def get_rollover_state(self):
return self.__rollover_state<EOL>
Return a string specifying how the mouse is currently interacting with 
this widget.

The interactions between each widget and the mouse are recalculated 
each time the mouse moves, i.e. on every ``on_mouse_motion`` event.
The following rollover states exist:

"base"
    The mouse is not interacting with the widget.
"over"
    The mouse is on top of the widget.
"down"
    The mouse is being pressed on the widget.  If the mouse is 
    released while in this state, an ``on_click`` event will be 
    triggered.