A class which draws a legend inside the plot canvas. More...

#include <qwt_plot_legenditem.h>

Inheritance diagram for QwtPlotLegendItem:

Classes
class	PrivateData

Public Types
enum	BackgroundMode { LegendBackground , ItemBackground }
	Background mode. 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_PlotArrowMarker , Rtti_PlotBoxChart , 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. More...

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

Public Member Functions
	QwtPlotLegendItem ()
	Constructor.

	~QwtPlotLegendItem () override
	Destructor.

virtual int	rtti () const override
	Get the runtime type information.

void	setAlignmentInCanvas (Qt::Alignment)
	Set the alignment in canvas.

Qt::Alignment	alignmentInCanvas () const
	Get the alignment in canvas.

void	setOffsetInCanvas (Qt::Orientations, int numPixels)
	Set the offset in canvas.

int	offsetInCanvas (Qt::Orientation) const
	Get the offset in canvas.

void	setMaxColumns (uint)
	Set the maximum number of columns.

uint	maxColumns () const
	Get the maximum number of columns.

void	setMargin (int)
	Set the margin.

int	margin () const
	Get the margin.

void	setSpacing (int)
	Set the spacing.

int	spacing () const
	Get the spacing.

void	setItemMargin (int)
	Set the item margin.

int	itemMargin () const
	Get the item margin.

void	setItemSpacing (int)
	Set the item spacing.

int	itemSpacing () const
	Get the item spacing.

void	setFont (const QFont &)
	Set the font.

QFont	font () const
	Get the font.

void	setBorderRadius (double)
	Set the border radius.

double	borderRadius () const
	Get the border radius.

void	setBorderPen (const QPen &)
	Set the border pen.

QPen	borderPen () const
	Get the border pen.

void	setBackgroundBrush (const QBrush &)
	Set the background brush.

QBrush	backgroundBrush () const
	Get the background brush.

void	setBackgroundMode (BackgroundMode)
	Set the background mode.

BackgroundMode	backgroundMode () const
	Get the background mode.

void	setTextPen (const QPen &)
	Set the text pen.

QPen	textPen () const
	Get the text pen.

virtual void	draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const override
	Draw the legend item.

void	clearLegend ()
	Clear the legend.

virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &) override
	Update the legend.

virtual QRect	geometry (const QRectF &canvasRect) const
	Get the geometry.

virtual QSize	minimumSize (const QwtLegendData &) const
	Get the minimum size.

virtual int	heightForWidth (const QwtLegendData &, int width) const
	Get the height for width.

QList< const QwtPlotItem * >	plotItems () const
	Get the plot items.

QList< QRect >	legendGeometries (const QwtPlotItem *) const
	Get the legend geometries.

Public Member Functions inherited from QwtPlotItem
	QwtPlotItem ()
	Default constructor.

	QwtPlotItem (const QString &title)
	Constructor with title as QString.

	QwtPlotItem (const QwtText &title)
	Constructor with title as QwtText.

virtual	~QwtPlotItem ()
	Destructor.

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

void	detach ()
	Detach the item from the plot.

QwtPlot *	plot () const
	Get the plot the item is attached to.

void	setTitle (const QString &title)
	Set the title using a QString.

void	setTitle (const QwtText &title)
	Set the title using a QwtText.

const QwtText &	title () const
	Get the title.

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

bool	testItemAttribute (ItemAttribute) const
	Test an item attribute.

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

bool	testItemInterest (ItemInterest) const
	Test an item interest.

void	setRenderHint (RenderHint, bool on=true)
	Set a render hint.

bool	testRenderHint (RenderHint) const
	Test a render hint.

void	setRenderThreadCount (uint numThreads)
	Set the number of render threads.

uint	renderThreadCount () const
	Get the number of render threads.

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

QSize	legendIconSize () const
	Get the legend icon size.

double	z () const
	Get the z-value.

void	setZ (double z)
	Set the z-value.

void	show ()
	Show the item.

void	hide ()
	Hide the item.

virtual void	setVisible (bool)
	Set the visibility.

bool	isVisible () const
	Check if the item is visible.

void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
	Set both axes.

void	setXAxis (QwtAxisId)
	Set the x-axis.

QwtAxisId	xAxis () const
	Get the x-axis.

void	setYAxis (QwtAxisId)
	Set the y-axis.

QwtAxisId	yAxis () const
	Get the y-axis.

virtual void	itemChanged ()
	Notify the plot that the item has changed.

virtual void	legendChanged ()
	Notify the item that the legend has changed.

virtual QRectF	boundingRect () const
	Get the bounding rectangle.

