W3C home > Mailing lists > Public > www-style@w3.org > March 2013

Re: [css3-values][css3-background][css3-transforms] <position> vs. transform-origin

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Sat, 23 Mar 2013 14:35:49 -0700
Message-ID: <CAAWBYDDSvok4RieH0v1ST=H49w4bz1J+7JrvJQ+Om2p+R=TDsg@mail.gmail.com>
To: Simon Sapin <simon.sapin@exyr.org>
Cc: Øyvind Stenhaug <oyvinds@opera.com>, www-style list <www-style@w3.org>
On Sat, Mar 23, 2013 at 9:52 AM, Simon Sapin <simon.sapin@exyr.org> wrote:
> Le 20/03/2013 23:11, Tab Atkins Jr. a écrit :
>> On Wed, Mar 20, 2013 at 7:23 AM, Øyvind Stenhaug <oyvinds@opera.com>
>> wrote:
>>> The transform-origin value type is different from that of
>>> background-position in that a third component value represents a position
>>> on
>>> the Z-axis rather than an offset to a preceding percentage/keyword.
>>> (<http://lists.w3.org/Archives/Public/www-style/2012Mar/0195.html> has a
>>> resolution concerning this.)
>>
>> I wish we could solve this. :/  The grammatical ambiguity is annoying.
>>   It would probably be worthwhile to define a <3d-position> type,
>> though, that just matches transform-origin's current grammar.
>
> Using '<position> <length>?' would be ambiguous, right? Even with tricks
> like "parsing <position> should consume as many tokens as possible"?

With a trick like that, it's not ambiguous.  But we try to avoid those
kinds of things when possible.

More importantly, specifying something like that wouldn't be backwards
compatible.

>>> That difference doesn't apply to perspective-origin, though, so that does
>>> seem to be an issue. Has been reported earlier here:
>>> http://lists.w3.org/Archives/Public/www-style/2012Jan/0964.html
>>
>> Looks like it got forgotten in the craziness of that thread.  It would
>> indeed be nice (and backwards-compatible) to upgrade
>> perspective-origin to a <position>.
>
> I read half of that thread but I’ll probably stop here :)
>
> Can we ask in the next conf call to have perspective-origin reference Values
> 3 for <position>, and leave the discussion of what <position> should be for
> another time?

It's an editorial change, but it would probably be nice to inform the
WG anyway. ^_^

~TJ
Received on Saturday, 23 March 2013 21:36:35 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:21:07 GMT