An item which draws scales and grid lines on a polar plot. More...

#include <qwt_polar_grid.h>

Inheritance diagram for QwtPolarGrid:

Classes
class	PrivateData

Public Types
enum	DisplayFlag { SmartOriginLabel = 1 , HideMaxRadiusLabel = 2 , ClipAxisBackground = 4 , SmartScaleDraw = 8 , ClipGridLines = 16 }
	Mysterious flags trying to avoid conflicts, when painting the scales and grid lines. More...

enum	GridAttribute { AutoScaling = 0x01 }
	Grid attributes. More...

Public Types inherited from QwtPolarItem
enum	RttiValues { Rtti_PolarItem = 0 , Rtti_PolarGrid , Rtti_PolarMarker , Rtti_PolarCurve , Rtti_PolarSpectrogram , Rtti_PolarUserItem = 1000 }
	Runtime type information. More...

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

enum	RenderHint { RenderAntialiased = 0x01 }
	Render hints. More...

Public Member Functions
	QwtPolarGrid ()
	Constructor.

virtual	~QwtPolarGrid ()
	Destructor.

virtual int	rtti () const QWT_OVERRIDE

void	setDisplayFlag (DisplayFlag, bool on=true)
	Change the display flags.

bool	testDisplayFlag (DisplayFlag) const

void	setGridAttribute (GridAttribute, bool on=true)
	Specify an attribute for the grid.

bool	testGridAttribute (GridAttribute) const

void	showGrid (int scaleId, bool show=true)
	Show/Hide grid lines for a scale.

bool	isGridVisible (int scaleId) const

void	showMinorGrid (int scaleId, bool show=true)
	Show/Hide minor grid lines for a scale.

bool	isMinorGridVisible (int scaleId) const

void	showAxis (int axisId, bool show=true)
	Show/Hide an axis.

bool	isAxisVisible (int axisId) const

void	setPen (const QPen &p)
	Assign a pen for all axes and grid lines.

void	setFont (const QFont &)
	Assign a font for all scale tick labels.

void	setMajorGridPen (const QPen &p)
	Assign a pen for the major grid lines.

void	setMajorGridPen (int scaleId, const QPen &p)
	Assign a pen for the major grid lines of a specific scale.

QPen	majorGridPen (int scaleId) const

void	setMinorGridPen (const QPen &p)
	Assign a pen for the minor grid lines.

void	setMinorGridPen (int scaleId, const QPen &p)
	Assign a pen for the minor grid lines of a specific scale.

QPen	minorGridPen (int scaleId) const

void	setAxisPen (int axisId, const QPen &p)
	Assign a pen for painting an axis.

QPen	axisPen (int axisId) const

void	setAxisFont (int axisId, const QFont &p)
	Assign a font for the tick labels of a specific axis.

QFont	axisFont (int axisId) const

void	setScaleDraw (int axisId, QwtScaleDraw *)
	Set a scale draw.

const QwtScaleDraw *	scaleDraw (int axisId) const
	Returns the scale draw of a specified axis.

QwtScaleDraw *	scaleDraw (int axisId)
	Returns the scale draw of a specified axis.

void	setAzimuthScaleDraw (QwtRoundScaleDraw *)
	Set a scale draw for the azimuth scale.

const QwtRoundScaleDraw *	azimuthScaleDraw () const

QwtRoundScaleDraw *	azimuthScaleDraw ()

virtual void	draw (QPainter *p, const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, double radius, const QRectF &rect) const QWT_OVERRIDE
	Draw the grid and axes.

virtual void	updateScaleDiv (const QwtScaleDiv &azimuthMap, const QwtScaleDiv &radialMap, const QwtInterval &) QWT_OVERRIDE
	Update the item to changes of the axes scale division.

virtual int	marginHint () const QWT_OVERRIDE

Public Member Functions inherited from QwtPolarItem
	QwtPolarItem (const QwtText &title=QwtText())
	Constructor.

virtual	~QwtPolarItem ()
	Destroy the QwtPolarItem.

