QwtPlotMarker - A class for drawing markers.

NAME

QwtPlotMarker − A class for drawing markers.

SYNOPSIS

#include <qwt_plot_marker.h>

Inherits QwtPlotItem.

Public Types

enum LineStyle { NoLine, HLine, VLine, Cross }

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.
enum ItemAttribute { Legend = 0x01, AutoScale = 0x02, Margins = 0x04 }
Plot Item Attributes.
enum ItemInterest { ScaleInterest = 0x01, LegendInterest = 0x02 }
Plot Item Interests.
enum RenderHint { RenderAntialiased = 0x1 }
Render hints.
typedef QFlags< ItemAttribute > ItemAttributes
typedef QFlags< ItemInterest > ItemInterests
typedef QFlags< RenderHint > RenderHints

Public Member Functions

QwtPlotMarker ()
Sets alignment to Qt::AlignCenter, and style to QwtPlotMarker::NoLine.
QwtPlotMarker (const QString &title)
Sets alignment to Qt::AlignCenter, and style to QwtPlotMarker::NoLine.
QwtPlotMarker (const QwtText &title)
Sets alignment to Qt::AlignCenter, and style to QwtPlotMarker::NoLine.
virtual ˜QwtPlotMarker ()
Destructor.
virtual int rtti () const override
double xValue () const
Return x Value.
double yValue () const
Return y Value.
QPointF value () const
Return Value.
void setXValue (double)
Set X Value.
void setYValue (double)
Set Y Value.
void setValue (double, double)
Set Value.
void setValue (const QPointF &)
Set Value.
void setLineStyle (LineStyle)
Set the line style.
LineStyle lineStyle () const
void setLinePen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
void setLinePen (const QPen &)
const QPen & linePen () const
void setSymbol (const QwtSymbol *)
Assign a symbol.
const QwtSymbol * symbol () const
void setLabel (const QwtText &)
Set the label.
QwtText label () const
void setLabelAlignment (Qt::Alignment)
Set the alignment of the label.
Qt::Alignment labelAlignment () const
void setLabelOrientation (Qt::Orientation)
Set the orientation of the label.
Qt::Orientation labelOrientation () const
void setSpacing (int)
Set the spacing.
int spacing () const
virtual void draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &) const override
virtual QRectF boundingRect () const override
virtual QwtGraphic legendIcon (int index, const QSizeF &) const override

Public Member Functions inherited from QwtPlotItem

QwtPlotItem ()
QwtPlotItem (const QString &title)
QwtPlotItem (const QwtText &title)
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)
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.
void show ()
Show the item.
void hide ()
Hide the item.
virtual void setVisible (bool)
bool isVisible () const
void setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
void setXAxis (QwtAxisId)
QwtAxisId xAxis () const
Return xAxis.
void setYAxis (QwtAxisId)
QwtAxisId yAxis () const
Return yAxis.
virtual void itemChanged ()
virtual void legendChanged ()
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.

Protected Member Functions

virtual void drawLines (QPainter *, const QRectF &, const QPointF &) const
virtual void drawSymbol (QPainter *, const QRectF &, const QPointF &) const
virtual void drawLabel (QPainter *, const QRectF &, const QPointF &) const

Protected Member Functions inherited from QwtPlotItem

QwtGraphic defaultIcon (const QBrush &, const QSizeF &) const
Return a default icon from a brush.

Detailed Description

A class for drawing markers.

A marker can be a horizontal line, a vertical line, a symbol, a label or any combination of them, which can be drawn around a center point inside a bounding rectangle.

The setSymbol() member assigns a symbol to the marker. The symbol is drawn at the specified point.

With setLabel(), a label can be assigned to the marker. The setLabelAlignment() member specifies where the label is drawn. All the Align*-constants in Qt::AlignmentFlags (see Qt documentation) are valid. The interpretation of the alignment depends on the marker’s line style. The alignment refers to the center point of the marker, which means, for example, that the label would be printed left above the center point if the alignment was set to Qt::AlignLeft | Qt::AlignTop.

