shouldRepaint method
Override this method to return true when the children need to be repainted.
This should compare the fields of the current delegate and the given
oldDelegate
and return true if the fields are such that the paint would
be different.
This is only called if shouldRelayout returns false so it doesn't need to check fields that have already been checked by your shouldRelayout.
Implementation
bool shouldRepaint(covariant BaseBoxyDelegate oldDelegate) => false;