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Re: Alignment of paragraphs with unicode-bidi: plaintext

From: Aharon (Vladimir) Lanin <aharon@google.com>
Date: Sun, 12 Feb 2012 12:31:06 +0200
Message-ID: <CA+FsOYZAfzDB=FReWrPhFuQ5yk1YvGtZj2EZEouBAzQ3ED9kjQ@mail.gmail.com>
To: public-i18n-bidi@w3.org, www-style@w3.org
Cc: rniwa@webkit.org, smontagu@smontagu.org, fantasai.lists@inkedblade.net, matial@il.ibm.com, CE Whitehead <cewcathar@hotmail.com>, Levi Weintraub <leviw@google.com>
FYI, I hope that in the near term WebKit's behavior will be changed to
match Gecko's in this respect (for text-align:start and end, paragraph
alignment follows paragraph direction in unicode-bidi:plaintext). It would
be good to ground that with an explicit statement in the spec, if that is
at all possible.

Thanks,
Aharon

On Tue, Dec 6, 2011 at 8:51 PM, CE Whitehead <cewcathar@hotmail.com> wrote:

>
>
> ------------------------------
> Date: Tue, 6 Dec 2011 10:25:36 -0800
> From: rniwa@webkit.org
> To: cewcathar@hotmail.com
> CC: smontagu@smontagu.org; public-i18n-bidi@w3.org; www-style@w3.org;
> matial@il.ibm.com; aharon@google.com
> Subject: RE: Alignment of paragraphs with unicode-bidi: plaintext
>
>
> On Dec 6, 2011 10:18 AM, "CE Whitehead" <cewcathar@hotmail.com> wrote:
> >
> >
> >
> >
> > ________________________________
>   >> From: aharon@google.com
>   >> Date: Tue, 6 Dec 2011 09:38:59 +0200
>   >> To: matial@il.ibm.com
>   >> CC: public-i18n-bidi@w3.org; smontagu@smontagu.org; www-style@w3.org
>   >>
>   >>> Subject: Re: Alignment of paragraphs with unicode-bidi: plaintext
>   >>>
>   >>> https://bugs.webkit.org/show_bug.cgi?id=71194 has been filed about
> this on WebKit, and there seems to be a consensus that
> unicode-bidi:plaintext would work better if it affected alignment (when
> text-align/text-align-last is start or end). There are two possible ways to
> proceed:
>   >>>
>   >>> - Change WebKit's behavior as proposed.
>   >>> - Wait for a change in the spec - or at least a sign that such a
> change is coming.
>   >>>
>   >>> Fantasai, any guidance?
>   >>>
>   >>> Aharon
>   >>>
>   >> Hmm Aharon, maybe alignment should work off the text/current
> paragraph's direction only when the paragraph has at least around 100 bytes
> (64, or maybe 128) or something of substance . . . to make direction worth
> determining.
>   >> (Just a thought.)
> > That'll makethe algorithm needlessly complicated, not to mention its
> behavior will be hard to determine and will have a surprising side-
> > effects. eg What happens if you initially had 101 characters and then
> removed 2?
>
>
>
> You are right, that would be a disaster.  Sorry that I don't have a better
> suggestion.
>
>
>
> Best,
>
>
> --C. E. Whitehead
> cewcathar@hotmail.com
> > Best,
> >
> > --C. E. Whitehead
> > cewcathar@hotmail.com
> >
> >
> > On Mon, Oct 31, 2011 at 5:52 PM, Aharon (Vladimir) Lanin <
> aharon@google.com> wrote:
> >>
> >> Sounds good.
> >>
> >> Fantasai, do you think it can be specified that way in Writing Modes
> level 3?
> >>
> >> Levi, how difficult would it be to implement in WebKit?
> >>
> >> Aharon
> >>
> >>
> >> On Mon, Oct 31, 2011 at 2:35 AM, Matitiahu Allouche <matial@il.ibm.com>
> wrote:
> >>>
> >>> My opinion, for what it's worth, is that plaintext paragraphs should
> be aligned in sync with paragraph direction for "text-align:start",
> opposite to paragraph direction for "text-align:end", to absolute right or
> left for "text-align:right" and "text-align:left" respectively.
> >>> "text-align:center" should not be a problem.
> >>> "text-align:justify" should not be a problem for lines down to the
> last one in the paragraph. The last one should be handled like for
> "text-align:start".
> >>>
> >>> The advantage of this proposal is that it provides more readability
> for common cases when most paragraphs follow the same direction and span at
> least a few lines.
> >>> For special cases when there are very short paragraphs with alternate
> directions, the author can specify "text-align:right" or "text-align:left",
> so we get the advantages of both solutions (Gecko and Chrome).
> >>>
> >>> Shalom (Regards),  Mati
> >>>       Bidi Architect
> >>>       Globalization Center Of Competency - Bidirectional Scripts
> >>>       IBM Israel
> >>>       Mobile: +972 52 2554160
> >>>
> >>>
> >>>
> >>>
> >>> From:        "Aharon (Vladimir) Lanin" <aharon@google.com>
> >>> To:        Simon Montagu <smontagu@smontagu.org>
> >>> Cc:        public-i18n-bidi@w3.org, "www-style@w3.org" <
> www-style@w3.org>
> >>> Date:        31/10/2011 00:27
> >>> Subject:        Re: Alignment of paragraphs with unicode-bidi:
> plaintext
> >>> ________________________________
> >>>
> >>>
> >>>
> >>> I can see arguments for either approach being better. On the one hand,
> text is more readable aligned to its own start side. On the other hand,
>  paragraphs with alternating alignment, especially when many are less than
> half a line long, can look "jagged", and in extreme cases can result in the
> user not even noticing the paragraphs aligned to the minority side.
> >>>
> >>> Furthermore, we would need to specify how allowing plaintext to base
> alignment on paragraph direction would play with text-align. Is it supposed
> to be limited to "text-align:start" and "text-align:end"?
> >>>
> >>> I would very much like to hear what people think about this.
> >>>
> >>> Aharon
> >>>
> >>>
> >>>
> >>> On Sun, Oct 30, 2011 at 1:28 PM, Simon Montagu <smontagu@smontagu.org>
> wrote:
> >>> As far as I can see, there is no explicit specification in CSS Writing
> Modes Module Level 3 of what effect "unicode-bidi: plaintext" should have
> on the default alignment of paragraphs.
> >>>
> >>> When implementing "unicode-bidi: plaintext" for Gecko, I took it for
> granted that each paragraph in the element would determine its
> directionality by the heuristic in the UBA, and then determine the start of
> the line box depending on the directionality of the paragraph.
> >>>
> >>> I just noticed that recent versions of Chrome behave differently:
> directionality is determined for each paragraph separately, but alignment
> is determined by the first paragraph in the element, and all subsequent
> paragraphs get the same alignment.
> >>>
> >>> As I said, there doesn't seem to be anything in the spec to say which
> approach is correct. I think the behaviour in Gecko is more intuitive and
> useful, but then I would, wouldn't I? Either way, it is probably worth
> adding something to the spec to make it explicit.
> >>>
> >>>
> >>>
> >>
> >
>
>
Received on Sunday, 12 February 2012 10:31:55 GMT

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