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diff --git a/tqtinterface/qt4/tools/linguist/book/linguist-programmer.leaf b/tqtinterface/qt4/tools/linguist/book/linguist-programmer.leaf deleted file mode 100644 index b20c2cd..0000000 --- a/tqtinterface/qt4/tools/linguist/book/linguist-programmer.leaf +++ /dev/null @@ -1,1145 +0,0 @@ -\chapter Programmers - -Support for multiple languages is extremely simple in Qt -applications, and adds little overhead to the programmer's workload. - -Qt minimizes the performance cost of using translations by -translating the phrases for each window as they are created. In most -applications the main window is created just once. Dialogs are often -created once and then shown and hidden as required. Once the initial -translation has taken place there is no further runtime overhead for -the translated windows. Only those windows that are created, -destroyed and subsequently created will have a translation -performance cost. - -Creating applications that can switch language at runtime is possible -with Qt, but requires a certain amount of programmer intervention and -will of course incur some runtime performance cost. - -\section1 Making the Application Translation Aware - -Programmers should make their application look for and load the -appropriate translation file and mark user-visible text and Ctrl -keyboard accelerators as targets for translation. - -Each piece of text that requires translating requires context to help -the translator identify where in the program the text occurs. In the -case of multiple identical texts that require different translations, -the translator also requires some information to disambiguate the -source texts. Marking text for translation will automatically cause -the class name to be used as basic context information. In some cases -the programmer may be required to add additional information to help -the translator. - -\section2 Creating Translation Files - -\index .ts Files -\index Translation Source Files - -Translation files consist of all the user-visible text and Ctrl key -accelerators in an application and translations of that text. -Translation files are created as follows: - -\index lupdate -\index lrelease - -\list 1 -\i Run \l lupdate initially to generate the first set of \c .ts -translation source files with all the user-visible text but no -translations. -\i The \c .ts files are given to the translator who adds translations -using \e {Qt Linguist}. \e {Qt Linguist} takes care of any changed -or deleted source text. -\i Run \l lupdate to incorporate any new text added to the -application. \l lupdate synchronizes the user-visible text from the -application with the translations; it does not destroy any data. -\i Steps 2 and 3 are repeated as often as necessary. -\i When a release of the application is needed \l lrelease is run to -read the \c .ts files and produce the \c .qm files used by the -application at runtime. -\endlist - -\index .pro Files -\index Project Files -\index qmake!Project Files - -For \l lupdate to work successfully, it must know which translation -files to produce. The files are simply listed in the application's \c -.pro Qt project file, for example: -\quotefile tt2/tt2.pro -\skipto TRANSLATIONS -\printline TRANSLATIONS -\printline - -See the \link lupdate "lupdate" \endlink and \link lrelease -"lrelease" \endlink sections. - -\section2 Loading Translations - -\quotefile tt1/main.cpp -\skipto main( -\printline main( -\printuntil QApplication - -\index main() - -This is how a simple \c main() function of a Qt application begins. - -\index QTranslator!load() -\index load()!QTranslator -\index QApplication!installTranslator() -\index installTranslator()!QApplication - -\quotefile tt1/main.cpp -\skipto main( -\printline main( -\printuntil app.installTrans - -For a translation-aware application a translator object is created, a -translation is loaded and the translator object installed into the -application. - -\quotefile tt2/main.cpp -\skipto main( -\printline main( -\printuntil app.installTrans - -In production applications a more flexible approach, for example, -loading translations according to locale, might be more appropriate. If -the \c .ts files are all named according to a convention such as -\e appname_locale, e.g. \c tt2_fr, \c tt2_de etc, then the -code above will load the current locale's translation at runtime. - -If there is no translation file for the current locale the application -will fall back to using the original source text. - -\section2 Making the Application Translate User-Visible Strings - -\index tr() -\index TQT_BASE_OBJECT_NAME!tr() - -User-visible strings are marked as translation targets by wrapping them -in a \c tr() call, for