QtGui.QFontMetrics Class Reference

The QFontMetrics class provides font metrics information. More...

Inheritance diagram for QtGui.QFontMetrics:

Collaboration diagram for QtGui.QFontMetrics:

Public Member Functions
override bool	Equals (object o)
override int	GetHashCode ()
	QFontMetrics (QFont arg1)
	QFontMetrics (QFontMetrics arg1)
	QFontMetrics (QFont arg1, IQPaintDevice pd)
virtual void	CreateProxy ()
new int	Ascent ()
new int	AverageCharWidth ()
new QRect	BoundingRect (QChar arg1)
new QRect	BoundingRect (QRect r, int flags, string text, int tabstops=0)
new QRect	BoundingRect (QRect r, int flags, string text, int tabstops, ref int tabarray)
new QRect	BoundingRect (string text)
new QRect	BoundingRect (int x, int y, int w, int h, int flags, string text, int tabstops=0)
new QRect	BoundingRect (int x, int y, int w, int h, int flags, string text, int tabstops, ref int tabarray)
new int	CharWidth (string str, int pos)
new int	Descent ()
new string	ElidedText (string text, Qt.TextElideMode mode, int width, int flags=0)
new int	Height ()
new bool	InFont (QChar arg1)
new bool	InFontUcs4 (uint ucs4)
new int	Leading ()
new int	LeftBearing (QChar arg1)
new int	LineSpacing ()
new int	LineWidth ()
new int	MaxWidth ()
new int	MinLeftBearing ()
new int	MinRightBearing ()
new int	OverlinePos ()
new int	RightBearing (QChar arg1)
new QSize	Size (int flags, string str, int tabstops=0)
new QSize	Size (int flags, string str, int tabstops, ref int tabarray)
new int	StrikeOutPos ()
new QRect	TightBoundingRect (string text)
new int	UnderlinePos ()
new int	Width (QChar arg1)
new int	Width (string arg1, int len=-1)
new int	Width (string arg1, int len, int flags)
new int	xHeight ()
new void	Dispose ()

Static Public Member Functions
static bool	operator!= (QFontMetrics arg1, QFontMetrics arg2)
static bool	operator== (QFontMetrics arg1, QFontMetrics arg2)

Protected Member Functions
	QFontMetrics (System.Type dummy)

Protected Attributes
SmokeInvocation	interceptor

Properties
virtual System.IntPtr	SmokeObject [get, set]

Detailed Description

The QFontMetrics class provides font metrics information.

QFontMetrics functions calculate the size of characters and strings for a given font. There are three ways you can create a QFontMetrics object:

Calling the QFontMetrics constructor with a QFont creates a font metrics object for a screen-compatible font, i.e. the font cannot be a printer font. If the font is changed later, the font metrics 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::fontMetrics() returns the font metrics for a widget's font. This is equivalent to QFontMetrics(widget->font()). If the widget's font is changed later, the font metrics object is not updated.

QPainter::fontMetrics() returns the font metrics for a painter's current font. If the painter's font is changed later, the font metrics object is not updated.

Once created, the object provides functions to access the individual metrics of the font, its characters, and for strings rendered in the font.

There are several functions that operate on the font: ascent(), descent(), height(), leading() and lineSpacing() return the basic size properties of the font. The underlinePos(), overlinePos(), strikeOutPos() and lineWidth() functions, return the properties of the line that underlines, overlines or strikes out the characters. These functions are all fast.

There are also some functions that operate on the set of glyphs in the font: minLeftBearing(), minRightBearing() and maxWidth(). These are by necessity slow, and we recommend avoiding them if possible.

For each character, you can get its width(), leftBearing() and rightBearing() and find out whether it is in the font using inFont(). You can also treat the character as a string, and use the string functions on it.

The string functions include width(), to return the width of a string in pixels (or points, for a printer), boundingRect(), to return a rectangle large enough to contain the rendered string, and size(), to return the size of that rectangle.

Example:

QFont font("times", 24);

QFontMetrics fm(font);

int pixelsWide = fm.width("What's the width of this text?");

int pixelsHigh = fm.height();

See also QFont, QFontInfo, QFontDatabase, QFontComboBox, and Character Map Example.

