Prevent vim from opening binary files accidentally?

I frequently accidentally open a binary executable, i.e. "foo", when I mean to open the associated source code "foo.cpp". The root of the problem is that tab completion, i.e. :e fo<tab> typically lands on the binary instead of the source code.

Is there a way to get vim to only tab complete names of text files? Or alternatively, change the tab completion order?

Sometimes my hasty tab completion error happens outside of vim; for those cases, what is the best way to prevent vim from opening files that are not text?