QwtPlotTradingCurve illustrates movements in the price of a financial instrument over time. More...

#include <qwt_plot_tradingcurve.h>

Inheritance diagram for QwtPlotTradingCurve:

Public Types
enum	SymbolStyle { NoSymbol = -1, Bar, CandleStick, UserSymbol = 100 }
	Symbol styles. More...

enum	Direction { Increasing, Decreasing }
	Direction of a price movement. More...

enum	PaintAttribute { ClipSymbols = 0x01 }

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

	QwtPlotTradingCurve (const QwtText &title)

virtual	~QwtPlotTradingCurve ()
	Destructor.

virtual int	rtti () const

void	setPaintAttribute (PaintAttribute, bool on=true)

bool	testPaintAttribute (PaintAttribute) const

void	setSamples (const QVector< QwtOHLCSample > &)

void	setSamples (QwtSeriesData< QwtOHLCSample > *)

void	setSymbolStyle (SymbolStyle style)

SymbolStyle	symbolStyle () const

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

void	setSymbolPen (const QPen &)
	Set the symbol pen. More...

QPen	symbolPen () const

void	setSymbolBrush (Direction, const QBrush &)

QBrush	symbolBrush (Direction) const

void	setSymbolExtent (double width)
	Set the extent of the symbol. More...

double	symbolExtent () const

void	setMinSymbolWidth (double)

double	minSymbolWidth () const

void	setMaxSymbolWidth (double)

double	maxSymbolWidth () const

virtual void	drawSeries (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const

virtual QRectF	boundingRect () const

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

Public Member Functions inherited from QwtPlotSeriesItem
	QwtPlotSeriesItem (const QString &title=QString::null)

	QwtPlotSeriesItem (const QwtText &title)

virtual	~QwtPlotSeriesItem ()
	Destructor.

void	setOrientation (Qt::Orientation)

Qt::Orientation	orientation () const

virtual void	draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &) const
	Draw the complete series. More...

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

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	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...

Protected Member Functions
void	init ()
	Initialize internal members.

virtual void	drawSymbols (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const

virtual void	drawUserSymbol (QPainter *, SymbolStyle, const QwtOHLCSample &, Qt::Orientation, bool inverted, double width) const
	Draw a symbol for a symbol style >= UserSymbol. More...

void	drawBar (QPainter *painter, const QwtOHLCSample &, Qt::Orientation, bool inverted, double width) const
	Draw a bar. More...

void	drawCandleStick (QPainter *, const QwtOHLCSample &, Qt::Orientation, double width) const
	Draw a candle stick. More...

virtual double	scaledSymbolWidth (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const

Protected Member Functions inherited from QwtPlotSeriesItem
virtual void	dataChanged ()
	dataChanged() indicates, that the series has been changed.

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

Protected Member Functions inherited from QwtAbstractSeriesStore
virtual	~QwtAbstractSeriesStore ()
	Destructor.

Detailed Description

QwtPlotTradingCurve illustrates movements in the price of a financial instrument over time.

QwtPlotTradingCurve supports candlestick or bar ( OHLC ) charts that are used in the domain of technical analysis.

While the length ( height or width depending on orientation() ) of each symbol depends on the corresponding OHLC sample the size of the other dimension can be controlled using:

setSymbolExtent()
setSymbolMinWidth()
setSymbolMaxWidth()

The extent is a size in scale coordinates, so that the symbol width is increasing when the plot is zoomed in. Minimum/Maximum width is in widget coordinates independent from the zoom level. When setting the minimum and maximum to the same value, the width of the symbol is fixed.

Member Enumeration Documentation

enum QwtPlotTradingCurve::Direction

Direction of a price movement.

Enumerator
Increasing	The closing price is higher than the opening price.
Decreasing	The closing price is lower than the opening price.

enum QwtPlotTradingCurve::PaintAttribute

Attributes to modify the drawing algorithm.

See Also: setPaintAttribute(), testPaintAttribute()

Enumerator
ClipSymbols	Check if a symbol is on the plot canvas before painting it.

enum QwtPlotTradingCurve::SymbolStyle

Symbol styles.

The default setting is QwtPlotSeriesItem::CandleStick.

See Also: setSymbolStyle(), symbolStyle()

Enumerator
NoSymbol	Nothing is displayed.
Bar	A line on the chart shows the price range (the highest and lowest prices) over one unit of time, e.g. one day or one hour. Tick marks project from each side of the line indicating the opening and closing price.
CandleStick	The range between opening/closing price are displayed as a filled box. The fill brush depends on the direction of the price movement. The box is connected to the highest/lowest values by lines.
UserSymbol	SymbolTypes >= UserSymbol are displayed by drawUserSymbol(), that needs to be overloaded and implemented in derived curve classes. See Also drawUserSymbol()

Constructor & Destructor Documentation

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

explicit

Constructor

Parameters

title Title of the curve

QwtPlotTradingCurve::QwtPlotTradingCurve ( const QwtText & title )

explicit

Constructor

Parameters

title Title of the curve

Member Function Documentation

QRectF QwtPlotTradingCurve::boundingRect ( ) const

virtual

Returns: Bounding rectangle of all samples. For an empty series the rectangle is invalid.

Reimplemented from QwtPlotSeriesItem.

void QwtPlotTradingCurve::drawBar	(	QPainter *	painter,
		const QwtOHLCSample &	sample,
		Qt::Orientation	orientation,
		bool	inverted,
		double	width
	)		const

protected

Draw a bar.

