AngularJS Simple Directive

Attached you will find an existing AngularJS directive I am having issues with. I need to be able to detect a user scroll, not on the entire $docuement or $window but on any DOM element that has scrolling. With that said, the task is as following: - on any scroll, addClass "test" to the body tag I have attached an initial directive in which I was working on, just need to addClass to body on any scroll.