QFont Class
The QFont class specifies a font used for drawing text. More...
| Header: | #include <QFont> |
| qmake: | QT += gui |
Note: All functions in this class are reentrant.
Public Types
| enum | Capitalization { MixedCase, AllUppercase, AllLowercase, SmallCaps, Capitalize } |
| enum | HintingPreference { PreferDefaultHinting, PreferNoHinting, PreferVerticalHinting, PreferFullHinting } |
| enum | SpacingType { PercentageSpacing, AbsoluteSpacing } |
| enum | Stretch { AnyStretch, UltraCondensed, ExtraCondensed, Condensed, ..., UltraExpanded } |
| enum | Style { StyleNormal, StyleItalic, StyleOblique } |
| enum | StyleHint { AnyStyle, SansSerif, Helvetica, Serif, ..., System } |
| enum | StyleStrategy { PreferDefault, PreferBitmap, PreferDevice, PreferOutline, ..., ForceIntegerMetrics } |
| enum | Weight { Thin, ExtraLight, Light, Normal, ..., Black } |
Public Functions
| QFont() | |
| QFont(const QString &family, int pointSize = -1, int weight = -1, bool italic = false) | |
| QFont(const QFont &font, QPaintDevice *pd) | |
| QFont(const QFont &font) | |
| ~QFont() | |
| bool | bold() const |
| Capitalization | capitalization() const |
| QString | defaultFamily() const |
| bool | exactMatch() const |
| QString | family() const |
| bool | fixedPitch() const |
| bool | fromString(const QString &descrip) |
| HintingPreference | hintingPreference() const |
| bool | isCopyOf(const QFont &f) const |
| bool | italic() const |
| bool | kerning() const |
| QString | key() const |
| QString | lastResortFamily() const |
| QString | lastResortFont() const |
| qreal | letterSpacing() const |
| SpacingType | letterSpacingType() const |
| bool | overline() const |
| int | pixelSize() const |
| int | pointSize() const |
| qreal | pointSizeF() const |
| QFont | resolve(const QFont &other) const |
| void | setBold(bool enable) |
| void | setCapitalization(Capitalization caps) |
| void | setFamily(const QString &family) |
| void | setFixedPitch(bool enable) |
| void | setHintingPreference(HintingPreference hintingPreference) |
| void | setItalic(bool enable) |
| void | setKerning(bool enable) |
| void | setLetterSpacing(SpacingType type, qreal spacing) |
| void | setOverline(bool enable) |
| void | setPixelSize(int pixelSize) |
| void | setPointSize(int pointSize) |
| void | setPointSizeF(qreal pointSize) |
| void | setStretch(int factor) |
| void | setStrikeOut(bool enable) |
| void | setStyle(Style style) |
| void | setStyleHint(StyleHint hint, StyleStrategy strategy = PreferDefault) |
| void | setStyleName(const QString &styleName) |
| void | setStyleStrategy(StyleStrategy s) |
| void | setUnderline(bool enable) |
| void | setWeight(int weight) |
| void | setWordSpacing(qreal spacing) |
| int | stretch() const |
| bool | strikeOut() const |
| Style | style() const |
| StyleHint | styleHint() const |
| QString | styleName() const |
| StyleStrategy | styleStrategy() const |
| void | swap(QFont &other) |
| QString | toString() const |
| bool | underline() const |
| int | weight() const |
| qreal | wordSpacing() const |
| operator QVariant() const | |
| bool | operator!=(const QFont &f) const |
| bool | operator<(const QFont &f) const |
| QFont & | operator=(const QFont &font) |
| QFont & | operator=(QFont &&other) |
| bool | operator==(const QFont &f) const |
Static Public Members
| void | insertSubstitution(const QString &familyName, const QString &substituteName) |
| void | insertSubstitutions(const QString &familyName, const QStringList &substituteNames) |
| void | removeSubstitutions(const QString &familyName) |
| QString | substitute(const QString &familyName) |
| QStringList | substitutes(const QString &familyName) |
| QStringList | substitutions() |
Related Non-Members
| uint | qHash(const QFont &font, uint seed = 0) |
| QDataStream & | operator<<(QDataStream &s, const QFont &font) |
| QDataStream & | operator>>(QDataStream &s, QFont &font) |
Detailed Description
The QFont class specifies a font used for drawing text.