Parameters

painter	Qt painter, initialized with pen/brush
sample	Sample, already translated into paint device coordinates
orientation	Vertical or horizontal
inverted	When inverted is false the open tick is painted to the left/top, otherwise it is painted right/bottom. The close tick is painted in the opposite direction of the open tick. painted in the opposite d opposite direction.
width	Width or height of the candle, depending on the orientation

See Also: Bar

void QwtPlotTradingCurve::drawCandleStick	(	QPainter *	painter,
		const QwtOHLCSample &	sample,
		Qt::Orientation	orientation,
		double	width
	)		const

protected

Draw a candle stick.

Parameters

painter	Qt painter, initialized with pen/brush
sample	Samples already translated into paint device coordinates
orientation	Vertical or horizontal
width	Width or height of the candle, depending on the orientation

See Also: CandleStick

void QwtPlotTradingCurve::drawSeries	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

virtual

Draw an interval of the curve

Parameters

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
canvasRect	Contents rectangle of the canvas
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.

See Also: drawSymbols()

Implements QwtPlotSeriesItem.

void QwtPlotTradingCurve::drawSymbols	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw symbols

Parameters

painter	Painter
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	Index of the first point to be painted
to	Index of the last point to be painted

See Also: drawSeries()

void QwtPlotTradingCurve::drawUserSymbol	(	QPainter *	painter,
		SymbolStyle	symbolStyle,
		const QwtOHLCSample &	sample,
		Qt::Orientation	orientation,
		bool	inverted,
		double	symbolWidth
	)		const

protectedvirtual

Draw a symbol for a symbol style >= UserSymbol.

The implementation does nothing and is intended to be overloaded

Parameters

painter	Qt painter, initialized with pen/brush
symbolStyle	Symbol style
sample	Samples already translated into paint device coordinates
orientation	Vertical or horizontal
inverted	True, when the opposite scale ( Qt::Vertical: x, Qt::Horizontal: y ) is increasing in the opposite direction as QPainter coordinates.
symbolWidth	Width of the symbol in paint device coordinates

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

virtual

Returns: A rectangle filled with the color of the symbol pen

Parameters

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

See Also: setLegendIconSize(), legendData()

Reimplemented from QwtPlotItem.

double QwtPlotTradingCurve::maxSymbolWidth ( ) const

Returns: Maximum for the symbol width

See Also: setMaxSymbolWidth(), minSymbolWidth(), symbolExtent()

double QwtPlotTradingCurve::minSymbolWidth ( ) const

Returns: Minmum for the symbol width

See Also: setMinSymbolWidth(), maxSymbolWidth(), symbolExtent()

int QwtPlotTradingCurve::rtti ( ) const

virtual

Returns: QwtPlotItem::Rtti_PlotTradingCurve

Reimplemented from QwtPlotItem.

double QwtPlotTradingCurve::scaledSymbolWidth	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect
	)		const

protectedvirtual

Calculate the symbol width in paint coordinates

The width is calculated by scaling the symbol extent into paint device coordinates bounded by the minimum/maximum symbol width.

Parameters

xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
canvasRect	Contents rectangle of the canvas

Returns: Symbol width in paint coordinates

See Also: symbolExtent(), minSymbolWidth(), maxSymbolWidth()

void QwtPlotTradingCurve::setMaxSymbolWidth ( double width )

Set a maximum for the symbol width

A value <= 0.0 means an unlimited width

Parameters

width Width in paint device coordinates

See Also: maxSymbolWidth(), setMinSymbolWidth(), setSymbolExtent()

void QwtPlotTradingCurve::setMinSymbolWidth ( double width )

Set a minimum for the symbol width

Parameters

width Width in paint device coordinates

See Also: minSymbolWidth(), setMaxSymbolWidth(), setSymbolExtent()

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

Specify an attribute how to draw the curve

Parameters

attribute	Paint attribute
on	On/Off

See Also: testPaintAttribute()

void QwtPlotTradingCurve::setSamples ( const QVector< QwtOHLCSample > & samples )

Initialize data with an array of samples.

Parameters

samples Vector of samples

See Also: QwtPlotSeriesItem::setData()

void QwtPlotTradingCurve::setSamples ( QwtSeriesData< QwtOHLCSample > * data )

Assign a series of samples

setSamples() is just a wrapper for setData() without any additional value - beside that it is easier to find for the developer.

Parameters

data Data

Warning: The item takes ownership of the data object, deleting it when its not used anymore.

void QwtPlotTradingCurve::setSymbolBrush	(	Direction	direction,
		const QBrush &	brush
	)

Set the symbol brush

Parameters

direction	Direction type
brush	Brush used to fill the body of all candlestick symbols with the direction

See Also: symbolBrush(), setSymbolPen()

void QwtPlotTradingCurve::setSymbolExtent ( double extent )

Set the extent of the symbol.

The width of the symbol is given in scale coordinates. When painting a symbol the width is scaled into paint device coordinates by scaledSymbolWidth(). The scaled width is bounded by minSymbolWidth(), maxSymbolWidth()

Parameters

extent Symbol width in scale coordinates

See Also: symbolExtent(), scaledSymbolWidth(), setMinSymbolWidth(), setMaxSymbolWidth()

void QwtPlotTradingCurve::setSymbolPen	(	const QColor &	color,
		qreal	width = `0.0`,
		Qt::PenStyle	style = `Qt::SolidLine`
	)

Build and assign the symbol 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