hamann-ausgabe-core/HaWeb/wwwroot/js/scrollbutton.mjs

const startup_scrollbutton = function () {

    // Script for showing and acting upon the "scroll to top button"
    const scrollFunction = function () {
        let button = document.getElementById("ha-scrollbutton");
        if (button !== null) {
            if (document.body.scrollTop > 300 || document.documentElement.scrollTop > 300) {
                // button.style.display = "block";
                button.style.pointerEvents = "auto";
                button.style.opacity = "1";
            } else {
                // button.style.display = "none";
                button.style.pointerEvents = "none";
                button.style.opacity = "0";
            }
        }
    }

    // Scroll button
    if (document.getElementById("ha-scrollbutton") !== null) {
        scrollFunction();
        document.getElementById("ha-scrollbutton").addEventListener("click", () => {
            document.body.scrollTop = 0; // For Safari
            document.documentElement.scrollTop = 0; // For Chrome, Firefox, IE and Opera
        })
        // TODO: workaround, bc window does not recieve scroll events anymore
        setInterval(() => scrollFunction(), 1500);
    }
};

export { startup_scrollbutton };