QwtPlotHistogram represents a series of samples, where an interval is associated with a value ( $y = f([x1,x2])$ ). More...

#include <qwt_plot_histogram.h>

Inheritance diagram for QwtPlotHistogram:

[legend]

List of all members.

Classes
class	PrivateData
Public Types
enum	HistogramStyle { Outline, Columns, Lines, UserStyle = 100 }
Public Member Functions
double	baseline () const
virtual QRectF	boundingRect () const
const QBrush &	brush () const
virtual void	drawSeries (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual QwtGraphic	legendIcon (int index, const QSizeF &) const
const QPen &	pen () const
	QwtPlotHistogram (const QString &title=QString::null)
	QwtPlotHistogram (const QwtText &title)
virtual int	rtti () const
void	setBaseline (double reference)
	Set the value of the baseline.
void	setBrush (const QBrush &)
void	setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
void	setPen (const QPen &)
void	setSamples (const QVector< QwtIntervalSample > &)
void	setSamples (QwtSeriesData< QwtIntervalSample > *)
void	setStyle (HistogramStyle style)
void	setSymbol (const QwtColumnSymbol *)
	Assign a symbol.
HistogramStyle	style () const
const QwtColumnSymbol *	symbol () const
virtual	~QwtPlotHistogram ()
	Destructor.
Protected Member Functions
virtual QwtColumnRect	columnRect (const QwtIntervalSample &, const QwtScaleMap &, const QwtScaleMap &) const
virtual void	drawColumn (QPainter *, const QwtColumnRect &, const QwtIntervalSample &) const
void	drawColumns (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
void	drawLines (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
void	drawOutline (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const
Private Member Functions
void	flushPolygon (QPainter *, double baseLine, QPolygonF &) const
	Internal, used by the Outline style.
void	init ()
	Initialize data members.
Private Attributes
PrivateData *	d_data

Detailed Description

QwtPlotHistogram represents a series of samples, where an interval is associated with a value ( $y = f([x1,x2])$ ).

The representation depends on the style() and an optional symbol() that is displayed for each interval.

Note:: The term "histogram" is used in a different way in the areas of digital image processing and statistics. Wikipedia introduces the terms "image histogram" and "color histogram" to avoid confusions. While "image histograms" can be displayed by a QwtPlotCurve there is no applicable plot item for a "color histogram" yet.

See also:: QwtPlotBarChart, QwtPlotMultiBarChart

Definition at line 39 of file qwt_plot_histogram.h.

Member Enumeration Documentation

enum QwtPlotHistogram::HistogramStyle

Histogram styles. The default style is QwtPlotHistogram::Columns.

See also:: setStyle(), style(), setSymbol(), symbol(), setBaseline()

Enumerator:

Outline	Draw an outline around the area, that is build by all intervals using the pen() and fill it with the brush(). The outline style requires, that the intervals are in increasing order and not overlapping.
Columns	Draw a column for each interval. When a symbol() has been set the symbol is used otherwise the column is displayed as plain rectangle using pen() and brush().
Lines	Draw a simple line using the pen() for each interval.
UserStyle	Styles >= UserStyle are reserved for derived classes that overload drawSeries() with additional application specific ways to display a histogram.

Definition at line 49 of file qwt_plot_histogram.h.

Constructor & Destructor Documentation

QwtPlotHistogram::QwtPlotHistogram ( const QString & title = QString::null ) [explicit]

Constructor

Parameters:

title Title of the histogram.

Definition at line 73 of file qwt_plot_histogram.cpp.

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

Constructor

Parameters:

title Title of the histogram.

Definition at line 63 of file qwt_plot_histogram.cpp.

QwtPlotHistogram::~QwtPlotHistogram ( ) [virtual]

Destructor.

Definition at line 80 of file qwt_plot_histogram.cpp.

Member Function Documentation

double QwtPlotHistogram::baseline ( ) const

Returns:: Value of the baseline

See also:: setBaseline()

Definition at line 252 of file qwt_plot_histogram.cpp.

QRectF QwtPlotHistogram::boundingRect ( ) const [virtual]

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

Reimplemented from QwtPlotSeriesItem.

Definition at line 261 of file qwt_plot_histogram.cpp.

const QBrush & QwtPlotHistogram::brush ( ) const

Returns:: Brush used in a style() depending way.

See also:: setPen(), brush()

Definition at line 188 of file qwt_plot_histogram.cpp.

QwtColumnRect QwtPlotHistogram::columnRect	(	const QwtIntervalSample &	sample,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap
	)		const `[protected, virtual]`

Calculate the area that is covered by a sample

Parameters:

sample	Sample
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.

Returns:: Rectangle, that is covered by a sample

Definition at line 599 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::drawColumn	(	QPainter *	painter,
		const QwtColumnRect &	rect,
		const QwtIntervalSample &	sample
	)		const `[protected, virtual]`

Draw a column for a sample in Columns style().

