QwtAbstractLegend Class Reference

Abstract base class for legend widgets. More...

#include <qwt_abstract_legend.h>

Inheritance diagram for QwtAbstractLegend:

Public Slots
virtual void	updateLegend (const QVariant &itemInfo, const QList< QwtLegendData > &data)=0
	Update the entries for a plot item.
Public Member Functions
	QwtAbstractLegend (QWidget *parent=NULL)
virtual	~QwtAbstractLegend ()
	Destructor.
virtual void	renderLegend (QPainter *painter, const QRectF &rect, bool fillBackground) const =0
virtual bool	isEmpty () const =0
virtual int	scrollExtent (Qt::Orientation) const

---

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.

See also:

QwtLegend

---

Constructor & Destructor Documentation

QwtAbstractLegend::QwtAbstractLegend

(

QWidget *

parent = NULL

)

[explicit]

Constructor

Parameters:

parent

Parent widget

---

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.

Parameters:

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 ),

Parameters:

orientation

Orientation

Returns:

Extent of the corresponding scroll element

Reimplemented in QwtLegend.

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

Update the entries for a plot item.

Parameters:

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

Implemented in QwtLegend.

List of all members.