How can I determine the direction of a jQuery scroll event?

Question

I\'m looking for something to this effect:

$(window).scroll(function(event){
   if (/* magic code*/ ){
       // upscroll code
   } else {
      // downscrol         


        

Answer 1

Store the previous scroll location, then see if the new one is greater than or less than that.

Here's a way to avoid any global variables (fiddle available here):

(function () {
    var previousScroll = 0;

    $(window).scroll(function(){
       var currentScroll = $(this).scrollTop();
       if (currentScroll > previousScroll){
           alert('down');
       } else {
          alert('up');
       }
       previousScroll = currentScroll;
    });
}()); //run this anonymous function immediately