When you create a QFont object you specify various attributes that you want the font to have. Qt will use the font with the specified attributes, or if no matching font exists, Qt will use the closest matching installed font. The attributes of the font that is actually used are retrievable from a QFontInfo object. If the window system provides an exact match exactMatch() returns true. Use QFontMetrics to get measurements, e.g. the pixel length of a string using QFontMetrics::width().
Note that a QGuiApplication instance must exist before a QFont can be used. You can set the application's default font with QGuiApplication::setFont().
If a chosen font does not include all the characters that need to be displayed, QFont will try to find the characters in the nearest equivalent fonts. When a QPainter draws a character from a font the QFont will report whether or not it has the character; if it does not, QPainter will draw an unfilled square.
Create QFonts like this:
The attributes set in the constructor can also be set later, e.g. setFamily(), setPointSize(), setPointSizeF(), setWeight() and setItalic(). The remaining attributes must be set after contstruction, e.g. setBold(), setUnderline(), setOverline(), setStrikeOut() and setFixedPitch(). QFontInfo objects should be created after the font's attributes have been set. A QFontInfo object will not change, even if you change the font's attributes. The corresponding "get" functions, e.g. family(), pointSize(), etc., return the values that were set, even though the values used may differ. The actual values are available from a QFontInfo object.
If the requested font family is unavailable you can influence the font matching algorithm by choosing a particular QFont::StyleHint and QFont::StyleStrategy with setStyleHint(). The default family (corresponding to the current style hint) is returned by defaultFamily().
The font-matching algorithm has a lastResortFamily() and lastResortFont() in cases where a suitable match cannot be found. You can provide substitutions for font family names using insertSubstitution() and insertSubstitutions(). Substitutions can be removed with removeSubstitutions(). Use substitute() to retrieve a family's first substitute, or the family name itself if it has no substitutes. Use substitutes() to retrieve a list of a family's substitutes (which may be empty).
Every QFont has a key() which you can use, for example, as the key in a cache or dictionary. If you want to store a user's font preferences you could use QSettings, writing the font information with toString() and reading it back with fromString(). The operator<<() and operator>>() functions are also available, but they work on a data stream.
It is possible to set the height of characters shown on the screen to a specified number of pixels with setPixelSize(); however using setPointSize() has a similar effect and provides device independence.
Loading fonts can be expensive, especially on X11. QFont contains extensive optimizations to make the copying of QFont objects fast, and to cache the results of the slow window system functions it depends upon.
The font matching algorithm works as follows:
- The specified font family is searched for.
- If not found, the styleHint() is used to select a replacement family.
- Each replacement font family is searched for.
- If none of these are found or there was no styleHint(), "helvetica" will be searched for.
- If "helvetica" isn't found Qt will try the lastResortFamily().
- If the lastResortFamily() isn't found Qt will try the lastResortFont() which will always return a name of some kind.
Note that the actual font matching algorithm varies from platform to platform.
In Windows a request for the "Courier" font is automatically changed to "Courier New", an improved version of Courier that allows for smooth scaling. The older "Courier" bitmap font can be selected by setting the PreferBitmap style strategy (see setStyleStrategy()).
Once a font is found, the remaining attributes are matched in order of priority:
- fixedPitch()
- pointSize() (see below)
- weight()
- style()
If you have a font which matches on family, even if none of the other attributes match, this font will be chosen in preference to a font which doesn't match on family but which does match on the other attributes. This is because font family is the dominant search criteria.
The point size is defined to match if it is within 20% of the requested point size. When several fonts match and are only distinguished by point size, the font with the closest point size to the one requested will be chosen.
The actual family, font size, weight and other font attributes used for drawing text will depend on what's available for the chosen family under the window system. A QFontInfo object can be used to determine the actual values used for drawing the text.
