W3C home > Mailing lists > Public > www-style@w3.org > September 2010

Re: [css3-backgrounds] Example XV inconsistent with prose of section 3.6

From: fantasai <fantasai.lists@inkedblade.net>
Date: Tue, 14 Sep 2010 00:08:31 -0700
Message-ID: <4C8F1F6F.3060002@inkedblade.net>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
CC: Sylvain Galineau <sylvaing@microsoft.com>, Brian Manthos <brianman@microsoft.com>, "www-style@w3.org" <www-style@w3.org>
On 09/13/2010 06:22 PM, Tab Atkins Jr. wrote:
> On Mon, Sep 13, 2010 at 6:15 PM, Sylvain Galineau wrote:
>>>>> 'center' and '50%' are equivalent in the context of a background-position.
>>>>
>>>> For rendering yes, for OM no...
>>>
>>> Ah, right.  Yeah, then that example is incorrect.
>>>
>> Why ? This module and its examples are not about the OM so I'm not clear on why
>> we can deem this example incorrect on OM grounds. But beyond that why is 50% not
>> equivalent to center in the OM ?
>
> Well, it's not specified in any significant way, but it would be
> expected that saying "center" would make the current OM return
> "center", and saying "50%" would make the current OM return "50%".

IIRC, Anne was going to define OM and serialization bits consistent
with the Computed Values line wherever that gave enough detail. In
this particular instance, there is enough detail: keywords compute
to percentage values.
   http://www.w3.org/TR/CSS21/colors.html#propdef-background-position
   http://www.w3.org/TR/css3-background/#the-background-position

> The Values API that Anne's been floating would differentiate between
> the two as well, claiming the type of the value to be "keyword" and
> "percentage" respectively.  (Like it allows you to differentiate
> between "red" and "#f00".)

Agreed with Sylvain on this one.

~fantasai
Received on Tuesday, 14 September 2010 07:09:07 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:20:31 GMT