A plot item, which displays any graphical shape, that can be defined by a QPainterPath. More...

#include <qwt_plot_shapeitem.h>

Inheritance diagram for QwtPlotShapeItem:

Public Types
enum	PaintAttribute { ClipPolygons = 0x01 }

enum	LegendMode { LegendShape, LegendColor }
	Mode how to display the item on the legend. More...

typedef QFlags< PaintAttribute >	PaintAttributes
	Paint attributes.

Public Types inherited from QwtPlotItem
enum	RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotLegend, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotSpectroCurve, Rtti_PlotIntervalCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotSVG, Rtti_PlotTradingCurve, Rtti_PlotBarChart, Rtti_PlotMultiBarChart, Rtti_PlotShape, Rtti_PlotTextLabel, Rtti_PlotZone, Rtti_PlotUserItem = 1000 }
	Runtime type information. More...

enum	ItemAttribute { Legend = 0x01, AutoScale = 0x02, Margins = 0x04 }
	Plot Item Attributes. More...

enum	ItemInterest { ScaleInterest = 0x01, LegendInterest = 0x02 }
	Plot Item Interests. More...

enum	RenderHint { RenderAntialiased = 0x1 }
	Render hints. More...

typedef QFlags< ItemAttribute >	ItemAttributes
	Plot Item Attributes.

typedef QFlags< ItemInterest >	ItemInterests
	Plot Item Interests.

typedef QFlags< RenderHint >	RenderHints
	Render hints.

Public Member Functions
	QwtPlotShapeItem (const QString &title=QString::null)
	Constructor. More...

	QwtPlotShapeItem (const QwtText &title)
	Constructor. More...

virtual	~QwtPlotShapeItem ()
	Destructor.

void	setPaintAttribute (PaintAttribute, bool on=true)

bool	testPaintAttribute (PaintAttribute) const

void	setLegendMode (LegendMode)

LegendMode	legendMode () const

void	setRect (const QRectF &)
	Set a path built from a rectangle. More...

void	setPolygon (const QPolygonF &)
	Set a path built from a polygon. More...

void	setShape (const QPainterPath &)
	Set the shape to be displayed. More...

QPainterPath	shape () const

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

void	setPen (const QPen &)
	Assign a pen. More...

QPen	pen () const

void	setBrush (const QBrush &)

QBrush	brush () const

void	setRenderTolerance (double)
	Set the tolerance for the weeding optimization. More...

double	renderTolerance () const

virtual QRectF	boundingRect () const
	Bounding rectangle of the shape.

virtual void	draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &rect) const

virtual QwtGraphic	legendIcon (int index, const QSizeF &) const

virtual int	rtti () const

Public Member Functions inherited from QwtPlotItem
	QwtPlotItem (const QwtText &title=QwtText())

virtual	~QwtPlotItem ()
	Destroy the QwtPlotItem.

void	attach (QwtPlot *plot)
	Attach the item to a plot. More...

void	detach ()
	This method detaches a QwtPlotItem from any QwtPlot it has been associated with. More...

QwtPlot *	plot () const
	Return attached plot.

void	setTitle (const QString &title)

void	setTitle (const QwtText &title)

const QwtText &	title () const

void	setItemAttribute (ItemAttribute, bool on=true)

bool	testItemAttribute (ItemAttribute) const

void	setItemInterest (ItemInterest, bool on=true)

bool	testItemInterest (ItemInterest) const

void	setRenderHint (RenderHint, bool on=true)

bool	testRenderHint (RenderHint) const

void	setRenderThreadCount (uint numThreads)

uint	renderThreadCount () const

void	setLegendIconSize (const QSize &)

QSize	legendIconSize () const

double	z () const

void	setZ (double z)
	Set the z value. More...

void	show ()
	Show the item.

void	hide ()
	Hide the item.

virtual void	setVisible (bool)

bool	isVisible () const

void	setAxes (int xAxis, int yAxis)

void	setXAxis (int axis)

int	xAxis () const
	Return xAxis.

void	setYAxis (int axis)

int	yAxis () const
	Return yAxis.

virtual void	itemChanged ()

virtual void	legendChanged ()

virtual void	getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasSize, double &left, double &top, double &right, double &bottom) const
	Calculate a hint for the canvas margin. More...

virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
	Update the item to changes of the axes scale division. More...

virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item to changes of the legend info. More...

QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding scale rectangle of 2 maps. More...

QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding paint rectangle of 2 maps. More...

virtual QList< QwtLegendData >	legendData () const
	Return all information, that is needed to represent the item on the legend. More...

Additional Inherited Members
Protected Member Functions inherited from QwtPlotItem
QwtGraphic	defaultIcon (const QBrush &, const QSizeF &) const
	Return a default icon from a brush. More...