example: -\code - button = new QPushButton( "&Quit", this ); -\endcode - -would become - -\code - button = new QPushButton( tr("&Quit"), this); -\endcode - -\index Q_OBJECT - -All \l TQT_BASE_OBJECT_NAME subclasses that use the \c Q_OBJECT macro implement -the \c tr() function. - -Although the \c tr() call is normally made directly since it is -usually called as a member function of a \l TQT_BASE_OBJECT_NAME subclass, in -other cases an explicit class name can be supplied, for example: - -\code - QPushButton::tr("&Quit") -\endcode - -or - -\code - TQT_BASE_OBJECT_NAME::tr("&Quit") -\endcode - -\section2 Distinguishing Identical Strings That Require Different -Translations - -\index Translation Contexts -\index Contexts!for Translation -\index lupdate - -The \l lupdate program automatically provides a \e context for every -source text. This context is the class name of the class that contains -the \c tr() call. This is sufficient in the vast majority of cases. -Sometimes however, the translator will need further information to -uniquely identify a source text; for example, a dialog that contained -two separate frames, each of which contained an "Enabled" option would -need each identified because in some languages the translation would -differ between the two. This is easily achieved using the -two argument form of the \c tr() call, e.g. - -\code - rbc = new QRadioButton( tr("Enabled", "Color frame"), this ); -\endcode - -and - -\code - rbh = new QRadioButton( tr("Enabled", "Hue frame"), this ); -\endcode - -\index Ctrl Key - -Ctrl key accelerators are also translatable: - -\quotefile tt3/mainwindow.cpp -\skipto quit() -\printline quit() -\printuntil Quit - -It is strongly recommended that the two argument form of \c tr() is used -for Ctrl key accelerators. The second argument is the only clue the -translator has as to the function performed by the accelerator. - -\section2 Helping The Translator With Navigation Information - -\index TRANSLATOR!in Comments -\index Translator Comments -\index Comments!for Translators - -In large complex applications it may be difficult for the translator to -see where a particular source text comes from. This problem can be -solved by adding a comment using the keyword \e TRANSLATOR which -describes the navigation steps to reach the text in question; e.g. - -\code - /* TRANSLATOR FindDialog - - Choose Edit|Find from the menu bar or press Ctrl+F to pop up the - Find dialog. - */ -\endcode - -These comments are particularly useful for widget classes. - -\section2 Coping With C++ Namespaces - -\index Namespaces -\index C++!Namespaces -\index lupdate - -C++ namespaces and the \c {using namespace} statement can confuse -\l lupdate. It will interpret \c MyClass::tr() as meaning just -that, not as \c MyNamespace::MyClass::tr(), even if \c MyClass is -defined in the \c MyNamespace namespace. Runtime translation of -these strings will fail because of that. - -\index TRANSLATOR!in Comments -\index Translator Comments -\index Comments!for Translators - -You can work around this limitation by putting a \e TRANSLATOR -comment at the beginning of the source files that use \c -MyClass::tr(): -\code - /* TRANSLATOR MyNamespace::MyClass */ -\endcode -After the comment, all references to \c MyClass::tr() will be -understood as meaning \c MyNamespace::MyClass::tr(). - -\section2 Translating Text that is Outside of a TQT_BASE_OBJECT_NAME subclass - -\section3 Using QApplication::translate() - -If the quoted text is not in a member function of a TQT_BASE_OBJECT_NAME subclass, -use either the tr() function of an appropriate class, or the -QApplication::translate() function directly: - -\code - void some_global_function( LoginWidget *logwid ) - { - QLabel *label = new QLabel( - LoginWidget::tr("Password:"), logwid ); - } - - void same_global_function( LoginWidget *logwid ) - { - QLabel *label = new QLabel( - tqApp->translate("LoginWidget", "Password:"), - logwid ); - } -\endcode - -\section3 Using QT_TR_NOOP() and QT_TRANSLATE_NOOP() - -If you need to have translatable text completely outside a function, -there are two macros to help: QT_TR_NOOP() and QT_TRANSLATE_NOOP(). -These macros merely mark the text for extraction by \l{lupdate}. -The macros expand to just the text (without the context). - -Example of QT_TR_NOOP(): -\code - QString FriendlyConversation::greeting( int greet_type ) - { - static const char* greeting_strings[] = { - QT_TR_NOOP( "Hello" ), - QT_TR_NOOP( "Goodbye" ) - }; - return tr( greeting_strings[greet_type] ); - } -\endcode - -Example of QT_TRANSLATE_NOOP(): -\code - static const char* greeting_strings[] = { - QT_TRANSLATE_NOOP( "FriendlyConversation", "Hello" ), - QT_TRANSLATE_NOOP( "FriendlyConversation", "Goodbye" ) - }; - - QString