Examples:
QFont f("Helvetica");
If you had both an Adobe and a Cronyx Helvetica, you might get either.
QFont f("Helvetica [Cronyx]");
You can specify the foundry you want in the family name. The font f in the above example will be set to "Helvetica [Cronyx]".
To determine the attributes of the font actually used in the window system, use a QFontInfo object, e.g.
To find out font metrics use a QFontMetrics object, e.g.
QFontMetrics fm(f1); int textWidthInPixels = fm.width("How many pixels wide is this text?"); int textHeightInPixels = fm.height();
For more general information on fonts, see the comp.fonts FAQ. Information on encodings can be found from Roman Czyborra's page.
See also QFontMetrics, QFontInfo, QFontDatabase, and Character Map Example.
Member Type Documentation
enum QFont::Capitalization
Rendering option for text this font applies to.
| Constant | Value | Description |
|---|---|---|
QFont::MixedCase | 0 | This is the normal text rendering option where no capitalization change is applied. |
QFont::AllUppercase | 1 | This alters the text to be rendered in all uppercase type. |
QFont::AllLowercase | 2 | This alters the text to be rendered in all lowercase type. |
QFont::SmallCaps | 3 | This alters the text to be rendered in small-caps type. |
QFont::Capitalize | 4 | This alters the text to be rendered with the first character of each word as an uppercase character. |
This enum was introduced or modified in Qt 4.4.
enum QFont::HintingPreference
This enum describes the different levels of hinting that can be applied to glyphs to improve legibility on displays where it might be warranted by the density of pixels.
| Constant | Value | Description |
|---|---|---|
QFont::PreferDefaultHinting | 0 | Use the default hinting level for the target platform. |
QFont::PreferNoHinting | 1 | If possible, render text without hinting the outlines of the glyphs. The text layout will be typographically accurate and scalable, using the same metrics as are used e.g. when printing. |
QFont::PreferVerticalHinting | 2 | If possible, render text with no horizontal hinting, but align glyphs to the pixel grid in the vertical direction. The text will appear crisper on displays where the density is too low to give an accurate rendering of the glyphs. But since the horizontal metrics of the glyphs are unhinted, the text's layout will be scalable to higher density devices (such as printers) without impacting details such as line breaks. |
QFont::PreferFullHinting | 3 | If possible, render text with hinting in both horizontal and vertical directions. The text will be altered to optimize legibility on the target device, but since the metrics will depend on the target size of the text, the positions of glyphs, line breaks, and other typographical detail will not scale, meaning that a text layout may look different on devices with different pixel densities. |
Please note that this enum only describes a preference, as the full range of hinting levels are not supported on all of Qt's supported platforms. The following table details the effect of a given hinting preference on a selected set of target platforms.
| PreferDefaultHinting | PreferNoHinting | PreferVerticalHinting | PreferFullHinting | |
|---|---|---|---|---|
| Windows Vista (w/o Platform Update) and earlier | Full hinting | Full hinting | Full hinting | Full hinting |
| Windows 7 and Windows Vista (w/Platform Update) and DirectWrite enabled in Qt | Full hinting | Vertical hinting | Vertical hinting | Full hinting |
| FreeType | Operating System setting | No hinting | Vertical hinting (light) | Full hinting |
| Cocoa on macOS | No hinting | No hinting | No hinting | No hinting |
Note: Please be aware that altering the hinting preference on Windows is available through the DirectWrite font engine. This is available on Windows Vista after installing the platform update, and on Windows 7. In order to use this extension, configure Qt using -directwrite. The target application will then depend on the availability of DirectWrite on the target system.
