Handling of frameworks using Qt-based translations

Thu Mar 20 20:30:07 UTC 2014

El Dijous, 20 de març de 2014, a les 07:06:58, Aurélien Gâteau va escriure:
> On Tue, Mar 18, 2014, at 9:49, Aurélien Gâteau wrote:
> 
> On Tue, Mar 18, 2014, at 9:07, Aleix Pol wrote:
> 
> On Tue, Mar 18, 2014 at 4:12 PM, Aurélien Gâteau <[1]agateau at kde.org>
> wrote:
> 
> On Tue, Mar 18, 2014, at 6:20, Aleix Pol wrote:
> 
> On Tue, Mar 18, 2014 at 2:05 PM, Aurélien Gâteau <[2]agateau at kde.org>
> wrote:
> 
> Hi,
> 
> 
> I started working on how to handle Qt based translations, and make it
> as
> 
> simple as possible to work with for framework maintainers as well as
> 
> framework users.
> 
> 
> I picked KBookmarks as my guinea pig and got to the point where
> 
> kbookmarkdialogtest shows a translated dialog.
> 
> 
> Here is how it currently works. All of this is liberally inspired from
> 
> the way Trojita works:
> 
> 
> # String extraction
> 
> 
> I created a src/Messages.sh which contains the following:
> 
> 
> lupdate -silent -recursive . -ts $podir/tmp.ts
> 
> lconvert $podir/tmp.ts --sort-contexts --output-format pot -o
> 
> $podir/kbookmarks5.pot
> 
> rm $podir/tmp.ts
> 
> 
> # String compilation
> 
> 
> I modified the toplevel CMakeLists.txt, adding these lines:
> 
> 
> if (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/po)
> 
>     include(${CMAKE_CURRENT_SOURCE_DIR}/QmSupport.cmake)
> 
>     qm_setup(kbookmarks5 po)
> 
> endif()
> 
> 
> I created a QmSupport.cmake file, which exposes a qm_setup() function.
> 
> This function does three things:
> 
> 1. Create a "qm" target which turns all .po into .qm files.
> 
> 
> 2. Call install(FILES...) on the generated qm files, installing them in
> 
> share/${name}/locale, where ${name} is the firt argument of qm_setup().
> 
> 
> 3. Generate a "${name}_translation.h" which contain two inline
> functions
> 
> to make it easy to load the translations.
> 
> Using the translation is then just a matter of including
> 
> ${name}_translation.h and calling ${name}_installTranslator(). If more
> 
> control is needed, ${name}_installTranslator() also accepts an optional
> 
> argument: the language. For even finer control, the .h also contains a
> 
> ${name}_createTranslator() function, which returns a QTranslator loaded
> 
> with strings for the right language.
> 
> 
> # Questions
> 
> 
> Does this approach sounds sane to you?
> 
> 
> I think QmSupport.cmake should go to extra-cmake-modules. Any
> 
> objections?
> 
> 
> Right now qm_setup() is very inflexible: it installs files and creates
> 
> the _translation.h file based on the name argument, meaning in my
> 
> example it creates share/kbookmarks5/locale/kbookmarks5_*.qm and
> 
> include/kbookmarks5_translation.h, which contains the functions
> 
> kbookmarks5_createTranslator and kbookmarks5_installTranslator.
> 
> 
> I think we want to be able to customize the install dir of the
> 
> _translation.h file because some frameworks install header files in a
> 
> subdir, others do not.
> 
> 
> Should we also be able to customize the install data dir for qm files,
> 
> as well as the prefix of the function names from _translation.h? I am
> 
> tempted to default to ${PROJECT_NAME} for the prefix of the function
> 
> names, its lowercase version for the install data dir and add an
> 
> optional PROJECT_NAME argument to qm_setup(). Opinions?
> 
> 
> I am attaching the diff of the current state. I do not intend to commit
> 
> it as is since po files are not supposed to be in the framework
> 
