A class which draws curves. Más...

#include <qwt_plot_curve.h>

Diagrama de herencias de QwtPlotCurve

Clases
class	PrivateData
Tipos públicos
enum	CurveType { Yfx, Xfy }
enum	CurveStyle { NoCurve, Lines, Sticks, Steps, Dots, UserCurve = 100 }
enum	CurveAttribute { Inverted = 1, Fitted = 2 }
enum	PaintAttribute { PaintFiltered = 1, ClipPolygons = 2 }
Métodos públicos
	QwtPlotCurve ()
	Constructor.
	QwtPlotCurve (const QwtText &title)
	QwtPlotCurve (const QString &title)
virtual	~QwtPlotCurve ()
	Destructor.
virtual int	rtti () const
void	setCurveType (CurveType)
CurveType	curveType () const
void	setPaintAttribute (PaintAttribute, bool on=true)
	Specify an attribute how to draw the curve.
bool	testPaintAttribute (PaintAttribute) const
	Return the current paint attributes.
void	setRawData (const double x, const double y, int size)
	Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.
void	setData (const double xData, const double yData, int size)
void	setData (const QwtArray< double > &xData, const QwtArray< double > &yData)
	Initialize data with x- and y-arrays (explicitly shared)
void	setData (const QwtArray< QwtDoublePoint > &data)
void	setData (const QwtData &data)
int	closestPoint (const QPoint &pos, double *dist=NULL) const
QwtData &	data ()
const QwtData &	data () const
int	dataSize () const
double	x (int i) const
double	y (int i) const
virtual QwtDoubleRect	boundingRect () const
double	minXValue () const
	boundingRect().left()
double	maxXValue () const
	boundingRect().right()
double	minYValue () const
	boundingRect().top()
double	maxYValue () const
	boundingRect().bottom()
void	setCurveAttribute (CurveAttribute, bool on=true)
	Specify an attribute for drawing the curve.
bool	testCurveAttribute (CurveAttribute) const
void	setPen (const QPen &)
	Assign a pen.
const QPen &	pen () const
	Return the pen used to draw the lines.
void	setBrush (const QBrush &)
	Assign a brush. In case of brush.style() != QBrush::NoBrush and style() != QwtPlotCurve::Sticks the area between the curve and the baseline will be filled. In case !brush.color().isValid() the area will be filled by pen.color(). The fill algorithm simply connects the first and the last curve point to the baseline. So the curve data has to be sorted (ascending or descending).
const QBrush &	brush () const
	Return the brush used to fill the area between lines and the baseline.
void	setBaseline (double ref)
	Set the value of the baseline.
double	baseline () const
void	setStyle (CurveStyle style)
	Set the curve's drawing style.
CurveStyle	style () const
	Return the current style.
void	setSymbol (const QwtSymbol &s)
	Assign a symbol.
const QwtSymbol &	symbol () const
	Return the current symbol.
void	setCurveFitter (QwtCurveFitter *)
QwtCurveFitter *	curveFitter () const
virtual void	draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &) const
	Draw the complete curve.
virtual void	draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
	Draw an interval of the curve.
void	draw (int from, int to) const
	Draw a set of points of a curve.
virtual void	updateLegend (QwtLegend *) const
	Update the widget that represents the curve on the legend.
Métodos protegidos
void	init ()
	Initialize data members.
virtual void	drawCurve (QPainter *p, int style, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
	Draw the line part (without symbols) of a curve interval.
virtual void	drawSymbols (QPainter *p, const QwtSymbol &, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
	Draw symbols.
void	drawLines (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
	Draw lines.
void	drawSticks (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
void	drawDots (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
void	drawSteps (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
void	fillCurve (QPainter *, const QwtScaleMap &, const QwtScaleMap &, QwtPolygon &) const
void	closePolyline (const QwtScaleMap &, const QwtScaleMap &, QwtPolygon &) const
	Complete a polygon to be a closed polygon including the area between the original polygon and the baseline.

Descripción detallada

A class which draws curves.

This class can be used to display data as a curve in the x-y plane. It supports different display styles, spline interpolation and symbols.

Usage

A. Assign curve properties

When a curve is created, it is configured to draw black solid lines with QwtPlotCurve::Lines and no symbols. You can change this by calling setPen(), setStyle() and setSymbol().

B. Assign or change data.

Data can be set in two ways:

setData() is overloaded to initialize the x and y data by copying from different data structures with different kind of copy semantics.
setRawData() only stores the pointers and size information and is provided for backwards compatibility. This function is less safe (you must not delete the data while they are attached), but has been more efficient, and has been more convenient for dynamically changing data. Use of setData() in combination with a problem-specific subclass of QwtData is always preferrable.

