__init__ (
        self,
        master,
        data,
        )

Widget with text "renorm to " and field for entries

get_sum_value ( self )

get valid value from Entry Widget or set to actual sum

recieve_change ( self,  change )

if the sum changes and the custom constraint is not active, display the actual sum

renorm_event ( self,  event=None )

do renorming of data