QwtPolarMarker and QwtLegend

Hi,

I use a QwtPolarMarker but it does not appear in the legend. I have looked at the documentation but have found nothing about this. Try to use legend->insert but dont'know which widget I should pass to this method.

Any help would be welcome.

Thank you.

Code:

---

marker->setItemAttribute( QwtPolarItem::Legend, true );

---

Uwe

Thank you.
And note for myself, read completely the documentation...

So, I have the marker in the legend but the associated symbol is not displayed in the legend.
Probably an other option that I haven't read in the documentation or is ti normal ?

Thanks.

The default representation of a plot item on the legend is its title and QwtPolarMarker has no special implementation - probably it should have one.

With Qwt 5.x and QwtPolar 1.0 you have to implement something like this:

Code:

---

virtual void YourMarker::updateLegend(QwtLegend *legend) const
{
    QwtPolarMarker::updateLegend( legend );
    QwtLegendItem *label = 
       dynamic_cast<QwtLegendItem *>( legend->find(this) );
    if ( label )
    {
        label->setSymbol( symbol() );
        label->setIdentifierMode( 
            QwtLegendItem::ShowSymbol | QwtLegendItem::ShowText );
    }
}

---

With Qwt 6.x + QwtPolar from SVN trunk you have to implement something like this:

Code:

---

virtual void YourMarker::drawLegendIdentifier(
    QPainter *painter, const QRectF &rect ) const
{
        QSize symbolSize = symbol()->boundingSize();
        symbolSize -= QSize( 2, 2 );
 
         // scale the symbol size down if it doesn't fit into rect.
 
        double xRatio = 1.0;
        if ( rect.width() < symbolSize.width() )
            xRatio = rect.width() / symbolSize.width();
 
        double yRatio = 1.0;
        if ( rect.height() < symbolSize.height() )
            yRatio = rect.height() / symbolSize.height();
 
        const double ratio = qMin( xRatio, yRatio );
 
        painter->save();
        painter->scale( ratio, ratio );
 
        symbol()->drawSymbol( painter, rect.center() / ratio );
 
        painter->restore();
}

---

Uwe

Hi,

That perfectly works !

Thank you.