C. Draw

draw() maps the data into pixel coordinates and paints them.

Example:: see examples/curvdemo

Ver también:: QwtData, QwtSymbol, QwtScaleMap

Documentación de las enumeraciones miembro de la clase

enum QwtPlotCurve::CurveAttribute

Curve attributes.

Ver también:: setCurveAttribute, testCurveAttribute

Valores de enumeraciones:

Inverted
Fitted

enum QwtPlotCurve::CurveStyle

Curve styles.

Ver también:: setStyle

Valores de enumeraciones:

NoCurve
Lines
Sticks
Steps
Dots
UserCurve

enum QwtPlotCurve::CurveType

Valores de enumeraciones:

Yfx
Xfy

enum QwtPlotCurve::PaintAttribute

Paint attributes

Ver también:: setPaintAttribute, testPaintAttribute

Valores de enumeraciones:

PaintFiltered
ClipPolygons

Documentación del constructor y destructor

QwtPlotCurve::QwtPlotCurve ( ) [explicit]

Constructor.

QwtPlotCurve::QwtPlotCurve ( const QwtText & title ) [explicit]

Constructor

Parámetros:

title title of the curve

QwtPlotCurve::QwtPlotCurve ( const QString & title ) [explicit]

Constructor

Parámetros:

title title of the curve

QwtPlotCurve::~QwtPlotCurve ( ) [virtual]

Destructor.

Documentación de las funciones miembro

double QwtPlotCurve::baseline ( ) const

Return the value of the baseline

Ver también:: setBaseline

QwtDoubleRect QwtPlotCurve::boundingRect ( ) const [virtual]

Returns the bounding rectangle of the curve data. If there is no bounding rect, like for empty data the rectangle is invalid.

Ver también:: QwtData::boundingRect(), QwtDoubleRect::isValid()

Reimplementado de QwtPlotItem.

const QBrush & QwtPlotCurve::brush ( ) const

Return the brush used to fill the area between lines and the baseline.

Ver también:: setBrush(), setBaseline(), baseline()

void QwtPlotCurve::closePolyline	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		QwtPolygon &	pa
	)		const `[protected]`

Complete a polygon to be a closed polygon including the area between the original polygon and the baseline.

Parámetros:

xMap	X map
yMap	Y map
pa	Polygon to be completed

int QwtPlotCurve::closestPoint	(	const QPoint &	pos,
		double *	dist = `NULL`
	)		const

QwtCurveFitter * QwtPlotCurve::curveFitter ( ) const

QwtPlotCurve::CurveType QwtPlotCurve::curveType ( ) const

Return the curve type

Ver también:: setCurveType()

QwtData & QwtPlotCurve::data ( ) [inline]

Devuelve:: the the curve data

const QwtData & QwtPlotCurve::data ( ) const [inline]

Devuelve:: the the curve data

int QwtPlotCurve::dataSize ( ) const

Return the size of the data arrays

Ver también:: setData()

void QwtPlotCurve::draw	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRect &
	)		const `[virtual]`

Draw the complete curve.

Parámetros:

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.

Ver también:: drawCurve(), drawSymbols()

Implementa QwtPlotItem.

void QwtPlotCurve::draw	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[virtual]`

Draw an interval of the curve.

Parámetros:

painter	Painter
xMap	maps x-values into pixel coordinates.
yMap	maps y-values into pixel coordinates.
from	index of the first point to be painted
to	index of the last point to be painted. If to < 0 the curve will be painted to its last point.

Ver también:: drawCurve(), drawSymbols(),

void QwtPlotCurve::draw	(	int	from,
		int	to
	)		const

Draw a set of points of a curve.

When observing an measurement while it is running, new points have to be added to an existing curve. drawCurve can be used to display them avoiding a complete redraw of the canvas.

Setting plot()->canvas()->setAttribute(Qt::WA_PaintOutsidePaintEvent, true); will result in faster painting, if the paint engine of the canvas widget supports this feature.

Parámetros:

from	Index of the first point to be painted
to	Index of the last point to be painted. If to < 0 the curve will be painted to its last point.

Ver también:: drawCurve(), drawSymbols()

void QwtPlotCurve::drawCurve	(	QPainter *	painter,
		int	style,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[protected, virtual]`

Draw the line part (without symbols) of a curve interval.

Parámetros:

painter	Painter
style	curve style, see QwtPlotCurve::CurveStyle
xMap	x map
yMap	y map
from	index of the first point to be painted
to	index of the last point to be painted

Ver también:: draw(), drawDots(), drawLines(), drawSteps(), drawSticks()

void QwtPlotCurve::drawDots	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[protected]`

Draw dots

Parámetros:

painter	Painter
xMap	x map
yMap	y map
from	index of the first point to be painted
to	index of the last point to be painted

Ver también:: draw(), drawCurve(), drawSticks(), drawLines(), drawSteps()

void QwtPlotCurve::drawLines	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[protected]`

Draw lines.

