React hook for visibility sensing a ref

It checks whether an element has scrolled into view or not. A lot of the logic is taken from react-visibility-sensor and is rewritten for the hooks proposal.

Note: This is using the new React Hooks API Proposal which is subject to change until React 16.7 final.

You'll need to install react, react-dom, etc at ^16.7.0-alpha.0

yarn add @rehooks/visibility-sensor

import useVisibilitySensor from "@rehooks/visibility-sensor";

function MyComponent() {
  const rootNode = useRef(null);
  const { isVisible, visibilityRect } = useVisibilitySensor(rootNode, {
    intervalCheck: false,
    scrollCheck: true,
    resizeCheck: true
  });
  return (
    <div ref={rootNode}>
      <p>
        {isVisible ? "Visible" : isVisible === null ? "Null" : "Not Visible"}
      </p>
    </div>
  );
}

The first argument of the useVisibilitySensor hook is a ref, the second argument is an options object. The available options are as follow:

intervalCheck: false - Accepts int | bool, if an int is supplied, that will be the interval in ms and it keeps checking for visibility

partialVisibility: false - Accepts bool | string : Tells the hook if partial visibility should be considered as visibility or not. Accepts false and directions top, bottom, left and right containment: null - A DOMNode element which defaults to window. The element relative to which visibility is checked against

scrollCheck: true - A bool to determine whether to check for scroll behavior or not

scrollDebounce: 250 - The debounce ms for scroll

scrollThrottle: -1 - The throttle ms for scroll. If throttle > -1, debounce is ignored.

resizeCheck: false - A bool to determine whether to check for resize behavior or not

resizeDebounce: 250 - The debounce ms for resize

resizeThrottle: -1 - The throttle ms for resize. If throttle > -1, debounce is ignored.

shouldCheckOnMount: true - A bool which determines whether an initial check on first render should happen or not.

minTopValue: 0 - An int top value to determine what amount of top visibility should be considered for visibility

• Init
• Scroll and Resize support
• Debounce and throttling
• Option to opt-out of initial check on mount
• Documentation of all options
• Tests _ WIP _
• More examples _ WIP _