Constructor & Destructor Documentation

QtGui.QFontMetrics.QFontMetrics ( System.Type  dummy )

protected

QtGui.QFontMetrics.QFontMetrics

(

QFont

arg1

)

Constructs a font metrics object for font.

The font metrics will be compatible with the paintdevice used to create font.

The font metrics 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 QFontMetrics(const QFont &, QPaintDevice *) to get the font metrics that are compatible with a certain paint device.

QtGui.QFontMetrics.QFontMetrics

(

QFontMetrics

arg1

)

Constructs a copy of fm.

QtGui.QFontMetrics.QFontMetrics	(	QFont	arg1,
		IQPaintDevice	pd
	)

Constructs a font metrics object for font and paintdevice.

The font metrics will be compatible with the paintdevice passed. If the paintdevice is 0, the metrics will be screen-compatible, ie. the metrics you get if you use the font for drawing text on a widgets or pixmaps, not on a QPicture or QPrinter.

The font metrics 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.

Member Function Documentation

new int QtGui.QFontMetrics.Ascent

(

)

Returns the ascent of the font.

The ascent of a font is the distance from the baseline to the highest position characters extend to. In practice, some font designers break this rule, e.g. when they put more than one accent on top of a character, or to accommodate an unusual character in an exotic language, so it is possible (though rare) that this value will be too small.

See also descent().

new int QtGui.QFontMetrics.AverageCharWidth

(

)

Returns the average width of glyphs in the font.

This function was introduced in Qt 4.2.

new QRect QtGui.QFontMetrics.BoundingRect

(

QChar

arg1

)

Returns the rectangle that is covered by ink if character ch were to be drawn at the origin of the coordinate system.

Note that the bounding rectangle may extend to the left of (0, 0) (e.g., for italicized fonts), and that the text output may cover all pixels in the bounding rectangle. For a space character the rectangle will usually be empty.

Note that the rectangle usually extends both above and below the base line.

Warning: The width of the returned rectangle is not the advance width of the character. Use boundingRect(const QString &) or width() instead.

See also width().

new QRect QtGui.QFontMetrics.BoundingRect	(	QRect	r,
		int	flags,
		string	text,
		int	tabstops = 0
	)

Returns the rectangle that is covered by ink if character ch were to be drawn at the origin of the coordinate system.

Note that the bounding rectangle may extend to the left of (0, 0) (e.g., for italicized fonts), and that the text output may cover all pixels in the bounding rectangle. For a space character the rectangle will usually be empty.

Note that the rectangle usually extends both above and below the base line.

Warning: The width of the returned rectangle is not the advance width of the character. Use boundingRect(const QString &) or width() instead.

See also width().

new QRect QtGui.QFontMetrics.BoundingRect	(	QRect	r,
		int	flags,
		string	text,
		int	tabstops,
		ref int	tabarray
	)

This is an overloaded function.

Returns the bounding rectangle of the characters in the string specified by text, which is the set of pixels the text would cover if drawn at (0, 0). The drawing, and hence the bounding rectangle, is constrained to the rectangle rect.

The flags argument is the bitwise OR of the following flags:

Qt::AlignLeft aligns to the left border, except for Arabic and Hebrew where it aligns to the right.

Qt::AlignRight aligns to the right border, except for Arabic and Hebrew where it aligns to the left.

Qt::AlignJustify produces justified text.

Qt::AlignHCenter aligns horizontally centered.

Qt::AlignTop aligns to the top border.

Qt::AlignBottom aligns to the bottom border.

Qt::AlignVCenter aligns vertically centered

Qt::AlignCenter (== Qt::AlignHCenter | Qt::AlignVCenter)

Qt::TextSingleLine ignores newline characters in the text.

Qt::TextExpandTabs expands tabs (see below)

Qt::TextShowMnemonic interprets "&x" as x; i.e., underlined.

Qt::TextWordWrap breaks the text to fit the rectangle.

Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical alignment defaults to Qt::AlignTop.

