Re: One key stroke --> two code-points

[Clytie Siddall <clytie riverland net au>]

Just checking: so this problem does not affect languages using  
precomposed Unicode?

Vietnamese users _should_ be using precomposed forms for our added and  
combined diacritics. But I wonder if we should be ready for the fact  
that they might not. I was using a keyboard layout for a while which  
was decomposed, and I didn't know it. That could happen to others, too.

Clytie

On 10/06/2008, at 2:35 PM, Anousak Souphavanh wrote:

> Thanks, Simos for your kind and time.
>
> Much appreciated to Javier for brought a good solution indeed.
>
> Lao input method  is need a similar solution. Javier please post your
> solution (where and how to define a new table for Khmer) so I can
> define these code points for Lao.
>
> > On Tue, Jun 10, 2008 at 1:58 AM, Simos Xenitellis
> > <simos lists googlemail com> wrote:
> > > O/H Javier SOLA έγραψε:
> > > > Thanks Simos !!
> > > >
> > > > Actually, we have had these additions for a while in X11.
> > >
> > > Hi Javier,
> > >
> > > Checking at
> > > http://gitweb.freedesktop.org/?p=xorg/lib/libX11.git;a=tree;f=nls/en_US.UTF-8
> > > does not show these lines at the end. It is possible that these  
> > > compose
> > > sequences were added as a patch to the distribution package.
> > > > We will  do an issue for GTK+, and use the variable meanwhile.
> > > >
> > > > What file is it in GTK+? I have not been able to find it.
> > >
> > > In GTK+ (HEAD), the relevant file is
> > > http://svn.gnome.org/viewvc/gtk%2B/trunk/gtk/gtkimcontextsimple.c?view=markup
> > >
> > > However, your case of compose sequences is different from the  
> > > existing
> > > compose sequences, that result to a single codepoint (you require  
> > > to produce
> > > two codepoints).
> > >
> > > Therefore, the type of support you are looking for is similar to  
> > > compose
> > > sequences that result to letter+diacritic mark. Several languages  
> > > have
> > > characters that no pre-composed  letters exist, so the compose  
> > > sequence
> > > produces letter+diacritic marks (more than one codepoint). Such  
> > > support is
> > > missing, and there are already bug reports for them.
> > >
> > > Bug 341341 – Compose mechanism in simple input method doesn't  
> > > support
> > > decomposed forms
> > > http://bugzilla.gnome.org/show_bug.cgi?id=341341
> > >
> > > Bug 345254 – dead accents should at least produce combining  
> > > characters
> > > http://bugzilla.gnome.org/show_bug.cgi?id=345254
> > >
> > > There is a shortcut when trying to solve the above cases of compose
> > > sequences, thus the solution I expect to be different from the  
> > > Khmer compose
> > > sequences.
> > > Specifically, for the Latin compose sequences, such as (it's a  
> > > made up
> > > example)
> > >
> > > <dead_acute> <t> : "t́" # LETTER T WITH ACUTE
> > >
> > > one could convert to something like    [ dead_acute, 't', 0].
> > > We would put 0 for the resulting codepoint because we can deduce  
> > > for this
> > > category of compose sequences that the actual codepoints are 't'  
> > > and 'acute'
> > > (the resulting codepoints match the body of the compose sequence).
> > >
> > > However, for the case of Khmer, the compose sequences look  
> > > independent from
> > > the resulting code points. Therefore, a new table should be  
> > > required.
> > >
> > > To cut the story short, I have filed a bug report for this,
> > > Bug 537457 – Support compose sequences that produce two+  
> > > codepoints
> > > http://bugzilla.gnome.org/show_bug.cgi?id=537457
> > >
> > > Simos
> > >
> > > > Thanks,
> > > >
> > > > Javier
> > > >
> > > > Simos Xenitellis wrote
> > > > > O/H Javier SOLA έγραψε:
> > > > > > Hi,
> > > > > >
> > > > > > I am working on Khmer localization (KhmerOS project).
> > > > > >
> > > > > > In Khmer, some of the basic vowels (which we include in the  
> > > > > > keyboard)
> > > > > > require two code-points, so one keystroke must generate two  
> > > > > > code points.
> > > > > >
> > > > > > It used to be that we could do the conversion in KBX by  
> > > > > > generating a
> > > > > > fictious code-point (Pablo Saratxaga explained this to us a few  
> > > > > > years ago),
> > > > > > which was later translated to two real code-points by puting  
> > > > > > the conversion
> > > > > > in the en-US locale file. I did work at the time.
> > > > > >
> > > > > > But now this seems to have stopped working. Does anybody knows  
> > > > > > how we
> > > > > > can fix this?
> > > > >
> > > > > These additions (pressing a single key and producing two  
> > > > > codepoints), are
> > > > > located at
> > > > > /usr/share/X11/locale/en_US.UTF-8/Compose
> > > > > The specific lines appear to be
> > > > >
> > > > > # Khmer digraphs
> > > > > # A keystroke has to generate several characters, so they are  
> > > > > defined
> > > > > # in this file
> > > > >
> > > > > <U17fb>    :   "ុះ"
> > > > > <U17fc>    :   "ុំ"
> > > > > <U17fd>    :   "េះ"
> > > > > <U17fe>    :   "ោះ"
> > > > > <U17ff>    :   "ាំ"
> > > > >
> > > > > GTK+ based applications duplicate the Compose file in the gtk+  
> > > > > library,
> > > > > and currently the version of the Compose file that exists in gtk 
> > > > > + does not
> > > > > include those specific compose sequences.
> > > > > I think these are a recent addition.
> > > > > Technically, it is possible for gtk+ to include compose  
> > > > > sequences that
> > > > > produce more than one code points (requires small change in the  
> > > > > code),
> > > > > however these recent Khmer digraphs are the only compose  
> > > > > sequences using the
> > > > > facility now.
> > > > >
> > > > > To cut the long story short, you can bypass for now the GTK+  
> > > > > version of
> > > > > the Compose file and use the Compose file that comes with X.Org  
> > > > > (shown
> > > > > above) by setting the environment variable GTK_IM_MODULE to "xim".
> > > > > This should not have adverse effect to the OLPC software.
> > > > >
> > > > > It is important that if other keyboard layouts as well require  
> > > > > compose
> > > > > sequences that produce
> > > > > two or more codepoints (such as Serbian), to add them to the  
> > > > > XOrg Compose
> > > > > file. In the next iteration of update of the GTK+, all these  
> > > > > compose
> > > > > sequences can make it in.
> > > > >
> > > > > Simos

from Clytie

Vietnamese Free Software Translation Team
http://vnoss.net/dokuwiki/doku.php?id=projects:l10n

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