Is it possible, in JavaScript, to detect when the screen is turned off in the Android & iOS browsers

Question

I was tracking down some ridiculously high load times that my app\'s javascript reported, and found that Android (and iOS) pause some JavaScript execution when the window is

Answer 1

Found a nice function here:

http://rakaz.nl/2009/09/iphone-webapps-101-detecting-essential-information-about-your-iphone.html

(function() {
    var timestamp = new Date().getTime();

    function checkResume() {
        var current = new Date().getTime();
        if (current - timestamp > 4000) {
            var event = document.createEvent("Events");
            event.initEvent("resume", true, true);
            document.dispatchEvent(event);
        }
        timestamp = current;
    }

    window.setInterval(checkResume, 1000);
})();   

To register for event:

addEventListener("resume", function() {
    alert('Resuming this webapp');
});

This is consistent with Cordova which also fires the resume event.