Endless looping of scrollview

autoscrolling.js

var Engine              = require("famous/core/Engine");
var Surface             = require("famous/core/Surface");
var Scrollview          = require('famous/views/Scrollview');

mainContext = Engine.createContext();

scrollview = new Scrollview({direction:0});

var surfaces = [];

scrollview.sequenceFrom(surfaces);

var cellCount = 10;
var cellWidth = 400;

for (var i = 0, temp; i < cellCount; i++) {
    temp = new Surface({
        content: "Surface: " + (i + 1),
        size: [cellWidth, 400],
        properties: {
            backgroundColor: "hsl(" + (i * 360 / 40) + ", 100%, 50%)",
            lineHeight: "200px",
            textAlign: "center"
        }
    });
    surfaces.push(temp);
}

var time = (new Date).getTime();

scrollview._scroller.positionFrom(function(){
    var position = (((new Date).getTime() - time) / 2.0) % ((cellCount*cellWidth) - mainContext.getSize()[0]);
    return position;
});

mainContext.add(scrollview);