question: can settings tiles be conditional on radio button selections?

[abhlabs]

I need a radio group that allows two options. Based on the user's selection, I need to enable different sets of text input tiles. This seems like it should be possible by using setState in the onChanged handler for the radio group, but I haven't been successful in my attempts.

This is a link to full source code that illustrates the problem:

https://github.com/abhlabs/flutter_settings_screens_test

If I've done something wrong in the code, please point me in the right direction.