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Re: mathcolor/mathbackground on <math/> and <semantics/> elements?

From: Karl Tomlinson <w3@karlt.net>
Date: Thu, 22 Apr 2010 15:31:56 +1200
To: www-math@w3.org
Message-ID: <87hbn4go2b.fsf@karlt.net>
Taking Bruce's comments out of order, hopefully not too out of context.

Bruce Miller writes:

> In other words, I think it would be more
> natural and useful for math@mathbackground
> to set the background for the contents, not the
> default.

I agree.

I guess what is not clear is how this should be specified.

> I believe the issue stems from there being two ways
> to think of mathbackground (& mathcolor) being
> allowed on mstyle.
>
> (1) is that mstyle is a presentation element, and
> so it accepts the mathbackground attribute. The
> effect is described in 3.1.10, namely it fills the
> bounding box of the element (and it's children).
>
> But
> (2) is that the mathbackground attribute is accepted
> on mstyle since the mathbackground attribute is
> accepted on _other_ presentation elements (see 3.3.4.1).
> In such cases, the effect is to change the default
> mathbackground.
>
> Those effects are subtly different, as you noticed.
> .. and in fact, I think (2), is kinda screwy
> [mathcolor seems to bypass the screwiness
> by having it's default be inherited, anyway].
>
> I would argue that (1) ought to take precedence
> since it's just so much more direct.

Perhaps only (1) should apply, but I think for that to be
the case it needs to be added to mstyle's exception list.

(1) is actually new to MathML3.
MathML2 already had (2).
Both (1) and (2) can actually coexist, but we don't like that
behavior.

Now that we have (1), we like that behavior better and so want
to deprecate (2).
Received on Thursday, 22 April 2010 03:32:56 GMT

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