android - move screen over image in titanium javascript -

i need create effect in site withe name:

link example site

//i need in javascript 

the problem created effect image designs. how can move trough entire image , show part of image in javascript android , ios?

i achieved using

index.xml

<alloy> <window class="container">     <label id="label" top="80" onclick="doclick">play sign</label>     <view height="84">         <imageview width="255" height="7224" id="sigimage" top="0" image="/testimages/0d8zt.png"></imageview>     </view> </window> </alloy> 

index.tss

".container": {     backgroundcolor:"white" } "label": {     width: ti.ui.size,     height: ti.ui.size,     color: "#000" }  "#label": {     font: {         fontsize: 18     } } 

index.js

var interval = null; var i=0;  function doclick(e) {     clearinterval(interval);     = 0;     replay(); } replay(); function replay(){     interval = setinterval(function(){         if(i<86){             $.sigimage.top = -i*84;             i++;             ti.api.info('i = '+i);         }else{             clearinterval(interval);         }     },10); }  $.index.open(); 

a little trick, hope you. :)