QwtLegendItem should show only checked entrys of QwtLegend (or visible PlotItems)

[HappyCoder]

Hello,

With the QwtLegend i manage the visibility of curves, markers etc. that are attached to to plot.
I can't use the attribute QwtPlotItem::Legend, because if i set it to false it disapears from QwtLegend.

The QwtPlotLegendItem inside of plot should show ONLY the visible items of the plot. How can i do this?

Stefan

[Uwe]

With the QwtLegend i manage the visibility of curves, markers etc. that are attached to to plot.
I can't use the attribute QwtPlotItem::Legend, because if i set it to false it disapears from QwtLegend.

Yes of course: setting QwtPlotItem::Legend to false has the meaning of not being relevant for the legend.

The QwtPlotLegendItem inside of plot should show ONLY the visible items of the plot. How can i do this?

Overload QwtPlotLegendItem::updateLegend(), something like this:

virtual void YourLegendItem::updateLegend( const QwtPlotItem *plotItem,
        const QList<QwtLegendData> &data )
{
    if ( !plotItem->isVisible() )
        QwtPlotLegendItem::updateLegend( plotItem, QList<QwtLegendData>() );
    else
        QwtPlotLegendItem::updateLegend( plotItem, data );
}

virtual void YourLegendItem::updateLegend( const QwtPlotItem *plotItem,
        const QList<QwtLegendData> &data )
{
    if ( !plotItem->isVisible() )
        QwtPlotLegendItem::updateLegend( plotItem, QList<QwtLegendData>() );
    else
        QwtPlotLegendItem::updateLegend( plotItem, data );
}

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