Question

I want axis labels for a plot I’m making, and naturally the y-axis label should be oriented vertically. I’m pretty sure QwtPlot does this, but I’m trying to keep things light so I’m just using a simple QWidget + QPainter for now. I didn’t see any way to change QLabel orientation in the documentation. Some solutions are given in this 2002 thread but I’d like something that doesn’t seem like such a hack. I’m using Qt 4.8 now, is there really no way to do this aside from QPainter::drawText()?

Answer 1

So indeed I gave up on finding any simple way to achieve this, and looking over Uwe Rathmann’s Qwt code indeed he uses QPainter::drawText() in his QwtPainter::drawText wrapper function, and a QTransform to achieve the rotation, in QwtScaleDraw::labelTransformation. So I’ve just put these together as follows:

void LabelWidget::paintEvent(QPaintEvent*)
{
    QPainter painter(this);
    painter.setPen(Qt::black);
    //... Need an appropriate call to painter.translate() for this to work properly
    painter.rotate(90);
    painter.drawText(QPoint(0,0), _text);
}

Didn’t need a QPixmap, it turns out.