FriendlyConversation::greeting( int greet_type ) - { - return tr( greeting_strings[greet_type] ); - } - - QString global_greeting( int greet_type ) - { - return tqApp->translate( "FriendlyConversation", - greeting_strings[greet_type] ); - } -\endcode - -\section1 Tutorials - -Three tutorials are presented. The first demonstrates the creation of -a \l QTranslator object. It also shows the simplest use of the \c -tr() function to mark user-visible source text for translation. The -second tutorial explains how to make the application load the -translation file applicable to the current locale. It also shows the -use of the two-argument form of \c tr() which provides additional -information to the translator. The third tutorial explains how -identical source texts can be distinguished even when they occur in -the same context. This tutorial also discusses how the translation -tools help minimize the translator's work when an application is -upgraded. - -\section2 Tutorial 1: Loading and Using Translations - -\img tt1_en.png -\caption Tutorial 1 Screenshot, English version - -\include tt1/tt1.pro -\caption \c tt1.pro - -\include tt1/main.cpp -\caption \c main.cpp - -This example is a reworking of the \link tutorial1-01.html -"hello-world" \endlink example from \link tutorial.html Tutorial -#1\endlink, with a Latin translation. The \e {Tutorial 1 Screenshot, -English version}, above, shows the English version. - -\quotefile tt1/main.cpp - -\section3 Line by Line Walk-through - -\quotefile tt1/main.cpp - -\skipto qtranslator -\printline qtranslator - -\index QTranslator - -This line includes the definition of the \l QTranslator class. -Objects of this class provide translations for user-visible text. - -\skipto QTranslator -\printuntil tor - -Creates a \l QTranslator object without a parent. - -\printline load - -\index tt1_la.qm - -Tries to load a file called \c tt1_la.qm (the \c .qm file extension is -implicit) that contains Latin translations for the source texts used in -the program. No error will occur if the file is not found. - -\index QApplication!installTranslator() -\index installTranslator()!QApplication - -\printline installTranslator - -Adds the translations from \c tt1_la.qm to the pool of translations used -by the program. - -\index Hello World - -\printline hello - -Creates a push button that displays "Hello world!". If \c tt1_la.qm -was found and contains a translation for "Hello world!", the -translation appears; if not, the source text appears. - -\index tr() -\index TQT_BASE_OBJECT_NAME!tr() - -All classes that inherit \l TQT_BASE_OBJECT_NAME have a \c tr() function. Inside -a member function of a \l TQT_BASE_OBJECT_NAME class, we simply write \c tr("Hello -world!") instead of \c QPushButton::tr("Hello world!") or \c -QObject::tr("Hello world!"). - -\section3 Running the Application in English - -\index English Language - -Since we haven't made the translation file \c tt1_la.qm, the source text -is shown when we run the application: - -\img tt1_en.png -\caption Tutorial 1 Screenshot, English version - -\section3 Creating a Latin Message File - -\index tt1.pro -\index Latin - -The first step is to create a project file, \c tt1.pro, that lists -all the source files for the project. The project file can be a qmake -project file, or even an ordinary makefile. Any file that contains - -\index SOURCES!in Project Files -\index TRANSLATIONS!in Project Files - -\quotefile tt1/tt1.pro -\skipto SOURCES -\printline SOURCES -\skipto TRANSLATIONS -\printline TRANSLATIONS - -will work. \e TRANSLATIONS specifies the message files we want to -maintain. In this example, we just maintain one set of translations, -namely Latin. - -\index .ts Files -\index Translation Source Files -\index .qm Files -\index Qt Message Files - -Note that the file extension is \c .ts, not \c .qm. The \c .ts -translation source format is designed for use during the -application's development. Programmers or release managers run the \l -lupdate program to generate and update \c .ts files with the source -text that is extracted from the source code. Translators read and -update the \c .ts files using \e {Qt Linguist} adding and editing -their translations. - -\index XML - -The \c .ts format is human-readable XML that can be emailed directly -and is easy to put under version control. If you edit this file -manually, be aware that the default encoding for XML is UTF-8, not -Latin-1 (ISO 8859-1). One way to type in a Latin-1 character such as -'\OSLASH' (Norwegian o with slash) is to use an XML entity: -"\ø". This will work for any Unicode character. - -Once the translations are complete the \l lrelease program is used to -convert the \c .ts files into