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

virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
	Update the item with new scale divisions.

QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the scale rectangle.

QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the paint rectangle.

virtual QList< QwtLegendData >	legendData () const
	Return legend data.

virtual QwtGraphic	legendIcon (int index, const QSizeF &) const
	Return a legend icon.

Protected Member Functions
virtual void	drawLegendData (QPainter , const QwtPlotItem , const QwtLegendData &, const QRectF &) const
	Draw the legend data.

virtual void	drawBackground (QPainter *, const QRectF &rect) const
	Draw the background.

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

Detailed Description

A class which draws a legend inside the plot canvas.

QwtPlotLegendItem can be used to draw a legend inside the plot canvas. It can be used together with a QwtLegend or instead of it to have more space for the plot canvas.

In opposite to QwtLegend the legend item is not interactive. To identify mouse clicks on a legend item an event filter needs to be installed catching mouse events on the plot canvas. The geometries of the legend items are available using legendGeometries().

The legend item is aligned to plot canvas according to its alignment() flags. It might have a background for the complete legend ( usually semi transparent ) or for each legend item.

Note: An external QwtLegend with a transparent background on top the plot canvas might be another option with a similar effect.

Member Enumeration Documentation

◆ BackgroundMode

enum QwtPlotLegendItem::BackgroundMode

Background mode.

Depending on the mode the complete legend or each item might have an background.

The default setting is LegendBackground.

See also: setBackgroundMode(), setBackgroundBrush(), drawBackground()

Enumerator
LegendBackground	The legend has a background.
ItemBackground	Each item has a background.

Constructor & Destructor Documentation

◆ QwtPlotLegendItem()

QwtPlotLegendItem::QwtPlotLegendItem ( )

explicit

Constructor.

Creates a legend item with default settings. The legend item is initialized with LegendInterest enabled and a z-value of 100.0.

Destructor

Member Function Documentation

◆ alignmentInCanvas()

Qt::Alignment QwtPlotLegendItem::alignmentInCanvas ( ) const

Get the alignment in canvas.

Get the alignment flags.

Returns: Alignment flags

See also: setAlignmentInCanvas()

◆ backgroundBrush()

QBrush QwtPlotLegendItem::backgroundBrush ( ) const

Get the background brush.

Get the brush used to fill the background.

Returns: Brush used to fill the background

See also: setBackgroundBrush(), backgroundMode(), drawBackground()

◆ backgroundMode()

QwtPlotLegendItem::BackgroundMode QwtPlotLegendItem::backgroundMode ( ) const

Get the background mode.

Returns: Background mode

See also: setBackgroundMode(), backgroundBrush(), drawBackground()

◆ borderPen()

QPen QwtPlotLegendItem::borderPen ( ) const

Get the border pen.

Get the pen for drawing the border.

Returns: Pen for drawing the border

See also: setBorderPen(), backgroundBrush()

◆ borderRadius()

double QwtPlotLegendItem::borderRadius ( ) const

Get the border radius.

Get the radius of the border.

Returns: Radius of the border

See also: setBorderRadius(), setBorderPen()

◆ clearLegend()

void QwtPlotLegendItem::clearLegend ( )

Clear the legend.

Remove all items from the legend.

◆ draw()

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

overridevirtual

Draw the legend item.

Draw the legend.

Parameters

[in]	painter	Painter
[in]	xMap	X Scale Map
[in]	yMap	Y Scale Map
[in]	canvasRect	Contents rectangle of the canvas in painter coordinates

Implements QwtPlotItem.

◆ drawBackground()

void QwtPlotLegendItem::drawBackground	(	QPainter *	painter,
		const QRectF &	rect
	)		const

protectedvirtual

Draw the background.

Draw a rounded rect.

Parameters

painter	Painter
rect	Bounding rectangle

See also: setBorderRadius(), setBorderPen(), setBackgroundBrush(), setBackgroundMode()

◆ drawLegendData()

void QwtPlotLegendItem::drawLegendData	(	QPainter *	painter,
		const QwtPlotItem *	plotItem,
		const QwtLegendData &	data,
		const QRectF &	rect
	)		const

protectedvirtual

Draw the legend data.

Draw an entry on the legend.

Parameters

painter	Qt Painter
plotItem	Plot item, represented by the entry
data	Attributes of the legend entry
rect	Bounding rectangle for the entry

◆ font()

QFont QwtPlotLegendItem::font ( ) const

Get the font.

Get the font used for drawing the text label.

