Code review comment for lp:~vanvugt/mir/parenting-client-api

+1 for a semantics-based API as opposed to a state-based one. I wouldn't want to have to use an API where there are hundreds of states to choose from and a small subset of each has some special meaning (a menu, a tooltip, a dialog, etc) and other combinations are not even valid - giving too much flexibility to the user to shoot themselves in the foot.

I'd like to be able to just call one function to create, say, a menu. Simple enough for the user to get started using our API, simple enough for us to manage. Of course, as the need arises, we can later break down the API and provide finer level of control as is being proposed here. We can do this on a case-by-case basis as we gain some insight into what users want to achieve and where it makes sense to have more flexibility. It's easy, and backwards-compatible, to do that. However, it's not easy to take it back cf. server ABI.

So IMO the API that is being proposed here is rather the implementation and could/should stay as an internal API, which could then be made public, with some extra state validation, if needed.