Qt 6.x
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QWindowsDirectWriteFontDatabase Class Reference

#include <qwindowsdirectwritefontdatabase_p.h>

+ Inheritance diagram for QWindowsDirectWriteFontDatabase:
+ Collaboration diagram for QWindowsDirectWriteFontDatabase:

Public Member Functions

 QWindowsDirectWriteFontDatabase ()
 
 ~QWindowsDirectWriteFontDatabase () override
 
void populateFontDatabase () override
 This function is called once at startup by Qt's internal font database.
 
void populateFamily (const QString &familyName) override
 This function is called whenever a lazily populated family, populated through registerFontFamily(), needs full population.
 
QFontEnginefontEngine (const QFontDef &fontDef, void *handle) override
 Returns the font engine that can be used to render the font described by the font definition, fontDef, in the specified script.
 
QStringList fallbacksForFamily (const QString &family, QFont::Style style, QFont::StyleHint styleHint, QChar::Script script) const override
 Returns a list of alternative fonts for the specified family and style and script using the styleHint given.
 
QStringList addApplicationFont (const QByteArray &fontData, const QString &fileName, QFontDatabasePrivate::ApplicationFont *font=nullptr) override
 Adds an application font described by the font contained supplied fontData or using the font contained in the file referenced by fileName.
 
void releaseHandle (void *handle) override
 Releases the specified font handle.
 
QFont defaultFont () const override
 Returns the default system font.
 
bool fontsAlwaysScalable () const override
 Return true if all fonts are considered scalable when using this font database.
 
bool isPrivateFontFamily (const QString &family) const override
 Returns true if the font family is private.
 
- Public Member Functions inherited from QWindowsFontDatabaseBase
 QWindowsFontDatabaseBase ()
 
 ~QWindowsFontDatabaseBase () override
 
QFontEnginefontEngine (const QFontDef &fontDef, void *handle) override
 Returns the font engine that can be used to render the font described by the font definition, fontDef, in the specified script.
 
QFontEnginefontEngine (const QByteArray &fontData, qreal pixelSize, QFont::HintingPreference hintingPreference) override
 Returns the font engine that will be used to back a QRawFont, based on the given \fontData, pixelSize, and hintingPreference.
 
QFontDef sanitizeRequest (QFontDef request) const
 
- Public Member Functions inherited from QPlatformFontDatabase
virtual ~QPlatformFontDatabase ()
 
virtual void populateFontDatabase ()
 This function is called once at startup by Qt's internal font database.
 
virtual bool populateFamilyAliases (const QString &missingFamily)
 
virtual void populateFamily (const QString &familyName)
 This function is called whenever a lazily populated family, populated through registerFontFamily(), needs full population.
 
virtual void invalidate ()
 This function is called whenever the font database is invalidated.
 
virtual QStringList fallbacksForFamily (const QString &family, QFont::Style style, QFont::StyleHint styleHint, QChar::Script script) const
 Returns a list of alternative fonts for the specified family and style and script using the styleHint given.
 
virtual QStringList addApplicationFont (const QByteArray &fontData, const QString &fileName, QFontDatabasePrivate::ApplicationFont *font=nullptr)
 Adds an application font described by the font contained supplied fontData or using the font contained in the file referenced by fileName.
 
virtual QFontEnginefontEngine (const QFontDef &fontDef, void *handle)
 Returns the font engine that can be used to render the font described by the font definition, fontDef, in the specified script.
 
virtual QFontEnginefontEngine (const QByteArray &fontData, qreal pixelSize, QFont::HintingPreference hintingPreference)
 Returns the font engine that will be used to back a QRawFont, based on the given \fontData, pixelSize, and hintingPreference.
 
virtual QFontEngineMultifontEngineMulti (QFontEngine *fontEngine, QChar::Script script)
 Returns a multi font engine in the specified script to encapsulate fontEngine with the option to fall back to the fonts given by fallbacks if fontEngine does not support a certain character.
 
virtual void releaseHandle (void *handle)
 Releases the specified font handle.
 
virtual QString fontDir () const
 Returns the directory containing the fonts used by the database.
 
virtual QFont defaultFont () const
 Returns the default system font.
 
virtual bool isPrivateFontFamily (const QString &family) const
 Returns true if the font family is private.
 
virtual QString resolveFontFamilyAlias (const QString &family) const
 Resolve alias to actual font family names.
 
virtual bool fontsAlwaysScalable () const
 Return true if all fonts are considered scalable when using this font database.
 
virtual QList< int > standardSizes () const
 Return list of standard font sizes when using this font database.
 

