A plot item, which displays a spectrogram. More...

#include <qwt_plot_spectrogram.h>

Inheritance diagram for QwtPlotSpectrogram:

Classes
class	PrivateData

Public Types
enum	DisplayMode { ImageMode = 0x01 , ContourMode = 0x02 }
	The display mode controls how the raster data will be represented. More...

Public Types inherited from QwtPlotRasterItem
enum	CachePolicy { NoCache , PaintCache }
	Cache policy The default policy is NoCache. More...

enum	PaintAttribute { PaintInDeviceResolution = 1 }
	Attributes to modify the drawing algorithm. More...

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_PlotGraphic , Rtti_PlotTradingCurve , Rtti_PlotBarChart , Rtti_PlotMultiBarChart , Rtti_PlotShape , Rtti_PlotTextLabel , Rtti_PlotZone , Rtti_PlotVectorField , 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/绘图项关注的事件类型 More...

enum	RenderHint { RenderAntialiased = 0x1 }
	Render hints. More...

Public Member Functions
	QwtPlotSpectrogram (const QString &title=QString())
	Sets the following item attributes:

virtual	~QwtPlotSpectrogram ()
	Destructor.

void	setDisplayMode (DisplayMode, bool on=true)
	The display mode controls how the raster data will be represented.

bool	testDisplayMode (DisplayMode) const
	The display mode controls how the raster data will be represented.

void	setData (QwtRasterData *data)
	Set the data to be displayed.

const QwtRasterData *	data () const

QwtRasterData *	data ()

void	setColorMap (QwtColorMap *)
	Change the color map.

const QwtColorMap *	colorMap () const

void	setColorTableSize (int numColors)
	Limit the number of colors being used by the color map.

int	colorTableSize () const

virtual QwtInterval	interval (Qt::Axis) const QWT_OVERRIDE

virtual QRectF	pixelHint (const QRectF &) const QWT_OVERRIDE
	Pixel hint.

void	setDefaultContourPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
	Build and assign the default pen for the contour lines.

void	setDefaultContourPen (const QPen &)
	Set the default pen for the contour lines.

QPen	defaultContourPen () const

virtual QPen	contourPen (double level) const
	Calculate the pen for a contour line.

void	setConrecFlag (QwtRasterData::ConrecFlag, bool on)
	Modify an attribute of the CONREC algorithm, used to calculate the contour lines.

bool	testConrecFlag (QwtRasterData::ConrecFlag) const
	Test an attribute of the CONREC algorithm, used to calculate the contour lines.

void	setContourLevels (const QList< double > &)
	Set the levels of the contour lines.

QList< double >	contourLevels () const

virtual int	rtti () const QWT_OVERRIDE

virtual void	draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const QWT_OVERRIDE
	Draw the spectrogram.

Public Member Functions inherited from QwtPlotRasterItem
	QwtPlotRasterItem (const QString &title=QString())
	Constructor.

	QwtPlotRasterItem (const QwtText &title)
	Constructor.

virtual	~QwtPlotRasterItem ()
	Destructor.

void	setPaintAttribute (PaintAttribute, bool on=true)
	Specify an attribute how to draw the raster item.

bool	testPaintAttribute (PaintAttribute) const

void	setAlpha (int alpha)
	Set an alpha value for the raster data.

int	alpha () const

void	setCachePolicy (CachePolicy)
	Change the cache policy.

CachePolicy	cachePolicy () const

void	invalidateCache ()
	Invalidate the paint cache.

virtual QRectF	boundingRect () const QWT_OVERRIDE

Public Member Functions inherited from QwtPlotItem
	QwtPlotItem ()
	Constructor.

	QwtPlotItem (const QString &title)
	Constructor.

	QwtPlotItem (const QwtText &title)
	Constructor.

virtual	~QwtPlotItem ()
	Destroy the QwtPlotItem.

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

void	detach ()
	This method detaches a QwtPlotItem from any QwtPlot it has been associated with.

QwtPlot *	plot () const
	Return attached plot.

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	setItemInterest (ItemInterest, bool on=true)
	Toggle an item interest.

bool	testItemInterest (ItemInterest) const
	Test an item interest.