This enum was introduced or modified in Qt 4.8.
enum QFont::SpacingType
| Constant | Value | Description |
|---|---|---|
QFont::PercentageSpacing | 0 | A value of 100 will keep the spacing unchanged; a value of 200 will enlarge the spacing after a character by the width of the character itself. |
QFont::AbsoluteSpacing | 1 | A positive value increases the letter spacing by the corresponding pixels; a negative value decreases the spacing. |
This enum was introduced or modified in Qt 4.4.
enum QFont::Stretch
Predefined stretch values that follow the CSS naming convention. The higher the value, the more stretched the text is.
| Constant | Value | Description |
|---|---|---|
QFont::AnyStretch | 0 | 0 Accept any stretch matched using the other QFont properties (added in Qt 5.8) |
QFont::UltraCondensed | 50 | 50 |
QFont::ExtraCondensed | 62 | 62 |
QFont::Condensed | 75 | 75 |
QFont::SemiCondensed | 87 | 87 |
QFont::Unstretched | 100 | 100 |
QFont::SemiExpanded | 112 | 112 |
QFont::Expanded | 125 | 125 |
QFont::ExtraExpanded | 150 | 150 |
QFont::UltraExpanded | 200 | 200 |
See also setStretch() and stretch().
enum QFont::Style
This enum describes the different styles of glyphs that are used to display text.
| Constant | Value | Description |
|---|---|---|
QFont::StyleNormal | 0 | Normal glyphs used in unstyled text. |
QFont::StyleItalic | 1 | Italic glyphs that are specifically designed for the purpose of representing italicized text. |
QFont::StyleOblique | 2 | Glyphs with an italic appearance that are typically based on the unstyled glyphs, but are not fine-tuned for the purpose of representing italicized text. |
See also Weight.
enum QFont::StyleHint
Style hints are used by the font matching algorithm to find an appropriate default family if a selected font family is not available.
| Constant | Value | Description |
|---|---|---|
QFont::AnyStyle | ? | leaves the font matching algorithm to choose the family. This is the default. |
QFont::SansSerif | Helvetica | the font matcher prefer sans serif fonts. |
QFont::Helvetica | 0 | is a synonym for SansSerif. |
QFont::Serif | Times | the font matcher prefers serif fonts. |
QFont::Times | ? | is a synonym for Serif. |
QFont::TypeWriter | Courier | the font matcher prefers fixed pitch fonts. |
QFont::Courier | ? | a synonym for TypeWriter. |
QFont::OldEnglish | ? | the font matcher prefers decorative fonts. |
QFont::Decorative | OldEnglish | is a synonym for OldEnglish. |
QFont::Monospace | ? | the font matcher prefers fonts that map to the CSS generic font-family 'monospace'. |
QFont::Fantasy | ? | the font matcher prefers fonts that map to the CSS generic font-family 'fantasy'. |
QFont::Cursive | ? | the font matcher prefers fonts that map to the CSS generic font-family 'cursive'. |
QFont::System | ? | the font matcher prefers system fonts. |
enum QFont::StyleStrategy
The style strategy tells the font matching algorithm what type of fonts should be used to find an appropriate default family.
The following strategies are available:
| Constant | Value | Description |
|---|---|---|
QFont::PreferDefault | 0x0001 | the default style strategy. It does not prefer any type of font. |
QFont::PreferBitmap | 0x0002 | prefers bitmap fonts (as opposed to outline fonts). |
QFont::PreferDevice | 0x0004 | prefers device fonts. |
QFont::PreferOutline | 0x0008 | prefers outline fonts (as opposed to bitmap fonts). |
QFont::ForceOutline | 0x0010 | forces the use of outline fonts. |
QFont::NoAntialias | 0x0100 | don't antialias the fonts. |
QFont::NoSubpixelAntialias | 0x0800 | avoid subpixel antialiasing on the fonts if possible. |
QFont::PreferAntialias | 0x0080 | antialias if possible. |
QFont::OpenGLCompatible | 0x0200 | forces the use of OpenGL compatible fonts. |
QFont::NoFontMerging | 0x8000 | If the font selected for a certain writing system does not contain a character requested to draw, then Qt automatically chooses a similar looking font that contains the character. The NoFontMerging flag disables this feature. Please note that enabling this flag will not prevent Qt from automatically picking a suitable font when the selected font does not support the writing system of the text. |
Any of these may be OR-ed with one of these flags:
| Constant | Value | Description |
|---|---|---|
QFont::PreferMatch | 0x0020 | prefer an exact match. The font matcher will try to use the exact font size that has been specified. |
QFont::PreferQuality | 0x0040 | prefer the best quality font. The font matcher will use the nearest standard point size that the font supports. |
QFont::ForceIntegerMetrics | 0x0400 | forces the use of integer values in font engines that support fractional font metrics. |
enum QFont::Weight
Qt uses a weighting scale from 0 to 99 similar to, but not the same as, the scales used in Windows or CSS. A weight of 0 will be thin, whilst 99 will be extremely black.