When a symbol() has been set the symbol is used otherwise the column is displayed as plain rectangle using pen() and brush().

Parameters:

painter	Painter
rect	Rectangle where to paint the column in paint device coordinates
sample	Sample to be displayed

Note:: In applications, where different intervals need to be displayed in a different way ( f.e different colors or even using different symbols) it is recommended to overload drawColumn().

Definition at line 650 of file qwt_plot_histogram.cpp.

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

Draw a histogram in Columns style()

Parameters:

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the histogram will be painted to its last point.

See also:: setStyle(), style(), setSymbol(), drawColumn()

Definition at line 458 of file qwt_plot_histogram.cpp.

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

Draw a histogram in Lines style()

Parameters:

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the histogram will be painted to its last point.

See also:: setStyle(), style(), setPen()

Definition at line 490 of file qwt_plot_histogram.cpp.

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

Draw a histogram in Outline style()

Parameters:

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the histogram will be painted to its last point.

See also:: setStyle(), style()

Warning:: The outline style requires, that the intervals are in increasing order and not overlapping.

Definition at line 373 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::drawSeries	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const `[virtual]`

Draw a subset of the histogram samples

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 sample to be painted
to	Index of the last sample to be painted. If to < 0 the series will be painted to its last sample.

See also:: drawOutline(), drawLines(), drawColumns

Implements QwtPlotSeriesItem.

Definition at line 333 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::flushPolygon	(	QPainter *	painter,
		double	baseLine,
		QPolygonF &	polygon
	)		const `[private]`

Internal, used by the Outline style.

Definition at line 549 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::init ( ) [private]

Initialize data members.

Definition at line 86 of file qwt_plot_histogram.cpp.

QwtGraphic QwtPlotHistogram::legendIcon	(	int	index,
		const QSizeF &	size
	)		const `[virtual]`

A plain rectangle without pen using the brush()

Parameters:

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

Returns:: A graphic displaying the icon

See also:: QwtPlotItem::setLegendIconSize(), QwtPlotItem::legendData()

Reimplemented from QwtPlotItem.

Definition at line 685 of file qwt_plot_histogram.cpp.

const QPen & QwtPlotHistogram::pen ( ) const

Returns:: Pen used in a style() depending way.

See also:: setPen(), brush()

Definition at line 162 of file qwt_plot_histogram.cpp.

int QwtPlotHistogram::rtti ( ) const [virtual]

Returns:: QwtPlotItem::Rtti_PlotHistogram

Reimplemented from QwtPlotItem.

Definition at line 289 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setBaseline ( double value )

Set the value of the baseline.

Each column representing an QwtIntervalSample is defined by its interval and the interval between baseline and the value of the sample.

The default value of the baseline is 0.0.

Parameters:

value Value of the baseline

See also:: baseline()

Definition at line 239 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setBrush ( const QBrush & brush )

Assign a brush, that is used in a style() depending way.

Parameters:

brush New brush

See also:: pen(), brush()

Definition at line 173 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::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 136 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setPen ( const QPen & pen )

Assign a pen, that is used in a style() depending way.

Parameters:

pen New pen

See also:: pen(), brush()

Definition at line 147 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setSamples ( const QVector< QwtIntervalSample > & samples )

Initialize data with an array of samples.

Parameters:

samples Vector of points

Definition at line 298 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setSamples ( QwtSeriesData< QwtIntervalSample > * 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.

Definition at line 314 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setStyle ( HistogramStyle style )

Set the histogram's drawing style

Parameters:

style Histogram style

See also:: HistogramStyle, style()

Definition at line 103 of file qwt_plot_histogram.cpp.

void QwtPlotHistogram::setSymbol ( const QwtColumnSymbol * symbol )

Assign a symbol.

In Column style an optional symbol can be assigned, that is responsible for displaying the rectangle that is defined by the interval and the distance between baseline() and value. When no symbol has been defined the area is displayed as plain rectangle using pen() and brush().

See also:: style(), symbol(), drawColumn(), pen(), brush()

Note:: In applications, where different intervals need to be displayed in a different way ( f.e different colors or even using different symbols) it is recommended to overload drawColumn().

Definition at line 207 of file qwt_plot_histogram.cpp.

QwtPlotHistogram::HistogramStyle QwtPlotHistogram::style ( ) const

Returns:: Style of the histogram

See also:: HistogramStyle, setStyle()

Definition at line 118 of file qwt_plot_histogram.cpp.

const QwtColumnSymbol * QwtPlotHistogram::symbol ( ) const

Returns:: Current symbol or NULL, when no symbol has been assigned

See also:: setSymbol()

Definition at line 223 of file qwt_plot_histogram.cpp.

Member Data Documentation

PrivateData* QwtPlotHistogram::d_data [private]

Reimplemented from QwtPlotSeriesItem.

Definition at line 135 of file qwt_plot_histogram.h.

The documentation for this class was generated from the following files:

Classes

Public Types

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation