How does works QwtScaleDraw::extent()?

[mastupristi]

that's right.

browsing the code I can see that the problem is the orientation, and if I set the right orientation the value are the same:

//
        QwtScaleDiv *sd = new QwtScaleDiv(-60, 0);
        QList< double > ld;
 
        double q;
        for(q=-60.0; q<=0.0; q+=5.0)
            ld.append(q);
 
        sd->setTicks(QwtScaleDiv::MajorTick, ld);
 
        QwtScaleWidget *w = new QwtScaleWidget;
        w->setScaleDiv(*sd);
 
        qDebug("orient w %d", w->scaleDraw()->orientation()); // here is Qt::Vertical
        qDebug("extent 2 %f", w->scaleDraw()->extent(w->font())); // is 31.0
 
        QwtScaleDraw *sdraw = new QwtScaleDraw;
        sdraw->setScaleDiv(*sd);
        qDebug("orient sdraw %d", sdraw->orientation()); // here is Qt:Horizontal
        sdraw->setAlignment(QwtScaleDraw::LeftScale); // Change to vertical
 
        qDebug("extent 1 %f", sdraw->extent(w->font())); // here is also 31.0

//
        QwtScaleDiv *sd = new QwtScaleDiv(-60, 0);
        QList< double > ld;

        double q;
        for(q=-60.0; q<=0.0; q+=5.0)
            ld.append(q);

        sd->setTicks(QwtScaleDiv::MajorTick, ld);

        QwtScaleWidget *w = new QwtScaleWidget;
        w->setScaleDiv(*sd);

        qDebug("orient w %d", w->scaleDraw()->orientation()); // here is Qt::Vertical
        qDebug("extent 2 %f", w->scaleDraw()->extent(w->font())); // is 31.0

        QwtScaleDraw *sdraw = new QwtScaleDraw;
        sdraw->setScaleDiv(*sd);
        qDebug("orient sdraw %d", sdraw->orientation()); // here is Qt:Horizontal
        sdraw->setAlignment(QwtScaleDraw::LeftScale); // Change to vertical

        qDebug("extent 1 %f", sdraw->extent(w->font())); // here is also 31.0

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best regards
max