If the CurveAttribute Fitted is enabled a QwtCurveFitter tries to interpolate/smooth the curve, before it is painted.

Parámetros:

painter	Painter
xMap	x map
yMap	y map
from	index of the first point to be painted
to	index of the last point to be painted

Ver también:: setCurveAttribute(), setCurveFitter(), draw(), drawLines(), drawDots(), drawSteps(), drawSticks()

void QwtPlotCurve::drawSteps	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[protected]`

Draw step function

The direction of the steps depends on Inverted attribute.

Parámetros:

painter	Painter
xMap	x map
yMap	y map
from	index of the first point to be painted
to	index of the last point to be painted

Ver también:: CurveAttribute, setCurveAttribute(), draw(), drawCurve(), drawDots(), drawLines(), drawSticks()

void QwtPlotCurve::drawSticks	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[protected]`

Draw sticks

Parámetros:

painter	Painter
xMap	x map
yMap	y map
from	index of the first point to be painted
to	index of the last point to be painted

Ver también:: draw(), drawCurve(), drawDots(), drawLines(), drawSteps()

void QwtPlotCurve::drawSymbols	(	QPainter *	painter,
		const QwtSymbol &	symbol,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const `[protected, virtual]`

Draw symbols.

Parámetros:

painter	Painter
symbol	Curve symbol
xMap	x map
yMap	y map
from	index of the first point to be painted
to	index of the last point to be painted

Ver también:: setSymbol(), draw(), drawCurve()

void QwtPlotCurve::fillCurve	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		QwtPolygon &	pa
	)		const `[protected]`

Fill the area between the curve and the baseline with the curve brush

Parámetros:

painter	Painter
xMap	x map
yMap	y map
pa	Polygon

Ver también:: setBrush(), setBaseline(), setCurveType()

void QwtPlotCurve::init ( ) [protected]

Initialize data members.

double QwtPlotCurve::maxXValue ( ) const [inline]

boundingRect().right()

double QwtPlotCurve::maxYValue ( ) const [inline]

boundingRect().bottom()

double QwtPlotCurve::minXValue ( ) const [inline]

boundingRect().left()

double QwtPlotCurve::minYValue ( ) const [inline]

boundingRect().top()

const QPen & QwtPlotCurve::pen ( ) const

Return the pen used to draw the lines.

Ver también:: setPen(), brush()

int QwtPlotCurve::rtti ( ) const [virtual]

Devuelve:: QwtPlotItem::Rtti_PlotCurve

Reimplementado de QwtPlotItem.

void QwtPlotCurve::setBaseline ( double reference )

Set the value of the baseline.

The baseline is needed for filling the curve with a brush or the Sticks drawing style. The default value is 0.0. The interpretation of the baseline depends on the CurveType. With QwtPlotCurve::Yfx, the baseline is interpreted as a horizontal line at y = baseline(), with QwtPlotCurve::Yfy, it is interpreted as a vertical line at x = baseline().

Parámetros:

reference baseline

Ver también:: baseline(), setBrush(), setStyle(), setCurveType()

void QwtPlotCurve::setBrush ( const QBrush & brush )

Assign a brush. In case of brush.style() != QBrush::NoBrush and style() != QwtPlotCurve::Sticks the area between the curve and the baseline will be filled. In case !brush.color().isValid() the area will be filled by pen.color(). The fill algorithm simply connects the first and the last curve point to the baseline. So the curve data has to be sorted (ascending or descending).

Parámetros:

brush New brush

Ver también:: brush(), setBaseline(), baseline()

void QwtPlotCurve::setCurveAttribute	(	CurveAttribute	attribute,
		bool	on = `true`
	)

Specify an attribute for drawing the curve.

The attributes can be used to modify the drawing style. The following attributes are defined:

Fitted: For Lines only. A QwtCurveFitter tries to interpolate/smooth the curve, before it is painted. Note that curve fitting requires temorary memory for calculating coefficients and additional points. If painting in Fitted mode is slow it might be better to fit the points, before they are passed to QwtPlotCurve.
Inverted: For Steps only. Draws a step function from the right to the left.

Parámetros:

attribute	Curve attribute
on	On/Off

/sa testCurveAttribute(), setCurveFitter()

void QwtPlotCurve::setCurveFitter ( QwtCurveFitter * curveFitter )

void QwtPlotCurve::setCurveType ( CurveType curveType )

Assign the curve type

QwtPlotCurve::Yfx Draws y as a function of x (the default). The baseline is interpreted as a horizontal line with y = baseline().

