Question

How can you reduce the ‘current’ time in setTimeOut? For example I have a countdown going from 100s, after 40s (so at 60s) I click a button and it instantly reduces to 50s (-10s).

The link in the example below enables after 100 seconds. Basically I’m looking for a way to reduce 10 seconds from the (current position in the) countdown every time a button is pressed.

function enableLink() {
    setTimeout('enableAnchor( "anchor0", "mylink.php" )', 100000);
}

If this isn’t possible, is there any language or library (JQuery or AJAX perhaps?) that would allow me to do this?

Answer 1

Don’t use the timer values for any real logic, do it by hand:

var msLeft = 100000,
    prev = new Date();

     //This timer is simply polling how much time has passed using accurate methods and reduces it accordingly from msLeft 
var timerId = window.setInterval( function() {
    var cur = new Date(),
        progress = cur - prev;

    prev = cur;
    msLeft -= progress;

    if( msLeft <= 0 ) {
        window.clearInterval(timerId);
        counteddown();
    }
}, 50 ); 

document.onclick = function() {
    msLeft -= 10000; //Each click reduces 10 seconds from the countdown
};

document.onkeyup = function() {
    msLeft += 10000; //Each keyup adds 10 seconds to the countdown
};

jsfiddle demo http://jsfiddle.net/JgzZQ/2/