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Re: Styling of embedded right-to-left text in source code visualization

From: Felix Sasaki <fsasaki@w3.org>
Date: Tue, 11 Sep 2007 14:36:36 +0900
Message-ID: <46E62964.5080800@w3.org>
To: Martin Duerst <duerst@it.aoyama.ac.jp>
CC: Najib Tounsi <ntounsi@emi.ac.ma>, Richard Ishida <ishida@w3.org>, public-i18n-its@w3.org

Hello Martin,

many thanks for the links and catching the missing bit of my proposal at 
http://lists.w3.org/Archives/Public/public-i18n-its/2007JulSep/0081.html .
I'd change
"For such display, a sophisticated editor that resolves directionality 
of the source text correctly"
to
"For such display, a sophisticated editor that resolves directionality 
of the source text correctly is necessary."
and add a link to
http://www.sw.it.aoyama.ac.jp/2005/pub/IUC28-bidi/IUC28.html .

Felix

Martin Duerst wrote:
> Hello Felix, Najib, others,
>
> For some work on this issue, please also see my IUC28 paper at
> http://www.sw.it.aoyama.ac.jp/2005/pub/IUC28-bidi/IUC28.html
> and the simulation page at
> http://www.sw.it.aoyama.ac.jp/cgi-bin/bidi-source-test
> and some additional info at
> http://www.sw.it.aoyama.ac.jp/2005/pub/IUC28-bidi/.
>
>
> At 04:17 07/09/08, Najib Tounsi wrote:
>   
>> Hi Felix,
>>
>> Felix Sasaki wrote:
>>     
>>> Hi Najib and Richard,
>>>
>>> at least with Najib we discussed styling of "right-to-left" text in source code visualization a while ago, 
>>>       
>> Yes,
>> http://lists.w3.org/Archives/Public/public-i18n-its/2007AprJun/0036.html
>> http://lists.w3.org/Archives/Public/public-i18n-its/2007AprJun/0038.html
>>
>> I've noted that rendering bidi text in source code is editor (or tool) dependent and have suggested that a user should set his/her preference: Override Yes or Not the bidi algorithm, so that, if Yes, punctuations in the markup  and  normal text can't interfere and give unexpected rendering.
>>     
>
> My guess is that almost always, in the above sense, the user would
> choose "override yes". Just blindly applying the Unicode bidi algorithm
> to something it's not designed to handle virtually always results in
> chaos that shows as garbage.
>
> But that's not the main problem. Even when we agree that the Unicode
> Bidi algorithm as such isn't suited for source display (be that HTML/
> XML or some programming language source or something else), there
> are many ways to do a better job, and different users may prefer
> different ways depending on their background and on the documents
> at hand.
>
>
>   
>> Richard had already discussed this problem,
>> http://www.w3.org/International/geo/html-tech/tech-bidi.html#d2e277
>> but there is no satisfactory solution yet.
>>
>> Editing source code is not a usuall activity so, between the next three lines
>> <p title="ATTRIBUTE">CONTENT</p> (normal styling)
>> <p title="TNETNOC<"ETUBIRTTA</p> (some browser styling)
>> <p title="ETUBIRTTA">TNETNOC</p> (memory order)
>> I prefer the third which is much sure for inserting a space for example.
>>     
>
> Assuming the usual "upper case is RTL" convention, I fully
> understand why you prefer the third, but I don't understand
> why you label it as "memory order". The first is in memory
> order, isn't it? The third is what we would like to see, but
> what as far as I understand, no editor currently does.
>
>
>   
>>> but now we are not sure what to do about this example:
>>>
>>> 1) http://www.w3.org/International/its/techniques/its-techniques.html#AuthDir (example 33, W3C on the right of the Hebrew text)
>>>       
>
> I see W3C on the left, not on the right, here. That seems okay.
> I'm not sure why you see this differently.
> An example with W3C (or something similar) in the middle would
> even be better, except that then the reader has to look at
> (and hopefully even understand) the Hebrew text on both sides.
>
> Just looking at Best Practice 16, I see that it says:
> "By default the text directionality in an XML document is assumed to be left-to-right."
> Where did you get that? Wouldn't it be possible for some spec to
> say that the default for them is RTL?
>
> For "Why do this", please add that the list of languages that may
> be written RTL is actually quite long.
>
> "has values that indicate that the normal directionality should be overridden"
> is a bit difficult to understand, or easy to misunderstand. I'd add
