Template:USTC-Software/js/mainpage

var $html_body = $('html,body'); var have_showed = false; var nav_top = document.getElementById("nav-top"); var animation_lists = document.querySelectorAll("div.animation"); var length = animation_lists.length; var ticking = false; var scrollPosition = 0; var hasShown = new Array(length); var windowHeight = window.innerHeight; var V = (window.jQuery) ? ($.Velocity) : (Velocity); for (var i = 0; i < length; i++) {

   hasShown[i] = false;

}

$(document).foundation();

nav_top.onclick = function(e) {

   e.preventDefault();
   $html_body.stop(true).animate({
       scrollTop: 0
   }, 500);

};

window.addEventListener('scroll', function(e) {

   scrollPosition = window.pageYOffset;
   if (!ticking) {
       window.requestAnimationFrame(function() {
           for (var i = 0; i < length; i++) {
               if ((!hasShown[i]) && (scrollPosition > (animation_lists[i].offsetTop - windowHeight * 0.25))) {
                   var child = animation_lists[i].children;
                   V(child[0], 'transition.expandIn', { visibility: 'visible', dalay: 1000 });
                   V(child[1], 'transition.expandIn', { visibility: 'visible', dalay: 2000 });
                   hasShown[i] = true;
               }
           }
           ticking = false;
       });
   }
   ticking = true;

})