The QPen class defines how a QPainter should draw lines and outlines of shapes. More...

#include <qpen.h>

Public Types
typedef QPenPrivate *	DataPtr

Public Member Functions
	QPen ()

	QPen (Qt::PenStyle)

	QPen (const QColor &color)

	QPen (const QBrush &brush, qreal width, Qt::PenStyle s=Qt::SolidLine, Qt::PenCapStyle c=Qt::SquareCap, Qt::PenJoinStyle j=Qt::BevelJoin)

	QPen (const QPen &pen) noexcept

	~QPen ()

QPen &	operator= (const QPen &pen) noexcept

	QPen (QPen &&other) noexcept

void	swap (QPen &other) noexcept

Qt::PenStyle	style () const

void	setStyle (Qt::PenStyle)
	[0] More...

QList< qreal >	dashPattern () const

void	setDashPattern (const QList< qreal > &pattern)

qreal	dashOffset () const

void	setDashOffset (qreal doffset)

qreal	miterLimit () const

void	setMiterLimit (qreal limit)

qreal	widthF () const

void	setWidthF (qreal width)

int	width () const

void	setWidth (int width)

QColor	color () const

void	setColor (const QColor &color)

QBrush	brush () const

void	setBrush (const QBrush &brush)

bool	isSolid () const

Qt::PenCapStyle	capStyle () const

void	setCapStyle (Qt::PenCapStyle pcs)

Qt::PenJoinStyle	joinStyle () const

void	setJoinStyle (Qt::PenJoinStyle pcs)

bool	isCosmetic () const

void	setCosmetic (bool cosmetic)

bool	operator== (const QPen &p) const

bool	operator!= (const QPen &p) const

	operator QVariant () const

bool	isDetached ()

DataPtr &	data_ptr ()

Friends
Q_GUI_EXPORT QDataStream &	operator>> (QDataStream &, QPen &)

Q_GUI_EXPORT QDataStream &	operator<< (QDataStream &, const QPen &)

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &stream, const QPen &pen)

QDataStream &	operator>> (QDataStream &stream, QPen &pen)

Detailed Description

The QPen class defines how a QPainter should draw lines and outlines of shapes.

\inmodule QtGui

A pen has a style(), width(), brush(), capStyle() and joinStyle().

The pen style defines the line type. The brush is used to fill strokes generated with the pen. Use the QBrush class to specify fill styles. The cap style determines the line end caps that can be drawn using QPainter, while the join style describes how joins between two lines are drawn. The pen width can be specified in both integer (width()) and floating point (widthF()) precision. A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the \l {QPainter::Coordinate Transformations}{transformation} set on the painter.

The various settings can easily be modified using the corresponding setStyle(), setWidth(), setBrush(), setCapStyle() and setJoinStyle() functions (note that the painter's pen must be reset when altering the pen's properties).

For example:

which is equivalent to

The default pen is a solid black brush with 1 width, square cap style (Qt::SquareCap), and bevel join style (Qt::BevelJoin).

In addition QPen provides the color() and setColor() convenience functions to extract and set the color of the pen's brush, respectively. Pens may also be compared and streamed.

For more information about painting in general, see the \l{Paint System} documentation.

Definition at line 60 of file qpen.h.

Member Typedef Documentation

◆ DataPtr

QPen::DataPtr

Definition at line 126 of file qpen.h.

Constructor & Destructor Documentation

◆ QPen() [1/6]

qpen_default_join QPen::QPen ( )

Constructs a default black solid line pen with 1 width.

Definition at line 270 of file qpen.cpp.

◆ QPen() [2/6]

QPen::QPen ( Qt::PenStyle style )

Constructs a black pen with 1 width and the given style.

See also: setStyle()

Definition at line 282 of file qpen.cpp.

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◆ QPen() [3/6]

QPen::QPen ( const QColor & color )

Constructs a solid line pen with 1 width and the given color.

See also: setBrush(), setColor()

Definition at line 299 of file qpen.cpp.

