Re: RTL support in CSS (Was: [css3-box] Float start/end issue)

Le 24/09/2014 17:44, Tab Atkins Jr. a écrit :
> On Wed, Sep 24, 2014 at 6:13 AM, Julien Wajsberg <jwajsberg@mozilla.com> wrote:
>> Le 23/09/2014 22:22, Tab Atkins Jr. a écrit :
>>> On Tue, Sep 23, 2014 at 8:29 AM, Julien Wajsberg <jwajsberg@mozilla.com> wrote:
>>>> Tab Atkins Jr wrote:
>>>> On Wed, May 28, 2014 at 2:17 AM, Salar Khalilzadeh <salar2k@gmail.com>
>>>> wrote:
>>>>> Back in 2009 a few values added to the float property in 'CSS basic box
>>>>> model' module  but they haven't finalized yet.
>>>>>
>>>>> These new values for float property would be very helpful for RTL
>>>>> languages.
>>>>> Please give the module more attention.
>>>>>
>>>>> I wanted to hint on the Issue 61 which says "Adding ‘start’ and ‘end’ was
>>>>> decided at 2009-12-02 telcon. Precise definitions not yet decided: does it
>>>>> depend on ‘direction’ of the element itself or its parent? "
>>>>> http://dev.w3.org/csswg/css-box/#the-float-property
>>>>>
>>>>> I strongly believe that start/end should depend on the element itself.
>>>>> They
>>>>> should follow the behavior of the float which applies on the element, so
>>>>> the
>>>>> new start/end values will depend on the direction of the element.
>>>>> Otherwise I as a developer have to wrap my element with another element
>>>>> and
>>>>> change the direction there!! what a waste.
>>>> On the other hand, that means you can't set "float: start;" on a bunch
>>>> of elements in some container and expect them to float to the same
>>>> side.
>>>>
>>>> We've addressed this in the Alignment module by having start/end base
>>>> themselves off the container's direction, and having separate
>>>> self-start/self-end values that base themselves on the item's
>>>> direction.
>>>>
>>>>
>>>> Is it something there is a good agreement about?
>>>>
>>>> I also agree that "start" and "end" should be relative to the containining
>>>> box's direction (so, I don't agree with the initial mail), for consistency
>>>> with other specs, especially [css-position-3], where we alway refer to the
>>>> containing box.
>>>>
>>>> I have no opinion about self-start/self-end, but from the initial message in
>>>> this thread it looks like there is at least some request.
>>>>
>>>> What's needed to move forward about this?
>>>>
>>>> [css-position-3] http://dev.w3.org/csswg/css-position-3
>>> What do you think needs to be moved forward on?  Alignment is stable
>>> in this regard; Box isn't a good reference for these topics (2.1 is
>>> still the correct reference).
>> Well, I'm looking forward seeing the "start" and "end" value specified
>> and implemented for the "float" property. I don't see this discussed in
>> 2.1 at all.
>>
>> Some context can be useful. I work on a core Firefox OS app and as I
>> result I have the luxury to be able to use new CSS features, and give
>> early feedback. These days we're working on supporting RTL languages.
>> The usual way of doing this is overriding all properties that use
>> left/right. There are tools that do this automatically. However while
>> this is good for one-shot conversion, this is really bad for long-term
>> maintainability. That's why I'm looking for the "native" CSS support for
>> this. "start" and "end" values for the "float" property is only one part
>> of the support obviously.
> Ah, gotcha.  Unfortunately, there's no real timeline for continuing
> work on 'float' right now. :/
>

Besides float, I'm interested in other RTL matters too:
offset-start/end, support in background-position, margin-start/end,
padding-start/end (and support in the shorthand notations). I think
border properties are important as well, but not so important for me.

Gecko currently supports: margin-start, margin-end, padding-start,
padding-end (prefixed), text-align: start/end, and of course the
standard support in flexible layout.

What could help pushing this forward? Should we continue implementing
this in Gecko behind prefs?

Thanks,
-- 
Julien