the \c .qm Qt message file format. The -\c .qm format is a compact binary format designed to deliver very -fast lookup performance. Both \l lupdate and \l lrelease read all the -project's source and header files (as specified in the HEADERS and -SOURCES lines of the project file) and extract the strings that -appear in \c tr() function calls. - -\index lupdate - -\l lupdate is used to create and update the message files (\c tt1_la.ts -in this case) to keep them in sync with the source code. It is safe to -run \l lupdate at any time, as \l lupdate does not remove any -information. For example, you can put it in the makefile, so the \c .ts -files are updated whenever the source changes. - -\index .ts Files -\index Translation Source Files -\index XML - -Try running \l lupdate right now, like this: -\code - lupdate -verbose tt1.pro -\endcode -(The \c -verbose option instructs \c lupdate to display messages that -explain what it is doing.) You should now have a file \c tt1_la.ts in -the current directory, containing this: -\code - <!DOCTYPE TS><TS> - <context> - <name>QPushButton</name> - <message> - <source>Hello world!</source> - <translation type="unfinished"></translation> - </message> - </context> - </TS> -\endcode -You don't need to understand the file format since it is read and -updated using tools (\l lupdate, \e {Qt Linguist}, \l lrelease). - -\section3 Translating to Latin with Qt Linguist - -\index Qt Linguist -\index Linguist - -We will use \e {Qt Linguist} to provide the translation, although -you can use any XML or plain text editor to enter a translation into a -\c .ts file. - -To start \e {Qt Linguist}, type -\code - linguist tt1_la.ts -\endcode - -You should now see the text "QPushButton" in the top left pane. -Double-click it, then click on "Hello world!" and enter "Orbis, te -saluto!" in the \e Translation pane (the middle right of the -window). Don't forget the exclamation mark! - -Click the \e Done checkbox and choose \e File|Save from the -menu bar. The \c .ts file will no longer contain -\code - <translation type='unfinished'></translation> -\endcode -but instead will have -\code - <translation>Orbis, te saluto!</translation> -\endcode - -\section3 Running the Application in Latin - -\index Latin -\index lrelease - -To see the application running in Latin, we have to generate a \c .qm -file from the \c .ts file. Generating a \c .qm file can be achieved -either from within \e {Qt Linguist} (for a single \c .ts file), or -by using the command line program \l lrelease which will produce one \c -.qm file for each of the \c .ts files listed in the project file. -Generate \c tt1_la.qm from \c tt1_la.ts by choosing -\e File|Release from \e {Qt Linguist}'s menu bar and pressing -\e Save in the file save dialog that pops up. Now run the \e tt1 example -program again. This time the button will be labelled "Orbis, te -saluto!". - -\img tt1_la.png -\caption Tutorial 1 Screenshot, Latin version - -\section2 Tutorial 2: Using Two or More Languages - -\img tt2_en.png -\caption Tutorial 2 Screenshot, English version - -\index .pro Files -\index Project Files -\index qmake!Project Files - -\include tt2/tt2.pro -\caption tt2.pro - -\index Translation Contexts -\index Contexts!for Translation - -This example is a slightly more involved and introduces a key -\e {Qt Linguist} concept: "contexts". - -\list -\i \c arrowpad.h contains the definition of \c ArrowPad, a custom widget; -\i \c arrowpad.cpp contains the implementation of \c ArrowPad; -\i \c mainwindow.h contains the definition of \c MainWindow, a subclass of - \l QMainWindow -\i \c mainwindow.cpp contains the implementation of \c MainWindow; -\i \c main.cpp contains main(). -\endlist - -\index tt2.pro -\index French Language -\index Dutch Language - -We will use two translations, French and Dutch, although there is no -effective limit on the number of possible translations that can be used -with an application. The relevant lines of \c tt2.pro are - -\quotefile tt2/tt2.pro -\skipto HEADERS -\printuntil tt2_nl.ts - -\index lupdate -\index tt2_fr.ts -\index tt2_nl.ts - -Run \l lupdate; it should produce two identical message files -\c tt2_fr.ts and \c tt2_nl.ts. These files will contain all the source -texts marked for translation with \c tr() calls and their contexts. - -\section3 Line by Line Walk-through - -\index ArrowPad!in Translation Tutorial -\index English Language - -In \c arrowpad.h we define the \c ArrowPad subclass which is a -subclass of \l QWidget. In the \e {Tutorial 2 Screenshot, English -version}, above, the central widget with the four buttons is an -\c ArrowPad. - -\quotefile tt2/arrowpad.h -\skipto class ArrowPad -\printline class ArrowPad - -\index Q_OBJECT -\index tr() -\index