QwtAbstractLegend(3)

📦
version 6.3.0 · 4 versions
, in alpine 3.24

💖 QwtAbstractLegend(3) 💖

okay so bestie, this page is from the Library Functions Manual, and it's all about QwtAbstractLegend — the abstract base class for legend widgets. It's giving "parent class energy," and honestly? Iconic. ✨

🌸 NAME 🌸

QwtAbstractLegend — Abstract base class for legend widgets.

🦋 SYNOPSIS 🦋

#include <qwt_abstract_legend.h>
  • Inherits: QFrame.
  • Inherited by: QwtLegend.

💅 Public Slots 💅

  • virtual void updateLegend (const QVariant &itemInfo, const QList< QwtLegendData > &data)=0 — Update the entries for a plot item. Pure virtual slot, so your subclass has to show up and do the work. 💖

🎀 Public Member Functions 🎀

  • QwtAbstractLegend (QWidget *parent=NULL) — Constructor, with parent defaulting to NULL.
  • virtual ~QwtAbstractLegend () — Destructor.
  • virtual void renderLegend (QPainter *painter, const QRectF &rect, bool fillBackground) const =0 — Pure virtual render function. You gotta implement it.
  • virtual bool isEmpty () const =0 — Pure virtual check for whether the legend is empty.
  • virtual int scrollExtent (Qt::Orientation) const — Virtual function for the scroll extent.

🌈 Detailed Description 🌈

Abstract base class for legend widgets. No cap. 🫶

Legends that need to be under control of the QwtPlot layout system need to be derived from QwtAbstractLegend. That's the whole vibe.

Note: Other type of legends can be implemented by connecting to the QwtPlot::legendDataChanged() signal. But as these legends are unknown to the plot layout system the layout code ( on screen and for QwtPlotRenderer ) need to be organized in application code.
  • See also: QwtLegend

Definition at line 34 of file qwt_abstract_legend.h.

🧚 Constructor & Destructor Documentation 🧚

💜 QwtAbstractLegend::QwtAbstractLegend (QWidget * parent = NULL) [explicit]

Constructor. Main character constructor behavior. 💅

  • parent — Parent widget

Definition at line 18 of file qwt_abstract_legend.cpp.

💜 QwtAbstractLegend::~QwtAbstractLegend () [virtual]

Destructor. Gotta clean up, bestie. 🎀

Definition at line 24 of file qwt_abstract_legend.cpp.

🔥 Member Function Documentation 🔥

⭐ virtual bool QwtAbstractLegend::isEmpty () const [pure virtual]

  • Returns: True, when no plot item is inserted

Implemented in QwtLegend.

⭐ virtual void QwtAbstractLegend::renderLegend (QPainter * painter, const QRectF & rect, bool fillBackground) const [pure virtual]

Render the legend into a given rectangle. Very demure, very mindful rendering. 🦋

  • painter — Painter
  • rect — Bounding rectangle
  • fillBackground — When true, fill rect with the widget background
  • See also: renderLegend() is used by QwtPlotRenderer

Implemented in QwtLegend.

⭐ int QwtAbstractLegend::scrollExtent (Qt::Orientation orientation) const [virtual]

Return the extent, that is needed for elements to scroll the legend ( usually scrollbars ),

  • orientation — Orientation
  • Returns: Extent of the corresponding scroll element

Reimplemented in QwtLegend.

Definition at line 35 of file qwt_abstract_legend.cpp.

⭐ virtual void QwtAbstractLegend::updateLegend (const QVariant & itemInfo, const QList< QwtLegendData > & data) [pure virtual], [slot]

Update the entries for a plot item. Your subclass has to implement this, periodt. 💖

  • itemInfo — Info about an item
  • data — List of legend entry attributes for the item

👑 Author 👑

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

okay that's the whole page, bestie — Qwt User's Guide source/version energy, tagged QwtAbstractLegend(3), and the footer date slot is literally blank so I'm not inventing one. 💅✨

📦 where this page comes from