You can calculate the offset
of the element and then compare that with the scroll
value like:
$(window).scroll(function() {
var hT = $('#scroll-to').offset().top,
hH = $('#scroll-to').outerHeight(),
wH = $(window).height(),
wS = $(this).scrollTop();
if (wS > (hT+hH-wH)){
console.log('H1 on the view!');
}
});
Check this Demo Fiddle
Updated Demo Fiddle no alert — instead FadeIn() the element
Updated code to check if the element is inside the viewport or not. Thus this works whether you are scrolling up or down adding some rules to the if statement:
if (wS > (hT+hH-wH) && (hT > wS) && (wS+wH > hT+hH)){
//Do something
}