[fxtf-drafts] can SVG container elements establish containing block for absolute/fixed positioned elements?

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

== can SVG container elements establish containing block for absolute/fixed positioned elements? ==
Currently the [spec for `filter`](https://drafts.fxtf.org/filter-effects-1/#FilterProperty), if interpreted literally, says that when `filter` is applied to SVG container elements, then those elements establish a containing block for fixed positioned and absolutely positioned elements.

It's not clear to me what this means, since it's not clear to me where the edges of such a containing block are.

On the other hand, it also doesn't make sense for these elements to escape the filter.  One way to avoid that would be to say that `<foreignObject>` establishes such a containing block, but I'm not sure if that would be web compatible.

I think this also applies to a number of other properties (`will-change`, `contain`, and a bunch of transform properties although those properties currently have [an exception](https://drafts.csswg.org/css-transforms/#transform-rendering) for elements not governed by the CSS rendering model... which in turn raises the question of how a transformed element that is position:fixed to an ancestor behaves.

Please view or discuss this issue at https://github.com/w3c/fxtf-drafts/issues/307 using your GitHub account

Received on Friday, 3 August 2018 17:55:07 UTC