QTranslator(3qt)QTranslator(3qt)NAME
QTranslator -
SYNOPSIS
#include <qtranslator.h>
Inherits QObject.
Public Members
QTranslator ( QObject * parent = 0, const char * name = 0 )
~QTranslator ()
QString find ( const char * context, const char * sourceText, const
char * comment = 0 ) const (obsolete)
virtual QTranslatorMessage findMessage ( const char * context, const
char * sourceText, const char * comment = 0 ) const
bool load ( const QString & filename, const QString & directory =
QString::null, const QString & search_delimiters = QString::null,
const QString & suffix = QString::null )
bool load ( const uchar * data, int len )
void clear ()
enum SaveMode { Everything, Stripped }
bool save ( const QString & filename, SaveMode mode = Everything )
void insert ( const QTranslatorMessage & message )
void insert ( const char * context, const char * sourceText, const
QString & translation ) (obsolete)
void remove ( const QTranslatorMessage & message )
void remove ( const char * context, const char * sourceText )
(obsolete)
bool contains ( const char * context, const char * sourceText, const
char * comment = 0 ) const
void squeeze ( SaveMode mode = Everything )
void unsqueeze ()
QValueList<QTranslatorMessage> messages () const
bool isEmpty () 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
translations, add new ones, remove them, load and save them, etc.
The most common use of QTranslator is to: load a translator file
created with Qt Linguist, install it using
QApplication::installTranslator(), and use it via QObject::tr(). For
example:
int main( int argc, char ** argv )
{
QApplication app( argc, argv );
QTranslator translator( 0 );
translator.load( "french.qm", "." );
app.installTranslator( &translator );
MyWidget m;
app.setMainWidget( &m );
m.show();
return app.exec();
}
Note that the translator must be created before the application's main
window.
Most applications will never need to do anything else with this class.
The other functions provided by this class are useful for applications
that work on translator files.
We call a translation a "messsage". For this reason, translation files
are sometimes referred to as "message files".
It is possible to lookup a translation using findMessage() (as tr() and
QApplication::translate() do) and contains(), to insert a new
translation messsage using insert(), and to remove one using remove().
Translation tools often need more information than the bare source text
and translation, for example, context information to help the
translator. But end-user programs that are using translations usually
only need lookup. To cater for these different needs, QTranslator can
use stripped translator files that use the minimum of memory and which
support little more functionality 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 to save 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 - usually the argument to tr().
The context - usually the class name for the tr() caller.
The comment - a comment that helps disambiguate different uses of the
same text in the same context.
The minimum for each item is just the information necessary for
findMessage() to return the right text. This may include the source,
context and comment, but usually it 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 this case the source text would be"
Cancel"). The context would (normally) be 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 enables 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(),
QApplication::translate(), Environment Classes, and
Internationalization with Qt.
Member Type Documentation
QTranslator::SaveMode
This enum type defines how QTranslator writes translation files. There
are two modes:
QTranslator::Everything - files are saved with all available
information
QTranslator::Stripped - files are saved with just enough information
for end-user applications
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 = 0, const char * name = 0 )
Constructs an empty message file object that is not connected to any
file. The object is called name with parent parent.
QTranslator::~QTranslator ()
Destroys the object and frees any allocated resources.
void QTranslator::clear ()
Empties this translator of all contents.
This function works with stripped translator files.
bool QTranslator::contains ( const char * context, const char * sourceText,
const char * comment = 0 ) const
Returns TRUE if this message file contains a message with the key
(context, sourceText, comment); otherwise returns FALSE.
This function works with stripped translator files.
(This is is a one-liner that calls findMessage().)
QString QTranslator::find ( const char * context, const char * sourceText,
const char * comment = 0 ) const
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
Please use findMessage() instead.
Returns the translation for the key (context, sourceText, comment) or
QString::null if there is none in this translator.
QTranslatorMessage QTranslator::findMessage ( const char * context, const char
* sourceText, const char * comment = 0 ) const [virtual]
Returns the QTranslatorMessage for the key (context, sourceText,
comment). If none is found, also tries (context, sourceText, "").
void QTranslator::insert ( const QTranslatorMessage & message )
Inserts message into this message file.
This function does not work with stripped translator files. It may
appear to, but that is not dependable.
See also remove().
void QTranslator::insert ( const char * context, const char * sourceText,
const QString & translation )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
bool QTranslator::isEmpty () const
Returns TRUE if this translator is empty, otherwise returns FALSE. This
function works with stripped and unstripped translation files.
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. The previous contents of this translator object is
discarded. Returns TRUE if the file is loaded successfully; otherwise
returns FALSE.
If the full file name does not exist, other file names are tried in the
following order:
<ol type=1>
File name with suffix appended (".qm" if the suffix is QString::null).
File name with text after a character in search_delimiters stripped
("_." is the default for search_delimiters if it is QString::null).
File name stripped and suffix appended.
File name stripped further, etc.
For example, an application running in the fr_CA locale (French-
speaking Canada) might call load("foo.fr_ca"," /opt/foolib"). load()
would then try to open the first existing readable file from this list:
<ol type=1>
/opt/foolib/foo.fr_ca
/opt/foolib/foo.fr_ca.qm
/opt/foolib/foo.fr
/opt/foolib/foo.fr.qm
/opt/foolib/foo
/opt/foolib/foo.qm
See also save().
Example: i18n/main.cpp.
bool QTranslator::load ( const uchar * data, int len )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Loads the .qm file data data of length len into the translator. Returns
TRUE if the data is loaded successfully; otherwise returns FALSE.
The data is not copied. The caller must be able to guarantee that data
will not be deleted or modified.
QValueList<;QTranslatorMessage> QTranslator::messages () const
Returns a list of the messages in the translator. This function is
rather slow. Because it is seldom called, it's optimized for simplicity
and small size, rather than speed.
If you want to iterate over the list, you should iterate over a copy,
e.g.
QValueList<QTranslatorMessage> list = myTranslator.messages();
QValueList<QTranslatorMessage>::Iterator it = list.begin();
while ( it != list.end() ) {
process_message( *it );
++it;
}
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 is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
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 (the default), all the information
is preserved. If mode is Stripped, any information that is not
necessary for findMessage() is stripped away.
See also load().
void QTranslator::squeeze ( SaveMode mode = Everything )
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. mode is for internal use.
See also save() and unsqueeze().
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 1992-2007 Trolltech ASA, 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 help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with a
web browser. This man page is provided as a convenience for those users
who prefer man pages, although this format is not officially supported
by Trolltech.
If you find errors in 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 (3.3.8).
Trolltech AS 2 February 2007 QTranslator(3qt)