If several of the horizontal or several of the vertical alignment flags are set, the resulting alignment is undefined.

If Qt::TextExpandTabs is set in flags, then: if tabArray is non-null, it specifies a 0-terminated sequence of pixel-positions for tabs; otherwise if tabStops is non-zero, it is used as the tab spacing (in pixels).

Note that the bounding rectangle may extend to the left of (0, 0), e.g. for italicized fonts, and that the text output may cover all pixels in the bounding rectangle.

Newline characters are processed as linebreaks.

Despite the different actual character heights, the heights of the bounding rectangles of "Yes" and "yes" are the same.

The bounding rectangle returned by this function is somewhat larger than that calculated by the simpler boundingRect() function. This function uses the maximum left and right font bearings as is necessary for multi-line text to align correctly. Also, fontHeight() and lineSpacing() are used to calculate the height, rather than individual character heights.

See also width(), QPainter::boundingRect(), and Qt::Alignment.

new QRect QtGui.QFontMetrics.BoundingRect

(

string

text

)

Returns the bounding rectangle of the characters in the string specified by text. The bounding rectangle always covers at least the set of pixels the text would cover if drawn at (0, 0).

Note that the bounding rectangle may extend to the left of (0, 0), e.g. for italicized fonts, and that the width of the returned rectangle might be different than what the width() method returns.

If you want to know the advance width of the string (to layout a set of strings next to each other), use width() instead.

Newline characters are processed as normal characters, not as linebreaks.

The height of the bounding rectangle is at least as large as the value returned by height().

See also width(), height(), QPainter::boundingRect(), and tightBoundingRect().

new QRect QtGui.QFontMetrics.BoundingRect	(	int	x,
		int	y,
		int	w,
		int	h,
		int	flags,
		string	text,
		int	tabstops = 0
	)

Returns the rectangle that is covered by ink if character ch were to be drawn at the origin of the coordinate system.

Note that the bounding rectangle may extend to the left of (0, 0) (e.g., for italicized fonts), and that the text output may cover all pixels in the bounding rectangle. For a space character the rectangle will usually be empty.

Note that the rectangle usually extends both above and below the base line.

Warning: The width of the returned rectangle is not the advance width of the character. Use boundingRect(const QString &) or width() instead.

See also width().

new QRect QtGui.QFontMetrics.BoundingRect	(	int	x,
		int	y,
		int	w,
		int	h,
		int	flags,
		string	text,
		int	tabstops,
		ref int	tabarray
	)

This is an overloaded function.

Returns the bounding rectangle for the given text within the rectangle specified by the x and y coordinates, width, and height.

If Qt::TextExpandTabs is set in flags and tabArray is non-null, it specifies a 0-terminated sequence of pixel-positions for tabs; otherwise, if tabStops is non-zero, it is used as the tab spacing (in pixels).

new int QtGui.QFontMetrics.CharWidth	(	string	str,
		int	pos
	)

Returns the width of the character at position pos in the string text.

The whole string is needed, as the glyph drawn may change depending on the context (the letter before and after the current one) for some languages (e.g. Arabic).

This function also takes non spacing marks and ligatures into account.

virtual void QtGui.QFontMetrics.CreateProxy ( )

virtual

new int QtGui.QFontMetrics.Descent

(

)

Returns the descent of the font.

The descent is the distance from the base line to the lowest point characters extend to. In practice, some font designers break this rule, e.g. to accommodate an unusual character in an exotic language, so it is possible (though rare) that this value will be too small.

See also ascent().

new void QtGui.QFontMetrics.Dispose

(

)

new string QtGui.QFontMetrics.ElidedText	(	string	text,
		Qt.TextElideMode	mode,
		int	width,
		int	flags = 0
	)

If the string text is wider than width, returns an elided version of the string (i.e., a string with "..." in it). Otherwise, returns the original string.

The mode parameter specifies whether the text is elided on the left (e.g., "...tech"), in the middle (e.g., "Tr...ch"), or on the right (e.g., "Trol...").

The width is specified in pixels, not characters.

The flags argument is optional and currently only supports Qt::TextShowMnemonic as value.

