How do I automate code-formatting in my Visual Studio language pack?

Question

I have a language package that I'm working on, and I've gotten some code-formatting into the package. I know how to get it to work by going into EDIT>ADVANCED>FORMAT DOCUMENT, but the documentation says that it's possible to make this happen automatically as the user types. It doesn't, however, go into any more detail that I can see.

So, how do I make my language pack do the formatting in real-time as the code is being written?

Edit: Here's what I've been referencing to so far: http://msdn.microsoft.com/en-us/library/bb164633.aspx