Your IP : 18.189.188.199

Current Path : /var/www/www-root/data/www/www.monolith-realty.ru/local/templates/catalogs/js/
Upload File :
Current File : /var/www/www-root/data/www/www.monolith-realty.ru/local/templates/catalogs/js/scroll.js

document.addEventListener("DOMContentLoaded", () => {
    "use strict";
  
    const root = (() => {
      if ("scrollingElement" in document) return document.scrollingElement;
      const html = document.documentElement;
      const start = html.scrollTop;
      html.scrollTop = start + 1;
      const end = html.scrollTop;
      html.scrollTop = start;
      return end > start ? html : document.body;
    })();
  
    const ease = (duration, elapsed, start, end) =>
      Math.round(end * (-Math.pow(2, -10 * elapsed/duration) + 1) + start);
  
    const getCoordinates = hash => {
      const start = root.scrollTop;
      const delta = (() => {
        if (hash.length < 2) return -start;
        const target = document.querySelector(hash);
        if (!target) return;
        const top = target.getBoundingClientRect().top;
        const max = root.scrollHeight - window.innerHeight;
        return start + top < max ? top : max - start;
      })();
      if (delta) return new Map([["start", start], ["delta", delta]]);
    };
  
    const scroll = link => {
      const hash = link.getAttribute("href");
      const coordinates = getCoordinates(hash);
      if (!coordinates) return;
  
      const tick = timestamp => {
        progress.set("elapsed", timestamp - start);
        root.scrollTop = ease(...progress.values(), ...coordinates.values());
        progress.get("elapsed") < progress.get("duration")
        ? requestAnimationFrame(tick)
        : complete(hash, coordinates);
      };
  
      const progress = new Map([["duration", 800]]);
      const start = performance.now();
      requestAnimationFrame(tick);
    };
  
    const complete = (hash, coordinates) => {
      history.pushState(null, null, hash);
      root.scrollTop = coordinates.get("start") + coordinates.get("delta");
    };
  
    const attachHandler = (links, index) => {
      const link = links.item(index);
      link.addEventListener("click", event => {
        event.preventDefault();
        scroll(link);
      });
      if (index) return attachHandler(links, index - 1);
    };
  
    const links = document.querySelectorAll("a.scroll");
    const last = links.length - 1;
    if (last < 0) return;
    attachHandler(links, last);
  });