◆ QPen() [4/6]

QPen::QPen	(	const QBrush &	brush,
		qreal	width,
		Qt::PenStyle	style = `Qt::SolidLine`,
		Qt::PenCapStyle	cap = `Qt::SquareCap`,
		Qt::PenJoinStyle	join = `Qt::BevelJoin`
	)

Constructs a pen with the specified brush, width, pen style, cap style and join style.

See also: setBrush(), setWidth(), setStyle(), setCapStyle(), setJoinStyle()

Definition at line 314 of file qpen.cpp.

◆ QPen() [5/6]

QPen::QPen ( const QPen & pen )

noexcept

Constructs a pen that is a copy of the given pen.

Definition at line 325 of file qpen.cpp.

◆ ~QPen()

QPen::~QPen ( )

Destroys the pen.

Definition at line 348 of file qpen.cpp.

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◆ QPen() [6/6]

QPen::QPen ( QPen && pen )

inlinenoexcept

Since: 5.4

Constructs a pen that is moved from the given pen.

The moved-from pen can only be assigned to, copied, or destroyed. Any other operation (prior to assignment) leads to undefined behavior.

Definition at line 73 of file qpen.h.

Member Function Documentation

◆ brush()

QBrush QPen::brush ( ) const

Returns the brush used to fill strokes generated with this pen.

Definition at line 777 of file qpen.cpp.

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◆ capStyle()

Qt::PenCapStyle QPen::capStyle ( ) const

Returns the pen's cap style.

See also: setCapStyle(), {QPen::Cap Style}{Cap Style}

Definition at line 698 of file qpen.cpp.

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◆ color()

QColor QPen::color ( ) const

Returns the color of this pen's brush.

See also: brush(), setColor()

Definition at line 754 of file qpen.cpp.

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◆ dashOffset()

qreal QPen::dashOffset ( ) const

Returns the dash offset for the pen.

See also: setDashOffset()

Definition at line 542 of file qpen.cpp.

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◆ dashPattern()

QList< qreal > QPen::dashPattern ( ) const

Returns the dash pattern of this pen.

See also: style(), isSolid()

Definition at line 456 of file qpen.cpp.

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◆ data_ptr()

DataPtr & QPen::data_ptr ( )

inline

Definition at line 127 of file qpen.h.

◆ isCosmetic()

bool QPen::isCosmetic ( ) const

Returns true if the pen is cosmetic; otherwise returns false.

Cosmetic pens are used to draw strokes that have a constant width regardless of any transformations applied to the QPainter they are used with. Drawing a shape with a cosmetic pen ensures that its outline will have the same thickness at different scale factors.

A zero width pen is cosmetic by default.

See also: setCosmetic(), widthF()

Definition at line 819 of file qpen.cpp.

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◆ isDetached()

bool QPen::isDetached ( )

Definition at line 886 of file qpen.cpp.

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◆ isSolid()

bool QPen::isSolid ( ) const

Returns true if the pen has a solid fill, otherwise false.

See also: style(), dashPattern()

Definition at line 800 of file qpen.cpp.

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◆ joinStyle()

Qt::PenJoinStyle QPen::joinStyle ( ) const

Returns the pen's join style.

See also: setJoinStyle(), {QPen::Join Style}{Join Style}

Definition at line 725 of file qpen.cpp.

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◆ miterLimit()

qreal QPen::miterLimit ( ) const

Returns the miter limit of the pen. The miter limit is only relevant when the join style is set to Qt::MiterJoin.

See also: setMiterLimit(), {QPen::Join Style}{Join Style}

Definition at line 584 of file qpen.cpp.

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◆ operator QVariant()

QPen::operator QVariant ( ) const

Returns the pen as a QVariant.

Definition at line 409 of file qpen.cpp.

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◆ operator!=()

bool QPen::operator!= ( const QPen & pen ) const

inline

Returns true if the pen is different from the given pen; otherwise false. Two pens are different if they have different styles, widths or colors.

See also: operator==()

Definition at line 114 of file qpen.h.

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◆ operator=()

QPen & QPen::operator= ( const QPen & pen )

noexcept

Assigns the given pen to this pen and returns a reference to this pen.

Move-assigns other to this QPen instance.

Since: 5.2

Definition at line 384 of file qpen.cpp.

