JSFiddle - React, Tailwind, and code Playground
HTML
<div id='drop'>Drop here</div>
<div id='drag'>Drag me</div>
CSS
div {
position: absolute;
}
div#drag {
width: 50px;
height: 50px;
background-color: blue;
-webkit-transform-origin: 50% 50%;
-webkit-animation: sway 1s infinite alternate;
}
div#drop {
width: 100px;
height: 100px;
background-color: green;
left: 200px;
top: 200px;
transform: perspective(50vh) rotateX(45deg) rotateZ(0deg);
}
div#drag.in-drop-zone {
background-color: yellow;
}
@-webkit-keyframes sway {
from {
-webkit-transform: rotate(-30deg);
}
to {
-webkit-transform: rotate(30deg);
}
}
JavaScript
var drag = document.getElementById('drag');
var drop = document.getElementById('drop');
var drop_bbox = drop.getBoundingClientRect();
window.addEventListener('touchmove', move, true);
window.addEventListener('mousemove', move, true);
function move(e) {
drag.style.left = e.clientX - 25 + 'px';
drag.style.top = e.clientY - 25 + 'px';
var drag_bbox = e.target.getBoundingClientRect();
drag.className = rectsIntersect(drag_bbox, drop_bbox) ? "in-drop-zone" : null;
}
function rectsIntersect(r1, r2) {
if (!r1 || !r2) return false;
return r2.left < (r1.left+r1.width) &&
(r2.left+r2.width) > r1.left &&
r2.top < (r1.top+r1.height) &&
(r2.top+r2.height) > r1.top;
};