> repository, but it should make it easy for you to try it if you are
> 
> interested.
> 
> 
> Aurélien
> 
> 
> _______________________________________________
> 
> Kde-frameworks-devel mailing list
> 
> [3]Kde-frameworks-devel at kde.org
> 
> [4]https://mail.kde.org/mailman/listinfo/kde-frameworks-devel
> 
> 
> 
> Hi Aurélien,
> Wouldn't it make sense that the library called the createTranslation
> itself, instead of expecting the application to call it? I can easily
> see applications forgetting it.
> Maybe using Q_COREAPP_STARTUP_FUNCTION?
> 
> 
> That could work, but would remove the ability to change the language
> later (Some Qt apps like to let the user use a different language than
> the system one for some reason). Not sure we care about this. It
> certainly sounds more foolproof. On the other hand, you already *must*
> load translations yourself if you are using any Qt standard dialog,
> otherwise it won't be translated either.
> 
> Aurélien
> 
> 
> _______________________________________________
> 
> Kde-frameworks-devel mailing list
> 
> [5]Kde-frameworks-devel at kde.org
> 
> [6]https://mail.kde.org/mailman/listinfo/kde-frameworks-devel
> 
> 
> Well, for KI18n changing the language at run-time is not possible.
> 
> Maybe we can set it up magically for general use and still install the
> createTranslation thing in case the application likes to do it
> specifically?
> 
> 
> That is right. Let's keep it simple then and not provide a feature
> which is not supported by KI18n-powered frameworks.
> 
> This means we need to add a generated .cpp file in the framework
> target(s). Going to look into it.
> 
> 
> Some feedback on this: using Q_COREAPP_STARTUP_FUNCTION works as
> expected. I think I have something usable now. Adapting a Qt-translated
> framework requires the following changes (using kbookmarks as example
> again):
> 
> 1. Create src/Messages.sh with the following content:
> 
>     rm -f $podir/tmp.ts
> 
>     lupdate -silent -recursive . -ts $podir/tmp.ts
> 
>     lconvert $podir/tmp.ts --sort-contexts --output-format pot -o
> $podir/kbookmarks5.pot
> 
>     rm $podir/tmp.ts
> 
> 
> Note: As much as possible of these lines should move to the l10n
> scripts to reduce duplication.
> 
> 2. Edit the top-level CMakeLists.txt, add the following *before*
> add_subdirectory(src):
> 
>     include(ECMSetupQtTranslations)
> 
>     ecm_setup_qt_translations(
> 
>         PO_DIR po
> 
>         POT_NAME kbookmarks5.pot
> 
>         INSTALL_SUB_DIR kbookmarks
> 
>         CREATE_LOADER)
> 
> 
> 
> 3. Edit src/CMakelists.txt, add ${ECM_QT_TRANSLATION_LOADER} to
> kbookmark_SRCS:
> 
> 
> 
>     set(kbookmarks_SRCS
> 
>       kbookmark.cpp
>       #...
> 
>       ${ECM_QT_TRANSLATION_LOADER}
> 
>     )
> 
> 
> 
> This works with the attached ECMSetupQtTranslations.cmake file.
> 
> 
> 
> When those changes are done, one gets translations installed and
> loaded, as long as the source used to build contains a properly
> populated po/ dir. This should be taken care of by the release scripts.
> 

Looks reasonable to me.

Cheers,
  Albert

> 
> 
> If this makes sense to you, I am going to propose
> ECMSetupQtTranslations.cmake for inclusion in extra-cmake-modules.
> 
> 
> 
> Aurélien
> 
> References
> 
> 1. mailto:agateau at kde.org
> 2. mailto:agateau at kde.org
> 3. mailto:Kde-frameworks-devel at kde.org
> 4. https://mail.kde.org/mailman/listinfo/kde-frameworks-devel
> 5. mailto:Kde-frameworks-devel at kde.org
> 6. https://mail.kde.org/mailman/listinfo/kde-frameworks-devel