QTranslator(3qt)QTranslator(3qt)NAME
QTranslator - Internationalization support for text output
#include <qtranslator.h>
Inherits QObject.
Public Members
QTranslator ( QObject * parent, const char * name = 0 )
~QTranslator ()
QString find ( const char *, const char *, const char * )
const
virtual QString find ( const char *, const char * ) const
(obsolete)
QTranslatorMessage findMessage ( const char *, const char
*, const char * ) const
bool load ( const QString & filename, const QString &
directory = QString::null, const QString &
search_delimiters = QString::null, const QString &
suffix = QString::null )
enum SaveMode { Everything, Stripped }
bool save ( const QString & filename, SaveMode mode =
Everything )
void clear ()
void insert ( const QTranslatorMessage & )
void insert ( const char *, const char *, const QString &
) (obsolete)
void remove ( const QTranslatorMessage & )
void remove ( const char *, const char * ) (obsolete)
bool contains ( const char *, const char *, const char * )
const
bool contains ( const char *, const char * ) const
(obsolete)
void squeeze ( SaveMode )
void squeeze ()
void unsqueeze ()
QValueList<QTranslatorMessage> messages () const
DESCRIPTION
The QTranslator class provides internationalization
support for text output.
An object of this class contains a set of
QTranslatorMessage objects, each of which specifies a
translation from a source language to a target language.
QTranslator provides functions to look up such
translations, add new ones, remove, load and save them,
etc.
The most common use of QTranslator is expected to be
loading a translator file, installing it using
QApplication::installTranslator(), and using it via
QObject::tr(), like this:
Trolltech AS 13 June 2001 1
QTranslator(3qt)QTranslator(3qt)
int main( int argc, char ** argv )
{
QApplication app( argc, argv );
QTranslator translator( 0 );
translator.load( "trfile.qm", "." );
app.installTranslator( &translator );
MyWidget m;
app.setMainWidget( &m );
m.show();
return app.exec();
}
Most applications will never need to do anything else with
this class. However, applications that work on translator
files need the other functions in this class.
It is possible to do lookup using findMessage() (as tr()
and QApplication::translate() do) and contains(), insert a
new translation message using insert() and removing them
using remove().
Since end-user programs and translation tools have rather
different requirements, QTranslator can use stripped
translator files in a way that uses a minimum of memory
and provides very little functionality other than
findMessage().
Thus, load() may not load enough information to make
anything more than findMessage() work. save() has an
argument indicating whether to save just this minimum of
information, or everything.
Everything means that for each translation item the
following information is kept:
The translated text - the return value from tr().
The input key:
The source text - the argument to tr(), normally.
The context - usually the class name for the tr() caller.
The comment - a comment which helps disambiguate different
uses of the same text in the same context.
The minimum is, for each item, just the information that
is necessary for findMessage() to return the right text.
This may include the source, context and comment, but
usually is just a hash value and the translated text.
For example, the "Cancel" in a dialog might have "Anuluj"
when the program runs in Polish, in which case the source
text would be" Cancel", the context would (normally) be
Trolltech AS 13 June 2001 2
QTranslator(3qt)QTranslator(3qt)
the dialog's class name, there would normally be no
comment, and the translated text would be" Anuluj".
But it's not always so simple: The Spanish version of a
printer dialog with settings for two-sided printing and
binding would probably require both "Activado" and
"Activada" as translations for" Enabled". In this case,
the source text would be "Enabled" in both cases and the
context would be the dialog's class name, but the two
items would have disambiguating comments such as "two-
sided printing" for one and "binding" for the other. The
comment enables the translator to choose the appropriate
gender for the Spanish version, and Qt to distinguish
between translations.
Note that when QTranslator loads a stripped file, most
functions do not work. The functions that do work with
stripped files are explicitly documented as such.
See also QTranslatorMessage,
QApplication::installTranslator(),
QApplication::removeTranslator(), QObject::tr() and
QApplication::translate().
Examples: i18n/main.cpp
Member Type Documentation
QTranslator::SaveMode
This enum type defines how QTranslator can write
translation files. There are two modes:
Everything - files are saved with all contents
Stripped - files are saved with just what's needed for
end-users
Note that when QTranslator loads a stripped file, most
functions do not work. The functions that do work with
stripped files are explicitly documented as such.
MEMBER FUNCTION DOCUMENTATIONQTranslator::QTranslator ( QObject * parent, const char * name =
0 )
Constructs an empty message file, not connected to any
file.
QTranslator::~QTranslator ()
Destructs the object and frees any allocated resources.
void QTranslator::clear ()
Empties this translator of all contents.
This function works with stripped translator files.
Trolltech AS 13 June 2001 3
QTranslator(3qt)QTranslator(3qt)bool QTranslator::contains ( const char * context, const char *
sourceText, const char * comment ) const
Returns TRUE if this message file contains a message with
the key ( context, sourceText, comment ), and FALSE if it
does not.
This function works with stripped translator files.
