A class for drawing symbols. More...

#include <qwt_symbol.h>

Public Types
enum	Style { NoSymbol = -1 , Ellipse , Rect , Diamond , Triangle , DTriangle , UTriangle , LTriangle , RTriangle , Cross , XCross , HLine , VLine , Star1 , Star2 , Hexagon , Path , Pixmap , Graphic , SvgDocument , UserStyle = 1000 }

enum	CachePolicy { NoCache , Cache , AutoCache }

Public Member Functions
	QwtSymbol (Style=NoSymbol)

	QwtSymbol (Style, const QBrush &, const QPen &, const QSize &)
	Constructor.

	QwtSymbol (const QPainterPath &, const QBrush &, const QPen &)
	Constructor.

virtual	~QwtSymbol ()
	Destructor.

void	setCachePolicy (CachePolicy)

CachePolicy	cachePolicy () const

void	setSize (const QSize &)

void	setSize (int width, int height=-1)
	Specify the symbol's size.

const QSize &	size () const

void	setPinPoint (const QPointF &pos, bool enable=true)
	Set and enable a pin point.

QPointF	pinPoint () const

void	setPinPointEnabled (bool)

bool	isPinPointEnabled () const

virtual void	setColor (const QColor &)
	Set the color of the symbol.

void	setBrush (const QBrush &)
	Assign a brush.

const QBrush &	brush () const

void	setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)

void	setPen (const QPen &)

const QPen &	pen () const

void	setStyle (Style)

Style	style () const

void	setPath (const QPainterPath &)
	Set a painter path as symbol.

const QPainterPath &	path () const

void	setPixmap (const QPixmap &)

const QPixmap &	pixmap () const

void	setGraphic (const QwtGraphic &)

const QwtGraphic &	graphic () const

void	setSvgDocument (const QByteArray &)

void	drawSymbol (QPainter *, const QRectF &) const
	Draw the symbol into a rectangle.

void	drawSymbol (QPainter *, const QPointF &) const
	Draw the symbol at a specified position.

void	drawSymbols (QPainter *, const QPolygonF &) const
	Draw symbols at the specified points.

void	drawSymbols (QPainter , const QPointF , int numPoints) const

virtual QRect	boundingRect () const

void	invalidateCache ()

Protected Member Functions
virtual void	renderSymbols (QPainter , const QPointF , int numPoints) const

Detailed Description

A class for drawing symbols.

Definition at line 31 of file qwt_symbol.h.

Member Enumeration Documentation

◆ CachePolicy

enum QwtSymbol::CachePolicy

Depending on the render engine and the complexity of the symbol shape it might be faster to render the symbol to a pixmap and to paint this pixmap.

F.e. the raster paint engine is a pure software renderer where in cache mode a draw operation usually ends in raster operation with the the backing store, that are usually faster, than the algorithms for rendering polygons. But the opposite can be expected for graphic pipelines that can make use of hardware acceleration.

The default setting is AutoCache

See also: setCachePolicy(), cachePolicy()

Note: The policy has no effect, when the symbol is painted to a vector graphics format ( PDF, SVG ).

Warning: Since Qt 4.8 raster is the default backend on X11

Enumerator

NoCache

Don't use a pixmap cache.

Cache

Always use a pixmap cache.

AutoCache

Use a cache when one of the following conditions is true:

The symbol is rendered with the software renderer ( QPaintEngine::Raster )

Definition at line 150 of file qwt_symbol.h.

◆ Style

enum QwtSymbol::Style

Symbol Style

See also: setStyle(), style()

Enumerator
NoSymbol	No Style. The symbol cannot be drawn.
Ellipse	Ellipse or circle.
Rect	Rectangle.
Diamond	Diamond.
Triangle	Triangle pointing upwards.
DTriangle	Triangle pointing downwards.
UTriangle	Triangle pointing upwards.
LTriangle	Triangle pointing left.
RTriangle	Triangle pointing right.
Cross	Cross (+)
XCross	Diagonal cross (X)
HLine	Horizontal line.
VLine	Vertical line.
Star1	X combined with +.
Star2	Six-pointed star.
Hexagon	Hexagon.
Path	The symbol is represented by a painter path, where the origin ( 0, 0 ) of the path coordinate system is mapped to the position of the symbol. See also setPath(), path()
Pixmap	The symbol is represented by a pixmap. The pixmap is centered or aligned to its pin point. See also setPinPoint()
Graphic	The symbol is represented by a graphic. The graphic is centered or aligned to its pin point. See also setPinPoint()
SvgDocument	The symbol is represented by a SVG graphic. The graphic is centered or aligned to its pin point. See also setPinPoint()
UserStyle	Styles >= QwtSymbol::UserSymbol are reserved for derived classes of QwtSymbol that overload drawSymbols() with additional application specific symbol types.

