Is there some way to extend the Unity Animation View?

Hi, Unity,

I like to use the Animation VIew's functions, and want to extend it with some extra functions.

Yeah, I know UnityEditor.AnimationWindow and many related classes are internal classes, if unity could make them public or give out some callback that would be great.
Buf before that, I could do with the reflection too.

I've just seen this on twitter
https://vine.co/v/MUralTrrK9r

Wonder how does he draw those icons on the animation view.

 

Oh, yeah, i see that's the built-in feature for sprite in Animation view. lol.

But I really want to be able to extend some more functions by myself, like temporarily disable a curve, merge clips, etc.

 

Did you ever figure this out?