JSFiddle - React, Tailwind, and code Playground

by Tan

HTML

<div id="container">
<div id="mydiv">
<img src="http://www.hloe.co.uk/world-map.gif">
</div>
</div>

<h2>Drag the image</h2>
Xtop = <span id="ptop"></span><br>
Yleft = <span id="pleft"></span>

CSS

#container {
  width: 300px;
  height: 300px;
  margin: auto;
  position: relative;
  overflow: hidden;
  border: 1px solid #999999;
  }

#mydiv {
  cursor: move;
  position: absolute;
  background-color: #dedede;
  }
#mydiv img {
  display: block;
  }

JavaScript

function id(x) {var y = document.getElementById(x);return y;}

/* Don't need this */
var ptop = id('ptop');
var pleft = id('pleft');

var mapBg = id('container').offsetWidth;

var start = id('mydiv');

var mapW = start.offsetWidth;
var mapH = start.offsetHeight;

start.style.left = "-" + ((mapW / 2) - (mapBg / 2)) + "px";
start.style.top = "-" + ((mapH / 2) - (mapBg / 2)) + "px";

//Make the DIV element draggagle:
dragElement(start);

function dragElement(elmnt) {
  var pos1 = 0, pos2 = 0, pos3 = 0, pos4 = 0;
  if (elmnt) {
    /* if present, the header is where you move the DIV from:*/
    elmnt.onmousedown = dragMouseDown;
  } else {
    /* otherwise, move the DIV from anywhere inside the DIV:*/
    elmnt.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";
    

    if (elmnt.offsetLeft < (mapBg-mapW)) {
      elmnt.style.left = (mapBg-mapW) + "px";
    }
    if (elmnt.offsetLeft > 0) {
      elmnt.style.left = 0 + "px";
    }
        if (elmnt.offsetTop < (mapBg-mapH)) {
      elmnt.style.top = (mapBg-mapH) + "px";
    }
    if (elmnt.offsetTop > 0) {
      elmnt.style.top = 0 + "px";
    }

/* Don't need this */
ptop.innerHTML = (elmnt.offsetTop) + "px";
pleft.innerHTML = (elmnt.offsetLeft) + "px";

  }

  function closeDragElement() {
    /* stop moving when mouse button is released:*/
   ...