[Lazarus] anyone has contact of Joerg Braun (german translation)

Martin lazarus at mfriebe.de
Tue Apr 13 18:00:32 CEST 2010


http://ik.homelinux.org/


On Mon, Apr 12, 2010 at 12:11, Hans-Peter Diettrich <DrDiettrich1 at aol.com>wrote:

> Zaher Dirkey schrieb:
>
>
>  Some time i feel the same, but all open source project have the same
>> problem for add official Right To Left, and many of them refuse to add the
>> BIDI to it, i have old experience with some PHP forum, the core team of
>> Lazaurs make it offical bidi and always accept my patches and that enough
>> to, may be take a long time, but all features need the same time.
>>
>
> One problem may be the extent of BiDi support, that is unknown to most
> (western) developers. E.g. I even don't know how to enter RTL text, so that
> all related code should be implemented and checked by people that are
> familiar with RTL applications and environment.
>
> Does there exist a list of things that should change in RTL mode?
>
> Newer Windows systems have an API for rendering full Unicode text,
> including an mix of LTR and RTL parts. Do there exist similar libraries for
> other platforms or widgetsets (Qt???)? If yes, these libraries should be
> explored and a compatible wrapper (class) should be constructed, for
> immediate use in most components (SynEdit may be an exception). If not, an
> API must be defined first, and then the platform specific libraries must be
> implemented accordingly.
>
> But there seem to exist more issues with RTL, like the rows in a grid
> running from right to left? Such behaviour can be tested by everybody, at
> least by faking RTL mode to make the different appearance occur.
>
>
>  Sorry for my poor English, i am writing in English as like writing
>> programming code :)
>>
>
> Does there exist a Wiki (Wikipedia?) entry, that describes *all* required
> changes in BiDi/RTL mode?
>

Let's seperate things into two groups:
1. Text
2. UI

For text, both Qt and GTK 2x support right to left languages. When there are
also non right to left chars (such as "arabic numbers" [the number used in
the arabic language are actually hindu numbers :)], and latin letters etc) .

Even on non BiDi system, you can write right to left languages. The problem
starts when you need to use non Right To Left chars inside a Right To Left
paragraph, or the other way around, when you have a Left To Right language
and you add there Right To Left chars. That called Bi-Directional or BiDi
for short. You have a full algorithm description for it in unicode,org (
http://www.unicode.org/reports/tr9/), including FAQ on the matter (
http://www.unicode.org/faq/bidi.html).

One more sophisticated problem in BiDi is the Arabic language. Many letters
in the Arabic language have several ways to be presented, because the Arabic
written language combine all (almost) letters like the lattin script
language. So Letters that at the beginning, middle or end of a word (depends
on few other rules) are different letter shapes.

My native language -> Hebrew does not have this problem at all.

You have in the Open Source few implementation of BiDi support such as
FreeBiDi, and the IBM's unicode library, but also with GTK2 and Qt3 and
above.

The Right To Left UI, is a whole different approach that actually everyone
here can help with. On Latin based languages, everything starts from Left To
Right, on Right To Left UI, everything starts from the Right.

So point 0,0 on Latin bases system should be on the top left, and on the
Right to left languages starts from the top right.
Some UI such as GTK2 (up to a point, it does not support all of what we
require in Lazarus) support it, and so does Qt, and Windows API (on a
native/enabled/unicode versions).

I hope Bidi and Right To Left is more clearer now :)


>
> DoDi
>
>
>
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Ido
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