window.scroll function freezes firefox

Question

I\'m working on a page with a fixed menu that picks up after the user has scrolled a certain distance from the top, and as they scroll down the page, different links from th

Answer 1

Executing too much code on scroll event is overkill, on each scroll, browsers trigger the scroll event hundred times, you can consider using a library that have methods like throttle or debounce.

http://documentcloud.github.com/underscore/#throttle

It's a very, very, bad idea to attach handlers to the window scroll event. Depending upon the browser the scroll event can fire a lot and putting code in the scroll callback will slow down any attempts to scroll the page (not a good idea). Any performance degradation in the scroll handler(s) as a result will only compound the performance of scrolling overall. Instead it's much better to use some form of a timer to check every X milliseconds OR to attach a scroll event and only run your code after a delay (or even after a given number of executions - and then a delay). http://ejohn.org/blog/learning-from-twitter/