[fix] ScrollView scrollEventThrottle logic

Fix #1726

packages/react-native-web/package.json

@@ -18,7 +18,6 @@
   "dependencies": {
     "array-find-index": "^1.0.2",
     "create-react-class": "^15.6.2",
-    "debounce": "^1.2.0",
     "deep-assign": "^3.0.0",
     "fbjs": "^1.0.0",
     "hyphenate-style-name": "^1.0.3",

packages/react-native-web/src/exports/ScrollView/ScrollViewBase.js

@@ -11,7 +11,6 @@ import type { ViewProps } from '../View';
 
 import * as React from 'react';
 import { forwardRef, useRef } from 'react';
-import debounce from 'debounce';
 import StyleSheet from '../StyleSheet';
 import View from '../View';
 
@@ -93,6 +92,7 @@ const ScrollViewBase = forwardRef<Props, *>((props, forwardedRef) => {
   } = props;
 
   const scrollState = useRef({ isScrolling: false, scrollLastTick: 0 });
+  const scrollTimeout = useRef(null);
 
   function createPreventableScrollHandler(handler: Function) {
     return (e: Object) => {
@@ -107,9 +107,11 @@ const ScrollViewBase = forwardRef<Props, *>((props, forwardedRef) => {
   function handleScroll(e: Object) {
     e.persist();
     e.stopPropagation();
-    // A scroll happened, so the scroll bumps the debounce.
-    const debouncedOnScrollEnd = debounce(handleScrollEnd, 100);
-    debouncedOnScrollEnd(e);
+    // A scroll happened, so the scroll resets the scrollend timeout.
+    if (scrollTimeout.current != null) {
+      clearTimeout(scrollTimeout.current);
+    }
+    scrollTimeout.current = setTimeout(handleScrollEnd, 100);
     if (scrollState.current.isScrolling) {
       // Scroll last tick may have changed, check if we need to notify
       if (shouldEmitScrollEvent(scrollState.current.scrollLastTick, scrollEventThrottle)) {

yarn.lock

@@ -6234,10 +6234,6 @@ de-indent@^1.0.2:
   resolved "https://registry.yarnpkg.com/de-indent/-/de-indent-1.0.2.tgz#b2038e846dc33baa5796128d0804b455b8c1e21d"
   integrity sha1-sgOOhG3DO6pXlhKNCAS0VbjB4h0=
 
-debounce@^1.2.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/debounce/-/debounce-1.2.0.tgz#44a540abc0ea9943018dc0eaa95cce87f65cd131"
-
 debug@2.6.9, debug@^2.1.2, debug@^2.2.0, debug@^2.3.3, debug@^2.6.0, debug@^2.6.8, debug@^2.6.9:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"