A plotting widget, displaying a polar coordinate system. More...

#include <qwt_polar_plot.h>

Inheritance diagram for QwtPolarPlot:

Public Types
enum	LegendPosition { LeftLegend, RightLegend, BottomLegend, TopLegend, ExternalLegend }

Public Slots
virtual void	replot ()
	Redraw the plot. More...

void	autoRefresh ()
	Replots the plot if QwtPlot::autoReplot() is `true`.

void	setAzimuthOrigin (double)
	Change the origin of the azimuth scale. More...

Signals
void	itemAttached (QwtPolarItem *plotItem, bool on)

void	legendDataChanged (const QVariant &itemInfo, const QList< QwtLegendData > &data)

void	layoutChanged ()

Public Member Functions
	QwtPolarPlot (QWidget *parent=NULL)

	QwtPolarPlot (const QwtText &title, QWidget *parent=NULL)

virtual	~QwtPolarPlot ()
	Destructor.

void	setTitle (const QString &)

void	setTitle (const QwtText &)

QwtText	title () const

QwtTextLabel *	titleLabel ()

const QwtTextLabel *	titleLabel () const

void	setAutoReplot (bool tf=true)
	Set or reset the autoReplot option. More...

bool	autoReplot () const

void	setAutoScale (int scaleId)
	Enable autoscaling. More...

bool	hasAutoScale (int scaleId) const

void	setScaleMaxMinor (int scaleId, int maxMinor)

int	scaleMaxMinor (int scaleId) const

int	scaleMaxMajor (int scaleId) const

void	setScaleMaxMajor (int scaleId, int maxMajor)

QwtScaleEngine *	scaleEngine (int scaleId)

const QwtScaleEngine *	scaleEngine (int scaleId) const

void	setScaleEngine (int scaleId, QwtScaleEngine *)

void	setScale (int scaleId, double min, double max, double step=0)
	Disable autoscaling and specify a fixed scale for a selected scale. More...

void	setScaleDiv (int scaleId, const QwtScaleDiv &)
	Disable autoscaling and specify a fixed scale for a selected scale. More...

const QwtScaleDiv *	scaleDiv (int scaleId) const
	Return the scale division of a specified scale. More...

QwtScaleDiv *	scaleDiv (int scaleId)
	Return the scale division of a specified scale. More...

QwtScaleMap	scaleMap (int scaleId, double radius) const

QwtScaleMap	scaleMap (int scaleId) const

void	updateScale (int scaleId)

double	azimuthOrigin () const

void	zoom (const QwtPointPolar &, double factor)
	Translate and in/decrease the zoom factor. More...

void	unzoom ()

QwtPointPolar	zoomPos () const

double	zoomFactor () const

QwtPolarCanvas *	canvas ()

const QwtPolarCanvas *	canvas () const

void	setPlotBackground (const QBrush &c)
	Set the background of the plot area. More...

const QBrush &	plotBackground () const

virtual void	drawCanvas (QPainter *, const QRectF &) const

void	insertLegend (QwtAbstractLegend *, LegendPosition=RightLegend, double ratio=-1.0)
	Insert a legend. More...

QwtAbstractLegend *	legend ()

const QwtAbstractLegend *	legend () const

void	updateLegend ()

void	updateLegend (const QwtPolarItem *)

QwtPolarLayout *	plotLayout ()

const QwtPolarLayout *	plotLayout () const

QwtInterval	visibleInterval () const

QRectF	plotRect () const

QRectF	plotRect (const QRectF &) const
	Calculate the bounding rect of the plot area. More...

int	plotMarginHint () const

virtual QVariant	itemToInfo (QwtPolarItem *) const
	Build an information, that can be used to identify a plot item on the legend. More...

virtual QwtPolarItem *	infoToItem (const QVariant &) const
	Identify the plot item according to an item info object, that has bee generated from itemToInfo(). More...