TQT_BASE_OBJECT_NAME!tr() -\index Translation Contexts -\index Contexts!for Translation - -When \l lupdate is run it not only extracts the source texts but it -also groups them into contexts. A context is the name of the class in -which the source text appears. Thus, in this example, "ArrowPad" is a -context: it is the context of the texts in the \c ArrowPad class. -The \c Q_OBJECT macro defines \c tr(x) in \c ArrowPad like this - -\index QApplication!translate() -\index translate()!QApplication - -\code - tqApp->translate( "ArrowPad", x ) -\endcode - -Knowing which class each source text appears in enables \e {Qt -Linguist} to group texts that are logically related together, e.g. -all the text in a dialog will have the context of the dialog's class -name and will be shown together. This provides useful information for -the translator since the context in which text appears may influence how -it should be translated. For some translations keyboard -accelerators may need to be changed and having all the source texts in a -particular context (class) grouped together makes it easier for the -translator to perform any accelerator changes without introducing -conflicts. - -In \c arrowpad.cpp we implement the \c ArrowPad class. - -\quotefile tt2/arrowpad.cpp -\skipto QPushButton -\printline QPushButton - -We call \c ArrowPad::tr() for each button's label since the labels are -user-visible text. - -\img tt2_en.png -\caption Tutorial 2 Screenshot, English version - -\index Q_OBJECT -\index MainWindow!in Translation Tutorial - -\quotefile tt2/mainwindow.h -\skipto QMainWindow -\printline QMainWindow -\printuntil Q_OBJECT - -In the \e {Tutorial 2 Screenshot, English version}, above, the whole -window is a \c MainWindow. This is defined in the \c mainwindow.h -header file. Here too, we use \c Q_OBJECT, so that \c MainWindow will -become a context in \e {Qt Linguist}. - -In the implementation of \c MainWindow, \c mainwindow.cpp, we create -an instance of our \c ArrowPad class - -\quotefile tt2/mainwindow.cpp -\skipto arrow pad -\printline arrow pad - -We also call \c MainWindow::tr() twice, once for the menu item and -once for the accelerator. - -\index Ctrl Key -\index Alt Key - -\skipto quit() -\printline quit() -\printuntil Ctrl+Q - -Note the use of \c tr() to support different keys in other languages. -"Ctrl+Q" is a good choice for Quit in English, but a Dutch translator -might want to use "Ctrl+A" (for Afsluiten) and a German translator -"Strg+E" (for Beenden). When using \c tr() for Ctrl key accelerators, -the two argument form should be used with the second argument -describing the function that the accelerator performs. - -\index main() - -Our \c main() function is defined in \c main.cpp as usual. - -\quotefile tt2/main.cpp -\skipto QTranslator -\printline QTranslator -\printuntil install - -\index QTextCodec!locale() -\index locale()!QTextCodec -\index LANG!Environment Variable -\index Environment Variables!LANG - -We choose which translation to use according to the current locale. -\l QTextCodec::locale() can be influenced by setting the \c LANG -environment variable, for example. Notice that the use of a naming -convention that incorporates the locale for \c .qm message files, -(and \c .ts files), makes it easy to implement choosing the -translation file according to locale. - -If there is no \c .qm message file for the locale chosen the original -source text will be used and no error raised. - -\section3 Translating to French and Dutch - -We'll begin by translating the example application into French. Start -\e {Qt Linguist} with \c tt2_fr.ts. You should get the seven source -texts ("\&Up", "\&Left", etc.) grouped in two contexts ("ArrowPad" -and "MainWindow"). - -Now, enter the following translations: - -\list -\i \c ArrowPad - \list - \i \&Up - \&Haut - \i \&Left - \&Gauche - \i \&Right - \&Droite - \i \&Down - \&Bas - \endlist -\i \c MainWindow - \list - \i E\&xit - \&Quitter - \i Ctrl+Q - Ctrl+Q - \i \&File - \&Fichier - \endlist -\endlist - -It's quickest to press \Key Alt+D (which clicks the \e {Done \& Next} -button) after typing each translation, since this marks the -translation as done and moves on to the next source text. - -Save the file and do the same for Dutch working with \c tt2_nl.ts: - -\list -\i \c ArrowPad - \list - \i \&Up - \&Boven - \i \&Left - \&Links - \i \&Right - \&Rechts - \i \&Down - \&Onder - \endlist -\i \c MainWindow - \list - \i E\&xit - \&Afsluiten - \i Ctrl+Q - Ctrl+A - \i File - \&Bestand - \endlist -\endlist - -We have to convert the \c tt1_fr.ts and \c tt1_nl.ts translation source -files into \c .qm files. We could use \e {Qt Linguist} as we've done -before; however using the command line tool \l lrelease