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Posted to fop-dev@xmlgraphics.apache.org by Kia Teymourian <ki...@cs.tu-berlin.de> on 2006/11/20 14:44:44 UTC
Re: PATCH for Arabic/Persian Text, and Bidi-override!
Hello,
for this creating this patch I solved already the first problem with
joining the Arabic Characters.
I have some questions regarding this matter:
1. ---
I need to send the Text charArray to Bidirectional Algorithm for
visually reordering of the Characters .
In class TextLayoutManager
org.apache.fop.layoutmgr.inline.TextLayoutManager
, I check the textArray and if the Array contains any Arabic characters
between U+0600 to U+06FF,
it will be sent to the bidirectional algorithm, afterwards to the
character joining algorithm.
My question is, can I use the java.text.bidi class? And say that Arabic
Bidi is just in JDK 1.4
supported. Or should FOP have its own Bidi class which is compatible
with JDK 1.3?
2.---
I need to change the page numbering format to Arabic-Indic numbering,
but FOP does not support it.
U+0660 ARABIC-INDIC DIGIT ZERO
U+0661 ARABIC-INDIC DIGIT ONE
U+0662 ARABIC-INDIC DIGIT TWO
U+0663 ARABIC-INDIC DIGIT THREE
...
U+0669 ARABIC-INDIC DIGIT NINE
Where is the page numbering calculated in FOP? I need to support this
<fo:page-sequence initial-page-number="١">
for PDF output?
Thanks,
Kia Teymourian
Kia Teymourian wrote:
> Hi all,
>
> thanks for your answers!
>
> Jeremias Maerki schrieb:
>> On 08.10.2006 23:01:13 Kia Teymourian wrote:
>>
>>> Hi all,
>>>
>>> I am working on a patch for Arabic/Persian Text decoration and
>>> Implementation of Bidi Algorithm.
>>>
>>> I have some questions about it and writing to you to ask for your
>>> assistance,
>>> could you please answer my questions!
>>>
>>> 1. Can I use java 1.5 or should preferably use 1.4 or JDK 1.3.
>>>
>>
>> Until further notice FOP must compile with JDK 1.3.
>> See: http://xmlgraphics.apache.org/fop/trunk/compiling.html
>>
>>
>>> 2. I have a long list of constants, Unicode Arabic Presentation forms.
>>> This list will be used, when the algorithm search for
>>> the correct glyphs forms. I think for the best Performance I should
>>> define some static final arrays, and write them directly in the
>>> class program codes. They are some defined Unicode constants, which I
>>> get from the Arabic Unicode definition.
>>> It is also to put them extern in some Text files, read them from
>>> there. Which form would be the best ?
>>>
>>
>> Whatever is fastest. I think both approaches are fine. Have you looked
>> at ICU4J? Maybe it already provides the functionality you need. I
>> haven't checked. At any rate, we've considered the use of ICU4J before.
>>
>>
>>> 3. I should add one or two new classes, something like
>>> ArabicTextHandler.java
>>> Can I add them to the package org.apache.fop.layoutmgr ? Where is the
>>> right package?
>>>
>>
>> Probably org.apache.fop.layoutmgr.inline.
>>
>>
>>> 4. Can I use some free TTF Fonts in my test cases, they are licensed
>>> under GPL.
>>> I am going to use Persian TTF fonts from
>>> http://www.farsiweb.ir/wiki/Persian_fonts
>>> Is there any license problems?
>>>
>>
>> Yes, the GPL is off-limits for software distributed by the ASF. :-(
>>
>> See: http://www.apache.org/legal/3party.html
>>
>>
>>> 5. The writing-mode which is entered in a block or block-container
>>> statement has to be known by the TextLayoutManager but is not delivered
>>> correctly. TextLayoutManager.addAreas(...) is called from
>>> BlockContainerLayoutManager.getNextKnuthElements(...) and
>>> BlockManager.getNextKnuthElements(...).
>>> Why? Could you please write me your comments about the implemented
>>> writing-mode!
>>>
>>
>> The writing mode is communicated to child layout managers through the
>> LayoutContext. See for example:
>> BlockContainerLayoutManager.createLayoutContext().
>>
>> Would you mind showing us a short description of your approach to
>> implementing this? We've had people before implementing in this
>> direction but it was often a hack and did not fit in the whole picture.
>> I just want to spare you a late disappointment. Thanks. Some
>> documentation will be extremely important for us, since the current
>> team knows just about nothing about Arabic text. For example, we will
>> not be able to determine if some output is correct or not.
>>
>> Jeremias Maerki
>>
>>
>
> My first post to the mailing list was in May 2006,
> http://www.mail-archive.com/fop-dev@xmlgraphics.apache.org/msg04325.html
> may be you mean this post.
> I could find several implementations, but now I am looking for the
> best one.
>
> The first and the most important step is to have a solution for
> finding the correct Arabic presentation forms or glyphs.
> As you know when we write an Arabic word, Arabic characters are
> connected together and will have a
> different presentation form or glyphs depending on their position in a
> word or as they have in isolated form.
