87 lines
2.1 KiB
JavaScript
87 lines
2.1 KiB
JavaScript
|
/**
|
||
|
|
* External dependencies
|
||
|
|
*/
|
||
|
|
import { useRef, useLayoutEffect, useState } from '@wordpress/element';
|
||
|
|
|
||
|
|
/** @typedef {import('react')} React */
|
||
|
|
|
||
|
|
/** @type {React.CSSProperties} */
|
||
|
|
const style = {
|
||
|
|
bottom: 0,
|
||
|
|
left: 0,
|
||
|
|
opacity: 0,
|
||
|
|
pointerEvents: 'none',
|
||
|
|
position: 'absolute',
|
||
|
|
right: 0,
|
||
|
|
top: 0,
|
||
|
|
zIndex: -1,
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns an element and a string (`above`, `visible` or `below`) based on the
|
||
|
|
* element position relative to the viewport.
|
||
|
|
* _Note: `usePositionRelativeToViewport` will return an empty position (``)
|
||
|
|
* until after first render_
|
||
|
|
*
|
||
|
|
* @return {Array} An array of {Element} `referenceElement` and {string} `positionRelativeToViewport`.
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
*
|
||
|
|
* ```js
|
||
|
|
* const App = () => {
|
||
|
|
* const [ referenceElement, positionRelativeToViewport ] = useContainerQueries();
|
||
|
|
*
|
||
|
|
* return (
|
||
|
|
* <>
|
||
|
|
* { referenceElement }
|
||
|
|
* { positionRelativeToViewport === 'below' && <p>Reference element is below the viewport.</p> }
|
||
|
|
* { positionRelativeToViewport === 'visible' && <p>Reference element is visible in the viewport.</p> }
|
||
|
|
* { positionRelativeToViewport === 'above' && <p>Reference element is above the viewport.</p> }
|
||
|
|
* </>
|
||
|
|
* );
|
||
|
|
* };
|
||
|
|
* ```
|
||
|
|
*/
|
||
|
|
export const usePositionRelativeToViewport = () => {
|
||
|
|
const [
|
||
|
|
positionRelativeToViewport,
|
||
|
|
setPositionRelativeToViewport,
|
||
|
|
] = useState( '' );
|
||
|
|
const referenceElementRef = useRef( null );
|
||
|
|
const intersectionObserver = useRef(
|
||
|
|
new IntersectionObserver(
|
||
|
|
( entries ) => {
|
||
|
|
if ( entries[ 0 ].isIntersecting ) {
|
||
|
|
setPositionRelativeToViewport( 'visible' );
|
||
|
|
} else {
|
||
|
|
setPositionRelativeToViewport(
|
||
|
|
entries[ 0 ].boundingClientRect.top > 0
|
||
|
|
? 'below'
|
||
|
|
: 'above'
|
||
|
|
);
|
||
|
|
}
|
||
|
|
},
|
||
|
|
{ threshold: 1.0 }
|
||
|
|
)
|
||
|
|
);
|
||
|
|
|
||
|
|
useLayoutEffect( () => {
|
||
|
|
const referenceElementNode = referenceElementRef.current;
|
||
|
|
const observer = intersectionObserver.current;
|
||
|
|
|
||
|
|
if ( referenceElementNode ) {
|
||
|
|
observer.observe( referenceElementNode );
|
||
|
|
}
|
||
|
|
|
||
|
|
return () => {
|
||
|
|
observer.unobserve( referenceElementNode );
|
||
|
|
};
|
||
|
|
}, [] );
|
||
|
|
|
||
|
|
const referenceElement = (
|
||
|
|
<div aria-hidden={ true } ref={ referenceElementRef } style={ style } />
|
||
|
|
);
|
||
|
|
|
||
|
|
return [ referenceElement, positionRelativeToViewport ];
|
||
|
|
};
|