@react-navigation/native/lib/module/useScrollToTop.js

import * as React from 'react';
import { useNavigation, useRoute } from '@react-navigation/core';

function getScrollableNode(ref) {
  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 wraped 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 default function useScrollToTop(ref) {
  const navigation = useNavigation();
  const route = useRoute();
  React.useEffect(() => {
    let current = navigation; // The screen might be inside another navigator such as stack nested in tabs
    // We need to find the closest tab navigator and add the listener there

    while (current && current.dangerouslyGetState().type !== 'tab') {
      current = current.dangerouslyGetParent();
    }

    if (!current) {
      return;
    }

    const unsubscribe = current.addListener( // We don't wanna import tab types here to avoid extra deps
    // in addition, there are multiple tab implementations
    // @ts-expect-error
    'tabPress', e => {
      // 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 = navigation === current || navigation.dangerouslyGetState().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);

        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 unsubscribe;
  }, [navigation, ref, route.key]);
}
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