(This is is a one-liner that calls find().).
bool QTranslator::contains ( const char * context, const char *
sourceText ) const
This function is obsolete. It is provided to keep old
source working, and will probably be removed in a future
version of Qt. We strongly advise against using it in new
code.
This is an overloaded member function, provided for
convenience. It differs from the above function only in
what argument(s) it accepts.
This version of the function assumes that the comment is
"".
QString QTranslator::find ( const char * context, const char *
sourceText, const char * comment ) const
Returns the translation for the key ( context, sourceText,
comment ), or QString::null if there is none in this
translator.
This function works with stripped translator files.
See also findMessage.
QString QTranslator::find ( const char * context, const char *
sourceText ) const [virtual]
This function is obsolete. It is provided to keep old
source working, and will probably be removed in a future
version of Qt. We strongly advise against using it in new
code.
This is an overloaded member function, provided for
convenience. It differs from the above function only in
what argument(s) it accepts.
Returns the translation for the key ( context, sourceText,
"" ), or QString::null if there is none in this
translator.
QTranslatorMessage QTranslator::findMessage ( const char *
context, const char * sourceText, const char * comment )
const
Returns the QTranslatorMessage for the key ( context,
sourceText, comment ).
Trolltech AS 13 June 2001 4
QTranslator(3qt)QTranslator(3qt)void QTranslator::insert ( const QTranslatorMessage & message )
Inserts message into this message file.
This function does not work with stripped translator
files. It may seem to, but that is not dependable.
See also remove().
void QTranslator::insert ( const char * context, const char *
sourceText, const QString & translation )
This function is obsolete. It is provided to keep old
source working, and will probably be removed in a future
version of Qt. We strongly advise against using it in new
code.
This is an overloaded member function, provided for
convenience. It differs from the above function only in
what argument(s) it accepts.
bool QTranslator::load ( const QString & filename, const QString
& directory = QString::null, const QString &
search_delimiters = QString::null, const QString & suffix
= QString::null )
Loads filename, which may be an absolute file name or
relative to directory. If the full filename does not
exist, other filenames are tried in the following order:
1 Filename with suffix appended (".qm" if suffix is
QString::null)
2 Filename with text after a character in
search_delimiters stripped ("_." is the default for
search_delimiters if it is QString::null)
3 Filename stripped and suffix appended.
4 Filename stripped further, etc.
For example, an application running in the fr_CA locale
(Frech-speaking Canada) might call load("foo.fr_ca",
"/opt/foolib"), which would then try to open these files:
1 /opt/foolib/foo.fr_ca
2 /opt/foolib/foo.fr_ca.qm
3 /opt/foolib/foo.fr
4 /opt/foolib/foo.fr.qm
5 /opt/foolib/foo
6 /opt/foolib/foo.qm
Trolltech AS 13 June 2001 5
QTranslator(3qt)QTranslator(3qt)
See also save().
QValueList<;QTranslatorMessage> QTranslator::messages () const
Returns a list of the messages in the translator. This
function is somewhat slow; since it's seldom called it's
optimized for simplicity and small size, not speed.
void QTranslator::remove ( const QTranslatorMessage & message )
Removes message from this translator.
This function works with stripped translator files.
See also insert().
void QTranslator::remove ( const char * context, const char *
sourceText )
This function is obsolete. It is provided to keep old
source working, and will probably be removed in a future
version of Qt. We strongly advise against using it in new
code.
This is an overloaded member function, provided for
convenience. It differs from the above function only in
what argument(s) it accepts.
Removes the translation associated to the key ( context,
sourceText," " ) from this translator.
bool QTranslator::save ( const QString & filename, SaveMode mode
= Everything )
Saves this message file to filename, overwriting the
previous contents of filename. If mode is Everything (this
is the default), all the information is preserved. If mode
is Stripped, all information that is not necessary for
findMessage() is stripped away.
See also load().
void QTranslator::squeeze ( SaveMode mode )
Converts this message file to the compact format used to
store message files on disk.
You should never need to call this directly; save() and
other functions call it as necessary.
See also save() and unsqueeze().
void QTranslator::squeeze ()
This is an overloaded member function, provided for
convenience. It differs from the above function only in
what argument(s) it accepts.
This function calls squeeze( Everything ). It is provided
for compatibility; in Qt 3.0 it will be replaced by a
Trolltech AS 13 June 2001 6
QTranslator(3qt)QTranslator(3qt)
default argument.
void QTranslator::unsqueeze ()
Converts this message file into an easily modifiable data
structure, less compact than the format used in the files.
You should never need to call this function; it is called
by insert() and friends as necessary.
See also squeeze().
SEE ALSO
http://doc.trolltech.com/qtranslator.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS,
http://www.trolltech.com. See the license file included
in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports
make our job much simpler. Thank you.
In case of content or formattting problems with this
manual page, please report them to qt-bugs@trolltech.com.
Please include the name of the manual page
(qtranslator.3qt) and the Qt version (2.3.1).
Trolltech AS 13 June 2001 7
