The QPainterPath class provides a container for painting operations, enabling graphical shapes to be constructed and reused. More...

Inheritance diagram for QtGui.QPainterPath:

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Collaboration diagram for QtGui.QPainterPath:

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Classes
class	Element
	The QPainterPath::Element class specifies the position and type of a subpath. More...

Public Types
enum	ElementType { CurveToDataElement = 3, CurveToElement = 2, LineToElement = 1, MoveToElement = 0 }
	More...

Public Member Functions
override bool	Equals (object o)

override int	GetHashCode ()

	QPainterPath ()


	QPainterPath (QPointF startPoint)


	QPainterPath (QPainterPath other)


virtual void	CreateProxy ()

new void	AddEllipse (QRectF rect)


new void	AddEllipse (QPointF center, double rx, double ry)


new void	AddEllipse (double x, double y, double w, double h)


new void	AddPath (QPainterPath path)


new void	AddPolygon (QPolygonF polygon)


new void	AddRect (QRectF rect)


new void	AddRect (double x, double y, double w, double h)


new void	AddRegion (QRegion region)


new void	AddRoundRect (QRectF rect, int roundness)


new void	AddRoundRect (QRectF rect, int xRnd, int yRnd)


new void	AddRoundRect (double x, double y, double w, double h, int roundness)


new void	AddRoundRect (double x, double y, double w, double h, int xRnd, int yRnd)


new void	AddRoundedRect (QRectF rect, double xRadius, double yRadius, Qt.SizeMode mode=Qt.SizeMode.AbsoluteSize)


new void	AddRoundedRect (double x, double y, double w, double h, double xRadius, double yRadius, Qt.SizeMode mode=Qt.SizeMode.AbsoluteSize)


new void	AddText (QPointF point, QFont f, string text)


new void	AddText (double x, double y, QFont f, string text)


new double	AngleAtPercent (double t)


new void	ArcMoveTo (QRectF rect, double angle)


new void	ArcMoveTo (double x, double y, double w, double h, double angle)


new void	ArcTo (QRectF rect, double startAngle, double arcLength)


new void	ArcTo (double x, double y, double w, double h, double startAngle, double arcLength)


new QRectF	BoundingRect ()


new void	CloseSubpath ()


new void	ConnectPath (QPainterPath path)


new bool	Contains (QPointF pt)


new bool	Contains (QRectF rect)


new bool	Contains (QPainterPath p)


new QRectF	ControlPointRect ()


new void	CubicTo (QPointF ctrlPt1, QPointF ctrlPt2, QPointF endPt)


new void	CubicTo (double ctrlPt1x, double ctrlPt1y, double ctrlPt2x, double ctrlPt2y, double endPtx, double endPty)


new QPointF	CurrentPosition ()


new QPainterPath.Element	ElementAt (int i)


new int	ElementCount ()


new QPainterPath	Intersected (QPainterPath r)


new bool	Intersects (QRectF rect)


new bool	Intersects (QPainterPath p)


new bool	IsEmpty ()


new double	Length ()


new void	LineTo (QPointF p)


new void	LineTo (double x, double y)


new void	MoveTo (QPointF p)


new void	MoveTo (double x, double y)


new double	PercentAtLength (double t)


new QPointF	PointAtPercent (double t)


new void	QuadTo (QPointF ctrlPt, QPointF endPt)


new void	QuadTo (double ctrlPtx, double ctrlPty, double endPtx, double endPty)


new void	SetElementPositionAt (int i, double x, double y)


new QPainterPath	Simplified ()


new double	SlopeAtPercent (double t)


new QPainterPath	Subtracted (QPainterPath r)


new QPainterPath	SubtractedInverted (QPainterPath r)


new void	Swap (QPainterPath other)


new QPolygonF	ToFillPolygon ()


new QPolygonF	ToFillPolygon (QMatrix matrix)


new QPolygonF	ToFillPolygon (QTransform matrix)


new System.Collections.Generic.List < QPolygonF >	ToFillPolygons ()


