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Internal/Contributor docs for the Qt SDK. <b>Note:</b> These are NOT official API docs; those are found <a href='https://doc.qt.io/'>here</a>.
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QFreeTypeFontDatabase Class Reference

#include <qfreetypefontdatabase_p.h>

+ Inheritance diagram for QFreeTypeFontDatabase:
+ Collaboration diagram for QFreeTypeFontDatabase:

Public Member Functions

void populateFontDatabase () override
 This function is called once at startup by Qt's internal font database.
 
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.
 
QStringList addApplicationFont (const QByteArray &fontData, const QString &fileName, QFontDatabasePrivate::ApplicationFont *applicationFont=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.
 
bool supportsVariableApplicationFonts () const override
 Returns true if this font database supports loading named instances from variable application fonts.
 
- Public Member Functions inherited from QPlatformFontDatabase
virtual ~QPlatformFontDatabase ()
 
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 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 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.
 

Static Public Member Functions

static void addNamedInstancesForFace (void *face, int faceIndex, const QString &family, const QString &styleName, QFont::Weight weight, QFont::Stretch stretch, QFont::Style style, bool fixedPitch, const QSupportedWritingSystems &writingSystems, const QByteArray &fileName, const QByteArray &fontData)
 
static QStringList addTTFile (const QByteArray &fontData, const QByteArray &file, QFontDatabasePrivate::ApplicationFont *applicationFont=nullptr)
 
- 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 37 of file qfreetypefontdatabase_p.h.

Member Function Documentation

◆ addApplicationFont()

QStringList QFreeTypeFontDatabase::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 85 of file qfreetypefontdatabase.cpp.

References addTTFile(), and fileName.

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◆ addNamedInstancesForFace()

void QFreeTypeFontDatabase::addNamedInstancesForFace ( void * face,
int faceIndex,
const QString & family,
const QString & styleName,
QFont::Weight weight,
QFont::Stretch stretch,
QFont::Style style,
bool fixedPitch,
const QSupportedWritingSystems & writingSystems,
const QByteArray & fileName,
const QByteArray & fontData )
static

Definition at line 98 of file qfreetypefontdatabase.cpp.

References QFile::decodeName(), fileName, i, j, Q_UNUSED, qCDebug, qt_getFreetype(), QPlatformFontDatabase::registerFont(), QFont::StyleItalic, QFont::StyleNormal, QFont::Tag::value(), var, and void.

Referenced by addTTFile().

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◆ addTTFile()

◆ fontEngine() [1/2]

QFontEngine * QFreeTypeFontDatabase::fontEngine ( const QByteArray & fontData,
qreal pixelSize,
QFont::HintingPreference hintingPreference )
overridevirtual

Returns the font engine that will be used to back a QRawFont, based on the given \fontData, pixelSize, and hintingPreference.

This function is called by QRawFont, and does not play a part in the normal operations of QFontDatabase.

Reimplemented from QPlatformFontDatabase.

Reimplemented in QWindowsFontDatabaseFT.

Definition at line 79 of file qfreetypefontdatabase.cpp.

References QFontEngineFT::create().

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◆ fontEngine() [2/2]

QFontEngine * QFreeTypeFontDatabase::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.

Reimplemented in QWindowsFontDatabaseFT, and QWasmFontDatabase.

Definition at line 59 of file qfreetypefontdatabase.cpp.

References QFontEngineFT::create(), QFile::encodeName(), QFontEngine::FaceId::filename, QFontEngine::FaceId::index, QFontEngine::FaceId::instanceIndex, QByteArray::isEmpty(), QUuid::toByteArray(), QFontEngine::FaceId::uuid, QFontEngine::FaceId::variableAxes, and QFontDef::variableAxisValues.

Referenced by QFontconfigDatabase::fontEngine(), QWindowsFontDatabaseFT::fontEngine(), QWindowsFontDatabaseFT::fontEngine(), and QWasmFontDatabase::fontEngine().

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◆ populateFontDatabase()

void QFreeTypeFontDatabase::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.

Reimplemented in QWindowsFontDatabaseFT, and QWasmFontDatabase.

Definition at line 33 of file qfreetypefontdatabase.cpp.

References addTTFile(), dir, QFile::encodeName(), file, QDir::Files, QPlatformFontDatabase::fontDir(), QList< QString >::fromReadOnlyData(), QByteArray(), qPrintable, and qWarning.

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◆ releaseHandle()

void QFreeTypeFontDatabase::releaseHandle ( void * handle)
overridevirtual

Releases the specified font handle.

Reimplemented from QPlatformFontDatabase.

Reimplemented in QWasmFontDatabase.

Definition at line 90 of file qfreetypefontdatabase.cpp.

References file.

Referenced by QWasmFontDatabase::releaseHandle().

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◆ supportsVariableApplicationFonts()

bool QFreeTypeFontDatabase::supportsVariableApplicationFonts ( ) const
overridevirtual

Returns true if this font database supports loading named instances from variable application fonts.

Since
6.7

Reimplemented from QPlatformFontDatabase.

Definition at line 352 of file qfreetypefontdatabase.cpp.


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