Check this fiddle.
I have added code to alert whenever .test div reaches at top (multiple times). If you need to call the alert/some code only once then you need to remove else part.
Below is the code.
$(document).ready(function() {
$('.test').attr("attop", false);
var lastScrollTop = 0;
$(window).on('scroll', function() {
var windowScrollTop = $(this).scrollTop();
if (windowScrollTop > lastScrollTop) {
var currentDiv = $('.test[attop="false"]:first');
if (currentDiv && currentDiv.length > 0) {
if (windowScrollTop >= currentDiv.offset().top) {
currentDiv.attr('attop', true);
alert('reached top');
}
}
} else {//this part needs to be removed to call only once
var currentTopDivs = $('.test[attop="true"]');
if (currentTopDivs && currentTopDivs.length > 0) {
$.each(currentTopDivs,function(i,elem){
if (windowScrollTop <= $(elem).offset().top) {
$(elem).attr('attop', false);
}
});
}
}
lastScrollTop = windowScrollTop;
});
});
Hope this is what you are trying to achieve.
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