JS How to control an anonymous function

Question

Scenario:

I have a function that I want to automatically invoke. But on a mouse click I want this function to stop. How to control an anonymous function in JS?

Example

HTML

<div id="seventyfive" style="position:absolute; font-size:10px; font-weight:bold">
<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Heart_coraz%C3%B3n.svg/200px-Heart_coraz%C3%B3n.svg.png" style="width:50px"/>
</div>

JS

(function pulse(back) {
    $('#seventyfive').animate(
        {
            'font-size': (back) ? '10px' : '15px',
            opacity: (back) ? 0.3 : 1
        }, 600, function(){pulse(!back)});
    $('#seventyfive img').animate(
        {
            'width': (back) ? '50px' : '40px'
        }, 600);
})(false);

var on = true;
$("#seventyfive").click(function(){

    on = !on;

    if(on){

       // Start/Stop Pulse function
    }

});

JSFiddle Example JSFiddle Example

Answer 1

You can benefit from hardware acceleration by using CSS, which massively improves performance.

 $("#seventyfive").click(function() { $(this).toggleClass("pulsing"); }); 

 .heart.pulsing img { animation: pulse 600ms ease infinite alternate; } @keyframes pulse { 0% { transform: none; } 100% { transform: scale(1.2); opacity: 0.3; } } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"></script> <div id="seventyfive" class="heart" style="position:absolute; font-size:10px; font-weight:bold"> <img src="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Heart_coraz%C3%B3n.svg/200px-Heart_coraz%C3%B3n.svg.png" style="width:50px" /> </div> 

With this, just apply the pulsing class to #seventyfive , and the heart will pulse. Notice that this animates opacity and transform , not font-size , to avoid triggering the browser to perform a re-layout.