CopperSpice API  1.7.2
QFontDatabase Class Reference

The QFontDatabase class provides information about the fonts available in the underlying window system. More...

Public Types

enum  WritingSystem
 

Public Methods

 QFontDatabase ()
 
bool bold (const QString &family, const QString &style) const
 
QStringList families (WritingSystem writingSystem=Any) const
 
QFont font (const QString &family, const QString &style, int pointSize) const
 
bool hasFamily (const QString &family) const
 
bool isBitmapScalable (const QString &family, const QString &style=QString ()) const
 
bool isFixedPitch (const QString &family, const QString &style=QString ()) const
 
bool isPrivateFamily (const QString &family) const
 
bool isScalable (const QString &family, const QString &style=QString ()) const
 
bool isSmoothlyScalable (const QString &family, const QString &style=QString ()) const
 
bool italic (const QString &family, const QString &style) const
 
QList< int > pointSizes (const QString &family, const QString &style=QString ())
 
QList< int > smoothSizes (const QString &family, const QString &style)
 
QStringList styles (const QString &family) const
 
QString styleString (const QFont &font) const
 
QString styleString (const QFontInfo &fontInfo) const
 
int weight (const QString &family, const QString &style) const
 
QList< WritingSystemwritingSystems () const
 
QList< WritingSystemwritingSystems (const QString &family) const
 

Static Public Methods

static int addApplicationFont (const QString &fileName)
 
static int addApplicationFontFromData (const QByteArray &fontData)
 
static QStringList applicationFontFamilies (int id)
 
static bool removeAllApplicationFonts ()
 
static bool removeApplicationFont (int id)
 
static QList< int > standardSizes ()
 
static QFont systemFont (SystemFont type)
 
static QString writingSystemName (WritingSystem writingSystem)
 
static QString writingSystemSample (WritingSystem writingSystem)
 

Friends

class QFontDialog
 

Detailed Description

The QFontDatabase class provides information about the fonts available in the underlying window system.

The most common uses of this class are to query the database for the list of font families() and for the pointSizes() and styles() that are available for each family. An alternative to pointSizes() is smoothSizes() which returns the sizes at which a given family and style will look attractive.

If the font family is available from two or more foundries the foundry name is included in the family name; for example: "Helvetica [Adobe]" and "Helvetica [Cronyx]". When you specify a family, you can either use the old hyphenated "foundry-family" format or the bracketed "family [foundry]" format; for example: "Cronyx-Helvetica" or "Helvetica [Cronyx]". If the family has a foundry it is always returned using the bracketed format, as is the case with the value returned by families().

The font() function returns a QFont given a family, style and point size.

A family and style combination can be checked to see if it is italic() or bold(), and to retrieve its weight(). Similarly we can call isBitmapScalable(), isSmoothlyScalable(), isScalable() and isFixedPitch().

Use the styleString() to obtain a text version of a style.

The QFontDatabase class also supports some static functions, for example, standardSizes(). You can retrieve the description of a writing system using writingSystemName(), and a sample of characters in a writing system with writingSystemSample().

Example:

QFontDatabase database;
QTreeWidget fontTree;
fontTree.setColumnCount(2);
fontTree.setHeaderLabels(QStringList() << "Font" << "Smooth Sizes");
for (const QString &family : database.families()) {
QTreeWidgetItem *familyItem = new QTreeWidgetItem(&fontTree);
familyItem->setText(0, family);
for (const QString &style : database.styles(family)) {
QTreeWidgetItem *styleItem = new QTreeWidgetItem(familyItem);
styleItem->setText(0, style);
QString sizes;
for (int points : database.smoothSizes(family, style)) {
sizes += QString::number(points) + " ";
}
styleItem->setText(1, sizes.trimmed());
}
}

This example gets the list of font families, the list of styles for each family, and the point sizes that are available for each combination of family and style, displaying this information in a tree view.

