I have a problem in Vaadin7.
I want to create a drag and drop between Task and List (Task dragable, List dropable).
My code is working but task is always dropped on the very bottom of the list.
I know that I’m adding the task to the end of layout, but how can I know where on the list, the Task was dropped?
I will be very grateful is someone could help me 
This is my code (drop handler):
@Override
public AcceptCriterion getAcceptCriterion() {
return AcceptAll.get();
}
@Override
public void drop(DragAndDropEvent event) {
DragAndDropWrapper dd = (DragAndDropWrapper)event.getTransferable().getSourceComponent();
Task t= (Task) dd.getData();
DragAndDropWrapper dd2 = (DragAndDropWrapper)event.getTargetDetails().getTarget();
List targetList = (List)dd2.getData();
String currentDraggedTaskId = t.getTask_id();
final int targetListId = Integer.parseInt( targetList.getId_list() );
try {
taskService.moveTask(currentDraggedTaskId, targetListId);
List targetListObj = (List)CollectionUtils.find(allLists, new Predicate() {
@Override
public boolean evaluate(Object object) {
List l = (List)(object);
return l.getId_list().equals(targetListId+"");
}
});
List oldList = (List)t.getParent().getParent();
oldList.removeComponent(t.getParent());
targetListObj.addComponent(t.getParent());
} catch (UnsupportedOperationException | SQLException e) {
Notification.show("err");
}
}