ensures that -\e all the \c .qm files for the application are created without us -having to remember to load and \e File|Release each one -individually from \e {Qt Linguist}. - -In practice we would include calls to \l lupdate and \l lrelease in the -application's makefile to ensure that the latest translations are -used. - -\omit -an example of a makefile or .pro file that did this would be nice -\endomit - -Type - -\code - lrelease tt2.pro -\endcode - -\index LANG!Environment Variable -\index export!Unix Command -\index setenv!Unix Command - -This should create both \c tt2_fr.qm and \c tt2_nl.qm. Set the \c -LANG environment variable to \c fr. In Unix, one of the two following -commands should work - -\code - export LANG=fr - setenv LANG fr -\endcode - -\index - -\index autoexec.bat -\index set!Windows Command - -In Windows, either modify \c autoexec.bat or run - -\code - set LANG=fr -\endcode - -When you run the program, you should now see the French version: - -\img tt2_fr.png -\caption Tutorial 2 Screenshot, French version - -Try the same with Dutch, by setting \c LANG=nl. Now the Dutch -version should appear: - -\img tt2_nl.png -\caption Tutorial 2 Screenshot, Dutch version - -\section3 Exercises - -Mark one of the translations in \e {Qt Linguist} as not done, i.e. -by unchecking the "done" checkbox; run \l lupdate, then \l lrelease, -then the example. What effect did this change have? - -\index Canada -\index French Canada - -Set \c LANG=fr_CA (French Canada) and run the example program again. -Explain why the result is the same as with \c LANG=fr. - -Change one of the accelerators in the Dutch translation to eliminate the -conflict between \e \&Bestand and \e \&Boven. - - -\section2 Tutorial 3: Disambiguating Identical Strings - -\img tt3_10_en.png -\caption Tutorial 3 Screenshot, "Troll Print 1.0", English version - -\include tt3/tt3.pro -\caption \c tt3.pro - -\index Portuguese Language -\index Brazilian Language - -We've included a translation file, \c tt3_pt.ts, which contains some -Portuguese translations for this example. - -\index Troll Print - -We will consider two releases of the same application: Troll Print -1.0 and 1.1. We will learn to reuse the translations created for one -release in a subsequent release. (In this tutorial, you need to edit -some source files. It's probably best to copy all the files to a new -temporary directory and work from there.) - -Troll Print is a toy example application that lets the user choose -printer settings. It comes in two versions: English and Portuguese. - -Version 1.0 consists of these files: - -\index tt3.pro -\index tt3_pt.ts - -\list -\i \c printpanel.h contains the definition of PrintPanel; -\i \c printpanel.cpp contains the implementation of PrintPanel; -\i \c mainwindow.h contains the definition of \c MainWindow; -\i \c mainwindow.cpp contains the implementation of \c MainWindow; -\i \c main.cpp contains main(); -\i \c tt3.pro is the \e qmake project file. -\i \c tt3_pt.ts is the Portuguese message file. -\endlist - -\section3 Line by Line Walk-through - -The PrintPanel is defined in \c printpanel.h. - -\quotefile tt3/printpanel.h -\skipto QVBox -\printline QVBox -\printuntil Q_OBJECT - -\index Q_OBJECT - -\index PrintPanel!in Translation Tutorial - -PrintPanel is a \l QWidget. It needs the \c Q_OBJECT macro for \c -tr() to work properly. - -The implementation file is \c printpanel.cpp. - -\quotefile tt3/printpanel.cpp -\skipto setSpacing -\skipto / -\printline / -\printline -\printline -\printline - -\index Troll Print - -Some of the code is commented out in Troll Print 1.0; you will uncomment -it later, for Troll Print 1.1. - -\quotefile tt3/printpanel.cpp -\skipto twoSided -\printline twoSided -\printuntil toggle -\printline -\printuntil toggle - -Notice the two occurrences of \c tr("Enabled") and of \c -tr("Disabled") in PrintPanel. Since both "Enabled"s and "Disabled"s -appear in the same context \e {Qt Linguist} will only display one -occurrence of each and will use the same translations for the -duplicates that it doesn't display. Whilst this is a useful -timesaver, in some languages, such as Portuguese, the second -occurrence requires a separate translation. We will see how \e {Qt -Linguist} can be made to display all the occurrences for separate -translation shortly. - -\index MainWindow!in Translation Tutorial - -The header file for \c MainWindow, \c mainwindow.h, contains no -surprises. In the implementation, \c mainwindow.cpp, we have some -user-visible source texts that must be marked for translation. - -\quotefile tt3/mainwindow.cpp -\skipto setCaption -\printline setCaption - -We must translate the window's caption. - -\skipto quit -\printline quit -\printuntil Help - -We also need to translate the menu items. Note that the two argument -form of \c tr() is used for the keyboard accelerator, "Ctrl+Q", since -the second argument is the only clue the translator has to indicate -what function that accelerator will perform. - -\quotefile tt3/main.cpp -\skipto QTranslator -\printuntil installTranslator - -\index main() - -The \c main() function in \c main.cpp is the same as the one in \link -{Tutorial 2...