See also
QFont, QFontInfo, QFontMetrics, QFontComboBox

Member Enumeration Documentation

ConstantValueDescription
QFontDatabase::Any0 
QFontDatabase::Latin1 
QFontDatabase::Greek2 
QFontDatabase::Cyrillic3 
QFontDatabase::Armenian4 
QFontDatabase::Hebrew5 
QFontDatabase::Arabic6 
QFontDatabase::Syriac7 
QFontDatabase::Thaana8 
QFontDatabase::Devanagari9 
QFontDatabase::Bengali10 
QFontDatabase::Gurmukhi11 
QFontDatabase::Gujarati12 
QFontDatabase::Oriya13 
QFontDatabase::Tamil14 
QFontDatabase::Telugu15 
QFontDatabase::Kannada16 
QFontDatabase::Malayalam17 
QFontDatabase::Sinhala18 
QFontDatabase::Thai19 
QFontDatabase::Lao20 
QFontDatabase::Tibetan21 
QFontDatabase::Myanmar22 
QFontDatabase::Georgian23 
QFontDatabase::Khmer24 
QFontDatabase::SimplifiedChinese25 
QFontDatabase::TraditionalChinese26 
QFontDatabase::Japanese27 
QFontDatabase::Korean28 
QFontDatabase::Vietnamese29 
QFontDatabase::Symbol30 
QFontDatabase::OtherSymbol(the same as Symbol)
QFontDatabase::Ogham? 
QFontDatabase::Runic? 
QFontDatabase::Nko? 

Constructor & Destructor Documentation

QFontDatabase::QFontDatabase ( )

Creates a font database object.

Method Documentation

int QFontDatabase::addApplicationFont ( const QString fileName)
static

Loads the font from the file specified by fileName and makes it available to the application. An ID is returned that can be used to remove the font again with removeApplicationFont() or to retrieve the list of family names contained in the font.

The function returns -1 if the font could not be loaded.

Currently only TrueType fonts, TrueType font collections, and OpenType fonts are supported.

Note
Adding application fonts on Unix/X11 platforms without fontconfig is currently not supported.
See also
addApplicationFontFromData(), applicationFontFamilies(), removeApplicationFont()
int QFontDatabase::addApplicationFontFromData ( const QByteArray fontData)
static

Loads the font from binary data specified by fontData and makes it available to the application. An ID is returned that can be used to remove the font again with removeApplicationFont() or to retrieve the list of family names contained in the font.

The function returns -1 if the font could not be loaded.

Currently only TrueType fonts and TrueType font collections are supported.

Note
Adding application fonts on Unix/X11 platforms without fontconfig is currently not supported.
See also
addApplicationFont(), applicationFontFamilies(), removeApplicationFont()
QStringList QFontDatabase::applicationFontFamilies ( int  id)
static

Returns a list of font families for the given application font identified by id.

See also
addApplicationFont(), addApplicationFontFromData()
bool QFontDatabase::bold ( const QString family,
const QString style 
) const

Returns true if the font that has family family and style style is bold, otherwise returns false.

See also
italic(), weight()
QStringList QFontDatabase::families ( WritingSystem  writingSystem = Any) const

Returns a sorted list of the available font families which support the writingSystem.

If a family exists in several foundries, the returned name for that font is in the form "family [foundry]". Examples: "Times [Adobe]", "Times [Cronyx]", "Palatino".

See also
writingSystems()
QFont QFontDatabase::font ( const QString family,
const QString style,
int  pointSize 
) const

Returns a QFont object that has family family, style style and point size pointSize. If no matching font could be created, a QFont object that uses the application's default font is returned.

bool QFontDatabase::hasFamily ( const QString family) const

Documentation pending.

bool QFontDatabase::isBitmapScalable ( const QString family,
const QString style = QString() 
) const

Returns true if the font that has family family and style style is a scalable bitmap font, otherwise returns false. Scaling a bitmap font usually produces an unattractive hardly readable result, because the pixels of the font are scaled. If you need to scale a bitmap font it is better to scale it to one of the fixed sizes returned by smoothSizes().