Note

QwtPlotTextLabel is intended to align a text label according to the geometry of canvas ( unrelated to plot coordinates )

Definition at line 45 of file qwt_plot_marker.h.

Member Enumeration Documentation

enum QwtPlotMarker::LineStyle

Line styles.

See also

setLineStyle(), lineStyle()

Enumerator

	*NoLine*		No line.
	*HLine*		A horizontal line.
	*VLine*		A vertical line.
	*Cross*		A crosshair.

Definition at line 53 of file qwt_plot_marker.h.

Constructor & Destructor Documentation

QwtPlotMarker::QwtPlotMarker () [explicit]

Sets alignment to Qt::AlignCenter, and style to QwtPlotMarker::NoLine.

Definition at line 53 of file qwt_plot_marker.cpp.

QwtPlotMarker::QwtPlotMarker (const QString & title) [explicit]

Sets alignment to Qt::AlignCenter, and style to QwtPlotMarker::NoLine.

Definition at line 60 of file qwt_plot_marker.cpp.

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

Sets alignment to Qt::AlignCenter, and style to QwtPlotMarker::NoLine.

Definition at line 68 of file qwt_plot_marker.cpp.

QwtPlotMarker::˜QwtPlotMarker () [virtual]

Destructor.

Definition at line 76 of file qwt_plot_marker.cpp.

Member Function Documentation

QRectF QwtPlotMarker::boundingRect () const [override], [virtual]

Returns

An invalid bounding rect: QRectF(1.0, 1.0, -2.0, -2.0)

Note

A width or height < 0.0 is ignored by the autoscaler

Reimplemented from QwtPlotItem.

Definition at line 572 of file qwt_plot_marker.cpp.

void QwtPlotMarker::draw (QPainter * painter, const QwtScaleMap & xMap,const QwtScaleMap & yMap, const QRectF & canvasRect) const [override],[virtual]

Draw the marker

Parameters

painter Painter
xMap x Scale Map
yMap y Scale Map
canvasRect Contents rectangle of the canvas in painter coordinates

Implements QwtPlotItem.

Definition at line 142 of file qwt_plot_marker.cpp.

void QwtPlotMarker::drawLabel (QPainter * painter, const QRectF &canvasRect, const QPointF & pos) const [protected], [virtual]

Align and draw the text label of the marker

Parameters

painter Painter
canvasRect Contents rectangle of the canvas in painter coordinates
pos Position of the marker, translated into widget coordinates

See also

drawLabel(), drawSymbol()

Definition at line 232 of file qwt_plot_marker.cpp.

void QwtPlotMarker::drawLines (QPainter * painter, const QRectF &canvasRect, const QPointF & pos) const [protected], [virtual]

Draw the lines marker

Parameters

painter Painter
canvasRect Contents rectangle of the canvas in painter coordinates
pos Position of the marker, translated into widget coordinates

See also

drawLabel(), drawSymbol()

Definition at line 163 of file qwt_plot_marker.cpp.

void QwtPlotMarker::drawSymbol (QPainter * painter, const QRectF &canvasRect, const QPointF & pos) const [protected], [virtual]

Draw the symbol of the marker

Parameters

painter Painter
canvasRect Contents rectangle of the canvas in painter coordinates
pos Position of the marker, translated into widget coordinates

See also

drawLabel(), QwtSymbol::drawSymbol()

Definition at line 203 of file qwt_plot_marker.cpp.

QwtText QwtPlotMarker::label () const

Returns

the label

See also

setLabel()

Definition at line 433 of file qwt_plot_marker.cpp.

Qt::Alignment QwtPlotMarker::labelAlignment () const

Returns

the label alignment

See also

setLabelAlignment(), setLabelOrientation()

Definition at line 465 of file qwt_plot_marker.cpp.