} Tutorial 2 \endlink. In particular it chooses a -translation file based on the current locale. - -\section3 Running Troll Print 1.0 in English and in Portuguese - -We will use the translations in the \c tt3_pt.ts file that is provided. - -Set the \c LANG environment variable to \c pt, and then run \c tt3. -You should still see the English version, as shown in the \e -{Tutorial 3 Screenshot, "Troll Print 1.0", English version}, above. -Now run \l lrelease, e.g. \c {lrelease tt3.pro}, and then run the -example again. Now you should see the Portuguese edition (Troll -Imprimir 1.0): - -\img tt3_10_pt_bad.png -\caption Tutorial 3 Screenshot, "Troll Imprimir 1.0", (Bad) Portuguese version - -Whilst the translation has appeared correctly, it is in fact wrong. In -good Portuguese, the second occurrence of "Enabled" should be -"Ativadas", not "Ativado" and the ending for the second translation of -"Disabled" must change similarly too. - -If you open \c tt3_pt.ts using \e {Qt Linguist}, you will see that -there is just one occurrence of "Enabled" and of "Disabled" in the -translation source file, even though there are two of each in the -source code. This is because \e {Qt Linguist} tries to minimize the -translator's work by using the same translation for duplicate source -texts. In cases such as this where an identical translation is wrong, -the programmer must disambiguate the duplicate occurrences. This is -easily achieved by using the two argument form of \c tr(). - -We can easily determine which file must be changed because the -translator's "context" is in fact the class name for the class where -the texts that must be changed appears. In this case the file is \c -printpanel.cpp, where the there are four lines to change. Add the -second argument "two-sided" in the appropriate \c tr() calls to the -first pair of radio buttons: - -\code - but = new QRadioButton( tr("Enabled", "two-sided"), twoSided ); - but = new QRadioButton( tr("Disabled", "two-sided"), twoSided ); -\endcode - -and add the second argument "colors" in the appropriate \c tr() calls -for the second pair of radio buttons: - -\code - but = new QRadioButton( tr("Enabled", "colors"), colors ); - but = new QRadioButton( tr("Disabled", "colors"), colors ); -\endcode - -\index lupdate -\index tt3_pt.ts - -Now run \l lupdate and open \c tt3_pt.ts with \e {Qt Linguist}. You -should now see two changes. - -First, the translation source file now contains \e three "Enabled", -"Disabled" pairs. The first pair is marked "(obs.)" signifying that they -are obsolete. This is because these texts appeared in \c tr() calls that -have been replaced by new calls with two arguments. The second pair has -"two-sided" as their comment, and the third pair has "colors" as their -comment. The comments are shown in the \e {Source text and comments} -area in \e {Qt Linguist}. - -Second, the translation text "Ativado" and "Desativado" have been -automatically used as translations for the new "Enabled" and "Disabled" -texts, again to minimize the translator's work. Of course in this case -these are not correct for the second occurrence of each word, but they -provide a good starting point. - -Change the second "Ativado" into "Ativadas" and the second -"Desativado" into "Desativadas", then save and quit. Run \l lrelease -to obtain an up-to-date binary \c tt3_pt.qm file, and run Troll Print -(or rather Troll Imprimir). - -\img tt3_10_pt_good.png -\caption Tutorial 3 Screenshot, "Troll Imprimir 1.0", (Good) Portuguese version - -\index Translator Comments -\index Comments!for Translators - -The second argument to \c tr() calls, called "comments" in \e {Qt -Linguist}, distinguish between identical source texts that occur in -the same context (class). They are also useful in other cases to give -clues to the translator, and in the case of Ctrl key accelerators are -the only means of conveying the function performed by the accelerator to -the translator. - -\index TRANSLATOR!in Comments -\index Translator Comments -\index Comments!for Translators - -An additional way of helping the translator is to provide information on -how to navigate to the particular part of the application that contains -the source texts they must translate. This helps them see the context -in which the translation appears