In article . com,
says...
Does anybody know of a shower curtain or screen that will roll back
into a cartridge or similiar when not in use. We are building a brand
new bathroom so doing structural work is not an issue, but I just
wondered if there was some way of hiding it when not in use.

You could make a rigid cubicle that folds out from the wall and is
pretty much concealed when not in use, but it would probably take a bit
of ingenuity to sort out the details.
Or how about a circular curtain that pulls up to the ceiling when not in
use?