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

void	detach ()
	This method detaches a QwtPolarItem from the QwtPolarPlot it has been associated with.

QwtPolarPlot *	plot () const

void	setTitle (const QString &title)
	Set a new title.

void	setTitle (const QwtText &title)
	Set a new title.

const QwtText &	title () const

void	setItemAttribute (ItemAttribute, bool on=true)
	Toggle an item attribute.

bool	testItemAttribute (ItemAttribute) const
	Test an item attribute.

void	setRenderHint (RenderHint, bool on=true)
	Toggle an render hint.

bool	testRenderHint (RenderHint) const
	Test a render hint.

void	setRenderThreadCount (uint numThreads)
	On multi core systems rendering of certain plot item ( f.e QwtPolarSpectrogram ) can be done in parallel in several threads.

uint	renderThreadCount () const

double	z () const
	Plot items are painted in increasing z-order.

void	setZ (double z)
	Set the z value.

void	show ()
	Show the item.

void	hide ()
	Hide the item.

virtual void	setVisible (bool)
	Show/Hide the item.

bool	isVisible () const

virtual void	itemChanged ()
	Update the legend and call QwtPolarPlot::autoRefresh for the parent plot.

virtual void	legendChanged ()
	Update the legend of the parent plot.

virtual QwtInterval	boundingInterval (int scaleId) const
	Interval, that is necessary to display the item.

void	setLegendIconSize (const QSize &)
	Set the size of the legend icon.

QSize	legendIconSize () const

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

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

Protected Member Functions
void	drawRays (QPainter *, const QRectF &, const QPointF &pole, double radius, const QwtScaleMap &azimuthMap, const QList< double > &) const
	Draw lines from the pole.

void	drawCircles (QPainter *, const QRectF &, const QPointF &pole, const QwtScaleMap &radialMap, const QList< double > &) const
	Draw circles.

void	drawAxis (QPainter *, int axisId) const
	Paint an axis.

Detailed Description

An item which draws scales and grid lines on a polar plot.

The QwtPolarGrid class can be used to draw a coordinate grid. A coordinate grid consists of major and minor gridlines. The locations of the gridlines are determined by the azimuth and radial scale divisions.

QwtPolarGrid is also responsible for drawing the axis representing the scales. It is possible to display 4 radial and one azimuth axis.

Whenever the scale divisions of the plot widget changes the grid is synchronized by updateScaleDiv().

See also: QwtPolarPlot, QwtPolar::Axis

Member Enumeration Documentation

◆ DisplayFlag

enum QwtPolarGrid::DisplayFlag

Mysterious flags trying to avoid conflicts, when painting the scales and grid lines.

The default setting enables all flags.

See also: setDisplayFlag(), testDisplayFlag()

Enumerator
SmartOriginLabel	Try to avoid situations, where the label of the origin is painted over another axis.
HideMaxRadiusLabel	Often the outermost tick of the radial scale is close to the canvas border. With HideMaxRadiusLabel enabled it is not painted.
ClipAxisBackground	The tick labels of the radial scales might be hard to read, when they are painted on top of the radial grid lines ( or on top of a curve/spectrogram ). When ClipAxisBackground the bounding rect of each label is added to the clip region.
SmartScaleDraw	Don't paint the backbone of the radial axes, when they are very close to a line of the azimuth grid.
ClipGridLines	All grid lines are clipped against the plot area before being painted. When the plot is zoomed in this will have an significant impact on the performance of the painting code.

◆ GridAttribute

enum QwtPolarGrid::GridAttribute

Grid attributes.

See also: setGridAttributes(), testGridAttributes()

Enumerator
AutoScaling	When AutoScaling is enabled, the radial axes will be adjusted to the interval, that is currently visible on the canvas plot.

Constructor & Destructor Documentation

◆ QwtPolarGrid()

QwtPolarGrid::QwtPolarGrid ( )

explicit

Constructor.

