ripple-core/public/js/jquery.onscreen.min.js

Ripple is an interactive audience response system that allows presenters to survey audience members in real time communication through their mobile devices.

// onScreen jQuery plugin v0.2.1
// (c) 2011 Ben Pickles
//
// http://benpickles.github.com/onScreen
//
// Released under MIT license.
(function(a){a.expr[":"].onScreen=function(b){var c=a(window),d=c.scrollTop(),e=c.height(),f=d+e,g=a(b),h=g.offset().top,i=g.height(),j=h+i;return h>=d&&h<f||j>d&&j<=f||i>e&&h<=d&&j>=f}})(jQuery);