and also helps them to find and test -the translations. This can be achieved by using a \e TRANSLATOR comment -in the source code: -\code - /* TRANSLATOR MainWindow - - In this application the whole application is a MainWindow. - Choose Help|About from the menu bar to see some text - belonging to MainWindow. - */ -\endcode - -Try adding these comments to some source files, particularly to -dialog classes, describing the navigation necessary to reach the -dialogs. You could also add them to the example files, e.g. \c -mainwindow.cpp and \c printpanel.cpp are appropriate files. Run \l -lupdate and then start \e {Qt Linguist} and load in \c tt3_pt.ts. -You should see the comments in the \e {Source text and comments} area -as you browse through the list of source texts. - -Sometimes, particularly with large programs, it can be difficult for -the translator to find their translations and check that they're -correct. Comments that provide good navigation information can save -them time: - -\code - /* TRANSLATOR ZClientErrorDialog - - Choose Client|Edit to reach the Client Edit dialog, then choose - Client Specification from the drop down list at the top and pick - client Bartel Leendert van der Waerden. Now check the Profile - checkbox and then click the Start Processing button. You should - now see a pop up window with the text "Error: Name too long!". - This window is a ZClientErrorDialog. - */ -\endcode - - -\section3 Troll Print 1.1 - -We'll now prepare release 1.1 of Troll Print. Start your favorite text -editor and follow these steps: - -\list -\i Uncomment the two lines that create a \l QLabel with the text - "\<b\>TROLL PRINT\</b\>" in \c printpanel.cpp. -\i Word-tidying: Replace "2-sided" by "Two-sided" in \c printpanel.cpp. -\i Replace "1.0" with "1.1" everywhere it occurs in \c mainwindow.cpp. -\i Update the copyright year to 1999-2000 in \c mainwindow.cpp. -\endlist - -(Of course the version number and copyright year would be consts or -#defines in a real application.) - -Once finished, run \l lupdate, then open \c tt3_pt.ts in \e {Qt -Linguist}. The following items are of special interest: - -\list -\i \c MainWindow - \list - \i Troll Print 1.0 - marked "(obs.)", obsolete - \i About Troll Print 1.0 - marked "(obs.)", obsolete - \i Troll Print 1.0. Copyright 1999 Macroshaft, Inc. - - marked "(obs.)", obsolete - \i Troll Print 1.1 - automatically translated as - "Troll Imprimir 1.1" - \i About Troll Print 1.1 - automatically translated as - "Troll Imprimir 1.1" - \i Troll Print 1.1. Copyright 1999-2000 Macroshaft, - Inc. - automatically translated as "Troll Imprimir 1.1. - Copyright 1999-2000 Macroshaft, Inc." - \endlist -\i \c PrintPanel - \list - \i 2-sided - marked "(obs.)", obsolete - \i \<b\>TROLL PRINT\</b\> - unmarked, i.e. untranslated - \i Two-sided - unmarked, i.e. untranslated. - \endlist -\endlist - -Notice that \l lupdate works hard behind the scenes to make revisions -easier, and it's pretty smart with numbers. - -Go over the translations in \c MainWindow and mark these as "done". -Translate "\<b\>TROLL PRINT\</b\>" as "\<b\>TROLL IMPRIMIR\</b\>". -When you're translating "Two-sided", press the \e {Guess Again} -button to translate "Two-sided", but change the "2" into "Dois". - -Save and quit, then run \l lrelease. The Portuguese version -should look like this: - -\img tt3_11_pt.png -\caption Tutorial 3 Screenshot, "Troll Imprimir 1.1", Portuguese version - -Choose \e{Ajuda|Sobre}, (\e{Help|About}), to see the about box - -\img tt3_11_about_pt.png -\caption Tutorial 3 Screenshot, About box, Portuguese version - -\index English Language -\index Translating Qt -\index Qt!Translating Qt - -If you choose \e {Ajuda|Sobre Qt}, (\e {Help|About Qt}), you'll get -an English dialog. Oops! Qt itself needs to be translated. See the -document \link i18n.html#qt-itself Internationalization with Qt -\endlink for details. - -Now set \c LANG=en to get the original English version: - -\img tt3_11_en.png -\caption Tutorial 3 Screenshot, "Troll Print 1.1", English version - -\section2 Summary - -These tutorials cover all that you need to know to prepare your Qt -applications for translation. - -At the beginning of a project add the translation source files to be -used to the project file and add calls to \l lupdate and \l lrelease to -the make file. - -During the project all the programmer must do is wrap any user-visible -text in \c tr() calls. They should also use the two argument form for -Ctrl key accelerators, or when asked by the translator for the cases -where the same text translates into two different forms in the same -context. The programmer should also include \e TRANSLATION comments to -help the translator navigate the application. |