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

React Native integration for React Navigation

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.useScrollToTop = useScrollToTop;
var _core = require("@react-navigation/core");
var React = _interopRequireWildcard(require("react"));
function _getRequireWildcardCache(e) { if ("function" != typeof WeakMap) return null; var r = new WeakMap(), t = new WeakMap(); return (_getRequireWildcardCache = function (e) { return e ? t : r; })(e); }
function _interopRequireWildcard(e, r) { if (!r && e && e.__esModule) return e; if (null === e || "object" != typeof e && "function" != typeof e) return { default: e }; var t = _getRequireWildcardCache(r); if (t && t.has(e)) return t.get(e); var n = { __proto__: null }, a = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var u in e) if ("default" !== u && {}.hasOwnProperty.call(e, u)) { var i = a ? Object.getOwnPropertyDescriptor(e, u) : null; i && (i.get || i.set) ? Object.defineProperty(n, u, i) : n[u] = e[u]; } return n.default = e, t && t.set(e, n), n; }
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 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;
  }
}
function useScrollToTop(ref) {
  const navigation = React.useContext(_core.NavigationContext);
  const route = (0, _core.useRoute)();
  if (navigation === undefined) {
    throw new Error("Couldn't find a navigation object. Is your component inside NavigationContainer?");
  }
  React.useEffect(() => {
    const tabNavigations = [];
    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 => {
        // 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);
          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]);
}
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