new System.Collections.Generic.List < QPolygonF >	ToFillPolygons (QMatrix matrix)


new System.Collections.Generic.List < QPolygonF >	ToFillPolygons (QTransform matrix)


new QPainterPath	ToReversed ()


new System.Collections.Generic.List < QPolygonF >	ToSubpathPolygons ()


new System.Collections.Generic.List < QPolygonF >	ToSubpathPolygons (QMatrix matrix)


new System.Collections.Generic.List < QPolygonF >	ToSubpathPolygons (QTransform matrix)


new void	Translate (QPointF offset)


new void	Translate (double dx, double dy)


new QPainterPath	Translated (QPointF offset)


new QPainterPath	Translated (double dx, double dy)


new QPainterPath	United (QPainterPath r)


new void	Dispose ()

Static Public Member Functions
static QPainterPath	operator* (QPainterPath arg1, QMatrix arg2)

static QPainterPath	operator* (QPainterPath arg1, QTransform arg2)

static bool	operator!= (QPainterPath arg1, QPainterPath arg2)


static QPainterPath	operator& (QPainterPath arg1, QPainterPath arg2)


static QPainterPath	operator+ (QPainterPath arg1, QPainterPath arg2)


static QPainterPath	operator- (QPainterPath arg1, QPainterPath arg2)


static bool	operator== (QPainterPath arg1, QPainterPath arg2)


static QPainterPath	operator\| (QPainterPath arg1, QPainterPath arg2)

Protected Member Functions
	QPainterPath (System.Type dummy)

Protected Attributes
SmokeInvocation	interceptor

Properties
new Qt.FillRule	FillRule `[get, set]`


virtual System.IntPtr	SmokeObject `[get, set]`

Detailed Description

The QPainterPath class provides a container for painting operations, enabling graphical shapes to be constructed and reused.

A painter path is an object composed of a number of graphical building blocks, such as rectangles, ellipses, lines, and curves. Building blocks can be joined in closed subpaths, for example as a rectangle or an ellipse. A closed path has coinciding start and end points. Or they can exist independently as unclosed subpaths, such as lines and curves.

A QPainterPath object can be used for filling, outlining, and clipping. To generate fillable outlines for a given painter path, use the QPainterPathStroker class. The main advantage of painter paths over normal drawing operations is that complex shapes only need to be created once; then they can be drawn many times using only calls to the QPainter::drawPath() function.

QPainterPath provides a collection of functions that can be used to obtain information about the path and its elements. In addition it is possible to reverse the order of the elements using the toReversed() function. There are also several functions to convert this painter path object into a polygon representation.

Composing a QPainterPath

A QPainterPath object can be constructed as an empty path, with a given start point, or as a copy of another QPainterPath object. Once created, lines and curves can be added to the path using the lineTo(), arcTo(), cubicTo() and quadTo() functions. The lines and curves stretch from the currentPosition() to the position passed as argument.

The currentPosition() of the QPainterPath object is always the end position of the last subpath that was added (or the initial start point). Use the moveTo() function to move the currentPosition() without adding a component. The moveTo() function implicitly starts a new subpath, and closes the previous one. Another way of starting a new subpath is to call the closeSubpath() function which closes the current path by adding a line from the currentPosition() back to the path's start position. Note that the new path will have (0, 0) as its initial currentPosition().

QPainterPath class also provides several convenience functions to add closed subpaths to a painter path: addEllipse(), addPath(), addRect(), addRegion() and addText(). The addPolygon() function adds an unclosed subpath. In fact, these functions are all collections of moveTo(), lineTo() and cubicTo() operations.

In addition, a path can be added to the current path using the connectPath() function. But note that this function will connect the last element of the current path to the first element of given one by adding a line.