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 QwtPlotRasterItem ) can be done in parallel in several threads.

uint	renderThreadCount () const

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

QSize	legendIconSize () 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

void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
	Set X and Y axis.

void	setXAxis (QwtAxisId)
	Set the X axis.

QwtAxisId	xAxis () const
	Return xAxis.

void	setYAxis (QwtAxisId)
	Set the Y axis.

QwtAxisId	yAxis () const
	Return yAxis.

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

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

virtual void	getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
	Calculate a hint for the canvas margin.

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

virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item to changes of the legend info.

QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding scale rectangle of 2 maps.

QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding paint rectangle of 2 maps.

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
virtual QImage	renderImage (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &area, const QSize &imageSize) const QWT_OVERRIDE
	Render an image from data and color map.

virtual QSize	contourRasterSize (const QRectF &, const QRect &) const
	Return the raster to be used by the CONREC contour algorithm.

virtual QwtRasterData::ContourLines	renderContourLines (const QRectF &rect, const QSize &raster) const
	Calculate contour lines.

virtual void	drawContourLines (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtRasterData::ContourLines &) const
	Paint the contour lines.

void	renderTile (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &tile, QImage *) const
	Render a tile of an image.

Protected Member Functions inherited from QwtPlotRasterItem
virtual QwtScaleMap	imageMap (Qt::Orientation, const QwtScaleMap &map, const QRectF &area, const QSize &imageSize, double pixelSize) const
	Calculate a scale map for painting to an image.

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

Detailed Description

A plot item, which displays a spectrogram.

A spectrogram displays 3-dimensional data, where the 3rd dimension ( the intensity ) is displayed using colors. The colors are calculated from the values using a color map.

On multi-core systems the performance of the image composition can often be improved by dividing the area into tiles - each of them rendered in a different thread ( see QwtPlotItem::setRenderThreadCount() ).

In ContourMode contour lines are painted for the contour levels.

See also: QwtRasterData, QwtColorMap, QwtPlotItem::setRenderThreadCount()

Member Enumeration Documentation

◆ DisplayMode

enum QwtPlotSpectrogram::DisplayMode

The display mode controls how the raster data will be represented.

See also: setDisplayMode(), testDisplayMode()

Enumerator
ImageMode	The values are mapped to colors using a color map.
ContourMode	The data is displayed using contour lines.

Constructor & Destructor Documentation

◆ QwtPlotSpectrogram()

QwtPlotSpectrogram::QwtPlotSpectrogram ( const QString & title = QString() )

explicit

Sets the following item attributes:

QwtPlotItem::AutoScale: true
QwtPlotItem::Legend: false

The z value is initialized by 8.0.

Parameters

title Title

See also: QwtPlotItem::setItemAttribute(), QwtPlotItem::setZ()

Member Function Documentation

◆ colorMap()

const QwtColorMap * QwtPlotSpectrogram::colorMap ( ) const

Returns: Color Map used for mapping the intensity values to colors

See also: setColorMap()

◆ colorTableSize()

int QwtPlotSpectrogram::colorTableSize ( ) const

Returns: Size of the color table, 0 means not using a color table

See also: QwtColorMap::colorTable(), setColorTableSize()

◆ contourLevels()

QList< double > QwtPlotSpectrogram::contourLevels ( ) const

Returns: Levels of the contour lines.

The levels are sorted in increasing order.

See also: contourLevels(), renderContourLines(), QwtRasterData::contourLines()

◆ contourPen()

QPen QwtPlotSpectrogram::contourPen ( double level ) const

virtual

Calculate the pen for a contour line.

The color of the pen is the color for level calculated by the color map

Parameters

level Contour level

Returns: Pen for the contour line

Note: contourPen is only used if defaultContourPen().style() == Qt::NoPen

See also: setDefaultContourPen(), setColorMap(), setContourLevels()

◆ contourRasterSize()

QSize QwtPlotSpectrogram::contourRasterSize	(	const QRectF &	area,
		const QRect &	rect
	)		const

protectedvirtual

Return the raster to be used by the CONREC contour algorithm.

