JSFiddle - React, Tailwind, and code Playground
HTML
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
<div class="column">1</div>
CSS
div{
height:100px;
margin-bottom:10px;
background:red;
}
.swoosh{
background:blue;
}
JavaScript
function isElementInViewport(el) {
// from http://stackoverflow.com/questions/123999/how-to-tell-if-a-dom-element-is-visible-in-the-current-viewport
var rect = el.getBoundingClientRect();
return (
rect.top >= 0 &&
rect.left >= 0 &&
rect.bottom <= (window.innerHeight || document. documentElement.clientHeight) && /*or $(window).height() */
rect.right <= (window.innerWidth || document. documentElement.clientWidth) /*or $(window).width() */
);
}
$.fn.checkViewportAndSetClass = function() {
$(this).each(function(){
if (isElementInViewport(this)) {
$(this).addClass("swoosh");
}
});
};
$('.column').checkViewportAndSetClass();
$(window).on("scroll", function() {
$('.column').checkViewportAndSetClass();
});