore,
  SCROLL_IDLE,
  ACTION_SCROLL_END,
+ UPDATE_SIZE,
 } from "./store";
-import { debounce, throttle, max, min } from "./utils";
+import { debounce, throttle, max, min, timeout } from "./utils";
 
 // Infer scroll state also from wheel events
 // Sometimes scroll events do not fire when frame dropped even if the visual have been already scrolled
@@ -51,6 +52,7 @@ export const createScroller = (
  isRtl: boolean
 ): Scroller => {
  let rootElement: HTMLElement | undefined;
+ let scrollToQueue: [() => void, () => void] | undefined;
  const scrollToKey = isHorizontal ? "scrollLeft" : "scrollTop";
 
  const getActualScrollSize = (): number => {
@@ -93,12 +95,37 @@ export const createScroller = (
  break;
  }
 
+ if (scrollToQueue) {
+ // Cancel waiting scrollTo
+ scrollToQueue[1]();
+ }
+
+ // Wait for the scroll destination items to be measured.
+ const unsubscribe = store._subscribe(UPDATE_SIZE, () => {
+ scrollToQueue && scrollToQueue[0]();
+ });
  try {
- // Wait for the scroll destination items to be measured.
- await store._waitForScrollDestinationItemsMeasured();
+ // The measurement will be done asynchronously and the timing is not predictable so we use promise.
+ // For example, ResizeObserver may not fire when window is not visible.
+ await new Promise<void>((resolve, reject) => {
+ let resolved = false;
+
+ const resolveQueue = () => {
+ if (resolved) return;
+ resolved = true;
+ resolve();
+ scrollToQueue = undefined;
+ };
+ scrollToQueue = [resolveQueue, reject];
+
+ // In some specific situation with VGrid, the promise never resolved so we cancel it if timed out.
+ timeout(resolveQueue, 250);
+ });
  } catch (e) {
  // canceled
  return;
+ } finally {
+ unsubscribe();
  }
  }
 

src/core/store.ts

@@ -12,7 +12,7 @@ import {
  estimateDefaultItemSize,
 } from "./cache";
 import type { Writeable } from "./types";
-import { abs, exists, max, min, timeout } from "./utils";
+import { abs, exists, max, min } from "./utils";
 
 type ItemJump = Readonly<[sizeDiff: number, index: number]>;
 export type ScrollJump = Readonly<number>;
@@ -73,7 +73,6 @@ export type VirtualStore = {
  _getJumpCount(): number;
  _flushJump(): ScrollJump | undefined;
  _getItemIndexForScrollTo(offset: number): number;
- _waitForScrollDestinationItemsMeasured(): Promise<void>;
  _subscribe(target: number, cb: Subscriber): () => void;
  _update(...action: Actions): void;
  _getScrollDirection(): ScrollDirection;
@@ -97,7 +96,6 @@ export const createVirtualStore = (
  let _scrollDirection: ScrollDirection = SCROLL_IDLE;
  let _resized = false;
  let _prevRange: ItemsRange = [0, initialItemCount];
- let _scrollToQueue: [() => void, () => void] | undefined;
 
  const subscribers = new Set<[number, Subscriber]>();
  const getScrollSize = (): number =>
@@ -187,28 +185,6 @@ export const createVirtualStore = (
  _getItemIndexForScrollTo(offset) {
  return findStartIndexWithOffset(cache, offset, 0, 0);
  },
- _waitForScrollDestinationItemsMeasured() {
- if (_scrollToQueue) {
- // Cancel waiting scrollTo
- _scrollToQueue[1]();
- }
- // The measurement will be done asynchronously and the timing is not predictable so we use promise.
- // For example, ResizeObserver may not fire when window is not visible.
- return new Promise((resolve, reject) => {
- let resolved: boolean | undefined = false;
-
- const resolveQueue = () => {
- if (resolved) return;
- resolved = true;
- resolve();
- _scrollToQueue = undefined;
- };
- _scrollToQueue = [resolveQueue, reject];
-
- // In some specific situation with VGrid, the promise never resolved so we cancel it if timed out.
- timeout(resolveQueue, 250);
- });
- },
  _subscribe(target, cb) {
  const sub: [number, Subscriber] = [target, cb];
  subscribers.add(sub);
@@ -340,11 +316,6 @@ export const createVirtualStore = (
  cb(shouldSync);
  });
  }
- if (_scrollToQueue) {
- if (type === ACTION_ITEM_RESIZE) {
- _scrollToQueue[0]();
- }
- }
  if (exists(updatedScrollState)) {
  onScrollStateChange(updatedScrollState);
  }