Check if element in viewport (even NOT FULL element, but partially)

gistfile1.txt

function isScrolledIntoView(elem){
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return Math.min(elemBottom, docViewBottom) >= Math.max(elemTop, docViewTop);
}