QSvgGenerator how to create groups and name objects

[Gilboonet]

Hello, I'm currently using QSvgGenerator to generate the a svg file, which is the final goal of my application

On the left is what I get with QSvgGenerator, the rendering is ok but I didn't find how to order the objects so that they are grouped convieniently to be processed (machine cut/fold/trace). It it possible to add groups with QSvgGenerator ? Maybe is there something to do with painter object ? I was able to gather lines of same kind into a sole path, but wasn't able to gather the texts (numbers) that not only created one group for each number, but also a blank group.

On the right, is what I have with my first version of the application, each page has only one path for each kind (cut, fold M, fold V, trace) and paths are named and groups are nested as needed, using external code to create the svg. I could use it again, but before I would like to know if there is a way to do the same using QSvgGenerator or maybe doing it indirectly by first using the Svg class ?

my export to svg code is straight forward, I'm using lines from may QGraphicsScene.

void MainWindow::exporte () {
    piecesMAJ();

    qreal s = 5.0f / 1.76f;
    QSvgGenerator SG;
    SG.setSize(QSize(210*s, 297*s));
    SG.setViewBox(QRect(0, 0, 210*s, 297*s));
    SG.setTitle("EXPORT SVG");
    //SG.setDescription(tr("An SVG drawing created by the SVG Generator "
    //                            "Example provided with Qt."));

    QPainter painter;
    QBuffer buffer;
    SG.setOutputDevice(&buffer);

    QPen penC = QPen(QBrush(Qt::red), 0.2, Qt::SolidLine);
    QPen penM = QPen(QBrush(Qt::darkRed), 0.1, Qt::DashLine);
    QPen pen0 = QPen(QBrush(Qt::black), 0.1, Qt::NoPen);
    QPen penV = QPen(QBrush(Qt::green), 0.1, Qt::DashDotDotLine);
    QPen penN = QPen(QBrush(Qt::blue), 0.2, Qt::SolidLine);

    painter.begin(&SG);
    QFont tf = QFont("Bitstream Vera Sans", 7*s);
    tf.setLetterSpacing(QFont::AbsoluteSpacing, -2);
    QFontMetrics fm(tf);
    painter.setFont(tf);

    QTransform tS;
    tS.scale(s, s);

    QPointF centre, b;
    Nums num1;
    for (auto && n : dep.pieces) {
        // ligne de coupe
        QList<QLineF>lCoupe, lPliM, lPliV;

        for (auto && l : n.lignes) {
            QLineF *ligne = new QLineF(l.p1 + n.bord->pos(), l.p2+n.bord->pos());
            *ligne = tS.map(*ligne);
            if (l.nb == 1) {
                lCoupe << *ligne;
                num1 = Nums(l.id1, l.id2);
                QString chNumero = QString::number(dep.nums[dep.nums.indexOf(num1)].num);
                centre =  ligne->center();
                painter.save();
                painter.translate(centre);
                painter.rotate(180- ligne->angle());
                b = QPointF(- fm.boundingRect(chNumero).width()/2, -1.8f);
                painter.setPen(penN);
                painter.drawText(b, chNumero);
                painter.restore();
            } else {
                if (l.cop < 0)
                    lPliV << *ligne;
                else if (l.cop > 0)
                    lPliM << *ligne;
                else
                    delete(ligne);
            }
        }

        if (!lCoupe.isEmpty()) {
            painter.setPen(penC);
            painter.drawPath(construitChemin(lCoupe));
        }

        if (!lCoupe.isEmpty()) {
            painter.setPen(penM);
            painter.drawPath(construitChemin(lPliM));
        }

        if (!lCoupe.isEmpty()) {
            painter.setPen(penV);
            painter.drawPath(construitChemin(lPliV));
        }
    }

    painter.end();

    QFileDialog::saveFileContent(buffer.data(), "myExport.svg");
}

QPainterPath MainWindow::construitChemin(QList<QLineF> lignes) {
    QPainterPath chemin;
    for (auto && l : lignes) {
        chemin.moveTo(l.p1().x(), l.p1().y());
        chemin.lineTo(l.p2().x(), l.p2().y());
    }
    return chemin;
}