Enables major and disables minor grid lines. The azimuth and right radial axis are visible. all other axes are hidden. Autoscaling is enabled.

Member Function Documentation

◆ axisFont()

QFont QwtPolarGrid::axisFont ( int axisId ) const

Returns: Font for the tick labels of a specific axis

Parameters

axisId Axis id (QwtPolar::Axis)

◆ axisPen()

QPen QwtPolarGrid::axisPen ( int axisId ) const

Returns: Pen for painting a specific axis

Parameters

axisId Axis id (QwtPolar::Axis)

See also: setAxisPen()

◆ azimuthScaleDraw() [1/2]

QwtRoundScaleDraw * QwtPolarGrid::azimuthScaleDraw ( )

Returns: Scale draw for the azimuth scale

See also: setAzimuthScaleDraw(), scaleDraw()

◆ azimuthScaleDraw() [2/2]

const QwtRoundScaleDraw * QwtPolarGrid::azimuthScaleDraw ( ) const

Returns: Scale draw for the azimuth scale

See also: setAzimuthScaleDraw(), scaleDraw()

◆ draw()

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

virtual

Draw the grid and axes.

Parameters

painter	Painter
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

Implements QwtPolarItem.

◆ drawAxis()

void QwtPolarGrid::drawAxis	(	QPainter *	painter,
		int	axisId
	)		const

protected

Paint an axis.

Parameters

painter	Painter
axisId	Axis id (QwtPolar::Axis)

◆ drawCircles()

void QwtPolarGrid::drawCircles	(	QPainter *	painter,
		const QRectF &	canvasRect,
		const QPointF &	pole,
		const QwtScaleMap &	radialMap,
		const QList< double > &	values
	)		const

protected

Draw circles.

Parameters

painter	Painter
canvasRect	Contents rect of the canvas in painter coordinates
pole	Position of the pole in painter coordinates
radialMap	Maps radius values into painter coordinates.
values	Radial values, indicating the distances from the pole

◆ drawRays()

void QwtPolarGrid::drawRays	(	QPainter *	painter,
		const QRectF &	canvasRect,
		const QPointF &	pole,
		double	radius,
		const QwtScaleMap &	azimuthMap,
		const QList< double > &	values
	)		const

protected

Draw lines from the pole.

Parameters

painter	Painter
canvasRect	Contents rect of the canvas in painter coordinates
pole	Position of the pole in painter coordinates
radius	Length of the lines in painter coordinates
azimuthMap	Maps azimuth values to values related to 0.0, M_2PI
values	Azimuth values, indicating the direction of the lines

◆ isAxisVisible()

bool QwtPolarGrid::isAxisVisible ( int axisId ) const

Returns: true if the axis is visible

Parameters

axisId Axis id (QwtPolar::Axis)

See also: showAxis()

◆ isGridVisible()

bool QwtPolarGrid::isGridVisible ( int scaleId ) const

Returns: true if grid lines are enabled

Parameters

scaleId Scale id ( QwtPolar::Scale )

See also: QwtPolar::Scale, showGrid()

◆ isMinorGridVisible()

bool QwtPolarGrid::isMinorGridVisible ( int scaleId ) const

Returns: true if minor grid lines are enabled

Parameters

scaleId Scale id ( QwtPolar::Scale )

See also: showMinorGrid()

◆ majorGridPen()

QPen QwtPolarGrid::majorGridPen ( int scaleId ) const

Returns: Pen for painting the major grid lines of a specific scale

Parameters

scaleId Scale id ( QwtPolar::Scale )

See also: setMajorGridPen(), minorGridPen()

◆ marginHint()

int QwtPolarGrid::marginHint ( ) const

virtual

Returns: Number of pixels, that are necessary to paint the azimuth scale

See also: QwtRoundScaleDraw::extent()

Reimplemented from QwtPolarItem.

