43e8916ff3
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@33428 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
85 lines
4.1 KiB
TeX
85 lines
4.1 KiB
TeX
\section{Internationalization}\label{internationalization}
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Although internationalization of an application (i18n for short) involves far
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more than just translating its text messages to another message - date, time and
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currency formats need changing too, some languages are written left to right
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and others right to left, character encoding may differ and many other things
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may need changing too - it is a necessary first step. wxWidgets provides
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facilities for message translation with its
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\helpref{wxLocale}{wxlocale} class and is itself fully translated into several
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languages. Please consult wxWidgets home page for the most up-to-date
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translations - and if you translate it into one of the languages not done
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yet, your translations would be gratefully accepted for inclusion into future
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versions of the library!
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The wxWidgets approach to i18n closely follows the GNU gettext package. wxWidgets uses the
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message catalogs which are binary compatible with gettext catalogs and this
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allows to use all of the programs in this package to work with them. But note
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that no additional libraries are needed during run-time, however, so you
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have only the message catalogs to distribute and nothing else.
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During program development you will need the gettext package for
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working with message catalogs. {\bf Warning:} gettext versions < 0.10 are known
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to be buggy, so you should find a later version of it!
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There are two kinds of message catalogs: source catalogs which are text files
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with extension .po and binary catalogs which are created from the source ones
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with {\it msgfmt} program (part of gettext package) and have the extension .mo.
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Only the binary files are needed during program execution.
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The program i18n involves several steps:
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\begin{enumerate}\itemsep=0pt
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\item Translating the strings in the program text using
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\helpref{wxGetTranslation}{wxgettranslation} or equivalently the
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\helpref{\_()}{underscore} macro.
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\item Extracting the strings to be translated from the program: this uses the
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work done in the previous step because {\tt xgettext} program used for string
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extraction recognises the standard \_() as well as (using its {\tt -k} option)
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our wxGetTranslation and extracts all strings inside the calls to these
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functions. Alternatively, you may use {\tt -a} option to extract all the
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strings, but it will usually result in many strings being found which don't
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have to be translated at all. This will create a text message catalog - a .po
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file.
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\item Translating the strings extracted in the previous step to other
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language(s). It involves editing the .po file.
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\item Compiling the .po file into .mo file to be used by the program.
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\item Setting the appropriate locale in your program to use the strings for the
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given language: see \helpref{wxLocale}{wxlocale}.
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\end{enumerate}
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If you want your app to run under MacOS X with internationlization as
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described above you'll need to make one modification to the Info.plist
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file which describes the contents of the "application bundle". This
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file (an XML text file in UTF-8 format) should have a
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CFBundleDevelopmentRegion entry describing the language of the developer
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- mostly English - and normally MacOS X will query the bundle for the
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presence of certain resource directories to find out which languages
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are supported (e.g. the directory German.lproj for German).
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Since wxWidgets based applications don't use these directories
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for storing resource information (they store the translation in the
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mo files instead) the application needs to be told explicitly which
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langauges are supported. This is done by adding a CFBundleLocalizations
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entry to Info.plist. This can look like this:
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\begin{verbatim}
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<key>CFBundleDevelopmentRegion</key>
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<string>English</string>
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<key>CFBundleLocalizations</key>
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<array>
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<string>en</string>
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<string>de</string>
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<string>fr</string>
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</array>
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\end{verbatim}
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See also the GNU gettext documentation linked from {\tt docs/html/index.htm} in
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your wxWidgets distribution.
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See also \helpref{Writing non-English applications}{nonenglishoverview}.
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It focuses on handling charsets related problems.
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Finally, take a look at the \helpref{i18n sample}{sampleinternat} which shows
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you how all this looks in practice.
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