QwtPlotCurve::Xfy Draws x as a function of y. The baseline is interpreted as a vertical line with x = baseline().

The baseline is used for aligning the sticks, or filling the curve with a brush.

Ver también:: curveType()

void QwtPlotCurve::setData ( const QwtArray< QwtDoublePoint > & data )

Initialize data with an array of points (explicitly shared).

Parámetros:

data Data

Ver también:: QwtPolygonFData

void QwtPlotCurve::setData	(	const QwtArray< double > &	xData,
		const QwtArray< double > &	yData
	)

Initialize data with x- and y-arrays (explicitly shared)

Parámetros:

xData	x data
yData	y data

Ver también:: QwtArrayData

void QwtPlotCurve::setData ( const QwtData & data )

Initialize data with a pointer to QwtData.

Parámetros:

data Data

Ver también:: QwtData::copy()

void QwtPlotCurve::setData	(	const double *	xData,
		const double *	yData,
		int	size
	)

Set data by copying x- and y-values from specified memory blocks. Contrary to setCurveRawData(), this function makes a 'deep copy' of the data.

Parámetros:

xData	pointer to x values
yData	pointer to y values
size	size of xData and yData

Ver también:: QwtCPointerData

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

Specify an attribute how to draw the curve.

The attributes can be used to modify the drawing algorithm.

The following attributes are defined:

PaintFiltered: Tries to reduce the data that has to be painted, by sorting out duplicates, or paintings outside the visible area. Might have a notable impact on curves with many close points. Only a couple of very basic filtering algos are implemented.
ClipPolygons: Clip polygons before painting them. In situations, where points are far outside the visible area this might be a great improvement for the painting performance ( especially on Windows ).

The default is, that no paint attributes are enabled.

Parámetros:

attribute	Paint attribute
on	On/Off /sa testPaintAttribute()

void QwtPlotCurve::setPen ( const QPen & pen )

Assign a pen.

Parámetros:

pen New pen

Ver también:: pen(), brush()

void QwtPlotCurve::setRawData	(	const double *	xData,
		const double *	yData,
		int	size
	)

Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

setRawData is provided for efficiency. It is important to keep the pointers during the lifetime of the underlying QwtCPointerData class.

Parámetros:

xData	pointer to x data
yData	pointer to y data
size	size of x and y

Ver también:: QwtCPointerData::setData.

void QwtPlotCurve::setStyle ( CurveStyle style )

Set the curve's drawing style.

Valid styles are:

NoCurve: Don't draw a curve. Note: This doesn't affect the symbol.
Lines: Connect the points with straight lines. The lines might be interpolated depending on the 'Fitted' option. Curve fitting can be configured using setCurveFitter.
Sticks: Draw vertical sticks from a baseline which is defined by setBaseline().
Steps: Connect the points with a step function. The step function is drawn from the left to the right or vice versa, depending on the 'Inverted' option.
Dots: Draw dots at the locations of the data points. Note: This is different from a dotted line (see setPen()).
UserCurve ...: Styles >= UserCurve are reserved for derived classes of QwtPlotCurve that overload drawCurve() with additional application specific curve types.

Ver también:: style()

void QwtPlotCurve::setSymbol ( const QwtSymbol & symbol )

Assign a symbol.

Parámetros:

symbol Symbol

Ver también:: symbol()

QwtPlotCurve::CurveStyle QwtPlotCurve::style ( ) const

Return the current style.

Ver también:: setStyle()

const QwtSymbol & QwtPlotCurve::symbol ( ) const

Return the current symbol.

Ver también:: setSymbol()

bool QwtPlotCurve::testCurveAttribute ( CurveAttribute attribute ) const

Devuelve:: true, if attribute is enabled

Ver también:: setCurveAttribute()

bool QwtPlotCurve::testPaintAttribute ( PaintAttribute attribute ) const

Return the current paint attributes.

Ver también:: setPaintAttribute

void QwtPlotCurve::updateLegend ( QwtLegend * legend ) const [virtual]

Update the widget that represents the curve on the legend.

Reimplementado de QwtPlotItem.

double QwtPlotCurve::x ( int i ) const [inline]

Parámetros:

i index

Devuelve:: x-value at position i

double QwtPlotCurve::y ( int i ) const [inline]

Parámetros:

i index

Devuelve:: y-value at position i

La documentación para esta clase fue generada a partir de los siguientes ficheros:

src/qwt/src/qwt_plot_curve.h
src/qwt/src/qwt_plot_curve.cpp

Clases

Tipos públicos

Métodos públicos

Métodos protegidos

Descripción detallada

Documentación de las enumeraciones miembro de la clase

Documentación del constructor y destructor

Documentación de las funciones miembro