KDE Core/KLocale/Frameworks

KDE Frameworks 5 Migration

This page summarises the steps required for the migration from KLocale to Qlocale in KDE Frameworks 5.

Split Locale and Translations

KLocale merges localisation and translation. In Qt these are separate. In Frameworks we will follow this model and split KLocale into 2. We will use QLocale everywhere for the localisation methods. We will use QTranslator / tr() in the tier 1 libraries where translation needs should be simple, but still hook this into the KDE translators workflow. In KDE applications we will use KLocalizedString (or a replacement) and i18n().

A initial step has been made by replacing many #include <klocale.h> references with klocalizedstring.h when i18n() is the only function required by a class. Some other redundant includes will also be removed to leave only necessary code in place.

Later KLocalizedString (or replacement) will need porting to use QLocale instead of KLocale.

It should probably be made a requirement for all libraries migrated to the tiers that the KLocale => QLocale change is made.

Replace KDE Global Locale

KDE4 provides an app with its own KLocale instance which applies throughout the application instance and can be manipulated within that application instance. KGlobal::locale() returns the applications locale, which defaults to the KDE Locale unless overridden using KGlobal::setLocale() or the applications config file. This allows apps to seamlessly run with an alternative locale than the system locale and is a feature we need to retain.

Qt5 provides a System Locale and a Default Locale. Both are declared as global static variables in qlocale.ccp with file scope:

#ifndef QT_NO_SYSTEMLOCALE
QT_BEGIN_NAMESPACE
class QSystemLocale;
static QSystemLocale *QSystemLocale_globalSystemLocale();
QT_END_NAMESPACE
#endif

static const QLocalePrivate *default_lp = 0;
static uint default_number_options = 0;

The System Locale is what the system is currently set to and remains the same unless updated by the system, but the Default Locale can be changed by the application:

static void setDefault(const QLocale &locale);

void QLocale::setDefault(const QLocale &locale)
{
    default_lp = locale.d();
    default_number_options = locale.numberOptions();
}

This suggest the Qt Default Locale functions exactly the same as the KDE Global Locale in applying per application instance and will take the place of the KDE Global Locale.

To confirm:

• This does apply at application level
• This does apply to any Qt based libraries called by the application

The default QLocale() constructor returns the Qt Default Locale which is usually the System Locale unless changed using QLocale::setDefault(). QLocale::system() will always return the System Locale which may differ from the Default, so should be avoided unless explicitly required.

This implies that all code accessing KGlobal::locale().xxx() should simply be changed to be QLocale().yyy(). Due to the static privates the repeated construction should not be a performance issue, but apps can create a local var if needed, or we could request a QApplication::locale()?

Running with an envvar locale override will force Qt to override the system locale with the chosen locale under UNIX, behaviour under other platforms is unclear.

QLocale doesn't offer setXxx() api to allow apps to temporarily override a setting while running, and probably never will. Usually in KDE this is abused for things like temp changes to the date format when the normal format options api should be used, or a different locale object created.

For example:

KGlobal::locale()->setDateFormat("%y-%M-%d");
label = KGlobal::formatDate(myDate);

When it should be:

label = KGlobal::formatDate(myDate, "%y-%M-%d");

And under Qt5 will become:

label = QLocale().toString(myDate, "yyyy-MM-dd");

I doubt there are few if any valid use cases that can't be easily recoded. If the app wants say the date format to persist they can just save it in a local string and use that whenever they call the method.

Side-note: QLocale::setDefault() could be used in KDE4 Workspace with a custom QSystemLocale to force all Qt apps to use the KDE settings.

API Migration

While Qt 4.8 / Qt 5.0 provides most of the API needed, this are usually with very different method names, enums, and format codes. Some APi will not be available before Qt 5.1.

Migration is likely to be a very manual affair. A conversion table is provided below. Note method footprints are simplified for clarity.

The setters are documented at the bottom, most are not used anywhere, in the KDE repo. Only those setters that are used have conversions documented below.

Some interim migration tools may be required in a temporary class, such as ISO code conversions and splitLocale(), etc. The need for this can be assessed as we go.

This will be a lot of work for apps, so while frameworks switches to using QLocale directly, it may be desirable to provide a transition version of the KLocale api that uses QLocale as its backend and translates between the two.

For example, the app code:

label = KGlobal::locale()->formatDate(date, "%y-%M-%d);

could be replaced with:

label = K5Locale()->formatDate(date, "%y-%M-%d);

with K5Locale in turn translating the format string to the format required by QLocale::toString().