Public Member Functions inherited from QwtPolarItemDict
	QwtPolarItemDict ()

	~QwtPolarItemDict ()

void	setAutoDelete (bool)

bool	autoDelete () const

const QwtPolarItemList &	itemList () const
	A QwtPolarItemList of all attached plot items. More...

void	detachItems (int rtti=QwtPolarItem::Rtti_PolarItem, bool autoDelete=true)

Protected Member Functions
virtual bool	event (QEvent *)
	Qt event handler. More...

virtual void	resizeEvent (QResizeEvent *)
	Resize and update internal layout.

virtual void	updateLayout ()
	Rebuild the layout.

virtual void	drawItems (QPainter *painter, const QwtScaleMap &radialMap, const QwtScaleMap &azimuthMap, const QPointF &pole, double radius, const QRectF &canvasRect) const

Protected Member Functions inherited from QwtPolarItemDict
void	insertItem (QwtPolarItem *)

void	removeItem (QwtPolarItem *)

Friends
class	QwtPolarItem

Detailed Description

A plotting widget, displaying a polar coordinate system.

An unlimited number of plot items can be displayed on its canvas. Plot items might be curves (QwtPolarCurve), markers (QwtPolarMarker), the grid (QwtPolarGrid), or anything else derived from QwtPolarItem.

The coordinate system is defined by a radial and a azimuth scale. The scales at the axes can be explicitely set (QwtScaleDiv), or are calculated from the plot items, using algorithms (QwtScaleEngine) which can be configured separately for each axis. Autoscaling is supported for the radial scale.

In opposite to QwtPlot the scales might be different from the view, that is displayed on the canvas. The view can be changed by zooming - f.e. by using QwtPolarPanner or QwtPolarMaginfier.

Member Enumeration Documentation

enum QwtPolarPlot::LegendPosition

Position of the legend, relative to the canvas.

See Also: insertLegend()

Enumerator
LeftLegend	The legend will be left from the canvas.
RightLegend	The legend will be right from the canvas.
BottomLegend	The legend will be below the canvas.
TopLegend	The legend will be between canvas and title.
ExternalLegend	External means that only the content of the legend will be handled by QwtPlot, but not its geometry. This might be interesting if an application wants to have a legend in an external window ( or on the canvas ). Note The legend is not painted by QwtPolarRenderer

Constructor & Destructor Documentation

QwtPolarPlot::QwtPolarPlot ( QWidget * parent = NULL )

explicit

Constructor

Parameters

parent Parent widget

QwtPolarPlot::QwtPolarPlot	(	const QwtText &	title,
		QWidget *	parent = `NULL`
	)

Constructor

Parameters

title	Title text
parent	Parent widget

Member Function Documentation

bool QwtPolarPlot::autoReplot ( ) const

Returns: true if the autoReplot option is set.

double QwtPolarPlot::azimuthOrigin ( ) const

The azimuth origin is the angle where the azimuth scale shows the value 0.0.

Returns: Origin of the azimuth scale

See Also: setAzimuthOrigin()

QwtPolarCanvas * QwtPolarPlot::canvas ( )

Returns: the plot's canvas

const QwtPolarCanvas * QwtPolarPlot::canvas ( ) const

Returns: the plot's canvas

void QwtPolarPlot::drawCanvas	(	QPainter *	painter,
		const QRectF &	canvasRect
	)		const

virtual

Redraw the canvas.

Parameters

painter	Painter used for drawing
canvasRect	Contents rect of the canvas

void QwtPolarPlot::drawItems	(	QPainter *	painter,
		const QwtScaleMap &	azimuthMap,
		const QwtScaleMap &	radialMap,
		const QPointF &	pole,
		double	radius,
		const QRectF &	canvasRect
	)		const

protectedvirtual

Redraw the canvas items.

Parameters

painter	Painter used for drawing
azimuthMap	Maps azimuth values to values related to 0.0, M_2PI
radialMap	Maps radius values into painter coordinates.
pole	Position of the pole in painter coordinates
radius	Radius of the complete plot area in painter coordinates
canvasRect	Contents rect of the canvas in painter coordinates

bool QwtPolarPlot::event ( QEvent * e )

protectedvirtual

Qt event handler.

