Visualizza wikitesto di Scroll orizzontale della pagina

[[GENERALE#jQuery e Javascript|&larr; jQuery e Javascript]] [[Category:Javascript]]

== Esempio ==
<pre>
<div id="board-scroll" class="items">
   <div class="item item1"></div>
   <div class="item item2"></div>
   <div class="item item3"></div>
   <div class="item item4"></div>
   <div class="item item5"></div>
   <div class="item item6"></div>
   <div class="item item7"></div>
   <div class="item item8"></div>
   <div class="item item9"></div>
   <div class="item item10"></div>
</div>
</pre>
Script:
 // scroll orizzontale
 scrollHorizontal( '#board-scroll' );
Css:
<pre>
   @supports ( display: grid ) {
     .items {
         width: 100%;
         overflow-x: scroll;
         overflow-y: hidden;
         white-space: nowrap;
         will-change: transform;
         user-select: none;
         cursor: pointer;
     }
     .item.active {
       background: rgba(255,255,255,0.3);
       cursor: grabbing;
       cursor: -webkit-grabbing;
     }
  }
</pre>

== Funzione ==
<pre>
/**
 * Scroll orizzontale tramite drag del mouse
 * @param string class_id class eo id dell'elemento che contiene gli elementi
 */
function scrollHorizontal( class_id ) {
   const slider = document.querySelector( class_id );
   let isDown = false;
   let startX;
   let scrollLeft;

   slider.addEventListener('mousedown', (e) => {
      isDown = true;
      slider.classList.add('active');
      startX = e.pageX - slider.offsetLeft;
      scrollLeft = slider.scrollLeft;
   });
   slider.addEventListener('mouseleave', () => {
      isDown = false;
      slider.classList.remove('active');
   });
   slider.addEventListener('mouseup', () => {
      isDown = false;
      slider.classList.remove('active');
   });
   slider.addEventListener('mousemove', (e) => {
      if (!isDown)
         return;
      e.preventDefault();
      const x = e.pageX - slider.offsetLeft;
      const walk = (x - startX) * 2; //scroll-fast
      slider.scrollLeft = scrollLeft - walk;
      console.log(walk);
   });
}
</pre>