Template:USTC-Software/js/addScrollBar

$(document).ready(function () {

   class ScrollBar {
       constructor(){
           this.show = false;
       }
       // add the div we want to use
       appendScrollBar(){

$('body').append('

' +

               '<img src=""/>' +

'

' + '

');

       }
       // basic operation
       maintainShow(){
           $(window).scroll(function () {
               let toTop = $(document).scrollTop();
               if (toTop > 300 && !this.show){
                   $(".scroll").css("bottom", "5%");
                   console.log('gt 300px');
                   this.show = true;
               }else if(toTop <= 300 && this.show){
                   $(".scroll").css("bottom", "100%");
                   console.log('lt 300px');
                   this.show = false;
               }
           });
       }
       // make the img clickable
       listenForClick(){
           $('.backHead').on('click', function () {
               $('body, html').animate({
                   scrollTop: 0,
                   screenLeft: 0
               }, 300);
               $(".scroll").css("bottom", "100%");
           });
       }

   }

   let scrollBar = new ScrollBar();
   scrollBar.appendScrollBar();
   scrollBar.maintainShow();
   scrollBar.listenForClick();

});