Simplify the check

Author: VickyStash

src/components/FlashList/useFlashListScrollKey.ts

@@ -1,9 +1,6 @@
 import type {FlashListProps} from '@shopify/flash-list';
 import {useEffect, useState} from 'react';
 
-// How long to keep MVCP enabled after `shouldMaintainVisibleContentPosition` drops back to false
-const MVCP_FALLOFF_MS = 500;
-
 type FlashListScrollKeyProps<T> = {
     /** The array of items to render in the list. */
     data: T[];
@@ -39,20 +36,7 @@ export default function useFlashListScrollKey<T>({data, keyExtractor, initialScr
         });
     }, [isInitialRender, initialScrollKey]);
 
-    // FlashList captures MVCP anchors on the render BEFORE a data change. Keep MVCP on at mount
-    // (warmup) and while the caller raises the prop, then disable after a short falloff.
-    const [isKeepingMVCPOn, setIsKeepingMVCPOn] = useState(true);
-    useEffect(() => {
-        if (shouldMaintainVisibleContentPosition) {
-            setIsKeepingMVCPOn(true);
-            return;
-        }
-        const timeoutID = setTimeout(() => setIsKeepingMVCPOn(false), MVCP_FALLOFF_MS);
-        return () => clearTimeout(timeoutID);
-    }, [shouldMaintainVisibleContentPosition]);
-
-    const shouldEnableMVCP = !!shouldMaintainVisibleContentPosition || isKeepingMVCPOn || !hasLinkingSettled;
-    const maintainVisibleContentPosition: FlashListProps<T>['maintainVisibleContentPosition'] = {disabled: !shouldEnableMVCP};
+    const maintainVisibleContentPosition: FlashListProps<T>['maintainVisibleContentPosition'] = {disabled: !shouldMaintainVisibleContentPosition && hasLinkingSettled};
 
     if (!isInitialRender || !initialScrollKey) {
         return {displayedData: data, onStartReached, maintainVisibleContentPosition};

src/pages/inbox/report/ReportActionsList.tsx

@@ -233,9 +233,7 @@ function ReportActionsList({
     const hasHeaderRendered = useRef(false);
 
     const lastAction = sortedVisibleReportActions.at(0);
-    const isLastActionFromCurrentUser = (isReportPreviewAction(lastAction) ? lastAction?.childLastActorAccountID : lastAction?.actorAccountID) === currentUserAccountID;
-    const prevLastActionID = usePrevious(lastAction?.reportActionID);
-    const shouldMaintainVisibleContentPosition = prevLastActionID !== undefined && prevLastActionID !== lastAction?.reportActionID && !isLastActionFromCurrentUser;
+    const [shouldMaintainVisibleContentPosition, setShouldMaintainVisibleContentPosition] = useState(() => scrollOffsetRef.current > CONST.REPORT.ACTIONS.ACTION_VISIBLE_THRESHOLD);
     const sortedVisibleReportActionsObjects: OnyxTypes.ReportActions = useMemo(
         () =>
             sortedVisibleReportActions.reduce((actions, action) => {
@@ -366,7 +364,9 @@ function ReportActionsList({
         unreadMarkerReportActionIndex,
         isInverted: true,
         onTrackScrolling: (event: NativeSyntheticEvent<NativeScrollEvent>) => {
-            scrollOffsetRef.current = event.nativeEvent.contentOffset.y;
+            const offset = event.nativeEvent.contentOffset.y;
+            scrollOffsetRef.current = offset;
+            setShouldMaintainVisibleContentPosition(offset > CONST.REPORT.ACTIONS.ACTION_VISIBLE_THRESHOLD);
             onScroll?.(event);
             // We use a timeout to wait for the scroll to finish before resetting the flag.
             // onMomentumScrollEnd would be ideal but it doesn't work on web.