[csswg-drafts] [mediaqueries-4] Drop overflow-block:optional-paged (#5287)

frivoal has just created a new issue for https://github.com/w3c/csswg-drafts:

== [mediaqueries-4] Drop overflow-block:optional-paged ==
The [`overflow-block` media feature](https://drafts.csswg.org/mediaqueries-4/#mf-overflow-block) describes the behavior of the device when content overflows the initial containing block in the block axis. The `none`, `scroll`, and `paged ` values correspond to well known behaviors, but `optional-paged` is more theoretical/speculative, and doesn't really correspond to anything that currently exists.

It was meant to match things like the (presto-based) Opera <=12 presentation mode. This was a user-activated mode, fundamentally similar to `scroll` (overflow triggers scrollbars; the ICB is the viewport, not the page area; and the whole css-page model doesn't apply), but in addition, it allowed the author to insert forced fragmentation breaks, leading to something akin to a paginated behavior. This was meant for making things like slide decks.

While I think experimenting with that sort of things is great, no current user agent behaves like that, so no current user agent will match that particular value. This makes it not useful.

Further, if someone were to experiment again within that space, we cannot be sure that the behavior they'd land on would be the same as the one opera had and that is currently used in the spec as the definition of `optional-paged`, which would make the value misleading.

If someone ever ships something of that nature, we should definitely look into making sure that whatever behavior they end up with can be covered by media queries, but until that happens, I think we should drop this speculative value.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5287 using your GitHub account

Received on Saturday, 4 July 2020 06:31:27 UTC