Qt Linguist Manual: Release Manager

Qt Project Files

lupdate and lrelease depend on information in the application's .pro Qt project file. There must be an entry in the TRANSLATIONS section of the project file for each language that is additional to the native language. A typical entry looks like this:

 TRANSLATIONS = arrowpad_fr.ts \
                arrowpad_nl.ts

Using a locale within the translation file name is useful for determining which language to load at runtime. This is explained in the Programmers chapter.

An example of a complete .pro file with four translation source files:

 HEADERS         = main-dlg.h \
                   options-dlg.h
 SOURCES         = main-dlg.cpp \
                   options-dlg.cpp \
                   main.cpp
 FORMS           = search-dlg.ui
 TRANSLATIONS    = superapp_dk.ts \
                   superapp_fi.ts \
                   superapp_no.ts \
                   superapp_se.ts

QTextCodec::setCodecForTr() makes it possible to choose a 8-bit encoding for literal strings that appear within tr() calls. This is useful for applications whose source language is, for example, Chinese or Japanese. If no encoding is set, tr() uses Latin1.

If you do use the QTextCodec::codecForTr() mechanism in your application, Qt Linguist needs you to set the CODECFORTR entry in the .pro file as well. For example:

 CODECFORTR      = ISO-8859-5

Also, if your compiler uses a different encoding for its runtime system as for its source code and you want to use non-ASCII characters in string literals, you will need to set the CODECFORSRC. For example:

 CODECFORSRC     = UTF-8

Microsoft Visual Studio 2005 .NET appears to be the only compiler for which this is necessary. However, if you want to write portable code, we recommend that you avoid non-ASCII characters in your source files. You can still specify non-ASCII characters portably using escape sequences, for example:

 label->setText(tr("F\374r \310lise"));

 Usage:
     lupdate [options] project-file
     lupdate [options] source-files -ts ts-files
 Options:
     -help  Display this information and exit
     -noobsolete
            Drop all obsolete strings
     -silent
            Don't explain what is being done
     -version
            Display the version of lupdate and exit

 Usage:
     lrelease [options] project-file
     lrelease [options] ts-files [-qm qm-file]
 Options:
     -help  Display this information and exit
     -compress
            Compress the .qm files
     -nounfinished
            Do not include unfinished translations
     -silent
            Don't explain what is being done
     -version
            Display the version of lrelease and exit