Isn't that the same as what we wrote ?
You have to think about how to split in different parts and add files to your project according to that, and give them proper names. About 20 or 30 files is no problem. But if you have 50 files, you could need a library.
I normally would make files like this: Menu, Menu_helper, Display, Keys, and so on.
The 'helper' files are usefull functions. Sometime I have also files with _glue, with functions to 'glue' the different parts together.
This is just normal programming. So I still don't know why there is a problem.