check if element got scrolled to top

Question

I want to check if an element is scrolled to top with an offset of ~ 100px.

I´ve got a page with 5 subcontents and 2 classes to make backgrounds. It looks like this:

Answer 1

You have to listen for the scroll event, then check each element against the currently scrolled distance, something like :

$(window).on('scroll', function() {
    var scrollTop = $(this).scrollTop();

    $('.background1, .background2').each(function() {
        var topDistance = $(this).offset().top;

        if ( (topDistance+100) < scrollTop ) {
            alert( $(this).text() + ' was scrolled to the top' );
        }
    });
});