Locale

KLocale	Qt 5.0	Qt 5.1
KLocale(QString catalog, KSharedConfig::Ptr config)	Use QLocale() - Config no longer used - Set catalog in translation system
KLocale(QString catalog, QString language, QString country, KConfig *config)	QLocale(Language laanguage, Country country) - Config no longer used - Set catalog in translation system
void reparseConfiguration()	No longer used
static void splitLocale(QString locale, QString language, QString country, QString modifier, QString charset)	Not public, need to instantiate a locale and obtain that way.	Qt to be make public?

Countries

QLocale uses an enum value where KDE uses a QString ISO Code. Support may be added to Qt 5.1 to convert between the two, or this may be provided in the planned QtIsoCodes addon.

KLocale API	kdelibs usage	Qt 5.0	Qt 5.1
ISO codes as strings		enum Country	Conversion methods to be added
allCountriesList()	-	Not in Qt - loop from QLocale::AnyCountry to QLocale::LastCountry	Qt to add
QString country()	klocalizedstring.cpp	Country country() or name.split('_').at(1)	Provide ISO conversion methods
QString countryCodeToName(QString country)	Various	QString nativeCountryName() or QString countryToString(Country country)	Add nativeCountryName(Country country) ???
QString defaultCountry()	-	QLocale::C
bool setCountry(QString country, KConfig *config)	-	Create new instance QLocale(Language language, Country country)
QString countryDivisionCode () const	-
bool setCountryDivisionCode (const QString &countryDivision)	-

Languages

QLocale uses an enum value where KDE uses a QString ISO Code. Support may be added to Qt 5.1 to convert between the two, or this may be provided in the planned QtIsoCodes addon. Need some more thought with regard to localisation and translation split.

KLocale	kdelibs	Qt 5.0	Qt 5.1
ISO codes as strings		enum Language	Conversion methods to be added
QStringList allLanguagesList() const	kswitchlanguagedialog_p.cpp	None, loop from QLocale::AnyLanguage to QLocale::LastLanguage	To be added
QString language()	Various	Language language() or name.split('_').at(0)	Provide ISO conversion methods
QString languageCodeToName(QString language)	Various	nativeLanguageName() or English languageToString(Language language)	Add nativeLanguageName(Language language) ???
QStringList languageList()	Various	uiLanguages()
static QString defaultLanguage()	Various	QLocale::C
bool setLanguage(QStringList languages)	kswitchlanguagedialog_p.cpp		KDE Platform module
bool setLanguage(const QString &language, KConfig *config)	-	Create new QLocale(Language language, Country country)

Calendar / Date / Time

Note that formatDate() and readDate() should actually be accessed via the calendar() instance or KLocalizedDate and these will be documented separately.

