knl_meowscendence/src/front/static/ts/views/drag.ts

import { setOnekoOffset } from "../oneko.ts";

export function dragElement(el) {
  var pos1 = 0, pos2 = 0, pos3 = 0, pos4 = 0;
  if (document.getElementById(el.id + "-header")) {
    // if present, the header is where you move the DIV from:
    document.getElementById(el.id + "-header").onmousedown = dragMouseDown;
  } else {
    // otherwise, move the DIV from anywhere inside the DIV:
    el.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:
    el.style.top = (el.offsetTop - pos2) + "px";
    el.style.left = (el.offsetLeft - pos1) + "px";
	setOnekoOffset();
  }

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