Returns: Font used for drawing the text label

See also: setFont()

◆ geometry()

QRect QwtPlotLegendItem::geometry ( const QRectF & canvasRect ) const

virtual

Get the geometry.

Calculate the geometry of the legend on the canvas.

Parameters

[in] canvasRect Geometry of the canvas

Returns: Geometry of the legend

◆ heightForWidth()

int QwtPlotLegendItem::heightForWidth	(	const QwtLegendData &	data,
		int	width
	)		const

virtual

Get the height for width.

Get the preferred height for a given width.

Parameters

[in]	data	Attributes of the legend entry
[in]	width	Width

Returns: The preferred height

◆ itemMargin()

int QwtPlotLegendItem::itemMargin ( ) const

Get the item margin.

Get the margin around each item.

Returns: Margin around each item

See also: setItemMargin(), itemSpacing(), margin(), spacing()

◆ itemSpacing()

int QwtPlotLegendItem::itemSpacing ( ) const

Get the item spacing.

Get the spacing inside of each item.

Returns: Spacing inside of each item

See also: setItemSpacing(), itemMargin(), margin(), spacing()

◆ legendGeometries()

QList< QRect > QwtPlotLegendItem::legendGeometries ( const QwtPlotItem * plotItem ) const

Get the legend geometries.

Get geometries of the items of a plot item.

Parameters

[in] plotItem Plot item

Returns: Geometries of the items of a plot item

Note: Usually a plot item has only one entry on the legend

◆ margin()

int QwtPlotLegendItem::margin ( ) const

Get the margin.

Get the margin around the legend items.

Returns: Margin around the legend items

See also: setMargin(), spacing(), itemMargin(), itemSpacing()

◆ maxColumns()

uint QwtPlotLegendItem::maxColumns ( ) const

Get the maximum number of columns.

Returns: Maximum number of columns

See also: setMaxColumns(), QwtDynGridLayout::maxColumns()

◆ minimumSize()

QSize QwtPlotLegendItem::minimumSize ( const QwtLegendData & data ) const

virtual

Get the minimum size.

Get the minimum size hint needed to display an entry.

Parameters

[in] data Attributes of the legend entry

Returns: Minimum size

◆ offsetInCanvas()

int QwtPlotLegendItem::offsetInCanvas ( Qt::Orientation orientation ) const

Get the offset in canvas.

Get the distance between the legend and the canvas border.

Parameters

[in] orientation Qt::Horizontal is for the left/right, Qt::Vertical for the top/bottom padding.

Returns: Distance between the legend and the canvas border

See also: setOffsetInCanvas()

◆ plotItems()

QList< const QwtPlotItem * > QwtPlotLegendItem::plotItems ( ) const

Get the plot items.

Get all plot items with an entry on the legend.

Returns: All plot items with an entry on the legend

Note: A plot item might have more than one entry on the legend

◆ rtti()

int QwtPlotLegendItem::rtti ( ) const

overridevirtual

Get the runtime type information.

Returns: QwtPlotItem::Rtti_PlotLegend

Reimplemented from QwtPlotItem.

◆ setAlignmentInCanvas()

void QwtPlotLegendItem::setAlignmentInCanvas ( Qt::Alignment alignment )

Set the alignment in canvas.

Set the alignment of the legend within the canvas.

Parameters

[in] alignment Alignment flags (e.g., Qt::AlignRight | Qt::AlignBottom)

Alignment means the position of the legend relative to the geometry of the plot canvas.

Note: To align a legend with many items horizontally, the number of columns needs to be limited.

See also: alignmentInCanvas(), setMaxColumns()

◆ setBackgroundBrush()

void QwtPlotLegendItem::setBackgroundBrush ( const QBrush & brush )

Set the background brush.

Parameters

[in] brush Brush used to fill the background

See also: backgroundBrush(), setBackgroundMode(), drawBackground()

◆ setBackgroundMode()

void QwtPlotLegendItem::setBackgroundMode ( BackgroundMode mode )

Set the background mode.

Parameters

[in] mode Background mode

Depending on the mode the complete legend or each item might have a background. The default setting is LegendBackground.

See also: backgroundMode(), setBackgroundBrush(), drawBackground()

◆ setBorderPen()

void QwtPlotLegendItem::setBorderPen ( const QPen & pen )

Set the border pen.

Set the pen for drawing the border.

Parameters

[in] pen Border pen

See also: borderPen(), setBackgroundBrush()

◆ setBorderRadius()

void QwtPlotLegendItem::setBorderRadius ( double radius )

Set the border radius.

Set the radius for the border.

