import { type EventArg, NavigationContext, type NavigationProp, type ParamListBase, useRoute, } from '@react-navigation/core'; import * as React from 'react'; import type { ScrollView } from 'react-native'; type ScrollOptions = { x?: number; y?: number; animated?: boolean }; type ScrollableView = | { scrollToTop(): void } | { scrollTo(options: ScrollOptions): void } | { scrollToOffset(options: { offset: number; animated?: boolean }): void } | { scrollResponderScrollTo(options: ScrollOptions): void }; type ScrollableWrapper = | { getScrollResponder(): React.ReactNode | ScrollView } | { getNode(): ScrollableView } | ScrollableView | null; function getScrollableNode(ref: React.RefObject) { if (ref.current == null) { return null; } if ( 'scrollToTop' in ref.current || 'scrollTo' in ref.current || 'scrollToOffset' in ref.current || 'scrollResponderScrollTo' in ref.current ) { // This is already a scrollable node. return ref.current; } else if ('getScrollResponder' in ref.current) { // If the view is a wrapper like FlatList, SectionList etc. // We need to use `getScrollResponder` to get access to the scroll responder return ref.current.getScrollResponder(); } else if ('getNode' in ref.current) { // When a `ScrollView` is wrapped in `Animated.createAnimatedComponent` // we need to use `getNode` to get the ref to the actual scrollview. // Note that `getNode` is deprecated in newer versions of react-native // this is why we check if we already have a scrollable node above. return ref.current.getNode(); } else { return ref.current; } } export function useScrollToTop(ref: React.RefObject) { const navigation = React.useContext(NavigationContext); const route = useRoute(); if (navigation === undefined) { throw new Error( "Couldn't find a navigation object. Is your component inside NavigationContainer?" ); } React.useEffect(() => { const tabNavigations: NavigationProp[] = []; let currentNavigation = navigation; // If the screen is nested inside multiple tab navigators, we should scroll to top for any of them // So we need to find all the parent tab navigators and add the listeners there while (currentNavigation) { if (currentNavigation.getState().type === 'tab') { tabNavigations.push(currentNavigation); } currentNavigation = currentNavigation.getParent(); } if (tabNavigations.length === 0) { return; } const unsubscribers = tabNavigations.map((tab) => { return tab.addListener( // We don't wanna import tab types here to avoid extra deps // in addition, there are multiple tab implementations // @ts-expect-error the `tabPress` event is only available when navigation type is tab 'tabPress', (e: EventArg<'tabPress', true>) => { // We should scroll to top only when the screen is focused const isFocused = navigation.isFocused(); // In a nested stack navigator, tab press resets the stack to first screen // So we should scroll to top only when we are on first screen const isFirst = tabNavigations.includes(navigation) || navigation.getState().routes[0].key === route.key; // Run the operation in the next frame so we're sure all listeners have been run // This is necessary to know if preventDefault() has been called requestAnimationFrame(() => { const scrollable = getScrollableNode(ref) as ScrollableWrapper; if (isFocused && isFirst && scrollable && !e.defaultPrevented) { if ('scrollToTop' in scrollable) { scrollable.scrollToTop(); } else if ('scrollTo' in scrollable) { scrollable.scrollTo({ y: 0, animated: true }); } else if ('scrollToOffset' in scrollable) { scrollable.scrollToOffset({ offset: 0, animated: true }); } else if ('scrollResponderScrollTo' in scrollable) { scrollable.scrollResponderScrollTo({ y: 0, animated: true }); } } }); } ); }); return () => { unsubscribers.forEach((unsubscribe) => unsubscribe()); }; }, [navigation, ref, route.key]); }