See also
isScalable(), isSmoothlyScalable()
bool QFontDatabase::isFixedPitch ( const QString family,
const QString style = QString() 
) const

Returns true if the font that has family family and style style is fixed pitch, otherwise returns false.

bool QFontDatabase::isPrivateFamily ( const QString family) const

Returns true if and only if the family font family is private.

This happens on Mac OS X and iOS, where the system UI fonts are not accessible to the user. For completeness, QFontDatabase::families() returns all font families, including the private ones. You should use this function if you are developing a font selection control in order to keep private fonts hidden.

See also
families()
bool QFontDatabase::isScalable ( const QString family,
const QString style = QString() 
) const

Returns true if the font that has family family and style style is scalable, otherwise returns false.

See also
isBitmapScalable(), isSmoothlyScalable()
bool QFontDatabase::isSmoothlyScalable ( const QString family,
const QString style = QString() 
) const

Returns true if the font that has family family and style style is smoothly scalable, otherwise returns false. If this function returns true, it's safe to scale this font to any size, and the result will always look attractive.

See also
isScalable(), isBitmapScalable()
bool QFontDatabase::italic ( const QString family,
const QString style 
) const

Returns true if the font that has family family and style style is italic, otherwise returns false.

See also
weight(), bold()
QList< int > QFontDatabase::pointSizes ( const QString family,
const QString style = QString() 
)

Returns a list of the point sizes available for the font with the given family and style. The list may be empty.

See also
smoothSizes(), standardSizes()
bool QFontDatabase::removeAllApplicationFonts ( )
static

Removes all application-local fonts previously added using addApplicationFont() and addApplicationFontFromData().

Returns true if unloading of the fonts succeeded, otherwise returns false.

See also
removeApplicationFont(), addApplicationFont(), addApplicationFontFromData()
bool QFontDatabase::removeApplicationFont ( int  id)
static

Removes the previously loaded application font identified by id. Returns true if unloading of the font succeeded, otherwise returns false.

See also
removeAllApplicationFonts(), addApplicationFont(), addApplicationFontFromData()
QList< int > QFontDatabase::smoothSizes ( const QString family,
const QString style 
)

Returns the point sizes of a font with the given family and style that will look attractive. The list may be empty. For non-scalable fonts and bitmap scalable fonts, this function is equivalent to pointSizes().

See also
pointSizes(), standardSizes()
QList< int > QFontDatabase::standardSizes ( )
static

Returns a list of standard font sizes.

See also
smoothSizes(), pointSizes()
QStringList QFontDatabase::styles ( const QString family) const

Returns a list of the styles available for the font family family. Some example styles: "Light", "Light Italic", "Bold", "Oblique", "Demi". The list may be empty.

See also
families()
QString QFontDatabase::styleString ( const QFont font) const

Returns a string that describes the style of the font. For example, "Bold Italic", "Bold", "Italic" or "Normal". An empty string may be returned.

QString QFontDatabase::styleString ( const QFontInfo fontInfo) const

Returns a string that describes the style of the fontInfo. For example, "Bold Italic", "Bold", "Italic" or "Normal". An empty string may be returned.

QFont QFontDatabase::systemFont ( SystemFont  type)
static

Documentation pending.

int QFontDatabase::weight ( const QString family,
const QString style 
) const

Returns the weight of the font that has family family and style style. If there is no such family and style combination, returns -1.

See also
italic(), bold()
QString QFontDatabase::writingSystemName ( WritingSystem  writingSystem)
static

Returns the names the writingSystem (e.g. for displaying to the user in a dialog).

QList< WritingSystem > QFontDatabase::writingSystems ( ) const

Returns a sorted list of the available writing systems. This is list generated from information about all installed fonts on the system.

See also
families()
QList< WritingSystem > QFontDatabase::writingSystems ( const QString family) const

Returns a sorted list of the writing systems supported by a given font family.

See also
families()
QString QFontDatabase::writingSystemSample ( WritingSystem  writingSystem)
static

Returns a string with sample characters from writingSystem.