Zoom in and out on Android?

I have updated Titanium sdk to 2.1.0GA, and I try to make ImageView to be able to zoom in and out, but it isn't working.

Here is my code.

var window = Ti.UI.createWindow({
    backgroundColor : 'black'
});
 
var img = Titanium.UI.createImageView({
    top : 0,
    left : 0,
    width : 'auto',
    height : 'auto',
    image : 'myimage.jpg',
    canScale : true,
    enableZoomControls : false
});
window.add(img);
window.open();