This enum contains the predefined font weights:
| Constant | Value | Description |
|---|---|---|
QFont::Thin | 0 | 0 |
QFont::ExtraLight | 12 | 12 |
QFont::Light | 25 | 25 |
QFont::Normal | 50 | 50 |
QFont::Medium | 57 | 57 |
QFont::DemiBold | 63 | 63 |
QFont::Bold | 75 | 75 |
QFont::ExtraBold | 81 | 81 |
QFont::Black | 87 | 87 |
Member Function Documentation
QFont::QFont()
Constructs a font object that uses the application's default font.
See also QGuiApplication::setFont() and QGuiApplication::font().
QFont::QFont(const QString &family, int pointSize = -1, int weight = -1, bool italic = false)
Constructs a font object with the specified family, pointSize, weight and italic settings.
If pointSize is zero or negative, the point size of the font is set to a system-dependent default value. Generally, this is 12 points.
The family name may optionally also include a foundry name, e.g. "Helvetica [Cronyx]". If the family is available from more than one foundry and the foundry isn't specified, an arbitrary foundry is chosen. If the family isn't available a family will be set using the font matching algorithm.
See also Weight, setFamily(), setPointSize(), setWeight(), setItalic(), setStyleHint(), and QGuiApplication::font().
QFont::QFont(const QFont &font, QPaintDevice *pd)
Constructs a font from font for use on the paint device pd.
QFont::QFont(const QFont &font)
Constructs a font that is a copy of font.
QFont::~QFont()
Destroys the font object and frees all allocated resources.
bool QFont::bold() const
Returns true if weight() is a value greater than QFont::Medium; otherwise returns false.
See also weight(), setBold(), and QFontInfo::bold().
Capitalization QFont::capitalization() const
Returns the current capitalization type of the font.
This function was introduced in Qt 4.4.
See also setCapitalization().
QString QFont::defaultFamily() const
Returns the family name that corresponds to the current style hint.
See also StyleHint, styleHint(), and setStyleHint().
bool QFont::exactMatch() const
Returns true if a window system font exactly matching the settings of this font is available.
See also QFontInfo.
QString QFont::family() const
Returns the requested font family name, i.e. the name set in the constructor or the last setFont() call.
See also setFamily(), substitutes(), and substitute().
bool QFont::fixedPitch() const
Returns true if fixed pitch has been set; otherwise returns false.
See also setFixedPitch() and QFontInfo::fixedPitch().
bool QFont::fromString(const QString &descrip)
Sets this font to match the description descrip. The description is a comma-separated list of the font attributes, as returned by toString().
See also toString().
HintingPreference QFont::hintingPreference() const
Returns the currently preferred hinting level for glyphs rendered with this font.
This function was introduced in Qt 4.8.
See also setHintingPreference().
[static] void QFont::insertSubstitution(const QString &familyName, const QString &substituteName)
Inserts substituteName into the substitution table for the family familyName.
See also insertSubstitutions(), removeSubstitutions(), substitutions(), substitute(), and substitutes().
[static] void QFont::insertSubstitutions(const QString &familyName, const QStringList &substituteNames)
Inserts the list of families substituteNames into the substitution list for familyName.
See also insertSubstitution(), removeSubstitutions(), substitutions(), and substitute().
bool QFont::isCopyOf(const QFont &f) const
Returns true if this font and f are copies of each other, i.e. one of them was created as a copy of the other and neither has been modified since. This is much stricter than equality.
See also operator=() and operator==().
bool QFont::italic() const
Returns true if the style() of the font is not QFont::StyleNormal
See also setItalic() and style().
bool QFont::kerning() const
Returns true if kerning should be used when drawing text with this font.
