Change div css when user scrolls past it, using jQuery

Question

When a user scrolls past a div I need it\'s css changed to position:fixed. Much like what is done here: http://imakewebthings.com/jquery-waypoints/shortcuts/sticky-elements/

Answer 1

I noticed in your answer #this disappears abruptly once you get down to #footer. I've tweaked your answer to allow for #this to stick to #footer and scroll which is a lot smoother.

My demo uses slightly different markup and is a little more verbose so jump over to jsFiddle and check it out.

Demo: jsfiddle.net/Marcel/e9hyw/

Answer 2

This is what finally worked for me:

    jQuery(document).ready(function() {
    var topOfrel = jQuery("#this").offset().top;
    var topOffooter = jQuery("#footer").offset().top - jQuery(window).height(); 
    var topOffootero = topOffooter ;
    var boxheight = jQuery(window).height() - 130;//adjusting for position below
    jQuery(window).scroll(function() {
        var topOfWindow = jQuery(window).scrollTop();
        if (topOfrel < topOfWindow && topOffooter > topOfWindow) {
            jQuery("#this").css("position", "fixed").css("top", "130px").css("overflow","auto").css("height", boxheight + "px");

        } else {
            jQuery("#this").css("position", "static");
        }
    });
});

Answer 3

the page you reference uses jQuery:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.min.js">

and also has other Javascript included on it that we don't see

incidentally you can view it here:

http://imakewebthings.com/jquery-waypoints/waypoints.js
http://imakewebthings.com/jquery-waypoints/shortcuts/sticky-elements/waypoints-sticky.js

the functions he uses can be seen there, but i would not say it's a quick answer. Based on his scripts he attaches a listener to the element after the page loads:

<script type="text/javascript">
    $(document).ready(function() {
        $('.my-sticky-element').waypoint('sticky');
    });
</script>

If you have specific questions ask away, but i doubt many will go through explaining the entire script for you.