Javascript countdown timer that stops when window is not in focus

Question

Ok , I\'m having trouble to solve this , I\'m a php / C# web developer , and have no experience or knowledge in Javascript, I have to do just this one thing that needs Javas

Answer 1

You could do this using jQuery.
Recycling an old Stackoverflow post, try this:

var window_focus;
var counter = 1000;

// on focus, set window_focus = true.
$(window).focus(function() {
    window_focus = true;
});

// when the window loses focus, set window_focus to false
$(window).focusout(function() {
    window_focus = false;
});

// this is set to the ('click' function, but you could start the interval/timer in a jQuery.ready function: http://api.jquery.com/ready/
$(document).one('click',function() {
    // Run this function every second. Decrement counter if window_focus is true.
    setInterval(function() {
        $('body').append('Count: ' + counter + '
');
        if(window_focus) { counter = counter-1; }
    }, 1000);
});

Demo and old post
DEMO | Old So post

Update
Probably because the demo runs in 4 iframes, the $(window).focus bit only works on the iframe actually running the code (the bottom-right window).

jQuery
jQuery.com (How jQuery works) | Example (back to basics halfway down the page) | If you use the 2nd link, also read this