public DragTargetList GenerateDragTargets(PageDragEndData dragEndData)
{
DragTargetList targets = new DragTargetList();
// Generate the set of targets from the element hierarchy
_manager.PropogateDragTargets(_floatingWindow, dragEndData, targets);
// Must have at least one target
if (targets.Count == 0)
targets.Add(new DragTargetNull());
return targets;
}