Handles QEvent::LayoutRequest and QEvent::PolishRequest

Parameters

e Qt Event

Returns: True, when the event was processed

bool QwtPolarPlot::hasAutoScale ( int scaleId ) const

Returns: true if autoscaling is enabled

Parameters

scaleId Scale index

See Also: setAutoScale()

QwtPolarItem * QwtPolarPlot::infoToItem ( const QVariant & itemInfo ) const

virtual

Identify the plot item according to an item info object, that has bee generated from itemToInfo().

The default implementation simply tries to unwrap a QwtPlotItem pointer:

if ( itemInfo.canConvert<QwtPlotItem *>() )

return qvariant_cast<QwtPlotItem *>( itemInfo );

Parameters

itemInfo Plot item

Returns: A plot item, when successful, otherwise a NULL pointer.

See Also: itemToInfo()

void QwtPolarPlot::insertLegend	(	QwtAbstractLegend *	legend,
		QwtPolarPlot::LegendPosition	pos = `RightLegend`,
		double	ratio = `-1.0`
	)

Insert a legend.

If the position legend is QwtPolarPlot::LeftLegend or QwtPolarPlot::RightLegend the legend will be organized in one column from top to down. Otherwise the legend items will be placed in a table with a best fit number of columns from left to right.

If pos != QwtPolarPlot::ExternalLegend the plot widget will become parent of the legend. It will be deleted when the plot is deleted, or another legend is set with insertLegend().

Parameters

legend	Legend
pos	The legend's position. For top/left position the number of colums will be limited to 1, otherwise it will be set to unlimited.
ratio	Ratio between legend and the bounding rect of title, canvas and axes. The legend will be shrinked if it would need more space than the given ratio. The ratio is limited to ]0.0 .. 1.0]. In case of <= 0.0 it will be reset to the default ratio. The default vertical/horizontal ratio is 0.33/0.5.

See Also: legend(), QwtPolarLayout::legendPosition(), QwtPolarLayout::setLegendPosition()

void QwtPolarPlot::itemAttached	(	QwtPolarItem *	plotItem,
		bool	on
	)

signal

A signal indicating, that an item has been attached/detached

Parameters

plotItem	Plot item
on	Attached/Detached

QVariant QwtPolarPlot::itemToInfo ( QwtPolarItem * plotItem ) const

virtual

Build an information, that can be used to identify a plot item on the legend.

The default implementation simply wraps the plot item into a QVariant object. When overloading itemToInfo() usually infoToItem() needs to reimplemeted too.

QVariant itemInfo;

qVariantSetValue( itemInfo, plotItem );

Parameters

plotItem Plot item

See Also: infoToItem()

void QwtPolarPlot::layoutChanged ( )

signal

A signal that is emitted, whenever the layout of the plot has been recalculated.

QwtAbstractLegend * QwtPolarPlot::legend ( )

Returns: the plot's legend

See Also: insertLegend()

const QwtAbstractLegend * QwtPolarPlot::legend ( ) const

Returns: the plot's legend

See Also: insertLegend()

void QwtPolarPlot::legendDataChanged	(	const QVariant &	itemInfo,
		const QList< QwtLegendData > &	data
	)

signal

A signal with the attributes how to update the legend entries for a plot item.

Parameters

itemInfo Info about a plot, build from itemToInfo()

See Also: itemToInfo(), infoToItem(), QwtAbstractLegend::updateLegend()

const QBrush & QwtPolarPlot::plotBackground ( ) const

Returns: plot background brush

See Also: plotBackground(), plotArea()

QwtPolarLayout * QwtPolarPlot::plotLayout ( )

Returns: Layout, responsible for the geometry of the plot components

const QwtPolarLayout * QwtPolarPlot::plotLayout ( ) const

Returns: Layout, responsible for the geometry of the plot components

int QwtPolarPlot::plotMarginHint ( ) const

Returns: Maximum of all item margin hints.

