Code sticky

{% javascript %}
  class StickyHeader extends HTMLElement {
    constructor() {
      super();
    }

    connectedCallback() {
      this.header = document.getElementById('shopify-section-header');
      this.headerBounds = {};
      this.currentScrollTop = 0;
      this.preventReveal = false;

      this.onScrollHandler = this.onScroll.bind(this);
      this.hideHeaderOnScrollUp = () => this.preventReveal = true;

      this.addEventListener('preventHeaderReveal', this.hideHeaderOnScrollUp);
      window.addEventListener('scroll', this.onScrollHandler, false);

      this.createObserver();
    }

    disconnectedCallback() {
      this.removeEventListener('preventHeaderReveal', this.hideHeaderOnScrollUp);
      window.removeEventListener('scroll', this.onScrollHandler);
    }

    createObserver() {
      let observer = new IntersectionObserver((entries, observer) => {
        this.headerBounds = entries[0].intersectionRect;
        observer.disconnect();
      });

      observer.observe(this.header);
    }

    onScroll() {
      const scrollTop = window.pageYOffset || document.documentElement.scrollTop;

      if (scrollTop > this.currentScrollTop && scrollTop > this.headerBounds.bottom) {
        requestAnimationFrame(this.hide.bind(this));
      } else if (scrollTop < this.currentScrollTop && scrollTop > this.headerBounds.bottom) {
        if (!this.preventReveal) {
          requestAnimationFrame(this.reveal.bind(this));
        } else {
          window.clearTimeout(this.isScrolling);

          this.isScrolling = setTimeout(() => {
            this.preventReveal = false;
          }, 66);

          requestAnimationFrame(this.hide.bind(this));
        }
      } else if (scrollTop <= this.headerBounds.top) {
        requestAnimationFrame(this.reset.bind(this));
      }


      this.currentScrollTop = scrollTop;
    }

    hide() {
      this.header.classList.add('shopify-section-header-hidden', 'shopify-section-header-sticky');
    }

    reveal() {
      this.header.classList.add('shopify-section-header-sticky', 'animate');
      this.header.classList.remove('shopify-section-header-hidden');
    }

    reset() {
      this.header.classList.remove('shopify-section-header-hidden', 'shopify-section-header-sticky', 'animate');
    }
  }

  customElements.define('sticky-header', StickyHeader);
{% endjavascript %}
<style>
#shopify-section-header {
  z-index: 3;
}

.shopify-section-header-sticky {
  position: sticky;
  top: 0;
  background: #fff;
}

.shopify-section-header-hidden {
  transform: translateY(-100%);
}

#shopify-section-header.animate {
  transition: transform 0.15s ease-out;
}
</style>