QwtPlotTextLabel Class Reference

A plot item, which displays a text label. More...

#include <qwt_plot_textlabel.h>

Inheritance diagram for QwtPlotTextLabel:

Classes
class	PrivateData

Public Member Functions
	QwtPlotTextLabel ()
	Constructor.
virtual int	rtti () const override
	Get the runtime type information.
void	setText (const QwtText &)
	Set the text.
QwtText	text () const
	Get the text.
void	setMargin (int margin)
	Set the margin.
int	margin () const
	Get the margin.
virtual QRectF	textRect (const QRectF &, const QSizeF &) const
	Align the text label.
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.
virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item with changes of the legend.
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	draw (QPainter *, const QwtScaleMap &, const QwtScaleMap &, const QRectF &) const override
	Draw the text label.
void	invalidateCache ()
	Invalidate the cached pixmap.
Protected Member Functions inherited from QwtPlotItem
QwtGraphic	defaultIcon (const QBrush &, const QSizeF &) const
	Create a default icon.

Additional Inherited Members
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...

Detailed Description

A plot item, which displays a text label.

QwtPlotTextLabel displays a text label aligned to the plot canvas.

     In opposite to QwtPlotMarker the position of the label is unrelated to
     plot coordinates.

     As drawing a text is an expensive operation the label is cached
     in a pixmap to speed up replots.

Example

The following code shows how to add a title.

QwtText title( "Plot Title" );
title.setRenderFlags( Qt::AlignHCenter | Qt::AlignTop );
 
QFont font;
font.setBold( true );
title.setFont( font );
 
QwtPlotTextLabel *titleItem = new QwtPlotTextLabel();
titleItem->setText( title );
titleItem->attach( plot );

See also

QwtPlotMarker

Constructor & Destructor Documentation

QwtPlotTextLabel()

QwtPlotTextLabel::QwtPlotTextLabel

(

)

Constructor.

Initializes an text label with an empty text. Sets the following item attributes:

• QwtPlotItem::AutoScale: false
• QwtPlotItem::Legend: false The z value is initialized by 150.

  See also

  QwtPlotItem::setItemAttribute(), QwtPlotItem::setZ()

  Destructor

Member Function Documentation

draw()

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

overrideprotectedvirtual

Draw the text label.

Parameters

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

See also

textRect()

Implements QwtPlotItem.

margin()

int QwtPlotTextLabel::margin

(

)

const

Get the margin.

Returns

Margin added to the contentsMargins() of the canvas

See also

setMargin()

rtti()

int QwtPlotTextLabel::rtti ( ) const

overridevirtual

Get the runtime type information.

Returns

QwtPlotItem::Rtti_PlotTextLabel

Reimplemented from QwtPlotItem.

setMargin()

void QwtPlotTextLabel::setMargin

(

int

margin

)

Set the margin.

Parameters

[in]

margin

Margin

The margin is the distance between the contentsRect() of the plot canvas and the rectangle where the label can be displayed.

See also

margin(), textRect()

setText()

void QwtPlotTextLabel::setText

(

const QwtText &

text

)

Set the text.

Parameters

[in]

text

Text to be displayed

The label will be aligned to the plot canvas according to the alignment flags of text.

See also

text(), QwtText::renderFlags()

text()

QwtText QwtPlotTextLabel::text

(

)

const

Get the text.

Returns

Text to be displayed

See also

setText()

textRect()

QRectF QwtPlotTextLabel::textRect ( const QRectF &  rect, const QSizeF &  textSize  ) const

virtual

Align the text label.

Parameters

[in]	rect	Canvas rectangle with margins subtracted
[in]	textSize	Size required to draw the text

Returns

A rectangle aligned according the the alignment flags of the text.

See also

setMargin(), QwtText::renderFlags(), QwtText::textSize()

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

• /home/runner/work/QWT/QWT/src/plot/qwt_plot_textlabel.h
• /home/runner/work/QWT/QWT/src/plot/qwt_plot_textlabel.cpp