See also setKerning().
QString QFont::key() const
Returns the font's key, a textual representation of a font. It is typically used as the key for a cache or dictionary of fonts.
See also QMap.
QString QFont::lastResortFamily() const
Returns the "last resort" font family name.
The current implementation tries a wide variety of common fonts, returning the first one it finds. Is is possible that no family is found in which case an empty string is returned.
See also lastResortFont().
QString QFont::lastResortFont() const
Returns a "last resort" font name for the font matching algorithm. This is used if the last resort family is not available. It will always return a name, if necessary returning something like "fixed" or "system".
The current implementation tries a wide variety of common fonts, returning the first one it finds. The implementation may change at any time, but this function will always return a string containing something.
It is theoretically possible that there really isn't a lastResortFont() in which case Qt will abort with an error message. We have not been able to identify a case where this happens. Please report it as a bug if it does, preferably with a list of the fonts you have installed.
See also lastResortFamily().
qreal QFont::letterSpacing() const
Returns the letter spacing for the font.
This function was introduced in Qt 4.4.
See also setLetterSpacing(), letterSpacingType(), and setWordSpacing().
SpacingType QFont::letterSpacingType() const
Returns the spacing type used for letter spacing.
This function was introduced in Qt 4.4.
See also letterSpacing(), setLetterSpacing(), and setWordSpacing().
bool QFont::overline() const
Returns true if overline has been set; otherwise returns false.
See also setOverline().
int QFont::pixelSize() const
Returns the pixel size of the font if it was set with setPixelSize(). Returns -1 if the size was set with setPointSize() or setPointSizeF().
See also setPixelSize(), pointSize(), QFontInfo::pointSize(), and QFontInfo::pixelSize().
int QFont::pointSize() const
Returns the point size of the font. Returns -1 if the font size was specified in pixels.
See also setPointSize() and pointSizeF().
qreal QFont::pointSizeF() const
Returns the point size of the font. Returns -1 if the font size was specified in pixels.
See also pointSize(), setPointSizeF(), pixelSize(), QFontInfo::pointSize(), and QFontInfo::pixelSize().
[static] void QFont::removeSubstitutions(const QString &familyName)
Removes all the substitutions for familyName.
This function was introduced in Qt 5.0.
See also insertSubstitutions(), insertSubstitution(), substitutions(), and substitute().
QFont QFont::resolve(const QFont &other) const
Returns a new QFont that has attributes copied from other that have not been previously set on this font.
void QFont::setBold(bool enable)
If enable is true sets the font's weight to QFont::Bold; otherwise sets the weight to QFont::Normal.
For finer boldness control use setWeight().
See also bold() and setWeight().
void QFont::setCapitalization(Capitalization caps)
Sets the capitalization of the text in this font to caps.
A font's capitalization makes the text appear in the selected capitalization mode.
This function was introduced in Qt 4.4.
See also capitalization().
void QFont::setFamily(const QString &family)
Sets the family name of the font. The name is case insensitive and may include a foundry name.
The family name may optionally also include a foundry name, e.g. "Helvetica [Cronyx]". If the family is available from more than one foundry and the foundry isn't specified, an arbitrary foundry is chosen. If the family isn't available a family will be set using the font matching algorithm.
See also family(), setStyleHint(), and QFontInfo.
void QFont::setFixedPitch(bool enable)
If enable is true, sets fixed pitch on; otherwise sets fixed pitch off.
See also fixedPitch() and QFontInfo.
void QFont::setHintingPreference(HintingPreference hintingPreference)
Set the preference for the hinting level of the glyphs to hintingPreference. This is a hint to the underlying font rendering system to use a certain level of hinting, and has varying support across platforms. See the table in the documentation for QFont::HintingPreference for more details.
The default hinting preference is QFont::PreferDefaultHinting.
This function was introduced in Qt 4.8.
See also hintingPreference().
void QFont::setItalic(bool enable)
Sets the style() of the font to QFont::StyleItalic if enable is true; otherwise the style is set to QFont::StyleNormal.