Definition at line 38 of file qwt_symbol.h.

Constructor & Destructor Documentation

◆ QwtSymbol() [1/3]

QwtSymbol::QwtSymbol ( Style style = NoSymbol )

explicit

Default Constructor

Parameters

style Symbol Style

The symbol is constructed with gray interior, black outline with zero width, no size and style 'NoSymbol'.

Definition at line 843 of file qwt_symbol.cpp.

◆ QwtSymbol() [2/3]

QwtSymbol::QwtSymbol	(	QwtSymbol::Style	style,
		const QBrush &	brush,
		const QPen &	pen,
		const QSize &	size )

Constructor.

Parameters

style	Symbol Style
brush	brush to fill the interior
pen	outline pen
size	size

See also: setStyle(), setBrush(), setPen(), setSize()

Definition at line 858 of file qwt_symbol.cpp.

◆ QwtSymbol() [3/3]

QwtSymbol::QwtSymbol	(	const QPainterPath &	path,
		const QBrush &	brush,
		const QPen &	pen )

Constructor.

The symbol gets initialized by a painter path. The style is set to QwtSymbol::Path, the size is set to empty ( the path is displayed unscaled ).

Parameters

path	painter path
brush	brush to fill the interior
pen	outline pen

See also: setPath(), setBrush(), setPen(), setSize()

Definition at line 878 of file qwt_symbol.cpp.

◆ ~QwtSymbol()

QwtSymbol::~QwtSymbol ( )

virtual

Destructor.

Definition at line 886 of file qwt_symbol.cpp.

Member Function Documentation

◆ boundingRect()

QRect QwtSymbol::boundingRect ( ) const

virtual

Calculate the bounding rectangle for a symbol at position (0,0).

Returns: Bounding rectangle

Definition at line 1637 of file qwt_symbol.cpp.

◆ brush()

const QBrush & QwtSymbol::brush ( ) const

Returns: Brush

See also: setBrush()

Definition at line 1123 of file qwt_symbol.cpp.

◆ cachePolicy()

QwtSymbol::CachePolicy QwtSymbol::cachePolicy ( ) const

Returns: Cache policy

See also: CachePolicy, setCachePolicy()

Definition at line 913 of file qwt_symbol.cpp.

◆ drawSymbol() [1/2]

void QwtSymbol::drawSymbol	(	QPainter *	painter,
		const QPointF &	pos ) const

inline

Draw the symbol at a specified position.

Parameters

painter	Painter
pos	Position of the symbol in screen coordinates

Definition at line 238 of file qwt_symbol.h.

◆ drawSymbol() [2/2]

void QwtSymbol::drawSymbol	(	QPainter *	painter,
		const QRectF &	rect ) const

Draw the symbol into a rectangle.

The symbol is painted centered and scaled into the target rectangle. It is always painted uncached and the pin point is ignored.

This method is primarily intended for drawing a symbol to the legend.

Parameters

painter	Painter
rect	Target rectangle for the symbol

Definition at line 1434 of file qwt_symbol.cpp.

◆ drawSymbols() [1/2]

void QwtSymbol::drawSymbols	(	QPainter *	painter,
		const QPointF *	points,
		int	numPoints ) const

Render an array of symbols

Painting several symbols is more effective than drawing symbols one by one, as a couple of layout calculations and setting of pen/brush can be done once for the complete array.

Parameters

painter	Painter
points	Array of points
numPoints	Number of points

Definition at line 1307 of file qwt_symbol.cpp.

◆ drawSymbols() [2/2]

void QwtSymbol::drawSymbols	(	QPainter *	painter,
		const QPolygonF &	points ) const

inline

Draw symbols at the specified points.

Parameters

painter	Painter
points	Positions of the symbols in screen coordinates

Definition at line 251 of file qwt_symbol.h.

◆ graphic()

const QwtGraphic & QwtSymbol::graphic ( ) const

Returns: Assigned graphic

See also: setGraphic()

Definition at line 1027 of file qwt_symbol.cpp.

◆ invalidateCache()

void QwtSymbol::invalidateCache ( )

Invalidate the cached symbol pixmap

The symbol invalidates its cache, whenever an attribute is changed that has an effect ob how to display a symbol. In case of derived classes with individual styles ( >= QwtSymbol::UserStyle ) it might be necessary to call invalidateCache() for attributes that are relevant for this style.