Below is a code snippet that shows how a QPainterPath object can be used:

QPainterPath path;

path.addRect(20, 20, 60, 60);

path.moveTo(0, 0);

path.cubicTo(99, 0, 50, 50, 99, 99);

path.cubicTo(0, 99, 50, 50, 0, 0);

QPainter painter(this);

painter.fillRect(0, 0, 100, 100, Qt::white);

painter.setPen(QPen(QColor(79, 106, 25), 1, Qt::SolidLine,

Qt::FlatCap, Qt::MiterJoin));

painter.setBrush(QColor(122, 163, 39));

painter.drawPath(path);

The painter path is initially empty when constructed. We first add a rectangle, which is a closed subpath. Then we add two bezier curves which together form a closed subpath even though they are not closed individually. Finally we draw the entire path. The path is filled using the default fill rule, Qt::OddEvenFill. Qt provides two methods for filling paths:

Qt::OddEvenFillQt::WindingFill

See the Qt::FillRule documentation for the definition of the rules. A painter path's currently set fill rule can be retrieved using the fillRule() function, and altered using the setFillRule() function.

QPainterPath Information

The QPainterPath class provides a collection of functions that returns information about the path and its elements.

The currentPosition() function returns the end point of the last subpath that was added (or the initial start point). The elementAt() function can be used to retrieve the various subpath elements, the number of elements can be retrieved using the elementCount() function, and the isEmpty() function tells whether this QPainterPath object contains any elements at all.

The controlPointRect() function returns the rectangle containing all the points and control points in this path. This function is significantly faster to compute than the exact boundingRect() which returns the bounding rectangle of this painter path with floating point precision.

Finally, QPainterPath provides the contains() function which can be used to determine whether a given point or rectangle is inside the path, and the intersects() function which determines if any of the points inside a given rectangle also are inside this path.

QPainterPath Conversion

For compatibility reasons, it might be required to simplify the representation of a painter path: QPainterPath provides the toFillPolygon(), toFillPolygons() and toSubpathPolygons() functions which convert the painter path into a polygon. The toFillPolygon() returns the painter path as one single polygon, while the two latter functions return a list of polygons.

The toFillPolygons() and toSubpathPolygons() functions are provided because it is usually faster to draw several small polygons than to draw one large polygon, even though the total number of points drawn is the same. The difference between the two is the number of polygons they return: The toSubpathPolygons() creates one polygon for each subpath regardless of intersecting subpaths (i.e. overlapping bounding rectangles), while the toFillPolygons() functions creates only one polygon for overlapping subpaths.

The toFillPolygon() and toFillPolygons() functions first convert all the subpaths to polygons, then uses a rewinding technique to make sure that overlapping subpaths can be filled using the correct fill rule. Note that rewinding inserts additional lines in the polygon so the outline of the fill polygon does not match the outline of the path.

Examples

Qt provides the Painter Paths Example and the Vector Deformation Demo which are located in Qt's example and demo directories respectively.

The Painter Paths Example shows how painter paths can be used to build complex shapes for rendering and lets the user experiment with the filling and stroking. The Vector Deformation Demo shows how to use QPainterPath to draw text.

Painter Paths ExampleVector Deformation Demo

See also QPainterPathStroker, QPainter, QRegion, and Painter Paths Example.

Member Enumeration Documentation

enum QtGui.QPainterPath.ElementType

This enum describes the types of elements used to connect vertices in subpaths.

Note that elements added as closed subpaths using the addEllipse(), addPath(), addPolygon(), addRect(), addRegion() and addText() convenience functions, is actually added to the path as a collection of separate elements using the moveTo(), lineTo() and cubicTo() functions.

See also elementAt() and elementCount().

Enumerator:

CurveToDataElement	The extra data required to describe a curve in a CurveToElement element.
CurveToElement	A curve. See also cubicTo() and quadTo().
LineToElement	A line. See also lineTo().
MoveToElement	A new subpath. See also moveTo().

Constructor & Destructor Documentation

QtGui.QPainterPath.QPainterPath ( System.Type dummy )

protected

QtGui.QPainterPath.QPainterPath ( )

Constructs an empty QPainterPath object.

