When start dragging an object, retrieve all the droppable objects and then adjust their position.
$('#dd').draggable({
onStartDrag: function(){
var droppables = $(this).data('draggable').droppables;
droppables.sort();
}
})
$("#sortable-list,.item").droppable({
onDrop : function(e, source) {
console.log(e.target)
e.stopPropagation();
}
});