@base-ui-components/react/esm/scroll-area/utils/onVisible.js

Base UI is a library of headless ('unstyled') React components and low-level hooks. You gain complete control over your app's CSS and accessibility features.

/**
 * Executes a callback when an element becomes visible.
 */
export function onVisible(element, callback) {
  if (typeof IntersectionObserver === 'undefined') {
    return () => {};
  }
  const observer = new IntersectionObserver(entries => {
    entries.forEach(entry => {
      if (entry.intersectionRatio > 0) {
        callback();
        observer.disconnect();
      }
    });
  });
  observer.observe(element);
  return () => {
    observer.disconnect();
  };
}