Merge pull request Expensify#88536 from callstack-internal/VickyStash/bugfix/88238-fix-new-message-indication

Author: mountiny

src/components/FlashList/InvertedFlashList/index.tsx

@@ -17,14 +17,18 @@ type InvertedFlashListProps<T> = FlashListProps<T> & {
 
     /** Ref to the underlying list instance. */
     ref: FlatListRefType;
+
+    /** Whether the list should handle `maintainVisibleContentPosition` */
+    shouldMaintainVisibleContentPosition?: boolean;
 };
 
-function InvertedFlashList<T>({data, keyExtractor, initialScrollKey, onStartReached: onStartReachedProp, ...restProps}: InvertedFlashListProps<T>) {
+function InvertedFlashList<T>({data, keyExtractor, initialScrollKey, onStartReached: onStartReachedProp, shouldMaintainVisibleContentPosition, ...restProps}: InvertedFlashListProps<T>) {
     const {displayedData, onStartReached, maintainVisibleContentPosition} = useFlashListScrollKey<T>({
         data,
         keyExtractor,
         initialScrollKey,
         onStartReached: onStartReachedProp,
+        shouldMaintainVisibleContentPosition,
     });
 
     return (

src/components/FlashList/useFlashListScrollKey.ts

@@ -13,9 +13,12 @@ type FlashListScrollKeyProps<T> = {
 
     /** Callback invoked when the user scrolls close to the start of the list. */
     onStartReached: FlashListProps<T>['onStartReached'];
+
+    /** Whether the list should handle `maintainVisibleContentPosition` */
+    shouldMaintainVisibleContentPosition?: boolean;
 };
 
-export default function useFlashListScrollKey<T>({data, keyExtractor, initialScrollKey, onStartReached}: FlashListScrollKeyProps<T>) {
+export default function useFlashListScrollKey<T>({data, keyExtractor, initialScrollKey, onStartReached, shouldMaintainVisibleContentPosition}: FlashListScrollKeyProps<T>) {
     const [isInitialRender, setIsInitialRender] = useState(true);
     const [hasLinkingSettled, setHasLinkingSettled] = useState(!initialScrollKey);
 
@@ -33,9 +36,7 @@ export default function useFlashListScrollKey<T>({data, keyExtractor, initialScr
         });
     }, [isInitialRender, initialScrollKey]);
 
-    // `undefined` = leave FlashList's default (MVCP enabled) while we're still pinning the linked item.
-    // `{disabled: true}` once that's done so MVCP can't interfere afterward.
-    const maintainVisibleContentPosition: FlashListProps<T>['maintainVisibleContentPosition'] = hasLinkingSettled ? {disabled: true} : undefined;
+    const maintainVisibleContentPosition: FlashListProps<T>['maintainVisibleContentPosition'] = {disabled: !shouldMaintainVisibleContentPosition && hasLinkingSettled};
 
     if (!isInitialRender || !initialScrollKey) {
         return {displayedData: data, onStartReached, maintainVisibleContentPosition};

src/pages/inbox/report/ReportActionsList.tsx

@@ -233,6 +233,7 @@ function ReportActionsList({
     const hasHeaderRendered = useRef(false);
 
     const lastAction = sortedVisibleReportActions.at(0);
+    const [shouldMaintainVisibleContentPosition, setShouldMaintainVisibleContentPosition] = useState(() => scrollOffsetRef.current > CONST.REPORT.ACTIONS.ACTION_VISIBLE_THRESHOLD);
     const sortedVisibleReportActionsObjects: OnyxTypes.ReportActions = useMemo(
         () =>
             sortedVisibleReportActions.reduce((actions, action) => {
@@ -363,7 +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.
@@ -927,6 +930,7 @@ function ReportActionsList({
                     extraData={extraData}
                     key={listID}
                     getItemType={(item) => item.actionName}
+                    shouldMaintainVisibleContentPosition={shouldMaintainVisibleContentPosition}
                     initialScrollKey={linkedReportActionID}
                     onContentSizeChange={() => {
                         trackVerticalScrolling(undefined);