Additional Inherited Members

- Static Public Member Functions inherited from QWindowsFontDatabaseBase
static int defaultVerticalDPI ()
 
static QSharedPointer< QWindowsFontEngineDatadata ()
 
static QFont systemDefaultFont ()
 
static HFONT systemFont ()
 
static LOGFONT fontDefToLOGFONT (const QFontDef &fontDef, const QString &faceName)
 
static QFont LOGFONT_to_QFont (const LOGFONT &lf, int verticalDPI=0)
 
static QString familyForStyleHint (QFont::StyleHint styleHint)
 
static QStringList extraTryFontsForFamily (const QString &family)
 
- Static Public Member Functions inherited from QPlatformFontDatabase
static QSupportedWritingSystems writingSystemsFromTrueTypeBits (quint32 unicodeRange[4], quint32 codePageRange[2])
 Helper function that determines the writing systems support by a given unicodeRange and codePageRange.
 
static QSupportedWritingSystems writingSystemsFromOS2Table (const char *os2Table, size_t length)
 Helper function that determines the writing system support based on the contents of the OS/2 table in the font.
 
static void registerFont (const QString &familyname, const QString &stylename, const QString &foundryname, QFont::Weight weight, QFont::Style style, QFont::Stretch stretch, bool antialiased, bool scalable, int pixelSize, bool fixedPitch, const QSupportedWritingSystems &writingSystems, void *handle)
 Registers a font with the given set of attributes describing the font's foundry, family name, style and stretch information, pixel size, and supported writing systems.
 
static void registerFontFamily (const QString &familyName)
 Registers a font family with the font database.
 
static void registerAliasToFontFamily (const QString &familyName, const QString &alias)
 Helper function that register the alias for the familyName.
 
static void repopulateFontDatabase ()
 Requests that the platform font database should be repopulated.
 
static bool isFamilyPopulated (const QString &familyName)
 Helper function that returns true if the font family has already been registered and populated.
 

Detailed Description

Definition at line 33 of file qwindowsdirectwritefontdatabase_p.h.

Constructor & Destructor Documentation

◆ QWindowsDirectWriteFontDatabase()

QWindowsDirectWriteFontDatabase::QWindowsDirectWriteFontDatabase ( )

Definition at line 21 of file qwindowsdirectwritefontdatabase.cpp.

References qCDebug.

◆ ~QWindowsDirectWriteFontDatabase()

QWindowsDirectWriteFontDatabase::~QWindowsDirectWriteFontDatabase ( )
override

Definition at line 26 of file qwindowsdirectwritefontdatabase.cpp.

References QHash< Key, T >::begin(), QHash< Key, T >::end(), and it.

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Member Function Documentation

◆ addApplicationFont()

QStringList QWindowsDirectWriteFontDatabase::addApplicationFont ( const QByteArray fontData,
const QString fileName,
QFontDatabasePrivate::ApplicationFont applicationFont = nullptr 
)
overridevirtual

Adds an application font described by the font contained supplied fontData or using the font contained in the file referenced by fileName.

Returns a list of family names, or an empty list if the font could not be added.

If applicationFont is non-null, its properties list should be filled with information from the loaded fonts. This is exposed through FontLoader in Qt Quick where it is needed for disambiguating fonts in the same family. When the function exits, the applicationFont should contain an entry of properties per font in the file, or it should be empty if no font was loaded.

Note
The default implementation of this function does not add an application font. Subclasses should reimplement this function to perform the necessary loading and registration of fonts.

Reimplemented from QPlatformFontDatabase.

Definition at line 238 of file qwindowsdirectwritefontdatabase.cpp.

References QFontDatabase::Any, file, fileName, fromDirectWriteStretch(), fromDirectWriteStyle(), fromDirectWriteWeight(), QString::isEmpty(), QByteArray::isEmpty(), QFontDatabase::Latin, QFile::open(), properties, QFontDatabasePrivate::ApplicationFont::properties, qCDebug, qCWarning, QIODevice::readAll(), QIODeviceBase::ReadOnly, QPlatformFontDatabase::registerFont(), ret, QSupportedWritingSystems::setSupported(), and SMOOTH_SCALABLE.

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◆ defaultFont()

QFont QWindowsDirectWriteFontDatabase::defaultFont ( ) const
overridevirtual

Returns the default system font.

See also
QGuiApplication::font()
Since
5.0

Reimplemented from QPlatformFontDatabase.

Definition at line 423 of file qwindowsdirectwritefontdatabase.cpp.

References QStringLiteral.

Referenced by populateFontDatabase().