◆ minorGridPen()

QPen QwtPolarGrid::minorGridPen ( int scaleId ) const

Returns: Pen for painting the minor grid lines of a specific scale

Parameters

scaleId Scale id ( QwtPolar::Scale )

◆ rtti()

int QwtPolarGrid::rtti ( ) const

virtual

Returns: QwtPlotItem::Rtti_PolarGrid

Reimplemented from QwtPolarItem.

◆ scaleDraw() [1/2]

QwtScaleDraw * QwtPolarGrid::scaleDraw ( int axisId )

Returns the scale draw of a specified axis.

Parameters

axisId axis index ( QwtPolar::AxisLeft <= axisId <= QwtPolar::AxisBottom)

Returns: specified scaleDraw for axis, or NULL if axis is invalid.

See also: setScaleDraw(), azimuthScaleDraw()

◆ scaleDraw() [2/2]

const QwtScaleDraw * QwtPolarGrid::scaleDraw ( int axisId ) const

Returns the scale draw of a specified axis.

Parameters

axisId axis index ( QwtPolar::AxisLeft <= axisId <= QwtPolar::AxisBottom)

Returns: specified scaleDraw for axis, or NULL if axis is invalid.

See also: azimuthScaleDraw()

◆ setAxisFont()

void QwtPolarGrid::setAxisFont	(	int	axisId,
		const QFont &	font
	)

Assign a font for the tick labels of a specific axis.

Parameters

axisId	Axis id (QwtPolar::Axis)
font	new Font

◆ setAxisPen()

void QwtPolarGrid::setAxisPen	(	int	axisId,
		const QPen &	pen
	)

Assign a pen for painting an axis.

Parameters

axisId	Axis id (QwtPolar::Axis)
pen	Pen

See also: axisPen()

◆ setAzimuthScaleDraw()

void QwtPolarGrid::setAzimuthScaleDraw ( QwtRoundScaleDraw * scaleDraw )

Set a scale draw for the azimuth scale.

Parameters

scaleDraw object responsible for drawing scales.

See also: azimuthScaleDraw(), setScaleDraw()

◆ setDisplayFlag()

void QwtPolarGrid::setDisplayFlag	(	DisplayFlag	flag,
		bool	on = `true`
	)

Change the display flags.

Parameters

flag	See DisplayFlag
on	true/false

◆ setFont()

void QwtPolarGrid::setFont ( const QFont & font )

Assign a font for all scale tick labels.

Parameters

font Font

See also: setAxisFont()

◆ setGridAttribute()

void QwtPolarGrid::setGridAttribute	(	GridAttribute	attribute,
		bool	on = `true`
	)

Specify an attribute for the grid.

Parameters

attribute	Grid attribute
on	On/Off

/sa GridAttribute, testGridAttribute(), updateScaleDiv(), QwtPolarPlot::zoom(), QwtPolarPlot::scaleDiv()

◆ setMajorGridPen() [1/2]

void QwtPolarGrid::setMajorGridPen ( const QPen & pen )

Assign a pen for the major grid lines.

Parameters

pen Pen

See also: setPen(), setMinorGridPen(), majorGridPen

◆ setMajorGridPen() [2/2]

void QwtPolarGrid::setMajorGridPen	(	int	scaleId,
		const QPen &	pen
	)

Assign a pen for the major grid lines of a specific scale.

Parameters

scaleId	Scale id ( QwtPolar::Scale )
pen	Pen

See also: setPen(), setMinorGridPen(), majorGridPen

◆ setMinorGridPen() [1/2]

void QwtPolarGrid::setMinorGridPen ( const QPen & pen )

Assign a pen for the minor grid lines.

Parameters

pen Pen

See also: setPen(), setMajorGridPen(), minorGridPen()

◆ setMinorGridPen() [2/2]

void QwtPolarGrid::setMinorGridPen	(	int	scaleId,
		const QPen &	pen
	)

Assign a pen for the minor grid lines of a specific scale.

Parameters

scaleId	Scale id ( QwtPolar::Scale )
pen	Pen

See also: setPen(), setMajorGridPen(), minorGridPen

◆ setPen()

void QwtPolarGrid::setPen ( const QPen & pen )

Assign a pen for all axes and grid lines.