See Also: QwtPolarItem::marginHint()

QRectF QwtPolarPlot::plotRect ( ) const

The plot area depends on the size of the canvas and the zoom parameters.

Returns: Bounding rect of the plot area

QRectF QwtPolarPlot::plotRect ( const QRectF & canvasRect ) const

Calculate the bounding rect of the plot area.

The plot area depends on the zoom parameters.

Parameters

canvasRect Rectangle of the canvas

Returns: Rectangle for displaying 100% of the plot

void QwtPolarPlot::replot ( )

virtualslot

Redraw the plot.

If the autoReplot option is not set (which is the default) or if any curves are attached to raw data, the plot has to be refreshed explicitly in order to make changes visible.

See Also: setAutoReplot()

Warning: Calls canvas()->repaint, take care of infinite recursions

const QwtScaleDiv * QwtPolarPlot::scaleDiv ( int scaleId ) const

Return the scale division of a specified scale.

scaleDiv(scaleId)->lBound(), scaleDiv(scaleId)->hBound() are the current limits of the scale.

Parameters

scaleId Scale index

Returns: Scale division

See Also: QwtScaleDiv, setScaleDiv(), setScale()

QwtScaleDiv * QwtPolarPlot::scaleDiv ( int scaleId )

Return the scale division of a specified scale.

scaleDiv(scaleId)->lBound(), scaleDiv(scaleId)->hBound() are the current limits of the scale.

Parameters

scaleId Scale index

Returns: Scale division

See Also: QwtScaleDiv, setScaleDiv(), setScale()

QwtScaleEngine * QwtPolarPlot::scaleEngine ( int scaleId )

Returns: Scale engine for a specific scale

Parameters

scaleId Scale index

See Also: setScaleEngine()

const QwtScaleEngine * QwtPolarPlot::scaleEngine ( int scaleId ) const

Returns: Scale engine for a specific scale

Parameters

scaleId Scale index

See Also: setScaleEngine()

QwtScaleMap QwtPolarPlot::scaleMap	(	int	scaleId,
		double	radius
	)		const

Build a scale map

The azimuth map translates between the scale values and angles from [0.0, 2 * PI[. The radial map translates scale values into the distance from the pole.

Parameters

scaleId	Scale index
radius	Radius of the plot are in pixels

Returns: Map for the scale on the canvas. With this map pixel coordinates can translated to plot coordinates and vice versa.

See Also: QwtScaleMap, transform(), invTransform()

QwtScaleMap QwtPolarPlot::scaleMap ( int scaleId ) const

Build a scale map

The azimuth map translates between the scale values and angles from [0.0, 2 * PI[. The radial map translates scale values into the distance from the pole. The radial map is calculated from the current geometry of the canvas.

Parameters

scaleId Scale index

Returns: Map for the scale on the canvas. With this map pixel coordinates can translated to plot coordinates and vice versa.

See Also: QwtScaleMap, transform(), invTransform()

int QwtPolarPlot::scaleMaxMajor ( int scaleId ) const

Returns: the maximum number of major ticks for a specified axis

Parameters

scaleId Scale index

See Also: setScaleMaxMajor()

int QwtPolarPlot::scaleMaxMinor ( int scaleId ) const

Returns: the maximum number of minor ticks for a specified axis

Parameters

scaleId Scale index

See Also: setScaleMaxMinor()

void QwtPolarPlot::setAutoReplot ( bool enable = true )

Set or reset the autoReplot option.

If the autoReplot option is set, the plot will be updated implicitly by manipulating member functions. Since this may be time-consuming, it is recommended to leave this option switched off and call replot() explicitly if necessary.

The autoReplot option is set to false by default, which means that the user has to call replot() in order to make changes visible.

Parameters

enable true or false. Defaults to true.

See Also: replot()

void QwtPolarPlot::setAutoScale ( int scaleId )

Enable autoscaling.

This member function is used to switch back to autoscaling mode after a fixed scale has been set. Autoscaling calculates a useful scale division from the bounding interval of all plot items with the QwtPolarItem::AutoScale attribute.

