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Re: [css3-backgrounds] Should a non-zero border-radius create a new stacking context ?

From: Robert O'Callahan <robert@ocallahan.org>
Date: Tue, 23 Nov 2010 11:52:12 +1300
Message-ID: <AANLkTikq5mAfN6sjyFk7-4uC=RMNcPr=fsvNKkAg7PAO@mail.gmail.com>
To: Sylvain Galineau <sylvaing@microsoft.com>
Cc: Brad Kemper <brad.kemper@gmail.com>, "www-style@w3.org" <www-style@w3.org>
On Tue, Nov 23, 2010 at 9:57 AM, Sylvain Galineau <sylvaing@microsoft.com>wrote:

>  I disagree that this adds complexity for authors; we can't argue that
> creating a stacking context for overflow != visible would have simplified
> things *and* that doing so in some cases makes them unacceptably harder.
> Especially when existing, heavily-used properties already do this.
>

Forcing stacking contexts for overflow != visible would have simplified
things for implementors, and added complexity for authors. (Although I claim
that special-casing border-radius + overflow-not-visible is more surprising
than just special-casing overflow-not-visible.)

If the side effects of creating a new stacking context is so likely to break
> pages then opacity and transforms are equally problematic for authors. If
> so I'd like to see evidence that working around this is a common issue for
> authors; I'm not claiming such evidence does not exist btw. Pointers
> definitely welcome.
>

I do not claim that forcing a stacking context for border-radius +
overflow-not-visible is likely to break existing pages.


>  In the absence of said evidence, a cogent argument as to why taking this
> kind of risk is acceptable in some cases but not others - opacity is very
> heavily used, at least as much as border-radius if not more so - would be
> most helpful.
>

As I explained above, AFAIK the primary reason for making opacity < 1 force
a stacking context is that it's impossible to define reasonable behavior
otherwise. This is not a problem for border-radius + overflow-not-visible.

Rob
-- 
"Now the Bereans were of more noble character than the Thessalonians, for
they received the message with great eagerness and examined the Scriptures
every day to see if what Paul said was true." [Acts 17:11]
Received on Monday, 22 November 2010 22:52:48 GMT

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