QtGui.QPainterPath.QPainterPath ( QPointF startPoint )

Creates a QPainterPath object with the given startPoint as its current position.

QtGui.QPainterPath.QPainterPath ( QPainterPath other )

Creates a QPainterPath object that is a copy of the given path.

Member Function Documentation

new void QtGui.QPainterPath.AddEllipse ( QRectF rect )

Creates an ellipse within the specified boundingRectangle and adds it to the painter path as a closed subpath.

The ellipse is composed of a clockwise curve, starting and finishing at zero degrees (the 3 o'clock position).

QLinearGradient myGradient;

QPen myPen;

QRectF boundingRectangle;

QPainterPath myPath;

myPath.addEllipse(boundingRectangle);

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddEllipse	(	QPointF	center,
		double	rx,
		double	ry
	)

Creates an ellipse within the specified boundingRectangle and adds it to the painter path as a closed subpath.

The ellipse is composed of a clockwise curve, starting and finishing at zero degrees (the 3 o'clock position).

QLinearGradient myGradient;

QPen myPen;

QRectF boundingRectangle;

QPainterPath myPath;

myPath.addEllipse(boundingRectangle);

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddEllipse	(	double	x,
		double	y,
		double	w,
		double	h
	)

Creates an ellipse within the specified boundingRectangle and adds it to the painter path as a closed subpath.

The ellipse is composed of a clockwise curve, starting and finishing at zero degrees (the 3 o'clock position).

QLinearGradient myGradient;

QPen myPen;

QRectF boundingRectangle;

QPainterPath myPath;

myPath.addEllipse(boundingRectangle);

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddPath ( QPainterPath path )

Adds the given path to this path as a closed subpath.

See also connectPath() and Composing a QPainterPath.

new void QtGui.QPainterPath.AddPolygon ( QPolygonF polygon )

Adds the given polygon to the path as an (unclosed) subpath.

Note that the current position after the polygon has been added, is the last point in polygon. To draw a line back to the first point, use the closeSubpath() function.

QLinearGradient myGradient;

QPen myPen;

QPolygonF myPolygon;

QPainterPath myPath;

myPath.addPolygon(myPolygon);

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddRect ( QRectF rect )

Adds the given rectangle to this path as a closed subpath.

The rectangle is added as a clockwise set of lines. The painter path's current position after the rectangle has been added is at the top-left corner of the rectangle.

QLinearGradient myGradient;

QPen myPen;

QRectF myRectangle;

QPainterPath myPath;

myPath.addRect(myRectangle);

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddRect	(	double	x,
		double	y,
		double	w,
		double	h
	)

Adds the given rectangle to this path as a closed subpath.

The rectangle is added as a clockwise set of lines. The painter path's current position after the rectangle has been added is at the top-left corner of the rectangle.

QLinearGradient myGradient;

QPen myPen;

QRectF myRectangle;

QPainterPath myPath;

myPath.addRect(myRectangle);

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddRegion ( QRegion region )

Adds the given region to the path by adding each rectangle in the region as a separate closed subpath.

See also addRect() and Composing a QPainterPath.

new void QtGui.QPainterPath.AddRoundedRect	(	QRectF	rect,
		double	xRadius,
		double	yRadius,
		Qt.SizeMode	mode = `Qt.SizeMode.AbsoluteSize`
	)

Adds the given rectangle rect with rounded corners to the path.

The xRadius and yRadius arguments specify the radii of the ellipses defining the corners of the rounded rectangle. When mode is Qt::RelativeSize, xRadius and yRadius are specified in percentage of half the rectangle's width and height respectively, and should be in the range 0.0 to 100.0.

This function was introduced in Qt 4.4.

See also addRoundedRect().

new void QtGui.QPainterPath.AddRoundRect	(	QRectF	rect,
		int	xRnd,
		int	yRnd
	)

Adds a rectangle r with rounded corners to the path.

The xRnd and yRnd arguments specify how rounded the corners should be. 0 is angled corners, 99 is maximum roundedness.

