useOnScreen

A hook that tracks whether an element is visible within the viewport using the Intersection Observer API. Perfect for implementing infinite scroll, lazy loading, or visibility-based animations.

Parameters

• ref: RefObject<Element> - Reference to the element to track
• rootMargin: string - Optional margin around the root (viewport). Default is “0px”

Returns

• boolean - Whether the element is currently intersecting with the viewport

Usage

import { useOnScreen } from '@rhinolabs/react-hooks';
import { useRef } from 'react';
 
function LazyImage() {
  const imageRef = useRef<HTMLImageElement>(null);
  const isVisible = useOnScreen(imageRef, '50px');
 
  return (
    <img
      ref={imageRef}
      src={isVisible ? 'actual-image.jpg' : 'placeholder.jpg'}
      alt="Lazy loaded image"
    />
  );
}

Notes

• Uses Intersection Observer API
• Automatically handles observer cleanup
• Supports custom root margins
• Perfect for lazy loading
• Efficient viewport tracking
• Updates state automatically
• No scroll event listeners needed