A larger size will improve the precision of the CONREC algorithm, but will slow down the time that is needed to calculate the lines.

The default implementation returns rect.size() / 2 bounded to the resolution depending on pixelSize().

Parameters

area	Rectangle, where to calculate the contour lines
rect	Rectangle in pixel coordinates, where to paint the contour lines

Returns: Raster to be used by the CONREC contour algorithm.

Note: The size will be bounded to rect.size().

See also: drawContourLines(), QwtRasterData::contourLines()

◆ data() [1/2]

QwtRasterData * QwtPlotSpectrogram::data ( )

Returns: Spectrogram data

See also: setData()

◆ data() [2/2]

const QwtRasterData * QwtPlotSpectrogram::data ( ) const

Returns: Spectrogram data

See also: setData()

◆ defaultContourPen()

QPen QwtPlotSpectrogram::defaultContourPen ( ) const

Returns: Default contour pen

See also: setDefaultContourPen()

◆ draw()

void QwtPlotSpectrogram::draw	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect
	)		const

virtual

Draw the spectrogram.

Parameters

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

See also: setDisplayMode(), renderImage(), QwtPlotRasterItem::draw(), drawContourLines()

Reimplemented from QwtPlotRasterItem.

◆ drawContourLines()

void QwtPlotSpectrogram::drawContourLines	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtRasterData::ContourLines &	contourLines
	)		const

protectedvirtual

Paint the contour lines.

Parameters

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

See also: renderContourLines(), defaultContourPen(), contourPen()

◆ interval()

QwtInterval QwtPlotSpectrogram::interval ( Qt::Axis axis ) const

virtual

Returns: Bounding interval for an axis

The default implementation returns the interval of the associated raster data object.

Parameters

axis	X, Y, or Z axis

See also: QwtRasterData::interval()

Reimplemented from QwtPlotRasterItem.

◆ pixelHint()

QRectF QwtPlotSpectrogram::pixelHint ( const QRectF & area ) const

virtual

Pixel hint.

The geometry of a pixel is used to calculated the resolution and alignment of the rendered image.

The default implementation returns data()->pixelHint( rect );

Parameters

area	In most implementations the resolution of the data doesn't depend on the requested area.

Returns: Bounding rectangle of a pixel

See also: QwtPlotRasterItem::pixelHint(), QwtRasterData::pixelHint(), render(), renderImage()

Reimplemented from QwtPlotRasterItem.

◆ renderContourLines()

QwtRasterData::ContourLines QwtPlotSpectrogram::renderContourLines	(	const QRectF &	rect,
		const QSize &	raster
	)		const

protectedvirtual

Calculate contour lines.

Parameters

rect	Rectangle, where to calculate the contour lines
raster	Raster, used by the CONREC algorithm

Returns: Calculated contour lines

See also: contourLevels(), setConrecFlag(), QwtRasterData::contourLines()

◆ renderImage()

QImage QwtPlotSpectrogram::renderImage	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	area,
		const QSize &	imageSize
	)		const

protectedvirtual

Render an image from data and color map.

For each pixel of area the value is mapped into a color.

Parameters

xMap	X-Scale Map
yMap	Y-Scale Map
area	Requested area for the image in scale coordinates
imageSize	Size of the requested image

Returns: A QImage::Format_Indexed8 or QImage::Format_ARGB32 depending on the color map.

See also: QwtRasterData::value(), QwtColorMap::rgb(), QwtColorMap::colorIndex()

Implements QwtPlotRasterItem.

◆ renderTile()

void QwtPlotSpectrogram::renderTile	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRect &	tile,
		QImage *	image
	)		const

protected

Render a tile of an image.

Rendering in tiles can be used to composite an image in parallel threads.

Parameters

xMap	X-Scale Map
yMap	Y-Scale Map
tile	Geometry of the tile in image coordinates
image	Image to be rendered

◆ rtti()

int QwtPlotSpectrogram::rtti ( ) const

virtual

Returns: QwtPlotItem::Rtti_PlotSpectrogram

Reimplemented from QwtPlotItem.

◆ setColorMap()

void QwtPlotSpectrogram::setColorMap ( QwtColorMap * colorMap )

Change the color map.