See also addRoundedRect().

new void QtGui.QPainterPath.AddRoundRect	(	double	x,
		double	y,
		double	w,
		double	h,
		int	roundness
	)

Adds a rectangle r with rounded corners to the path.

The xRnd and yRnd arguments specify how rounded the corners should be. 0 is angled corners, 99 is maximum roundedness.

See also addRoundedRect().

new void QtGui.QPainterPath.AddRoundRect	(	double	x,
		double	y,
		double	w,
		double	h,
		int	xRnd,
		int	yRnd
	)

Adds a rectangle r with rounded corners to the path.

The xRnd and yRnd arguments specify how rounded the corners should be. 0 is angled corners, 99 is maximum roundedness.

See also addRoundedRect().

new void QtGui.QPainterPath.AddText	(	QPointF	point,
		QFont	f,
		string	text
	)

Adds the given text to this path as a set of closed subpaths created from the font supplied. The subpaths are positioned so that the left end of the text's baseline lies at the specified point.

QLinearGradient myGradient;

QPen myPen;

QFont myFont;

QPointF baseline(x, y);

QPainterPath myPath;

myPath.addText(baseline, myFont, tr("Qt"));

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new void QtGui.QPainterPath.AddText	(	double	x,
		double	y,
		QFont	f,
		string	text
	)

Adds the given text to this path as a set of closed subpaths created from the font supplied. The subpaths are positioned so that the left end of the text's baseline lies at the specified point.

QLinearGradient myGradient;

QPen myPen;

QFont myFont;

QPointF baseline(x, y);

QPainterPath myPath;

myPath.addText(baseline, myFont, tr("Qt"));

QPainter painter(this);

painter.setBrush(myGradient);

painter.setPen(myPen);

painter.drawPath(myPath);

new double QtGui.QPainterPath.AngleAtPercent ( double t )

Returns the angle of the path tangent at the percentage t. The argument t has to be between 0 and 1.

Positive values for the angles mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.

Note that similarly to the other percent methods, the percentage measurement is not linear with regards to the length if curves are present in the path. When curves are present the percentage argument is mapped to the t parameter of the Bezier equations.

new void QtGui.QPainterPath.ArcMoveTo	(	QRectF	rect,
		double	angle
	)

Creates a move to that lies on the arc that occupies the given rectangle at angle.

Angles are specified in degrees. Clockwise arcs can be specified using negative angles.

This function was introduced in Qt 4.2.

Member Data Documentation

SmokeInvocation QtGui.QPainterPath.interceptor

protected

Property Documentation

new Qt.FillRule QtGui.QPainterPath.FillRule

getset

Returns the painter path's currently set fill rule.

Sets the fill rule of the painter path to the given fillRule. Qt provides two methods for filling paths:

Qt::OddEvenFill (default)Qt::WindingFill

virtual System.IntPtr QtGui.QPainterPath.SmokeObject

getset

new void QtGui.QPainterPath.CubicTo	(	QPointF	ctrlPt1,
		QPointF	ctrlPt2,
		QPointF	endPt
	)

new void QtGui.QPainterPath.CubicTo	(	double	ctrlPt1x,
		double	ctrlPt1y,
		double	ctrlPt2x,
		double	ctrlPt2y,
		double	endPtx,
		double	endPty
	)

new void QtGui.QPainterPath.QuadTo	(	QPointF	ctrlPt,
		QPointF	endPt
	)

new void QtGui.QPainterPath.QuadTo	(	double	ctrlPtx,
		double	ctrlPty,
		double	endPtx,
		double	endPty
	)

new void QtGui.QPainterPath.ArcTo	(	QRectF	rect,
		double	startAngle,
		double	arcLength
	)

new void QtGui.QPainterPath.SetElementPositionAt	(	int	i,
		double	x,
		double	y
	)

new QPainterPath QtGui.QPainterPath.Translated	(	double	dx,
		double	dy
	)

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Properties

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Property Documentation