Qt::Orientation QwtPlotMarker::labelOrientation () const

Returns

the label orientation

See also

setLabelOrientation(), labelAlignment()

Definition at line 493 of file qwt_plot_marker.cpp.

QwtGraphic QwtPlotMarker::legendIcon (int index, const QSizeF & size) const[override], [virtual]

Returns

Icon representing the marker on the legend

Parameters

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

See also

setLegendIconSize(), legendData()

Reimplemented from QwtPlotItem.

Definition at line 598 of file qwt_plot_marker.cpp.

const QPen & QwtPlotMarker::linePen () const

Returns

the line pen

See also

setLinePen()

Definition at line 567 of file qwt_plot_marker.cpp.

QwtPlotMarker::LineStyle QwtPlotMarker::lineStyle () const

Returns

the line style

See also

setLineStyle()

Definition at line 381 of file qwt_plot_marker.cpp.

int QwtPlotMarker::rtti () const [override], [virtual]

Returns

QwtPlotItem::Rtti_PlotMarker

Reimplemented from QwtPlotItem.

Definition at line 82 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setLabel (const QwtText & label)

Set the label.

Parameters

label Label text

See also

label()

Definition at line 420 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setLabelAlignment (Qt::Alignment align)

Set the alignment of the label. In case of QwtPlotMarker::HLine the alignment is relative to the y position of the marker, but the horizontal flags correspond to the canvas rectangle. In case of QwtPlotMarker::VLine the alignment is relative to the x position of the marker, but the vertical flags correspond to the canvas rectangle.

In all other styles the alignment is relative to the marker’s position.

Parameters

align Alignment.

See also

labelAlignment(), labelOrientation()

Definition at line 452 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setLabelOrientation (Qt::Orientation orientation)

Set the orientation of the label. When orientation is Qt::Vertical the label is rotated by 90.0 degrees ( from bottom to top ).

Parameters

orientation Orientation of the label

See also

labelOrientation(), setLabelAlignment()

Definition at line 480 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setLinePen (const QColor & color, qreal width = 0.0,Qt::PenStyle style = Qt::SolidLine)

Build and assign a line 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 541 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setLinePen (const QPen & pen)

Specify a pen for the line.

Parameters

pen New pen

See also

linePen()

Definition at line 552 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setLineStyle (LineStyle style)

Set the line style.

Parameters

style Line style.

See also

lineStyle()

Definition at line 366 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setSpacing (int spacing)

Set the spacing. When the label is not centered on the marker position, the spacing is the distance between the position and the label.

Parameters

spacing Spacing

See also

spacing(), setLabelAlignment()

Definition at line 507 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setSymbol (const QwtSymbol * symbol)

Assign a symbol.

Parameters

symbol New symbol

See also

symbol()

Definition at line 391 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setValue (const QPointF & pos)

Set Value.

Definition at line 106 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setValue (double x, double y)

Set Value.

Definition at line 112 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setXValue (double x)

Set X Value.

Definition at line 123 of file qwt_plot_marker.cpp.

void QwtPlotMarker::setYValue (double y)

Set Y Value.

Definition at line 129 of file qwt_plot_marker.cpp.

int QwtPlotMarker::spacing () const

Returns

the spacing

See also

setSpacing()

Definition at line 523 of file qwt_plot_marker.cpp.

const QwtSymbol * QwtPlotMarker::symbol () const

Returns

the symbol

See also

setSymbol(), QwtSymbol

Definition at line 410 of file qwt_plot_marker.cpp.

QPointF QwtPlotMarker::value () const

Return Value.

Definition at line 88 of file qwt_plot_marker.cpp.

double QwtPlotMarker::xValue () const

Return x Value.

Definition at line 94 of file qwt_plot_marker.cpp.

double QwtPlotMarker::yValue () const

Return y Value.

Definition at line 100 of file qwt_plot_marker.cpp.

Author

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Updated 2026-06-01 - jenkler.se | uex.se