Move selection + control key

In a JGoView, normal behaviour of action “move selection” while control key is pressed is to make a copy of selection instead of move it. We have a class that extends JGoView and we want to avoid to copy the selection if user has pressed control key while moving. How can we do this?
Thanks in advance.

I think you can just call JGoView.setInternalMouseActions(DnDConstants.ACTION_MOVE).