Class Roo.dd.DropTarget.*over
The function a {link Roo.dd.DragSource} calls continuously while it is being dragged over the target.
This method will be called on every mouse movement while the drag source is over the drop target.
This default implementation simply returns the dropAllowed config value.
IMPORTANT : it should set this.dropAllowed
Config Options - Has None
Public Properties - Has None
Public Methods - Has None