See also italic() and QFontInfo.
void QFont::setKerning(bool enable)
Enables kerning for this font if enable is true; otherwise disables it. By default, kerning is enabled.
When kerning is enabled, glyph metrics do not add up anymore, even for Latin text. In other words, the assumption that width('a') + width('b') is equal to width("ab") is not necessarily true.
See also kerning() and QFontMetrics.
void QFont::setLetterSpacing(SpacingType type, qreal spacing)
Sets the letter spacing for the font to spacing and the type of spacing to type.
Letter spacing changes the default spacing between individual letters in the font. The spacing between the letters can be made smaller as well as larger either in percentage of the character width or in pixels, depending on the selected spacing type.
This function was introduced in Qt 4.4.
See also letterSpacing(), letterSpacingType(), and setWordSpacing().
void QFont::setOverline(bool enable)
If enable is true, sets overline on; otherwise sets overline off.
See also overline() and QFontInfo.
void QFont::setPixelSize(int pixelSize)
Sets the font size to pixelSize pixels.
Using this function makes the font device dependent. Use setPointSize() or setPointSizeF() to set the size of the font in a device independent manner.
See also pixelSize().
void QFont::setPointSize(int pointSize)
Sets the point size to pointSize. The point size must be greater than zero.
See also pointSize() and setPointSizeF().
void QFont::setPointSizeF(qreal pointSize)
Sets the point size to pointSize. The point size must be greater than zero. The requested precision may not be achieved on all platforms.
See also pointSizeF(), setPointSize(), and setPixelSize().
void QFont::setStretch(int factor)
Sets the stretch factor for the font.
The stretch factor matches a condensed or expanded version of the font or applies a stretch transform that changes the width of all characters in the font by factor percent. For example, setting factor to 150 results in all characters in the font being 1.5 times (ie. 150%) wider. The minimum stretch factor is 1, and the maximum stretch factor is 4000. The default stretch factor is AnyStretch, which will accept any stretch factor and not apply any transform on the font.
The stretch factor is only applied to outline fonts. The stretch factor is ignored for bitmap fonts.
Note: When matching a font with a native non-default stretch factor, requesting a stretch of 100 will stretch it back to a medium width font.
See also stretch() and QFont::Stretch.
void QFont::setStrikeOut(bool enable)
If enable is true, sets strikeout on; otherwise sets strikeout off.
See also strikeOut() and QFontInfo.
void QFont::setStyle(Style style)
Sets the style of the font to style.
See also style(), italic(), and QFontInfo.
void QFont::setStyleHint(StyleHint hint, StyleStrategy strategy = PreferDefault)
Sets the style hint and strategy to hint and strategy, respectively.
If these aren't set explicitly the style hint will default to AnyStyle and the style strategy to PreferDefault.
Qt does not support style hints on X11 since this information is not provided by the window system.
See also StyleHint, styleHint(), StyleStrategy, styleStrategy(), and QFontInfo.
void QFont::setStyleName(const QString &styleName)
Sets the style name of the font to styleName. When set, other style properties like style() and weight() will be ignored for font matching.
This function was introduced in Qt 4.8.
See also styleName().
void QFont::setStyleStrategy(StyleStrategy s)
Sets the style strategy for the font to s.
See also styleStrategy() and QFont::StyleStrategy.
void QFont::setUnderline(bool enable)
If enable is true, sets underline on; otherwise sets underline off.
See also underline() and QFontInfo.
void QFont::setWeight(int weight)
Sets the weight of the font to weight, using the scale defined by QFont::Weight enumeration.
See also weight() and QFontInfo.
void QFont::setWordSpacing(qreal spacing)
Sets the word spacing for the font to spacing.
Word spacing changes the default spacing between individual words. A positive value increases the word spacing by a corresponding amount of pixels, while a negative value decreases the inter-word spacing accordingly.
Word spacing will not apply to writing systems, where indiviaul words are not separated by white space.
This function was introduced in Qt 4.4.
See also wordSpacing() and setLetterSpacing().
int QFont::stretch() const
Returns the stretch factor for the font.