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◆ operator==()

bool QPen::operator== ( const QPen & pen ) const

Returns true if the pen is equal to the given pen; otherwise false. Two pens are equal if they have equal styles, widths and colors.

See also: operator!=()

Definition at line 862 of file qpen.cpp.

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◆ setBrush()

void QPen::setBrush ( const QBrush & brush )

Sets the brush used to fill strokes generated with this pen to the given brush.

See also: brush(), setColor()

Definition at line 788 of file qpen.cpp.

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◆ setCapStyle()

void QPen::setCapStyle ( Qt::PenCapStyle style )

Sets the pen's cap style to the given style. The default value is Qt::SquareCap.

See also: capStyle(), {QPen::Cap Style}{Cap Style}

Definition at line 712 of file qpen.cpp.

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◆ setColor()

void QPen::setColor ( const QColor & color )

Sets the color of this pen's brush to the given color.

See also: setBrush(), color()

Definition at line 767 of file qpen.cpp.

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◆ setCosmetic()

void QPen::setCosmetic ( bool cosmetic )

Sets this pen to cosmetic or non-cosmetic, depending on the value of cosmetic.

See also: isCosmetic()

Definition at line 833 of file qpen.cpp.

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◆ setDashOffset()

void QPen::setDashOffset ( qreal offset )

Sets the dash offset (the starting point on the dash pattern) for this pen to the offset specified. The offset is measured in terms of the units used to specify the dash pattern.

\table \row

\inlineimage qpen-dashpattern.png
For example, a pattern where each stroke is four units long, followed by a gap of two units, will begin with the stroke when drawn as a line.

However, if the dash offset is set to 4.0, any line drawn will begin with the gap. Values of the offset up to 4.0 will cause part of the stroke to be drawn first, and values of the offset between 4.0 and 6.0 will cause the line to begin with part of the gap. \endtable

Note: This implicitly converts the style of the pen to Qt::CustomDashLine.

Definition at line 565 of file qpen.cpp.

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◆ setDashPattern()

void QPen::setDashPattern ( const QList< qreal > & pattern )

Sets the dash pattern for this pen to the given pattern. This implicitly converts the style of the pen to Qt::CustomDashLine.

The pattern must be specified as an even number of positive entries where the entries 1, 3, 5... are the dashes and 2, 4, 6... are the spaces. For example:

\table 100% \row

\inlineimage qpen-custom.png
\endtable

The dash pattern is specified in units of the pens width; e.g. a dash of length 5 in width 10 is 50 pixels long. Note that a pen with zero width is equivalent to a cosmetic pen with a width of 1 pixel.

Each dash is also subject to cap styles so a dash of 1 with square cap set will extend 0.5 pixels out in each direction resulting in a total width of 2.

Note that the default cap style is Qt::SquareCap, meaning that a square line end covers the end point and extends beyond it by half the line width.

See also: setStyle(), dashPattern(), setCapStyle(), setCosmetic()

Definition at line 520 of file qpen.cpp.

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◆ setJoinStyle()

void QPen::setJoinStyle ( Qt::PenJoinStyle style )

Sets the pen's join style to the given style. The default value is Qt::BevelJoin.

See also: joinStyle(), {QPen::Join Style}{Join Style}

Definition at line 739 of file qpen.cpp.

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◆ setMiterLimit()

void QPen::setMiterLimit ( qreal limit )

Sets the miter limit of this pen to the given limit.

The miter limit describes how far a miter join can extend from the join point. This is used to reduce artifacts between line joins where the lines are close to parallel.

This value does only have effect when the pen style is set to Qt::MiterJoin. The value is specified in units of the pen's width, e.g. a miter limit of 5 in width 10 is 50 pixels long. The default miter limit is 2, i.e. twice the pen width in pixels.

See also: miterLimit(), setJoinStyle(), {QPen::Join Style}{Join Style}

Definition at line 606 of file qpen.cpp.

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◆ setStyle()

void QPen::setStyle ( Qt::PenStyle style )

[0]

Sets the pen style to the given style.

