It seems if I'm scrolling the window, the window.setInterval doesn't get attached / fired while the scrolling is happening or after. Has anyone else seen the same issue?

I mean...

• What could be causeing this?
• What can I do to fix this?

It seems if I'm scrolling the window, the window.setInterval doesn't get attached / fired while the scrolling is happening or after. Has anyone else seen the same issue?

I mean...

• What could be causeing this?
• What can I do to fix this?

• javascript
• ios
• mobile-safari
• setinterval
• dom-events

• Maybe it will stop all scripts when scrolling to save memory and make the animation goes faster. Just guessing. – Derek 朕會功夫 Commented Oct 2, 2012 at 1:52
• @Derek, no, everything else seems to execute fine, up to the point of the line right before setInterval. – Johnny Commented Oct 2, 2012 at 1:54

4 Answers 4

iOS halts almost everything in response to user touch to guarantee it feels responsive. The setInterval issue is known, and there doesn't appear to be a workaround.

setInterval pauses in iphone/ipad (mobile Safari) during scrolling

EDIT

During the "freeze" the timer will not catch up once the user releases the screen. The missed events are not deferred, but lost entirely (a bug).

Found this (scary but amazing) workaround, and it's working for me in iOS 6.0:

https://gist.github.com/3755461

I'm not completely sure, but you could use a setTimeout instead of setInterval? It's generally bad practice to use setInterval anyway.

var delay = 100;
(function callee() {
    setTimeout(callee, delay);
})();

iOS6 Safari suffers from a bug that kills timers that are created while a page is scrolling.

There is a fix to this problem provided by kTmnh by recreating timers after scrolling finishes

https://gist.github.com/3798925.