Detailed Description

A plot item, which displays any graphical shape, that can be defined by a QPainterPath.

A QPainterPath is a shape composed from intersecting and uniting regions, rectangles, ellipses or irregular areas defined by lines, and curves. QwtPlotShapeItem displays a shape with a pen and brush.

QwtPlotShapeItem offers a couple of optimizations like clipping or weeding. These algorithms need to convert the painter path into polygons that might be less performant for paths built from curves and ellipses.

See Also: QwtPlotZone

Member Enumeration Documentation

enum QwtPlotShapeItem::LegendMode

Mode how to display the item on the legend.

Enumerator
LegendShape	Display a scaled down version of the shape.
LegendColor	Display a filled rectangle.

enum QwtPlotShapeItem::PaintAttribute

Attributes to modify the drawing algorithm. The default disables all attributes

See Also: setPaintAttribute(), testPaintAttribute()

Enumerator

ClipPolygons

Clip polygons before painting them. In situations, where points are far outside the visible area (f.e when zooming deep) this might be a substantial improvement for the painting performance

But polygon clipping will convert the painter path into polygons what might introduce a negative impact on the performance of paths composed from curves or ellipses.

Constructor & Destructor Documentation

QwtPlotShapeItem::QwtPlotShapeItem ( const QString & title = QString::null )

explicit

Constructor.

Sets the following item attributes:

QwtPlotItem::AutoScale: true
QwtPlotItem::Legend: false

Parameters

title Title

QwtPlotShapeItem::QwtPlotShapeItem ( const QwtText & title )

explicit

Constructor.

Sets the following item attributes:

QwtPlotItem::AutoScale: true
QwtPlotItem::Legend: false

Parameters

title Title

Member Function Documentation

QBrush QwtPlotShapeItem::brush ( ) const

Returns: Brush used to fill the shape

See Also: setBrush(), pen()

void QwtPlotShapeItem::draw	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect
	)		const

virtual

Draw the shape item

Parameters

painter	Painter
xMap	X-Scale Map
yMap	Y-Scale Map
canvasRect	Contents rect of the plot canvas

Implements QwtPlotItem.

QwtGraphic QwtPlotShapeItem::legendIcon	(	int	index,
		const QSizeF &	size
	)		const

virtual

Returns: A rectangle filled with the color of the brush ( or the pen )

Parameters

index	Index of the legend entry ( usually there is only one )
size	Icon size

See Also: setLegendIconSize(), legendData()

Reimplemented from QwtPlotItem.

QwtPlotShapeItem::LegendMode QwtPlotShapeItem::legendMode ( ) const

Returns: Mode how to represent the item on the legend

See Also: legendMode()

QPen QwtPlotShapeItem::pen ( ) const

Returns: Pen used to draw the outline of the shape

See Also: setPen(), brush()

double QwtPlotShapeItem::renderTolerance ( ) const

Returns: Tolerance for the weeding optimization

See Also: setRenderTolerance()

int QwtPlotShapeItem::rtti ( ) const

virtual

Returns: QwtPlotItem::Rtti_PlotShape

Reimplemented from QwtPlotItem.

void QwtPlotShapeItem::setBrush ( const QBrush & brush )

Assign a brush.

The brush is used to fill the path

Parameters

brush Brush

See Also: brush(), pen()

void QwtPlotShapeItem::setLegendMode ( LegendMode mode )

Set the mode how to represent the item on the legend

Parameters

mode Mode

See Also: legendMode()

void QwtPlotShapeItem::setPaintAttribute	(	PaintAttribute	attribute,
		bool	on = `true`
	)

Specify an attribute how to draw the shape

Parameters

attribute	Paint attribute
on	On/Off

See Also: testPaintAttribute()

void QwtPlotShapeItem::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()

void QwtPlotShapeItem::setPen ( const QPen & pen )

Assign a pen.

The pen is used to draw the outline of the shape

Parameters

pen Pen

See Also: pen(), brush()

void QwtPlotShapeItem::setPolygon ( const QPolygonF & polygon )

Set a path built from a polygon.

Parameters

polygon Polygon

See Also: setShape(), setRect(), shape()

void QwtPlotShapeItem::setRect ( const QRectF & rect )

Set a path built from a rectangle.

Parameters

rect Rectangle

See Also: setShape(), setPolygon(), shape()

void QwtPlotShapeItem::setRenderTolerance ( double tolerance )

Set the tolerance for the weeding optimization.

After translating the shape into target device coordinate ( usually widget geometries ) the painter path can be simplified by a point weeding algorithm ( Douglas-Peucker ).

For shapes built from curves and ellipses weeding might have the opposite effect because they have to be expanded to polygons.

Parameters

tolerance Accepted error when reducing the number of points A value <= 0.0 disables weeding.