See the \l Qt::PenStyle documentation for a list of the available styles. Since Qt 4.1 it is also possible to specify a custom dash pattern using the setDashPattern() function which implicitly converts the style of the pen to Qt::CustomDashLine.

Note: This function resets the dash offset to zero.

See also: style(), {QPen::Pen Style}{Pen Style}

Definition at line 52 of file doc_src_groups.cpp.

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◆ setWidth()

void QPen::setWidth ( int width )

Sets the pen width to the given width in pixels with integer precision.

A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the \l {QPainter::Coordinate Transformations}{transformation} set on the painter.

Setting a pen width with a negative value is not supported.

See also: setWidthF(), width()

Definition at line 654 of file qpen.cpp.

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◆ setWidthF()

void QPen::setWidthF ( qreal width )

Sets the pen width to the given width in pixels with floating point precision.

A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the \l {QPainter::Coordinate Transformations}{transformation} on the painter.

Setting a pen width with a negative value is not supported.

See also: setWidth(), widthF()

Definition at line 680 of file qpen.cpp.

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◆ style()

Qt::PenStyle QPen::style ( ) const

Returns the pen style.

See also: setStyle(), {QPen::Pen Style}{Pen Style}

Definition at line 421 of file qpen.cpp.

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◆ swap()

void QPen::swap ( QPen & other )

inlinenoexcept

Since: 4.8

Swaps pen other with this pen. This operation is very fast and never fails.

Definition at line 76 of file qpen.h.

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◆ width()

int QPen::width ( ) const

Returns the pen width with integer precision.

See also: setWidth(), widthF()

Definition at line 622 of file qpen.cpp.

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◆ widthF()

qreal QPen::widthF ( ) const

Returns the pen width with floating point precision.

See also: setWidthF(), width()

Definition at line 634 of file qpen.cpp.

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Friends And Related Function Documentation

◆ operator<< [1/2]

QDataStream & operator<<	(	QDataStream &	stream,
		const QPen &	pen
	)

friend

Writes the given pen to the given stream and returns a reference to the stream.

See also: {Serializing Qt Data Types}

Definition at line 906 of file qpen.cpp.

◆ operator<<() [2/2]

QDataStream & operator<<	(	QDataStream &	stream,
		const QPen &	pen
	)

See also: {Serializing Qt Data Types}

Definition at line 906 of file qpen.cpp.

◆ operator>> [1/2]

QDataStream & operator>>	(	QDataStream &	stream,
		QPen &	pen
	)

friend

Reads a pen from the given stream into the given pen and returns a reference to the stream.

See also: {Serializing Qt Data Types}

Definition at line 954 of file qpen.cpp.

◆ operator>>() [2/2]

QDataStream & operator>>	(	QDataStream &	stream,
		QPen &	pen
	)

See also: {Serializing Qt Data Types}

Definition at line 954 of file qpen.cpp.

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

src/gui/painting/qpen.h
src/corelib/doc/snippets/code/doc_src_groups.cpp
src/gui/painting/qpen.cpp

Public Types

Public Member Functions

Friends

Related Functions

Detailed Description

Member Typedef Documentation

◆ DataPtr

Constructor & Destructor Documentation

◆ QPen() [1/6]

◆ QPen() [2/6]

◆ QPen() [3/6]

◆ QPen() [4/6]

◆ QPen() [5/6]

◆ ~QPen()

◆ QPen() [6/6]

Member Function Documentation

◆ brush()

◆ capStyle()

◆ color()

◆ dashOffset()

◆ dashPattern()

◆ data_ptr()

◆ isCosmetic()

◆ isDetached()

◆ isSolid()

◆ joinStyle()

◆ miterLimit()

◆ operator QVariant()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ setBrush()

◆ setCapStyle()

◆ setColor()

◆ setCosmetic()

◆ setDashOffset()

◆ setDashPattern()

◆ setJoinStyle()

◆ setMiterLimit()

◆ setStyle()

◆ setWidth()

◆ setWidthF()

◆ style()

◆ swap()

◆ width()

◆ widthF()

Friends And Related Function Documentation

◆ operator<< [1/2]

◆ operator<<() [2/2]

◆ operator>> [1/2]

◆ operator>>() [2/2]