The elide mark will follow the layout direction; it will be on the right side of the text for right-to-left layouts, and on the left side for right-to-left layouts. Note that this behavior is independent of the text language.

This function was introduced in Qt 4.2.

override bool QtGui.QFontMetrics.Equals

(

object

o

)

override int QtGui.QFontMetrics.GetHashCode

(

)

new int QtGui.QFontMetrics.Height

(

)

Returns the height of the font.

This is always equal to ascent()+descent()+1 (the 1 is for the base line).

See also leading() and lineSpacing().

new bool QtGui.QFontMetrics.InFont

(

QChar

arg1

)

Returns true if character ch is a valid character in the font; otherwise returns false.

new bool QtGui.QFontMetrics.InFontUcs4

(

uint

ucs4

)

Returns true if the given character encoded in UCS-4/UTF-32 is a valid character in the font; otherwise returns false.

This function was introduced in Qt 4.8.

new int QtGui.QFontMetrics.Leading

(

)

Returns the leading of the font.

This is the natural inter-line spacing.

See also height() and lineSpacing().

new int QtGui.QFontMetrics.LeftBearing

(

QChar

arg1

)

Returns the left bearing of character ch in the font.

The left bearing is the right-ward distance of the left-most pixel of the character from the logical origin of the character. This value is negative if the pixels of the character extend to the left of the logical origin.

See width(QChar) for a graphical description of this metric.

See also rightBearing(), minLeftBearing(), and width().

new int QtGui.QFontMetrics.LineSpacing

(

)

Returns the distance from one base line to the next.

This value is always equal to leading()+height().

See also height() and leading().

new int QtGui.QFontMetrics.LineWidth

(

)

Returns the width of the underline and strikeout lines, adjusted for the point size of the font.

See also underlinePos(), overlinePos(), and strikeOutPos().

new int QtGui.QFontMetrics.MaxWidth

(

)

Returns the width of the widest character in the font.

new int QtGui.QFontMetrics.MinLeftBearing

(

)

Returns the minimum left bearing of the font.

This is the smallest leftBearing(char) of all characters in the font.

Note that this function can be very slow if the font is large.

See also minRightBearing() and leftBearing().

new int QtGui.QFontMetrics.MinRightBearing

(

)

Returns the minimum right bearing of the font.

This is the smallest rightBearing(char) of all characters in the font.

Note that this function can be very slow if the font is large.

See also minLeftBearing() and rightBearing().

static bool QtGui.QFontMetrics.operator!= ( QFontMetrics  arg1, QFontMetrics  arg2  )

static

Returns true if other is not equal to this object; otherwise returns false.

Two font metrics are considered equal if they were constructed from the same QFont and the paint devices they were constructed for are considered compatible.

See also operator==().

static bool QtGui.QFontMetrics.operator== ( QFontMetrics  arg1, QFontMetrics  arg2  )

static

Returns true if other is equal to this object; otherwise returns false.

Two font metrics are considered equal if they were constructed from the same QFont and the paint devices they were constructed for are considered compatible.

See also operator!=().

new int QtGui.QFontMetrics.OverlinePos

(

)

Returns the distance from the base line to where an overline should be drawn.

See also underlinePos(), strikeOutPos(), and lineWidth().

new int QtGui.QFontMetrics.RightBearing

(

QChar

arg1

)

Returns the right bearing of character ch in the font.

The right bearing is the left-ward distance of the right-most pixel of the character from the logical origin of a subsequent character. This value is negative if the pixels of the character extend to the right of the width() of the character.

See width() for a graphical description of this metric.

See also leftBearing(), minRightBearing(), and width().

new QSize QtGui.QFontMetrics.Size	(	int	flags,
		string	str,
		int	tabstops = 0
	)

Returns the size in pixels of text.

The flags argument is the bitwise OR of the following flags:

Qt::TextSingleLine ignores newline characters.

Qt::TextExpandTabs expands tabs (see below)

Qt::TextShowMnemonic interprets "&x" as x; i.e., underlined.

Qt::TextWordBreak breaks the text to fit the rectangle.

