[Fribidi-discuss] Re: Some thoughts about BiDi Quirks Handling

[Dom Lachowicz]

On Sat, 2002-09-21 at 08:21, Martin Sevior wrote:
> 
> 
> On Sat, 21 Sep 2002, Omer Zak wrote:
> 
> > Due to Microsoft's actions, there are more than one version of BiDi
> > algorithm in use.  The Hebrew versions of different MS-Word versions
> > implement slightly different BiDi algorithms.  I don't know what is the
> > situation in Arabic and Persian.
> >
> > In order for AbiWord and other Free Software word processors to fully
> > replace Microsoft wordprocessors, it must be possible for them to
> > faithfully import files produced by Microsoft wordprocessors, in *.doc
> > and/or *.rtf formats.
> >
> > But in addition to support for those file formats, the Free Software
> > wordprocessors need to implement compatible BiDi algorithms, so that the
> > imported documents will look the same in both Microsoft wordprocessors and
> > in Free wordprocessors.
> >
> > The question is how to accommodate the above.
> >
> > Possible approaches:
> > --------------------
> > 1. Implement few "quirks" flags in FriBidi (the FriBidiEnv structure has
> >    room for those flags).  When set, those flags would cause FriBidi to
> >    behave like one of the incompatible BiDi algorithms.
> > 2. Add to FriBidi special code, which would flag the characters in a
> >    string, which would be reordered differently in the different BiDi
> >    algorithms.  The wordprocessor would then display those characters in a
> >    different way, and let the user determine whether they were reordered
> >    the way he intended to or not.
> > 3. The import filters, used by the Free wordprocessors to import files
> >    created by a given version of Microsoft wordprocessor, would insert
> >    explicit BiDi overrides at those places where the BiDi algorithms would
> >    produce different visual orderings of characters.
> >
> > Of the possible approaches, I favor the most the "quirks" flags approach.
> > When importing a document, the user has anyway to specify which
> > wordprocessor created it.  It is not a big deal to specify also the
> > corresponding BiDi algorithm version.
> >
> 
> Actually you don't need to do this for AbiWord. It detects file type
> automatically. I don't know if wv (our MS Word import library) could be
> made to also detect which version of MS created it. If so the user would
> not need to enter this information.
> 
> Dom, is this true? IS there a MS Word version in the *.doc format?

I prefer the "Quirks" approach suggested by Omer. MSWord's FIB (file
information block) tells you which version of the Microsoft Word format
the document is saved in. We can faithfully identify versions 2 through
9 at the moment.

Dom