>
> We could have 4 different presentation forms for a single Arabic
> character:
> Isolated, when the Character are alone
> Initial, when the Character are at the Start position of the Character
> array of the Arabic Word
> End, when the Character are at the End position of the Character array
> of the Arabic Word
> Middle, when the Character are in the middle of a Character array.
>
> Arabic Unicode Characters are between, arabicStart = 0x0600; and
> arabicEnd = 0x06FF;
> and we send a word to the algorithm if they contain an Arabic Character.
>
> For instance, we should find for the following word the correct
> Presentation form.
>
> <fo:block font-size="14pt" font-family="Tahoma" line-height="14pt"
> space-after.optimum="12pt" writing-mode="rl-tb" >
> تیموریان
> </fo:block>
> This is the form so as they are saved in FO file.
> We should find the correct Presentation and change this word to
>
> <fo:block font-size="14pt" font-family="Tahoma" line-height="14pt"
> space-after.optimum="12pt" writing-mode="rl-tb" >
> ﺗﯿﻤﻮﺭﯾﺎﻥ
> </fo:block>
>
> finding the correct presentation form and reverse the Character array.
> you can see the difference and test it with a font which contains
> glyphs for the whole Unicode range of Arabic presentation forms A and B.
> You can easily find the characters on these links :
> http://www.alanwood.net/unicode/arabic.html
> http://www.alanwood.net/unicode/arabic_presentation_forms_b.html
>
> I have the implementation for this step but am looking for the best
> performance and compiling with java 1.3
>
> The second step is to implement the Bidi Algorithm and the
> writing-mode, rt-tb, lr-tb
> and bidi-override.
>
> Sebastian Weber had already some changes for the writing-mode="rl-tb"
>
> http://www.anneundsebp.de/fop/fop.html
>
> Please check the points 4 and 5 about the TextLayoutManger and getWMctm()
>
> As you see we should reverse the character Array, and put the Arabic
> words from the right to left, but
> the ARABIC-INDIC DIGITs should be written from the left side,
> it means, we should not reverse these character arrays
> 0660-066D ARABIC-INDIC DIGITs
> 06F0-06F9 EXTENDED ARABIC-INDIC DIGITs
>
> and then the correct implementation of :
> http://www.w3.org/TR/2001/REC-xsl-20011015/slice5.html#section-N6720-Unicode-BIDI-Processing
>
> I am working on this Patch and will send you my questions.
> And I will also send you some documentations about the Arabic texts
> and Bidirectional algorithm,
> or write them in Wiki.
>
> regards
> Kia Teymourian
>
>
>
Re: PATCH for Arabic/Persian Text, and Bidi-override!
Posted by Kia Teymourian <ki...@cs.tu-berlin.de>.
Manuel Mall schrieb:
> On Monday 20 November 2006 21:44, Kia Teymourian wrote:
>
>> Hello,
>> for this creating this patch I solved already the first problem with
>> joining the Arabic Characters.
>> I have some questions regarding this matter:
>>
>> 1. ---
>> I need to send the Text charArray to Bidirectional Algorithm for
>> visually reordering of the Characters .
>> In class TextLayoutManager
>> org.apache.fop.layoutmgr.inline.TextLayoutManager
>> , I check the textArray and if the Array contains any Arabic
>> characters between U+0600 to U+06FF,
>> it will be sent to the bidirectional algorithm, afterwards to the
>> character joining algorithm.
>>
>> My question is, can I use the java.text.bidi class? And say that
>> Arabic Bidi is just in JDK 1.4
>> supported. Or should FOP have its own Bidi class which is compatible
>> with JDK 1.3?
>>
>>
> I would use a 'compromise' approach ATM. Use the 1.4 class but wrap it
> into something which checks using for example classForName if its
> available. If its not present just log a warning saying BIDI supports
> requires at least JDK 1.4..
>
> Manuel
> <snip />
>
>
Thanks for the fast answer and sorry for my typing mistake at the
beginning of my last e-mail!
I will create a new package in src/java-1.4
Kia
Re: PATCH for Arabic/Persian Text, and Bidi-override!
Posted by Manuel Mall <ma...@apache.org>.
On Monday 20 November 2006 21:44, Kia Teymourian wrote:
> Hello,
> for this creating this patch I solved already the first problem with
> joining the Arabic Characters.
> I have some questions regarding this matter:
>
> 1. ---
> I need to send the Text charArray to Bidirectional Algorithm for
> visually reordering of the Characters .
> In class TextLayoutManager
> org.apache.fop.layoutmgr.inline.TextLayoutManager
> , I check the textArray and if the Array contains any Arabic
> characters between U+0600 to U+06FF,
> it will be sent to the bidirectional algorithm, afterwards to the
> character joining algorithm.
>
> My question is, can I use the java.text.bidi class? And say that
> Arabic Bidi is just in JDK 1.4
> supported. Or should FOP have its own Bidi class which is compatible
> with JDK 1.3?
>
I would use a 'compromise' approach ATM. Use the 1.4 class but wrap it
into something which checks using for example classForName if its
available. If its not present just log a warning saying BIDI supports
requires at least JDK 1.4..
Manuel
<snip />