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◆ fallbacksForFamily()

QStringList QWindowsDirectWriteFontDatabase::fallbacksForFamily ( const QString family,
QFont::Style  style,
QFont::StyleHint  styleHint,
QChar::Script  script 
) const
overridevirtual

Returns a list of alternative fonts for the specified family and style and script using the styleHint given.

Default implementation returns a list of fonts for which style and script support has been reported during the font database population.

Reimplemented from QPlatformFontDatabase.

Definition at line 226 of file qwindowsdirectwritefontdatabase.cpp.

References QWindowsFontDatabaseBase::extraTryFontsForFamily(), QPlatformFontDatabase::fallbacksForFamily(), QWindowsFontDatabaseBase::familyForStyleHint(), and qCDebug.

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◆ fontEngine()

QFontEngine * QWindowsDirectWriteFontDatabase::fontEngine ( const QFontDef fontDef,
void handle 
)
overridevirtual

Returns the font engine that can be used to render the font described by the font definition, fontDef, in the specified script.

This function is called by QFontDatabase both for system fonts provided by the platform font database, as well as for application fonts added by the application developer.

The handle is the QPlatformFontDatabase specific handle passed when registering the font family via QPlatformFontDatabase::registerFont.

The function is called for both fonts added via a filename as well as fonts added from QByteArray data. Subclasses will need to handle both cases via its platform specific handle.

Reimplemented from QPlatformFontDatabase.

Definition at line 215 of file qwindowsdirectwritefontdatabase.cpp.

References QWindowsFontDatabaseBase::defaultVerticalDPI(), fontEngine(), QFontDef::pixelSize, and Q_ASSERT.

Referenced by fontEngine().

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◆ fontsAlwaysScalable()

bool QWindowsDirectWriteFontDatabase::fontsAlwaysScalable ( ) const
overridevirtual

Return true if all fonts are considered scalable when using this font database.

Defaults to false.

Since
5.0

Reimplemented from QPlatformFontDatabase.

Definition at line 354 of file qwindowsdirectwritefontdatabase.cpp.

◆ isPrivateFontFamily()

bool QWindowsDirectWriteFontDatabase::isPrivateFontFamily ( const QString family) const
overridevirtual

Returns true if the font family is private.

For any given family name, the result is platform dependent.

Reimplemented from QPlatformFontDatabase.

Definition at line 359 of file qwindowsdirectwritefontdatabase.cpp.

References Q_UNUSED.

◆ populateFamily()

void QWindowsDirectWriteFontDatabase::populateFamily ( const QString familyName)
overridevirtual

This function is called whenever a lazily populated family, populated through registerFontFamily(), needs full population.

You are expected to fully populate the family by calling registerFont() for each font that matches the family name.

Reimplemented from QPlatformFontDatabase.

Definition at line 80 of file qwindowsdirectwritefontdatabase.cpp.

References QFontDatabase::Any, QVarLengthArray< T, Prealloc >::at(), QVarLengthArray< T, Prealloc >::data(), QHash< Key, T >::end(), QHash< Key, T >::find(), font, fromDirectWriteStretch(), fromDirectWriteStyle(), fromDirectWriteWeight(), i, QString::isEmpty(), it, j, MAKE_TAG, qCDebug, qCWarning, qt_error_string(), qt_writing_system_for_script(), QPlatformFontDatabase::registerFont(), QChar::script(), QSupportedWritingSystems::setSupported(), SMOOTH_SCALABLE, QFontDatabase::WritingSystemsCount, and QPlatformFontDatabase::writingSystemsFromOS2Table().

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◆ populateFontDatabase()

void QWindowsDirectWriteFontDatabase::populateFontDatabase ( )
overridevirtual

This function is called once at startup by Qt's internal font database.

Reimplement this function in a subclass for a convenient place to initialize the internal font database.

You may lazily populate the database by calling registerFontFamily() instead of registerFont(), in which case you'll get a callback to populateFamily() when the required family needs population. You then call registerFont() to finish population of the family.

The default implementation does nothing.

Reimplemented from QPlatformFontDatabase.

Definition at line 365 of file qwindowsdirectwritefontdatabase.cpp.

References QWindowsFontDatabaseBase::data(), defaultFont(), QFont::families(), i, QHash< Key, T >::insert(), QString::isEmpty(), qCDebug, qDebug, QPlatformFontDatabase::registerFontFamily(), and QWindowsFontDatabaseBase::systemDefaultFont().

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◆ releaseHandle()

void QWindowsDirectWriteFontDatabase::releaseHandle ( void handle)
overridevirtual

Releases the specified font handle.

Reimplemented from QPlatformFontDatabase.

Definition at line 348 of file qwindowsdirectwritefontdatabase.cpp.


The documentation for this class was generated from the following files: