QwtAbstractLegend - Man Page
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.
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
Definition at line 34 of file qwt_abstract_legend.h.
Constructor & Destructor Documentation
QwtAbstractLegend::QwtAbstractLegend (QWidget * parent = NULL) [explicit]
Constructor
- Parameters
parent Parent widget
Definition at line 18 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.
- 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.
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.
- Parameters
itemInfo Info about an item
data List of legend entry attributes for the item
Author
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