If Qt::TextExpandTabs is set in flags, then: if tabArray is non-null, it specifies a 0-terminated sequence of pixel-positions for tabs; otherwise if tabStops is non-zero, it is used as the tab spacing (in pixels).

Newline characters are processed as linebreaks.

Despite the different actual character heights, the heights of the bounding rectangles of "Yes" and "yes" are the same.

See also boundingRect().

new QSize QtGui.QFontMetrics.Size	(	int	flags,
		string	str,
		int	tabstops,
		ref int	tabarray
	)

Returns the size in pixels of text.

The flags argument is the bitwise OR of the following flags:

Qt::TextSingleLine ignores newline characters.

Qt::TextExpandTabs expands tabs (see below)

Qt::TextShowMnemonic interprets "&x" as x; i.e., underlined.

Qt::TextWordBreak breaks the text to fit the rectangle.

If Qt::TextExpandTabs is set in flags, then: if tabArray is non-null, it specifies a 0-terminated sequence of pixel-positions for tabs; otherwise if tabStops is non-zero, it is used as the tab spacing (in pixels).

Newline characters are processed as linebreaks.

Despite the different actual character heights, the heights of the bounding rectangles of "Yes" and "yes" are the same.

See also boundingRect().

new int QtGui.QFontMetrics.StrikeOutPos

(

)

Returns the distance from the base line to where the strikeout line should be drawn.

See also underlinePos(), overlinePos(), and lineWidth().

new QRect QtGui.QFontMetrics.TightBoundingRect

(

string

text

)

Returns a tight bounding rectangle around the characters in the string specified by text. The bounding rectangle always covers at least the set of pixels the text would cover if drawn at (0, 0).

Note that the bounding rectangle may extend to the left of (0, 0), e.g. for italicized fonts, and that the width of the returned rectangle might be different than what the width() method returns.

If you want to know the advance width of the string (to layout a set of strings next to each other), use width() instead.

Newline characters are processed as normal characters, not as linebreaks.

Warning: Calling this method is very slow on Windows.

This function was introduced in Qt 4.3.

See also width(), height(), and boundingRect().

new int QtGui.QFontMetrics.UnderlinePos

(

)

Returns the distance from the base line to where an underscore should be drawn.

See also overlinePos(), strikeOutPos(), and lineWidth().

new int QtGui.QFontMetrics.Width

(

QChar

arg1

)

This is an overloaded function.

Returns the logical width of character ch in pixels. This is a distance appropriate for drawing a subsequent character after ch.

Some of the metrics are described in the image to the right. The central dark rectangles cover the logical width() of each character. The outer pale rectangles cover the leftBearing() and rightBearing() of each character. Notice that the bearings of "f" in this particular font are both negative, while the bearings of "o" are both positive.

Warning: This function will produce incorrect results for Arabic characters or non-spacing marks in the middle of a string, as the glyph shaping and positioning of marks that happens when processing strings cannot be taken into account. When implementing an interactive text control, use QTextLayout instead.

See also boundingRect().

new int QtGui.QFontMetrics.Width	(	string	arg1,
		int	len = -1
	)

Returns the width in pixels of the first len characters of text. If len is negative (the default), the entire string is used.

Note that this value is not equal to boundingRect().width(); boundingRect() returns a rectangle describing the pixels this string will cover whereas width() returns the distance to where the next string should be drawn.

See also boundingRect().

new int QtGui.QFontMetrics.Width	(	string	arg1,
		int	len,
		int	flags
	)

Returns the width in pixels of the first len characters of text. If len is negative (the default), the entire string is used.

Note that this value is not equal to boundingRect().width(); boundingRect() returns a rectangle describing the pixels this string will cover whereas width() returns the distance to where the next string should be drawn.

See also boundingRect().

new int QtGui.QFontMetrics.xHeight

(

)

Returns the 'x' height of the font. This is often but not always the same as the height of the character 'x'.

Member Data Documentation

SmokeInvocation QtGui.QFontMetrics.interceptor

protected

Property Documentation

virtual System.IntPtr QtGui.QFontMetrics.SmokeObject

getset