How to detect 2 elements colliding or overlapping in jQuery

Having issues with collision detection on those 2 <div> tags of yours? Maybe you don’t want to use a plugin either? Well here’s a simple way to solve your issue.

Below is a very simple way to detect collision between DOM elements. This can be coupled with a window resize function “$( window ).resize(function(){});” to allow for continuous detection.

CSS

div{
    width:200px;
    height:200px;
    background:#EEE;
}
#two{
    position:absolute;
    left:100px;
    top:50px;
    background:#F60;
}

HTML

<div id="one">One</div>
 
<div id="two">Two</div>
 
<div id="three">Three</div>

<span id="result"></span>

JavaScript

console.log(isOverlap("#one","#two"));//true
console.log(isOverlap("#one","#three"));//false
console.log(isOverlap("#two","#three"));//true

var overlap = isOverlap("#one","#two");

if (overlap) {
 // Do something when elements are overlapping
} else {
 // Do something when elements are not overlapping
}

// jQuery required    

$("#result").text(isOverlap("#one","#two")+","+isOverlap("#one","#three")+","+isOverlap("#two","#three"));

function isOverlap(idOne,idTwo){
        var objOne=$(idOne),
            objTwo=$(idTwo),
            offsetOne = objOne.offset(),
            offsetTwo = objTwo.offset(),
            topOne=offsetOne.top,
            topTwo=offsetTwo.top,
            leftOne=offsetOne.left,
            leftTwo=offsetTwo.left,
            widthOne = objOne.width(),
            widthTwo = objTwo.width(),
            heightOne = objOne.height(),
            heightTwo = objTwo.height();
        var leftTop = leftTwo > leftOne && leftTwo < leftOne+widthOne                  && topTwo > topOne && topTwo < topOne+heightOne,             rightTop = leftTwo+widthTwo > leftOne && leftTwo+widthTwo < leftOne+widthOne                  && topTwo > topOne && topTwo < topOne+heightOne,             leftBottom = leftTwo > leftOne && leftTwo < leftOne+widthOne                  && topTwo+heightTwo > topOne && topTwo+heightTwo < topOne+heightOne,             rightBottom = leftTwo+widthTwo > leftOne && leftTwo+widthTwo < leftOne+widthOne                  && topTwo+heightTwo > topOne && topTwo+heightTwo < topOne+heightOne;
        return leftTop || rightTop || leftBottom || rightBottom;
}

View On Github (Via: artwl)