> "in addition to values to indicate the base directionality".
>
>
>   
>>> versus this example:
>>>
>>> 2) http://www.w3.org/TR/its/#directionality-implementation (example 33, "W3C" on the left of the Hebrew text)
>>>
>>> we thought that the ITS 1.0 spec would be right, but have discovered now the visualization at
>>>
>>> 3) http://www.w3.org/International/questions/qa-bidi-controls (example below "The HTML4 standard introduced markup to produce exactly the same effects as these Unicode characters.". "W3C" is on the right of the Hebrew text)
>>>       
>
> That also has W3C on the left, and is also okay.
>
>   
>>> So we need to discuss again what the appropriate visualization for "right-to-left" source code is. 1) and 3) visualize as if the outcome of the BIDI algorithm is overridden via the "dir" attribute, 2) is the other way round.
>>>       
>
> I still don't see the differences between the three examples, but I think
> I know now what you mean. Your question is whether it's okay to use something
> like the <span dir="rtl"> below (Hebrew is ???? due to my mailer) to tweak
> source code display or not.
>
> <span class="attribute">its:dir</span>="rtl"&gt;</span>
> <span dir="rtl">?????? ???????, W3C</span>
> <span class="element">&lt;/quote</span>&gt;
>
> (btw, the span coverage for the closing element is really a bit strange)
>
>
>   
>> In my opinion, assume that editors are doing correct bidi-rendering, i.e. W3C is on the Left of the text, and, may be, add the same note as Richard (On the top right of http://www.w3.org/International/questions/qa-bidi-controls):
>> "Note also that the examples of source text assume a sophisticated editor that resolves directionality of the source text correctly. This is to ensure that you understand the concepts being described. Many editors are not yet this sophisticated."
>>     
>
> I agree that having such a note is a good thing. "Many" above is an understatement
> as far as I understand, but it's probably difficult to be more explicit
> (e.g.: "We currently don't know of any editor that is that sophisticated.").
> Our simulation script isn't an editor, and so doesn't count here.
>
> The problem with that Note is that it doesn't apply to the text immediately
> on the right (which is final rendering, not source code), and where it
> would apply (the box that says "Using XHTML, the earlier example would be coded as:",
> it actually DOESN'T apply (because W3C is on the right).
>
>   
>> The question remains: For source text, is correct bidi-rendering desirable for a given user for a given need?
>>     
>
> What do you mean by "correct bidi rendering"? If you mean
> "fully apply the Unicode bidi algorithm and nothing else",
> then I'd clearly say NO. If you mean "something better
> than just the Unicode bidi algorith", my answer would be
> clearly YES, but depending on the material and on personal
> preferences, there may be several ways.
>
> Although there are several ways (an Arabic user who only
> occasionally views/reads Latin would want to view an
> XML document with mostly Arabic content and mostly Arabic
> element/attribute names in overall RTL mode,...), for the
> example above, what has been done e.g. at
> http://www.w3.org/International/its/techniques/its-techniques.html#AuthDir
> seems perfectly reasonable to me, although it requires a
> highly sophisticated editor that not only parses tags,
> but the whole element structure/nesting, and understands
> its:dir. You can see how that would work at
> http://www.sw.it.aoyama.ac.jp/cgi-bin/bidi-source-test
> if you change "its:dir" to "dir" and select markup language
> xhtml (rather than xml).
>
> Regards,     Martin.
>
>   
>> Regards, Najib
>>     
>>> Many thanks for your input in advance,
>>>
>>> Felix
>>>
>>>
>>>
>>>       
>> -- 
>> Najib TOUNSI (mailto:tounsi @ w3.org)
>> Bureau W3C au Maroc (http://www.w3c.org.ma/)
>> Ecole Mohammadia d'Ingenieurs, BP 765 Agdal-RABAT Maroc (Morocco)
>> Phone : +212 (0) 37 68 71 50 (P1711)  Fax : +212 (0) 37 77 88 53
>> Mobile: +212 (0) 61 22 00 30 
>>
>>     
>
>
> #-#-#  Martin J. Du"rst, Assoc. Professor, Aoyama Gakuin University
> #-#-#  http://www.sw.it.aoyama.ac.jp       mailto:duerst@it.aoyama.ac.jp     
>
>
>   
Received on Tuesday, 11 September 2007 05:36:54 GMT

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