QFontInfo Class
The QFontInfo class provides general information about fonts. 更多...
| 头文件: | #include <QFontInfo> |
| qmake: | QT += gui |
Note: All functions in this class are reentrant.
公有函数
| QFontInfo(const QFont &font) | |
| QFontInfo(const QFontInfo &fi) | |
| ~QFontInfo() | |
| bool | bold() const |
| bool | exactMatch() const |
| QString | family() const |
| bool | fixedPitch() const |
| bool | italic() const |
| int | pixelSize() const |
| int | pointSize() const |
| qreal | pointSizeF() const |
| QFont::Style | style() const |
| QFont::StyleHint | styleHint() const |
| QString | styleName() const |
| void | swap(QFontInfo &other) |
| int | weight() const |
| QFontInfo & | operator=(const QFontInfo &fi) |
详细描述
The QFontInfo class provides general information about fonts.
The QFontInfo class provides the same access functions as QFont, e.g. family(), pointSize(), italic(), weight(), fixedPitch(), styleHint() etc. But whilst the QFont access functions return the values that were set, a QFontInfo object returns the values that apply to the font that will actually be used to draw the text.
For example, when the program asks for a 25pt Courier font on a machine that has a non-scalable 24pt Courier font, QFont will (normally) use the 24pt Courier for rendering. In this case, QFont::pointSize() returns 25 and QFontInfo::pointSize() returns 24.
There are three ways to create a QFontInfo object.
- Calling the QFontInfo constructor with a QFont creates a font info object for a screen-compatible font, i.e. the font cannot be a printer font. If the font is changed later, the font info object is not updated.
(Note: If you use a printer font the values returned may be inaccurate. Printer fonts are not always accessible so the nearest screen font is used if a printer font is supplied.)
- QWidget::fontInfo() returns the font info for a widget's font. This is equivalent to calling QFontInfo(widget->font()). If the widget's font is changed later, the font info object is not updated.
- QPainter::fontInfo() returns the font info for a painter's current font. If the painter's font is changed later, the font info object is not updated.
参见 QFont, QFontMetrics, and QFontDatabase.
成员函数
QFontInfo::QFontInfo(const QFont &font)
Constructs a font info object for font.
The font must be screen-compatible, i.e. a font you use when drawing text in widgets or pixmaps, not QPicture or QPrinter.
The font info object holds the information for the font that is passed in the constructor at the time it is created, and is not updated if the font's attributes are changed later.
Use QPainter::fontInfo() to get the font info when painting. This will give correct results also when painting on paint device that is not screen-compatible.
QFontInfo::QFontInfo(const QFontInfo &fi)
Constructs a copy of fi.
QFontInfo::~QFontInfo()
Destroys the font info object.
bool QFontInfo::bold() const
Returns true if weight() would return a value greater than QFont::Normal; otherwise returns false.
参见 weight() and QFont::bold().
bool QFontInfo::exactMatch() const
Returns true if the matched window system font is exactly the same as the one specified by the font; otherwise returns false.
参见 QFont::exactMatch().
QString QFontInfo::family() const
Returns the family name of the matched window system font.
参见 QFont::family().
bool QFontInfo::fixedPitch() const
Returns the fixed pitch value of the matched window system font.
参见 QFont::fixedPitch().
bool QFontInfo::italic() const
Returns the italic value of the matched window system font.
参见 QFont::italic().
int QFontInfo::pixelSize() const
Returns the pixel size of the matched window system font.
参见 QFont::pointSize().
int QFontInfo::pointSize() const
Returns the point size of the matched window system font.
参见 pointSizeF() and QFont::pointSize().
qreal QFontInfo::pointSizeF() const
Returns the point size of the matched window system font.
参见 QFont::pointSizeF().
QFont::Style QFontInfo::style() const
Returns the style value of the matched window system font.
参见 QFont::style().
QFont::StyleHint QFontInfo::styleHint() const
Returns the style of the matched window system font.
Currently only returns the style hint set in QFont.
参见 QFont::styleHint() and QFont::StyleHint.
QString QFontInfo::styleName() const
Returns the style name of the matched window system font on systems that support it.
This function was introduced in Qt 4.8.
参见 QFont::styleName().
void QFontInfo::swap(QFontInfo &other)
Swaps this font info instance with other. This function is very fast and never fails.
This function was introduced in Qt 5.0.
int QFontInfo::weight() const
Returns the weight of the matched window system font.
参见 QFont::weight() and bold().
QFontInfo &QFontInfo::operator=(const QFontInfo &fi)
Assigns the font info in fi.