a droppable element is still dropable event if it's covered by another droppable element

You have 3 draggable windows

These windows contains many items

Each item can be drag and drop from a window to another

If window B is covering window C, when you want to drag and drop an item from A to B, events of window C are triggered.

I seems I can't fix it with a greedy cause the greedy stop bubbling to parents and in this case windows are side by side at the same level

See related example : http://pastebin.me/176e9a8ff3745da229114b87af190088