W3C home > Mailing lists > Public > www-style@w3.org > April 2014

Re: [css-backgrounds] background-position-x/-y, logical positions, and initial value failure

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Wed, 23 Apr 2014 09:08:41 -0700
Message-ID: <CAAWBYDC9nBzkeDAuHW8NOk0oyzHbrX=VpVsA0FrSLpN0OgrB-w@mail.gmail.com>
To: Simon Sapin <simon.sapin@exyr.org>
Cc: fantasai <fantasai.lists@inkedblade.net>, "www-style@w3.org" <www-style@w3.org>, MURAKAMI Shinyu <murakami@antenna.co.jp>
On Wed, Apr 23, 2014 at 8:01 AM, Simon Sapin <simon.sapin@exyr.org> wrote:
> On 18/04/2014 01:50, fantasai wrote:
>> Now, what's the initial value of these properties?
>> With margin it's 0. No problem. Everybody is zero, we get
>> zero margins. No conflicts.
>>     margin-left: 0;
>>     margin-right: 0;
>>     margin-top: 0;
>>     margin-bottom: 0;
>> is exactly equivalent to
>>     margin-inline-start: 0;
>>     margin-inline-end: 0;
>>     margin-block-start: 0;
>>     margin-block-end: 0;
>> no matter the writing mode. If you tweak any values, the
>> cascade then says which wins.
>
> Where is this defined? How does the cascade say which wins?

In the normal way?  Note the assumption that the physical and logical
properties are aliases of each other, based on WM/direction.
(Implicitly requiring separate cascade of WM/direction first.)

Once you've figured out that, say, margin-left and margin-inline-start
are aliasing each other, then the cascade works as normal.  The only
issue of this thread was what fantasai brought up, about which wins
when there are *no* declarations and the initial values differ between
the two sets.

~TJ
Received on Wednesday, 23 April 2014 16:09:28 UTC

This archive was generated by hypermail 2.3.1 : Monday, 2 May 2016 14:39:21 UTC