Autoscaling is only supported for the radial scale and enabled as default.

Parameters

scaleId Scale index

See Also: hasAutoScale(), setScale(), setScaleDiv(), QwtPolarItem::boundingInterval()

void QwtPolarPlot::setAzimuthOrigin ( double origin )

slot

Change the origin of the azimuth scale.

The azimuth origin is the angle where the azimuth scale shows the value 0.0. The default origin is 0.0.

Parameters

origin New origin

See Also: azimuthOrigin()

void QwtPolarPlot::setPlotBackground ( const QBrush & brush )

Set the background of the plot area.

The plot area is the circle around the pole. It's radius is defined by the radial scale.

Parameters

brush Background Brush

See Also: plotBackground(), plotArea()

void QwtPolarPlot::setScale	(	int	scaleId,
		double	min,
		double	max,
		double	stepSize = `0`
	)

Disable autoscaling and specify a fixed scale for a selected scale.

Parameters

scaleId	Scale index
min
max	minimum and maximum of the scale
stepSize	Major step size. If `step == 0`, the step size is calculated automatically using the maxMajor setting.

See Also: setScaleMaxMajor(), setAutoScale()

void QwtPolarPlot::setScaleDiv	(	int	scaleId,
		const QwtScaleDiv &	scaleDiv
	)

Disable autoscaling and specify a fixed scale for a selected scale.

Parameters

scaleId	Scale index
scaleDiv	Scale division

See Also: setScale(), setAutoScale()

void QwtPolarPlot::setScaleEngine	(	int	scaleId,
		QwtScaleEngine *	scaleEngine
	)

Change the scale engine for an axis

Parameters

scaleId	Scale index
scaleEngine	Scale engine

See Also: axisScaleEngine()

void QwtPolarPlot::setScaleMaxMajor	(	int	scaleId,
		int	maxMajor
	)

Set the maximum number of major scale intervals for a specified scale

Parameters

scaleId	Scale index
maxMajor	maximum number of major steps

See Also: scaleMaxMajor()

void QwtPolarPlot::setScaleMaxMinor	(	int	scaleId,
		int	maxMinor
	)

Set the maximum number of major scale intervals for a specified scale

Parameters

scaleId	Scale index
maxMinor	maximum number of minor steps

See Also: scaleMaxMajor()

void QwtPolarPlot::setTitle ( const QString & title )

Change the plot's title

Parameters

title New title

void QwtPolarPlot::setTitle ( const QwtText & title )

Change the plot's title

Parameters

title New title

QwtText QwtPolarPlot::title ( ) const

Returns: the plot's title

QwtTextLabel * QwtPolarPlot::titleLabel ( )

Returns: the plot's title

const QwtTextLabel * QwtPolarPlot::titleLabel ( ) const

Returns: the plot's titel label.

void QwtPolarPlot::unzoom ( )

Unzoom the plot

See Also: zoom()

void QwtPolarPlot::updateLegend ( )

Emit legendDataChanged() for all plot item

See Also: QwtPlotItem::legendData(), legendDataChanged()

void QwtPolarPlot::updateLegend ( const QwtPolarItem * plotItem )

Emit legendDataChanged() for a plot item

Parameters

plotItem Plot item

See Also: QwtPlotItem::legendData(), legendDataChanged()

void QwtPolarPlot::updateScale ( int scaleId )

Rebuild the scale

Parameters

scaleId Scale index

QwtInterval QwtPolarPlot::visibleInterval ( ) const

Returns: Bounding interval of the radial scale that is visible on the canvas.

void QwtPolarPlot::zoom	(	const QwtPointPolar &	zoomPos,
		double	zoomFactor
	)

Translate and in/decrease the zoom factor.

In zoom mode the zoom position is in the center of the canvas. The radius of the circle depends on the size of the plot canvas, that is devided by the zoom factor. Thus a factor < 1.0 zoom in.

Setting an invalid zoom position disables zooming.

Parameters