@jbrowse/core/esm/util/useMeasure.js

JBrowse 2 core libraries used by plugins

import { useEffect, useRef, useState } from 'react';
export default function useMeasure() {
    const ref = useRef(null);
    const [dims, setDims] = useState({
        width: undefined,
        height: undefined,
    });
    useEffect(() => {
        if (!ref.current) {
            return;
        }
        const RS = typeof window !== 'undefined' && 'ResizeObserver' in window
            ? window.ResizeObserver
            : undefined;
        if (!RS) {
            return;
        }
        const observer = new RS(entries => {
            setDims({
                width: entries[0].contentRect.width,
                height: entries[0].contentRect.height,
            });
        });
        observer.observe(ref.current);
        return () => {
            observer.disconnect();
        };
    }, []);
    return [ref, dims];
}