Parameters

pen Pen

See also: setMajorGridPen(), setMinorGridPen(), setAxisPen()

◆ setScaleDraw()

void QwtPolarGrid::setScaleDraw	(	int	axisId,
		QwtScaleDraw *	scaleDraw
	)

Set a scale draw.

Parameters

axisId	axis index ( QwtPolar::AxisLeft <= axisId <= QwtPolar::AxisBottom)
scaleDraw	object responsible for drawing scales.

See also: scaleDraw(), setAzimuthScaleDraw()

◆ showAxis()

void QwtPolarGrid::showAxis	(	int	axisId,
		bool	show = `true`
	)

Show/Hide an axis.

Parameters

axisId	Axis id (QwtPolar::Axis)
show	true/false

See also: isAxisVisible()

◆ showGrid()

void QwtPolarGrid::showGrid	(	int	scaleId,
		bool	show = `true`
	)

Show/Hide grid lines for a scale.

Parameters

scaleId	Scale id ( QwtPolar::Scale )
show	true/false

◆ showMinorGrid()

void QwtPolarGrid::showMinorGrid	(	int	scaleId,
		bool	show = `true`
	)

Show/Hide minor grid lines for a scale.

To display minor grid lines. showGrid() needs to be enabled too.

Parameters

scaleId	Scale id ( QwtPolar::Scale )
show	true/false

See also: showGrid

◆ testDisplayFlag()

bool QwtPolarGrid::testDisplayFlag ( DisplayFlag flag ) const

Returns: true, if flag is enabled

Parameters

flag	See DisplayFlag

◆ testGridAttribute()

bool QwtPolarGrid::testGridAttribute ( GridAttribute attribute ) const

Returns: true, if attribute is enabled

See also: GridAttribute, setGridAttribute()

◆ updateScaleDiv()

void QwtPolarGrid::updateScaleDiv	(	const QwtScaleDiv &	azimuthScaleDiv,
		const QwtScaleDiv &	radialScaleDiv,
		const QwtInterval &	interval
	)

virtual

Update the item to changes of the axes scale division.

If AutoScaling is enabled the radial scale is calculated from the interval, otherwise the scales are adopted to the plot scales.

Parameters

azimuthScaleDiv	Scale division of the azimuth-scale
radialScaleDiv	Scale division of the radius-axis
interval	The interval of the radius-axis, that is visible on the canvas

See also: QwtPolarPlot::setGridAttributes()

Reimplemented from QwtPolarItem.

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

/home/runner/work/QWT/QWT/src/qwt_polar_grid.h
/home/runner/work/QWT/QWT/src/qwt_polar_grid.cpp

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ DisplayFlag

◆ GridAttribute

Constructor & Destructor Documentation

◆ QwtPolarGrid()

Member Function Documentation

◆ axisFont()

◆ axisPen()

◆ azimuthScaleDraw() [1/2]

◆ azimuthScaleDraw() [2/2]

◆ draw()

◆ drawAxis()

◆ drawCircles()

◆ drawRays()

◆ isAxisVisible()

◆ isGridVisible()

◆ isMinorGridVisible()

◆ majorGridPen()

◆ marginHint()

◆ minorGridPen()

◆ rtti()

◆ scaleDraw() [1/2]

◆ scaleDraw() [2/2]

◆ setAxisFont()

◆ setAxisPen()

◆ setAzimuthScaleDraw()

◆ setDisplayFlag()

◆ setFont()

◆ setGridAttribute()

◆ setMajorGridPen() [1/2]

◆ setMajorGridPen() [2/2]

◆ setMinorGridPen() [1/2]

◆ setMinorGridPen() [2/2]

◆ setPen()

◆ setScaleDraw()

◆ showAxis()

◆ showGrid()

◆ showMinorGrid()

◆ testDisplayFlag()

◆ testGridAttribute()

◆ updateScaleDiv()