Items selection by mouse rectangle with map not facing north

[JaiPasdeBol]

Hi,

I noticed a very little problem that I think I solved. When you select items by drawing a rectangle with the SHIFT key pushed: it works perfectly when the map is north oriented. But it doesn't really well when your map is oriented at 45° for exemple. (The rectangle we use for the selection isn't oriented correctly) So I had this method in QGVMap class:

QList<QGVDrawItem*> QGVMap::search(const QPolygonF& projPolygon, Qt::ItemSelectionMode mode) const
{
    QList<QGVDrawItem*> result;
    for (QGraphicsItem* item : geoView()->scene()->items(projPolygon, mode)) {
        QGVDrawItem* geoObject = QGVMapQGItem::geoObjectFromQGItem(item);
        if (geoObject)
            result << geoObject;
    }
    return result;
}

And I add some code in QGVMapQGView::selectObjectsByRect(QMouseEvent* event, QRect selRect)

void QGVMapQGView::selectObjectsByRect(QMouseEvent* event, QRect selRect)
{
    if (!mMouseActions.testFlag(QGV::MouseAction::Selection)) {
        changeState(QGV::MapState::Idle);
        return;
    }
    event->accept();
    if (event->modifiers() == Qt::ShiftModifier) {
        mGeoMap->unselectAll();
    }
    const QRectF projSelRect = QRectF(mapToScene(selRect.topLeft()), mapToScene(selRect.bottomRight()));
    //Construction of the polygon
    QPolygonF projSelPolygon;
        projSelPolygon<<mapToScene(selRect.topLeft());
        projSelPolygon<<mapToScene(selRect.bottomRight());
    QPointF centreRect((selRect.topLeft().x()+selRect.bottomRight().x())/2,(selRect.topLeft().y()+selRect.bottomRight().y())/2.);
    QPolygonF projSelPolygon2 = QTransform().rotate(-mAzimuth).translate(-centreRect.x(),-centreRect.y()).map(projSelPolygon);
    projSelPolygon.clear();
    projSelPolygon<<projSelPolygon2[0];
    projSelPolygon<<QPointF(projSelPolygon2[1].x(),projSelPolygon2[0].y());
    projSelPolygon<<projSelPolygon2[1];
    projSelPolygon<<QPointF(projSelPolygon2[0].x(),projSelPolygon2[1].y());
    projSelPolygon = QTransform().translate(centreRect.x(),centreRect.y()).rotate(mAzimuth).map(projSelPolygon);

    auto selList = mGeoMap->search(projSelPolygon, Qt::ContainsItemShape);
    for (auto* geoObject : selList) {
        geoObject->setSelected(!geoObject->isSelected());
    }
}

I think it works fine with this, but you may have a better solution. Thanks for your work on this library.

[AmonRaNet]

I have pushed fix to master. Technically is easier to map every corner of selection rect to scene coordinates (rotation will be included) and then simply select nodes by closed polygon containing these points. P.S. Now selection by polygon is public interface for QGVMap.