Code review comment for lp:~gerboland/unity-api/surfaceSizerCallback

> Oh and document the signature of the callable please. Will it get info about
> fullscreen, for example?
Sadly not, I need to add a feature request for Mir for that. IMO the surface type and other info that we get from a standard Mir surface would be good info to have, opposed to this limited subset.

> I wonder if instead we should just pass availableGeometry, with Mir being
> responsible for policy, should we involve the shell like this?
I dislike this idea, as effectively we'd need to educate Mir about the entire QML scene: which areas are off-limits for a non-fullscreen surfaces, what to do for surfaces of different types, stages, etc. Defining a vocabulary for that would be a nightmare IMO. And if Mir makes a decision that shell doesn't like, shell will immediately impose its will anyway - so where's the gain?

Policy I hope to define in Mir relate more to clients expectations, I want to ensure that client surfaces behave in a consistent way across mir server implementations. Shells should treat client surfaces in ways that they expect, that parent/child relationship is obeyed, focus handing is correct, input is delivered to the correct surface, siblings can attach to eachother/their parent and stay there, things like that.