その横メニューは、何が見えているかを知っている

import React from 'react';
import {
  ScrollMenu,
  VisibilityContext,
  type publicApiType,
} from 'react-horizontal-scrolling-menu';
import 'react-horizontal-scrolling-menu/dist/styles.css';

const items = Array.from({ length: 10 }, (_, i) => `item-${i + 1}`);

export function App() {
  return (
    <ScrollMenu LeftArrow={LeftArrow} RightArrow={RightArrow}>
      {items.map((id) => (
        <Card itemId={id} key={id} title={id} />
      ))}
    </ScrollMenu>
  );
}

function LeftArrow() {
  const visibility = React.useContext<publicApiType>(VisibilityContext);
  const isFirstVisible = visibility.useIsVisible('first', true);
  return (
    <button
      disabled={isFirstVisible}
      onClick={() => visibility.scrollPrev()}
    >
      ←
    </button>
  );
}

function RightArrow() {
  const visibility = React.useContext<publicApiType>(VisibilityContext);
  const isLastVisible = visibility.useIsVisible('last', false);
  return (
    <button
      disabled={isLastVisible}
      onClick={() => visibility.scrollNext()}
    >
      →
    </button>
  );
}

function Card({ itemId, title }: { itemId: string; title: string }) {
  const visibility = React.useContext<publicApiType>(VisibilityContext);
  const isVisible = visibility.useIsVisible(itemId);
  return (
    <div className="card" data-visible={isVisible}>
      <div>{title}</div>
      <div>visible: {String(isVisible)}</div>
    </div>
  );
}