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
Constructor & Destructor Documentation
QwtAbstractLegend::QwtAbstractLegend (QWidget *parent = NULL) [explicit]
ConstructorParameters:
- 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, boolfillBackground) 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::Orientationorientation) 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
Author
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