See also setStretch().
bool QFont::strikeOut() const
Returns true if strikeout has been set; otherwise returns false.
See also setStrikeOut().
Style QFont::style() const
Returns the style of the font.
See also setStyle().
StyleHint QFont::styleHint() const
Returns the StyleHint.
The style hint affects the font matching algorithm. See QFont::StyleHint for the list of available hints.
See also setStyleHint(), QFont::StyleStrategy, and QFontInfo::styleHint().
QString QFont::styleName() const
Returns the requested font style name, it will be used to match the font with irregular styles (that can't be normalized in other style properties). It depends on system font support, thus only works for macOS and X11 so far. On Windows irregular styles will be added as separate font families so there is no need for this.
This function was introduced in Qt 4.8.
See also setStyleName(), setFamily(), and setStyle().
StyleStrategy QFont::styleStrategy() const
Returns the StyleStrategy.
The style strategy affects the font matching algorithm. See QFont::StyleStrategy for the list of available strategies.
See also setStyleStrategy(), setStyleHint(), and QFont::StyleHint.
[static] QString QFont::substitute(const QString &familyName)
Returns the first family name to be used whenever familyName is specified. The lookup is case insensitive.
If there is no substitution for familyName, familyName is returned.
To obtain a list of substitutions use substitutes().
See also setFamily(), insertSubstitutions(), insertSubstitution(), and removeSubstitutions().
[static] QStringList QFont::substitutes(const QString &familyName)
Returns a list of family names to be used whenever familyName is specified. The lookup is case insensitive.
If there is no substitution for familyName, an empty list is returned.
See also substitute(), insertSubstitutions(), insertSubstitution(), and removeSubstitutions().
[static] QStringList QFont::substitutions()
Returns a sorted list of substituted family names.
See also insertSubstitution(), removeSubstitution(), and substitute().
void QFont::swap(QFont &other)
Swaps this font instance with other. This function is very fast and never fails.
This function was introduced in Qt 5.0.
QString QFont::toString() const
Returns a description of the font. The description is a comma-separated list of the attributes, perfectly suited for use in QSettings.
See also fromString().
bool QFont::underline() const
Returns true if underline has been set; otherwise returns false.
See also setUnderline().
int QFont::weight() const
Returns the weight of the font, using the same scale as the QFont::Weight enumeration.
See also setWeight(), Weight, and QFontInfo.
qreal QFont::wordSpacing() const
Returns the word spacing for the font.
This function was introduced in Qt 4.4.
See also setWordSpacing() and setLetterSpacing().
QFont::operator QVariant() const
Returns the font as a QVariant
bool QFont::operator!=(const QFont &f) const
Returns true if this font is different from f; otherwise returns false.
Two QFonts are considered to be different if their font attributes are different.
See also operator==().
bool QFont::operator<(const QFont &f) const
Provides an arbitrary comparison of this font and font f. All that is guaranteed is that the operator returns false if both fonts are equal and that (f1 < f2) == !(f2 < f1) if the fonts are not equal.
This function is useful in some circumstances, for example if you want to use QFont objects as keys in a QMap.
See also operator==(), operator!=(), and isCopyOf().
QFont &QFont::operator=(const QFont &font)
Assigns font to this font and returns a reference to it.
QFont &QFont::operator=(QFont &&other)
Move-assigns other to this QFont instance.
This function was introduced in Qt 5.2.
bool QFont::operator==(const QFont &f) const
Returns true if this font is equal to f; otherwise returns false.
Two QFonts are considered equal if their font attributes are equal.
See also operator!=() and isCopyOf().
Related Non-Members
uint qHash(const QFont &font, uint seed = 0)
Returns the hash value for font. If specified, seed is used to initialize the hash.
This function was introduced in Qt 5.3.
QDataStream &operator<<(QDataStream &s, const QFont &font)
Writes the font font to the data stream s. (toString() writes to a text stream.)
See also Format of the QDataStream operators.
QDataStream &operator>>(QDataStream &s, QFont &font)
Reads the font font from the data stream s. (fromString() reads from a text stream.)
See also Format of the QDataStream operators.
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