Re: [w3ctag/design-reviews] Review request for ResizeObserver (#187)

> Is this going to be launched as an Origin Trial? If so, this seems to be in good shape.

I was not thinking Origin Trial, but after talking it over, seems like a good idea. This is the current plan.

> The question about "previous value" keeps coming up in our discussion

I am unsure about the usefullness of "previous value". None of the current examples use it. My guiding principle was not to include anything that is not obviously useful. It is trivial to implement it on top of RO. Did you have any particular examples in mind?

> Regarding which value to deliver, what's the argument against reporting any/all of border/client/content sizes?

This is an interesting question. In theory, RO handlers should not depend on other sizes. If it does, and other size changes, RO will not be notified (unless other size change also triggers content size change), and RO element will be out of sync. We cannot enforce not using other sizes, but not having other sizes reported discourages their use.

I've also noticed that TAG was wondering about 2nd implementation. In summer of 2016, an intern at FF started a ResizeObserver [implementation](https://bugzilla.mozilla.org/show_bug.cgi?id=1272409). It never landed, but we did have spec [clarification discussions](https://github.com/WICG/ResizeObserver/issues/21), they did use my tests, 

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3ctag/design-reviews/issues/187#issuecomment-332623620