JS function to track user scrolling

Scroller JS Class

(function() {

  var Scroller = {

    init: function() {

      this.scrollWindow     = $(window);
      this.scrollDocument   = $(document);
      this.scrollElements   = $('body > div');
      this.windowHeight     = this.scrollWindow.height();
      this.documentHeight   = this.scrollDocument.height();
      this.scrollTopCurrent = this.scrollWindow.scrollTop();
      var parent            = this;

      this.scrollWindow.scroll( function() {  
        var scrollerTop = parent.scrollWindow.scrollTop();
        console.log( parent.scrollDirection( scrollerTop ) );
        console.log( parent.scrollPercentage( scrollerTop ) );
        console.log( parent.scrollPixel( scrollerTop ) );
        console.log( parent.scrollElement( scrollerTop ) );
      });

    },

    scrollDirection: function( scrollerTop ) {
      var direction = '';
      if ( this.scrollTopCurrent < scrollerTop ) {
        direction = 'down';
      } else {
        direction = 'up';
      }
      this.scrollTopCurrent = scrollerTop;
      return "Scroll Direction : " + direction;
    },

    scrollPercentage: function( scrollerTop ) {
      var percent_scrolled = 0;
      percent_scrolled     = Math.round( ( scrollerTop / this.documentHeight ) * 100 );
      return "% Scrolled : " + percent_scrolled;
    },
    
    scrollPixel: function( scrollerTop ) {
      var pixelsScrolled = 0;
      pixelsScrolled     = scrollerTop;
      return "Pixels Scrolled : " + pixelsScrolled;
    },
    
    scrollElement: function( scrollerTop ) {
      
      this.scrollElements.each( function( index ) {
        
        var element        = $(this);
        var elementHeight  = element.height();
        var elementOffset  = element.offset();
        var elementClass   = element.attr('class');
        var elementVisible = scrollerTop < ( elementHeight + elementOffset.top ) ? elementClass + ' is visible' : elementClass + ' is not visible';
        return elementVisible;
        
      });
      
    }

  }

  Scroller.init();

})();