Drag drop from Datagrid to Tree

Hello,
I'm trying to implement drag-drop between datagrid and tree. I need to
simply drag and drop single or multiple datagrid items in a tree node.
Looks like just enabling dragEnabled, dropEnabled and dragMoveEnabled
doesn't work. And hence I added dragEnter, dragOver and dragDrop event
handlers on Tree.

When dragOver or dragDrop event gets triggered, how do I know on which
node is the dragged item hovering over? I did not get any source in my
dragOver's or dragDrop's DragEvent.

Any way how to go about it?

Screenshots for reference:
http://snag.gy/MSx7S.jpg
http://snag.gy/meLwE.jpg