:animated Selector

animated ( ) version added: 1.2

Description: Select all elements that are in the progress of an animation at the time the selector is run.

Note: If you use a custom jQuery build without the effects module, the :animated selector will throw an error.

Examples:

Example: Change the color of any div that is animated. 

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>css demo</title>

  <style>

  div {
    background: yellow;
    border: 1px solid #AAA;
    width: 80px;
    height: 80px;
    margin: 0 5px;
    float: left;
  }
  div.colored {
    background: green;
  }

  </style>

  <script src="//code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
  

<button id="run">Run</button>

<div></div>
<div id="mover"></div>
<div></div>

<script>

$( "#run" ).click(function() {
  $( "div:animated" ).toggleClass( "colored" );
});

function animateIt() {
  $( "#mover" ).slideToggle( "slow", animateIt );
}

animateIt();

</script>

  
</body>
</html>

Demo: