Yes know the Logger Manual. But it does not tell you how to make your own version of a maxon::LoggerType::File(). It only teaches you how to log message to the existing logger types.
What I wanted to do was create a maxon::LoggerType::EncryptedFile(), but I don't see how to do this.
I also thought maybe it is possible to use the maxon::LoggerType::File and some how create my own URL handler possibly, which seems like what you tried? If you get this working then please do let me know.
The observer is what I was going to fall back on, but it kinda defeats the entire purpose. Since I have a method that I push all my log events to anyway (which then call my custom maxon logger and it nicely writes to the console and a un-encrypted file which works great). So I could just write my own file right here and be done with it. But I was really hoping I could just easily change the unencrypted file to an encrypted one and keep using the actual Maxon API itself. But I may still use the observer so I can at least learn something more about the MAXON API.
And as @zipit said I could use the existing loggers and encrypt my messages before I log them. But that means I have to then identify each message in the log file itself so that I can decrypt them (ie some start, end points, message length etc...). Do-able, but why not just have an encrypted logger type if possible, since that is effectively what you are writing anyway. So for me it is part learning the MAXON API and part coming up with the solution. And instead of wrapping I could just open my own file, add to my own file and save my own file again, removing the logger completely from the entire workflow.