ente/web/packages/shared/hooks/useWindowSize.tsx

// https://usehooks.com/useWindowSize/
import { useEffect, useState } from "react";

// Hook
export default function useWindowSize() {
    // Initialize state with undefined width/height so server and client renders match
    // Learn more here: https://joshwcomeau.com/react/the-perils-of-rehydration/
    const [windowSize, setWindowSize] = useState<{
        width: number;
        height: number;
    }>({
        width: undefined,
        height: undefined,
    });

    useEffect(() => {
        // Handler to call on window resize
        function handleResize() {
            // Set window width/height to state
            setWindowSize({
                width: window.innerWidth,
                height: window.innerHeight,
            });
        }

        // Add event listener
        window.addEventListener("resize", handleResize);

        // Call handler right away so state gets updated with initial window size
        handleResize();

        // Remove event listener on cleanup
        return () => window.removeEventListener("resize", handleResize);
    }, []); // Empty array ensures that effect is only run on mount

    return windowSize;
}