See also: CachePolicy, setCachePolicy(), drawSymbols()

Definition at line 1770 of file qwt_symbol.cpp.

◆ isPinPointEnabled()

bool QwtSymbol::isPinPointEnabled ( ) const

Returns: True, when the pin point translation is enabled

See also: setPinPoint(), setPinPointEnabled()

Definition at line 1291 of file qwt_symbol.cpp.

◆ path()

const QPainterPath & QwtSymbol::path ( ) const

Returns: Painter path for displaying the symbol

See also: setPath()

Definition at line 977 of file qwt_symbol.cpp.

◆ pen()

const QPen & QwtSymbol::pen ( ) const

Returns: Pen

See also: setPen(), brush()

Definition at line 1171 of file qwt_symbol.cpp.

◆ pinPoint()

QPointF QwtSymbol::pinPoint ( ) const

Returns: Pin point

See also: setPinPoint(), setPinPointEnabled()

Definition at line 1267 of file qwt_symbol.cpp.

◆ pixmap()

const QPixmap & QwtSymbol::pixmap ( ) const

Returns: Assigned pixmap

See also: setPixmap()

Definition at line 1002 of file qwt_symbol.cpp.

◆ renderSymbols()

void QwtSymbol::renderSymbols	(	QPainter *	painter,
		const QPointF *	points,
		int	numPoints ) const

protectedvirtual

Render the symbol to series of points

Parameters

painter	Qt painter
points	Positions of the symbols
numPoints	Number of points

Definition at line 1513 of file qwt_symbol.cpp.

◆ setBrush()

void QwtSymbol::setBrush ( const QBrush & brush )

Assign a brush.

The brush is used to draw the interior of the symbol.

Parameters

brush Brush

See also: brush()

Definition at line 1107 of file qwt_symbol.cpp.

◆ setCachePolicy()

void QwtSymbol::setCachePolicy ( QwtSymbol::CachePolicy policy )

Change the cache policy

The default policy is AutoCache

Parameters

policy Cache policy

See also: CachePolicy, cachePolicy()

Definition at line 899 of file qwt_symbol.cpp.

◆ setColor()

void QwtSymbol::setColor ( const QColor & color )

virtual

Set the color of the symbol.

Change the color of the brush for symbol types with a filled area. For all other symbol types the color will be assigned to the pen.

Parameters

color Color

See also: setBrush(), setPen(), brush(), pen()

Definition at line 1186 of file qwt_symbol.cpp.

◆ setGraphic()

void QwtSymbol::setGraphic ( const QwtGraphic & graphic )

Set a graphic as symbol

Parameters

graphic Graphic

See also: graphic(), setPixmap()

Note: the style() is set to QwtSymbol::Graphic; brush() and pen() have no effect

Definition at line 1017 of file qwt_symbol.cpp.

◆ setPath()

void QwtSymbol::setPath ( const QPainterPath & path )

Set a painter path as symbol.

The symbol is represented by a painter path, where the origin ( 0, 0 ) of the path coordinate system is mapped to the position of the symbol.

When the symbol has valid size the painter path gets scaled to fit into the size. Otherwise the symbol size depends on the bounding rectangle of the path.

Example: The following code defines a symbol drawing an arrow:

#include <qwt_symbol.h>
 
     QwtSymbol *symbol = new QwtSymbol();
 
     QPen pen( Qt::black, 2 );
     pen.setJoinStyle( Qt::MiterJoin );
 
     symbol->setPen( pen );
     symbol->setBrush( Qt::red );
 
     QPainterPath path;
     path.moveTo( 0, 8 );
     path.lineTo( 0, 5 );
     path.lineTo( -3, 5 );
     path.lineTo( 0, 0 );
     path.lineTo( 3, 5 );
     path.lineTo( 0, 5 );
 
     QTransform transform;
     transform.rotate( -30.0 );
     path = transform.map( path );
 
     symbol->setPath( path );
     symbol->setPinPoint( QPointF( 0.0, 0.0 ) );
 
     setSize( 10, 14 );

Parameters

path	Painter path

Note: The style is implicitly set to QwtSymbol::Path.

See also: path(), setSize()

Definition at line 966 of file qwt_symbol.cpp.

