Abstract base class for legend widgets. More...

Inheritance diagram for QwtAbstractLegend:

Public Slots
virtual void	updateLegend (const QVariant &itemInfo, const QList< QwtLegendData > &data)=0

Public Member Functions
	QwtAbstractLegend (QWidget *parent=nullptr)
	Constructor for QwtAbstractLegend.

	~QwtAbstractLegend () override
	Destructor for QwtAbstractLegend.

virtual void	renderLegend (QPainter *painter, const QRectF &rect, bool fillBackground) const =0

virtual bool	isEmpty () const =0

virtual int	scrollExtent (Qt::Orientation) const
	Return the extent needed for scroll elements.

Detailed Description

Abstract base class for legend widgets.

Legends that need to be under control of the QwtPlot layout system need to be derived from QwtAbstractLegend.

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.

Constructor & Destructor Documentation

QwtAbstractLegend::QwtAbstractLegend ( QWidget * parent = nullptr )

explicit

Parameters

parent Parent widget

virtual bool QwtAbstractLegend::isEmpty ( ) const

pure virtual

Implemented in QwtLegend.

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

pure virtual

Implemented in QwtLegend.

int QwtAbstractLegend::scrollExtent ( Qt::Orientation orientation ) const

virtual

Return the extent needed for scroll elements.

Returns the space needed for elements to scroll the legend (usually scrollbars).

Parameters

orientation Orientation (Horizontal or Vertical)

Reimplemented in QwtLegend.

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