Often it is useful to display the mapping between intensities and colors as an additional plot axis, showing a color bar.

Parameters

colorMap Color Map

See also: colorMap(), QwtScaleWidget::setColorBarEnabled(), QwtScaleWidget::setColorMap()

◆ setColorTableSize()

void QwtPlotSpectrogram::setColorTableSize ( int numColors )

Limit the number of colors being used by the color map.

When using a color table the mapping from the value into a color is usually faster as it can be done by simple lookups into a precalculated color table.

Setting a table size > 0 enables using a color table, while setting the size to 0 disables it.

The default size = 0, and no color table is used.

Parameters

numColors Number of colors. 0 means not using a color table

Note: The colorTableSize has no effect when using a color table of QwtColorMap::Indexed, where the size is always 256.

See also: QwtColorMap::colorTable(), colorTableSize()

◆ setConrecFlag()

void QwtPlotSpectrogram::setConrecFlag	(	QwtRasterData::ConrecFlag	flag,
		bool	on
	)

Modify an attribute of the CONREC algorithm, used to calculate the contour lines.

Parameters

flag	CONREC flag
on	On/Off

See also: testConrecFlag(), renderContourLines(), QwtRasterData::contourLines()

◆ setContourLevels()

void QwtPlotSpectrogram::setContourLevels ( const QList< double > & levels )

Set the levels of the contour lines.

Parameters

levels Values of the contour levels

See also: contourLevels(), renderContourLines(), QwtRasterData::contourLines()

Note: contourLevels returns the same levels but sorted.

◆ setData()

void QwtPlotSpectrogram::setData ( QwtRasterData * data )

Set the data to be displayed.

The ownership of the data is managed by QwtPlotSpectrogram

Parameters

data	Spectrogram Data

See also: data()

◆ setDefaultContourPen() [1/2]

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

Build and assign the default pen for the contour lines.

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()

◆ setDefaultContourPen() [2/2]

void QwtPlotSpectrogram::setDefaultContourPen ( const QPen & pen )

Set the default pen for the contour lines.

If the spectrogram has a valid default contour pen a contour line is painted using the default contour pen. Otherwise (pen.style() == Qt::NoPen) the pen is calculated for each contour level using contourPen().

See also: defaultContourPen(), contourPen()

◆ setDisplayMode()

void QwtPlotSpectrogram::setDisplayMode	(	DisplayMode	mode,
		bool	on = `true`
	)

The display mode controls how the raster data will be represented.

Parameters

mode	Display mode
on	On/Off

The default setting enables ImageMode.

See also: DisplayMode, displayMode()

◆ testConrecFlag()

bool QwtPlotSpectrogram::testConrecFlag ( QwtRasterData::ConrecFlag flag ) const

Test an attribute of the CONREC algorithm, used to calculate the contour lines.

Parameters

flag	CONREC flag

Returns: true, is enabled

The default setting enables QwtRasterData::IgnoreAllVerticesOnLevel

See also: setConrecClag(), renderContourLines(), QwtRasterData::contourLines()

◆ testDisplayMode()

bool QwtPlotSpectrogram::testDisplayMode ( DisplayMode mode ) const

The display mode controls how the raster data will be represented.

Parameters

mode	Display mode

Returns: true if mode is enabled

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

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

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ DisplayMode

Constructor & Destructor Documentation

◆ QwtPlotSpectrogram()

Member Function Documentation

◆ colorMap()

◆ colorTableSize()

◆ contourLevels()

◆ contourPen()

◆ contourRasterSize()

◆ data() [1/2]

◆ data() [2/2]

◆ defaultContourPen()

◆ draw()

◆ drawContourLines()

◆ interval()

◆ pixelHint()

◆ renderContourLines()

◆ renderImage()

◆ renderTile()

◆ rtti()

◆ setColorMap()

◆ setColorTableSize()

◆ setConrecFlag()

◆ setContourLevels()

◆ setData()

◆ setDefaultContourPen() [1/2]

◆ setDefaultContourPen() [2/2]

◆ setDisplayMode()

◆ testConrecFlag()

◆ testDisplayMode()