[fullscreen] Fullscreen on non-HTML elements? (#22)

Should fullscreen request be allowed on non-HTML elements?

It seems impls disagree with each other. IE/Edge treats it as an error to request fullscreen on inner SVG elements. Firefox and Chrome, on the other hand, do allow requesting fullscreen on such kind of elements. They do make the window fullscreen, but the target element does not actually become fullscreen at all.

As of Gecko, inner SVG and MathML elements are not allowed to be out-of-flow. I didn't find any spec mentions whether they can or cannot be out-of-flow, but the current behavior looks reasonable. However, that means the fullscreen stylesheet just makes no sense for those elements.

Thus, I tend to think requesting fullscreen on non-HTML elements should be an error.

Thoughts?

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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fullscreen/issues/22