KLocale API	kdelibs usage	Qt 5.0	Qt 5.1
enum CalendarSystem
enum DateFormat
enum DateTimeComponent
enum DateTimeComponentFormat
enum DateTimeFormatOption
enum DateTimeFormatStandard
enum DateTimeParseMode
enum ReadDateFlags
enum ReadTimeFlags
enum TimeFormatOption
enum TimeProcessingOption
enum WeekNumberSystem
KCalendarSystem *calendar()
CalendarSystem calendarSystem()	Only calendar related classes	-	Should be added
void setCalendarSystem(CalendarSystem calendarSystem)	Only calendar related classes	-	Use api parm
QString calendarType()	Deprecated	-	-
void setCalendar(QString calendarType)	Deprecated	-	-
QString dateFormat()	Only calendar related classes	QString dateFormat() - but different formats!	QString dateFormat(FullPattern) - but different formats!
void setDateFormat(QString format)	Only calendar related classes	Use api parm
QString dateFormatShort()	Only calendar related classes	QString dateFormat(ShortFormat) - but different formats!	QString dateFormat(ShortPattern) - but different formats!
void setDateFormatShort(QString format)	Only calendar related classes	Use api parm
QString timeFormat()	Only calendar related classes	QString timeFormat() - but different formats!	QString timeFormat(FullPattern) - but different formats!
void setTimeFormat(QString format)	Only calendar related classes	Use api parm
bool dateMonthNamePossessive()	Only calendar related classes	Remove
QString dayPeriodText(QTime &time, DateTimeComponentFormat format)	Only calendar related classes	amText() and pmText()	New Qt dayPeriodText() api
int weekDayOfPray()	Only calendar related classes	Remove, try replace with weekend days instead
WeekNumberSystem weekNumberSystem()	Only calendar related classes	Not supported	New Qt api
int weekStartDay()	Only calendar related classes	QList<Qt::DayOfWeek> weekdays()
void setWeekStartDay(int day)	-	-	Use new api parm
int workingWeekEndDay()	Only calendar related classes	QList<Qt::DayOfWeek> weekdays()
int workingWeekStartDay()	Only calendar related classes	QList<Qt::DayOfWeek> weekdays()
bool use12Clock()	-	Remove
QString formatDate(QDate date, DateFormat format)	templateinterface.cpp, khtmlview.cpp, knewstuff2/ui/itemsview.cpp	QString toString(QDate date, FormatType format)	QString toString(QDate date, FormatPattern format)
QDate readDate(QString str, bool *ok)	kdatetable.cpp	QDate toDate(QString string, FormatType format) - for ok uses date.isValid()	QDate toDate(QString string, FormatPattern format) - for ok uses date.isValid()
QDate readDate(QString intstr, const QString fmt, bool *ok)	-	QDate toDate(QString string, QString format) - for ok uses date.isValid() - different formats!
QDate readDate(QString str, ReadDateFlags flags, bool *ok)	-	Not supported, use other methods	New Qt api
QString formatLocaleTime(QTime pTime, TimeFormatOptions options)	-	QString toString(QTime time, QString format) or QString toString(QTime time, FormatType format)	New Qt api???
QTime readLocaleTime(QString str, bool *ok, TimeFormatOptions options, TimeProcessingOptions processing)	-	QTime toTime(QString string, FormatType format) or QTime toTime(QString string, QString format)	New Qt api???
QString formatTime(QTime pTime, bool includeSecs, bool isDuration)	ktexteditor/templateinterface.cpp, ktimecombobox.cpp, kio/global.cpp	QString toString(QTime time, QString format) or QString toString(QTime time, FormatType format)	New Qt api???
QTime readTime(QString str, bool *ok)	ktimecombobox.cpp	QTime toTime(QString string, FormatType format) or QTime toTime(QString string, QString format)	New Qt api???
QTime readTime(QString str, ReadTimeFlags flags, bool *ok)	-	QTime toTime(QString string, FormatType format) or QTime toTime(QString string, QString format)	New Qt api???
QString formatDuration(unsigned long mSec)	-	Not supported	New Qt api
QString prettyFormatDuration(unsigned long mSec)	kdeui/jobs/kwidgetjobtracker.cpp	Not supported	New Qt api
QString formatDateTime(QDateTime dateTime, DateFormat format, bool includeSecs)	Various	QString toString(QDateTime dateTime, FormatType format)	QString toString(QDateTime dateTime, FormatPattern format)
QString formatDateTime(KDateTime dateTime, DateFormat format, DateTimeFormatOptions options)	-	???	???

Numbers

Note that the QString methods now only apply the C locale, to localise properly you must use the QLocale methods.

KLocale	kdelibs	Qt 5.0	Qt 5.1
int decimalPlaces()	-	Not in Qt	Add to Qt
void setDecimalPlaces(int digits)	-	Use precision parm of toString() methods - note defaults to 6 places!	-
QString decimalSymbol()	kdatetime.cpp, knumvalidator.h, knumvalidator.cpp	QChar decimalPoint()	Add to Qt
QString negativeSign()	knumvalidator.h, knumvalidator.cpp	QChar negativeSign()	Add to Qt
QString positiveSign()	knumvalidator.h, knumvalidator.cpp	QChar positiveSign()	Add to Qt
QString thousandsSeparator()	knumvalidator.h, knumvalidator.cpp	QChar groupSeparator()	Add to Qt
QString formatLong(long num)	kio/kfileitemdelegate.cpp
QString formatNumber(double num, int precision)	About 9 uses
QString formatNumber(QString numStr, bool round, int precision)	None?
double readNumber(QString numStr, bool *ok)	kfontchooser.cpp

Currency / Money

Basic functions supported in Qt 5.0, more in 5.1, advanced features of KCurrencyCode to be moved to new QtIsoCodes library.

KLocale	kdelibs	Qt 5.0	Qt 5.1
KCurrencyCode *currency()
QString currencyCode()
static QString defaultCurrencyCode()
QStringList currencyCodeList()
QString currencySymbol()
int monetaryDecimalPlaces()
QString monetaryDecimalSymbol()
QString monetaryThousandsSeparator()
SignPosition negativeMonetarySignPosition()
bool negativePrefixCurrencySymbol()
SignPosition positiveMonetarySignPosition()
bool positivePrefixCurrencySymbol()
QString formatMoney(double num, QString currency, int precision)
double readMoney(QString numStr, bool *ok)

Digit Sets

Not supported directly in Qt 5.0, some conversion happens implicitly, defer to 5.1 if really needed. In ICU fully supported implicitly.

