QwtPlotTextLabel(3)

📦

version 6.3.0 · 4 versions

6.3.0 · alpine 3.24 (latest)
6.1.5 · epel 9
6.2.0 · epel 10, fedora 43, fedora 44
6.1.4 · debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute

QwtPlotTextLabel(3) 💅✨

okay bestie, welcome to the Library Functions Manual page for QwtPlotTextLabel(3) — manual name folded in right here like a little name tag, no cap. 🫶

✨ NAME ✨

QwtPlotTextLabel — a plot item, which displays a text label. 💖

🦋 SYNOPSIS 🦋

#include <qwt_plot_textlabel.h>

Inherits QwtPlotItem — yes, she’s part of the plot-item family. 🌸

💖 Public Member Functions 💖

QwtPlotTextLabel () — Constructor.
virtual ~QwtPlotTextLabel () — Destructor.
virtual int rtti () const override
void setText (const QwtText &)
QwtText text () const
void setMargin (int margin)
int margin () const
virtual QRectF textRect (const QRectF &, const QSizeF &) const — Align the text label.

🌈 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 QRectF boundingRect () const
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 void draw (QPainter *, const QwtScaleMap &, const QwtScaleMap &, const QRectF &) const override
void invalidateCache () — Invalidate all internal cache.

🧚 Protected Member Functions inherited from QwtPlotItem 🧚

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

👑 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_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

🌟 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

Definition at line 47 of file qwt_plot_textlabel.h.

🎀 Constructor & Destructor Documentation 🎀

QwtPlotTextLabel::QwtPlotTextLabel ()

Constructor. Initializes an text label with an empty text.

Sets the following item attributes:

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

The z value is initialized by 150.

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

Definition at line 82 of file qwt_plot_textlabel.cpp.

QwtPlotTextLabel::~QwtPlotTextLabel () [virtual]

Destructor.

Definition at line 94 of file qwt_plot_textlabel.cpp.

💀 Member Function Documentation 💀

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

Draw the text label.

Parameters:

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

void QwtPlotTextLabel::invalidateCache () [protected]

Invalidate all internal cache.

Definition at line 270 of file qwt_plot_textlabel.cpp.

int QwtPlotTextLabel::margin () const

Returns Margin added to the contentsMargins() of the canvas.

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

Returns QwtPlotItem::Rtti_PlotTextLabel.

Reimplemented from QwtPlotItem.

Definition at line 100 of file qwt_plot_textlabel.cpp.

void QwtPlotTextLabel::setMargin (int margin)

Set the margin.

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

Parameters:

margin — Margin

void QwtPlotTextLabel::setText (const QwtText & text)

Set the text.

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

Parameters:

text — Text to be displayed

See also text(), QwtText::renderFlags().

Definition at line 115 of file qwt_plot_textlabel.cpp.

QwtText QwtPlotTextLabel::text () const

Returns Text to be displayed.

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

Align the text label.

Parameters:

rect — Canvas rectangle with margins subtracted
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().

Definition at line 263 of file qwt_plot_textlabel.cpp.

🙈 Author 🙈

Generated automatically by Doxygen for Qwt User's Guide from the source code.

xoxo, bestie — the footer situation is Qwt User's Guide + QwtPlotTextLabel(3), and there’s no date printed on this page, so I’m not inventing one. 💖🫶

📦 where this page comes from

alpine 3.24: qwt-doc 6.3.0-r0 · custom
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-04: a language model's rewrite of the original, under its terms