Parameters

[in] radius A value <= 0 defines a rectangular border

See also: borderRadius(), setBorderPen()

◆ setFont()

void QwtPlotLegendItem::setFont ( const QFont & font )

Set the font.

Change the font used for drawing the text label.

Parameters

[in] font Legend font

See also: font()

◆ setItemMargin()

void QwtPlotLegendItem::setItemMargin ( int margin )

Set the item margin.

Set the margin around each item.

Parameters

[in] margin Margin

See also: itemMargin(), setItemSpacing(), setMargin(), setSpacing()

◆ setItemSpacing()

void QwtPlotLegendItem::setItemSpacing ( int spacing )

Set the item spacing.

Set the spacing inside of each item.

Parameters

[in] spacing Spacing

See also: itemSpacing(), setItemMargin(), setMargin(), setSpacing()

◆ setMargin()

void QwtPlotLegendItem::setMargin ( int margin )

Set the margin.

Set the margin around legend items.

Parameters

[in] margin Margin in pixels

The default setting for the margin is 0.

See also: margin(), setSpacing(), setItemMargin(), setItemSpacing

◆ setMaxColumns()

void QwtPlotLegendItem::setMaxColumns ( uint maxColumns )

Set the maximum number of columns.

Limit the number of columns.

Parameters

[in] maxColumns Maximum number of columns. 0 means unlimited.

When aligning the legend horizontally (Qt::AlignLeft, Qt::AlignRight), the number of columns needs to be limited to avoid the width of the legend growing with an increasing number of entries.

See also: maxColumns(), QwtDynGridLayout::setMaxColumns()

◆ setOffsetInCanvas()

void QwtPlotLegendItem::setOffsetInCanvas	(	Qt::Orientations	orientations,
		int	numPixels
	)

Set the offset in canvas.

Set the distance between the legend and the canvas border.

Parameters

[in]	orientations	Qt::Horizontal is for the left/right, Qt::Vertical for the top/bottom offset.
[in]	numPixels	Distance in pixels

The default setting is 10 pixels.

See also: setMargin()

◆ setSpacing()

void QwtPlotLegendItem::setSpacing ( int spacing )

Set the spacing.

Set the spacing between the legend items.

Parameters

[in] spacing Spacing in pixels

See also: spacing(), setMargin()

◆ setTextPen()

void QwtPlotLegendItem::setTextPen ( const QPen & pen )

Set the text pen.

Set the pen for drawing text labels.

Parameters

[in] pen Text pen

See also: textPen(), setFont()

◆ spacing()

int QwtPlotLegendItem::spacing ( ) const

Get the spacing.

Get the spacing between the legend items.

Returns: Spacing between the legend items

See also: setSpacing(), margin(), itemSpacing(), itemMargin()

◆ textPen()

QPen QwtPlotLegendItem::textPen ( ) const

Get the text pen.

Get the pen for drawing text labels.

Returns: Pen for drawing text labels

See also: setTextPen(), font()

◆ updateLegend()

void QwtPlotLegendItem::updateLegend	(	const QwtPlotItem *	plotItem,
		const QList< QwtLegendData > &	data
	)

overridevirtual

Update the legend.

Update the legend items according to modifications of a plot item.

Parameters

[in]	plotItem	Plot item
[in]	data	Attributes of the legend entries

Reimplemented from QwtPlotItem.

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

/home/runner/work/QWT/QWT/src/plot/qwt_plot_legenditem.h
/home/runner/work/QWT/QWT/src/plot/qwt_plot_legenditem.cpp

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ BackgroundMode

Constructor & Destructor Documentation

◆ QwtPlotLegendItem()

Member Function Documentation

◆ alignmentInCanvas()

◆ backgroundBrush()

◆ backgroundMode()

◆ borderPen()

◆ borderRadius()

◆ clearLegend()

◆ draw()

◆ drawBackground()

◆ drawLegendData()

◆ font()

◆ geometry()

◆ heightForWidth()

◆ itemMargin()

◆ itemSpacing()

◆ legendGeometries()

◆ margin()

◆ maxColumns()

◆ minimumSize()

◆ offsetInCanvas()

◆ plotItems()

◆ rtti()

◆ setAlignmentInCanvas()

◆ setBackgroundBrush()

◆ setBackgroundMode()

◆ setBorderPen()

◆ setBorderRadius()

◆ setFont()

◆ setItemMargin()

◆ setItemSpacing()

◆ setMargin()

◆ setMaxColumns()

◆ setOffsetInCanvas()

◆ setSpacing()

◆ setTextPen()

◆ spacing()

◆ textPen()

◆ updateLegend()