Make an element Draggable !

drag-util.js

export function dragElement(elmnt, dragElement = elmnt) {
  let pos1 = 0;
  let pos2 = 0;
  let pos3 = 0;
  let pos4 = 0;

  dragElement.onmousedown = dragMouseDown;

  function dragMouseDown(e) {
    e = e || window.event;
    e.preventDefault();

    // Get the mouse cursor position at startup:
    pos3 = e.clientX;
    pos4 = e.clientY;
    document.onmouseup = closeDragElement;

    // Call a function whenever the cursor moves:
    document.onmousemove = elementDrag;
  }

  function elementDrag(e) {
    e = e || window.event;
    e.preventDefault();

    // Calculate the new cursor position:
    pos1 = pos3 - e.clientX;
    pos2 = pos4 - e.clientY;
    pos3 = e.clientX;
    pos4 = e.clientY;

    // Set the element's new position:
    elmnt.style.top = `${elmnt.offsetTop - pos2}px`;
    elmnt.style.left = `${elmnt.offsetLeft - pos1}px`;
  }

  function closeDragElement() {
    // Stop moving when mouse button is released:
    document.onmouseup = null;
    document.onmousemove = null;
  }
}