◆ setPen() [1/2]

void QwtSymbol::setPen	(	const QColor &	color,
		qreal	width = 0.0,
		Qt::PenStyle	style = Qt::SolidLine )

Build and assign a pen

In Qt5 the default pen width is 1.0 ( 0.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() ). This method has been introduced to hide this incompatibility.

Parameters

color	Pen color
width	Pen width
style	Pen style

See also: pen(), brush()

Definition at line 1141 of file qwt_symbol.cpp.

◆ setPen() [2/2]

void QwtSymbol::setPen ( const QPen & pen )

Assign a pen

The pen is used to draw the symbol's outline.

Parameters

pen Pen

See also: pen(), setBrush()

Definition at line 1155 of file qwt_symbol.cpp.

◆ setPinPoint()

void QwtSymbol::setPinPoint	(	const QPointF &	pos,
		bool	enable = true )

Set and enable a pin point.

The position of a complex symbol is not always aligned to its center ( f.e an arrow, where the peak points to a position ). The pin point defines the position inside of a Pixmap, Graphic, SvgDocument or PainterPath symbol where the represented point has to be aligned to.

Parameters

pos	Position
enable	En/Disable the pin point alignment

See also: pinPoint(), setPinPointEnabled()

Definition at line 1249 of file qwt_symbol.cpp.

◆ setPinPointEnabled()

void QwtSymbol::setPinPointEnabled ( bool on )

En/Disable the pin point alignment

Parameters

on	Enabled, when on is true

See also: setPinPoint(), isPinPointEnabled()

Definition at line 1278 of file qwt_symbol.cpp.

◆ setPixmap()

void QwtSymbol::setPixmap ( const QPixmap & pixmap )

Set a pixmap as symbol

Parameters

pixmap Pixmap

See also: pixmap(), setGraphic()

Note: the style() is set to QwtSymbol::Pixmap; brush() and pen() have no effect

Definition at line 992 of file qwt_symbol.cpp.

◆ setSize() [1/2]

void QwtSymbol::setSize ( const QSize & size )

Set the symbol's size

Parameters

size Size

See also: size()

Definition at line 1081 of file qwt_symbol.cpp.

◆ setSize() [2/2]

void QwtSymbol::setSize	(	int	width,
		int	height = -1 )

Specify the symbol's size.

If the 'h' parameter is left out or less than 0, and the 'w' parameter is greater than or equal to 0, the symbol size will be set to (w,w).

Parameters

width	Width
height	Height (defaults to -1)

See also: size()

Definition at line 1067 of file qwt_symbol.cpp.

◆ setStyle()

void QwtSymbol::setStyle ( QwtSymbol::Style style )

Specify the symbol style

Parameters

style Style

See also: style()

Definition at line 1782 of file qwt_symbol.cpp.

◆ setSvgDocument()

void QwtSymbol::setSvgDocument ( const QByteArray & svgDocument )

Set a SVG icon as symbol

Parameters

svgDocument SVG icon

See also: setGraphic(), setPixmap()

Note: the style() is set to QwtSymbol::SvgDocument; brush() and pen() have no effect

Definition at line 1044 of file qwt_symbol.cpp.

◆ size()

const QSize & QwtSymbol::size ( ) const

Returns: Size

See also: setSize()

Definition at line 1094 of file qwt_symbol.cpp.

◆ style()

QwtSymbol::Style QwtSymbol::style ( ) const

Returns: Current symbol style

See also: setStyle()

Definition at line 1795 of file qwt_symbol.cpp.

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ CachePolicy

◆ Style

Constructor & Destructor Documentation

◆ QwtSymbol() [1/3]

◆ QwtSymbol() [2/3]

◆ QwtSymbol() [3/3]

◆ ~QwtSymbol()

Member Function Documentation

◆ boundingRect()

◆ brush()

◆ cachePolicy()

◆ drawSymbol() [1/2]

◆ drawSymbol() [2/2]

◆ drawSymbols() [1/2]

◆ drawSymbols() [2/2]

◆ graphic()

◆ invalidateCache()

◆ isPinPointEnabled()

◆ path()

◆ pen()

◆ pinPoint()

◆ pixmap()

◆ renderSymbols()

◆ setBrush()

◆ setCachePolicy()

◆ setColor()

◆ setGraphic()

◆ setPath()

◆ setPen() [1/2]

◆ setPen() [2/2]

◆ setPinPoint()

◆ setPinPointEnabled()

◆ setPixmap()

◆ setSize() [1/2]

◆ setSize() [2/2]

◆ setStyle()

◆ setSvgDocument()

◆ size()

◆ style()