fancy product designer move element by API

i've been searching for how to move an item (text, image, design ...) by API; not using drag and drop.
(JQuery Plugin fancy product designer)

here is a fonctionnal code:

bgObject.canvas.setBackgroundImage(bgObject.canvas.source, bgObject.canvas.renderAll.bind(bgObject.canvas), {

  x:bgObject.params.x - 1,

  y:bgObject.params.y   

});

bgObject.params.x --;

where is bgObject is the object loaded by the plugin, you can get it by firing the elementAdded event
example:

var bgObject= null;

          $('#clothing-designer')

.bind('elementAdded', function(evt, obj)  {

   if(obj.title == "Default Image") {

                                            bgObject = obj; 

                                        }

});

Note that if you try to understand the code, we are moving a canvas object.
Canvas and many other objects are parts of fabric framework.
 readingits  documentation may be very helpful :
http://fabricjs.com/docs/
http://fabricjs.com/docs/fabric.Canvas.html (canvas)

that's all !