KLocale	kdelibs	Qt 5.0	Qt 5.1
QList<DigitSet> allDigitSetsList()
DigitSet digitSet()
DigitSet monetaryDigitSet()
DigitSet dateTimeDigitSet()
QString digitSetToName(DigitSet digitSet, bool withDigits)
QString convertDigits(const QString &str, DigitSet digitSet, bool ignoreContext)

Binary Units

Not supported in QLocale or ICU. Should be able to add api to Qt 5.1. May require transition code independent from KLocale?

KLocale	kdelibs	Qt 5.0	Qt 5.1
enum BinarySizeUnits
enum BinaryUnitDialect
BinaryUnitDialect binaryUnitDialect()
QString formatByteSize(double size)
QString formatByteSize(double size, int precision, BinaryUnitDialect dialect, BinarySizeUnits specificUnit)

Measurement Systems

KLocale::pageSize() is widely misunderstood in KDE to mean the printers default paper size, i.e. what is actually in the printer, which should come from QPrnterInfo instead. It is actually the default page size for apps like KWord to use. No equivalent in QLocale but is in CLDR/ICU so will be added to Qt. In the interim the measure system could be an analog, i.e. Imperial = Letter, otherwise A4.

Need more checks on use of setPageSize, many false positives from QPrinter.

KLocale	kdelibs	Qt 5.0	Qt 5.1
enum MeasureSystem { Metric, Imperial }		enum MeasurementSystem { MetricSystem, ImperialSystem }
MeasureSystem measureSystem()	None	MeasurementSystem measurementSystem()
int pageSize()	None	Not in Qt, use meaurementSystem() == ImperialSystem as analog	Add to Qt
void setPageSize(int paperFormat)		Not in Qt

Encoding

Not too sure if this belongs in Locale or Translation? Is this something for QString?

KLocale	kdelibs	Qt 5.0	Qt 5.1
QTextCodec *codecForEncoding()
const QByteArray encoding()
bool setEncoding(int mibEnum)
int encodingMib()
int fileEncodingMib()

Translations

Replace with QTranslator / tr() at lowest level, or new KTranslator at higher level.

KLocale	kdelibs	Qt 5.0	Qt 5.1
QStringList installedLanguages()
bool isApplicationTranslatedInto(QString language)
bool useTranscript()
QString localizedFilePath(QString filePath)
static QString langLookup(QString fname, const char *rtype)
bool nounDeclension()
QString removeAcceleratorMarker(QString label)
void copyCatalogsTo(KLocale *locale)
void insertCatalog(QString catalog)
void removeCatalog(QString catalog)
void setActiveCatalog(QString catalog)
static void setMainCatalog(const char *catalog)
QString translateQt(const char *context, const char *sourceText, const char *comment)
void translateRaw(const char *singular, const char *plural, unsigned long n, QString *lang, QString *trans)
void translateRaw(const char *ctxt, const char *singular, const char *plural, unsigned long n, QString *lang, QString *trans)
void translateRaw(const char *msg, QString *lang, QString *trans)
void translateRaw(const char *ctxt, const char *msg, QString *lang, QString *trans)
void translateRawFrom(const char *catname, const char *msg, QString *lang, QString *trans)
void translateRawFrom(const char *catname, const char *singular, const char *plural, unsigned long n, QString *lang, QString *trans)
void translateRawFrom(const char *catname, const char *ctxt, const char *msg, QString *lang, QString *trans)
void translateRawFrom(const char *catname, const char *ctxt, const char *singular, const char *plural, unsigned long n, QString *lang, QString *trans)

Setters Usage

Search using lxr of all places using KLocale setters.

Many hits, need more checks:

setCountry()
setEncoding()
setLanguage()
setLanguage()
setPageSize()

Some uses, most are very simple to port away in KDE 4.9:

setCalendar() - Date widgets, etc
setCalendarSystem() - Date widgets, etc
setDateFormat() - Some uses
setDateFormatShort() - Clock Applet
setTimeFormat() - Some uses
setWeekStartDay() - KMyMoney

No real code, only kcm and tests

setBinaryUnitDialect()
setCountryDivisionCode()
setCurrencyCode()
setCurrencySymbol()
setDateMonthNamePossessive()
setDateTimeDigitSet()
setDecimalPlaces()
setDecimalSymbol()
setDigitSet()
setFracDigits()
setMeasureSystem()
setMonetaryDecimalPlaces()
setMonetaryDecimalSymbol()
setMonetaryDigitSet()
setMonetaryThousandsSeparator()
setNegativeMonetarySignPosition()
setNegativePrefixCurrencySymbol()
setNegativeSign()
setPositiveMonetarySignPosition()
setPositivePrefixCurrencySymbol()
setPositiveSign()
setThousandsSeparator()
setWeekDayOfPray()
setWeekNumberSystem()
setWorkingWeekEndDay()
setWorkingWeekStartDay()