For Qt 4.6.x, how to auto-size text to fit in a specified width?

Question

Inside of my QGraphicsRectItem::paint(), I am trying to draw the name of the item within its rect(). However, for each of the different items, they can be of variable width

Answer 1

Here is my code the fit (in heigth) a text, works quite well (error < 2% I guess)

void scalePainterFontSizeToFit(QPainter &painter, QFont &r_font, float _heightToFitIn)
{
    float oldFontSize, newFontSize, oldHeight;

    // Init
    oldFontSize=r_font.pointSizeF();

    // Loop
    for (int i=0 ; i<3 ; i++)
    {
        oldHeight = painter.fontMetrics().boundingRect('D').height();
        newFontSize = (_heightToFitIn / oldHeight) * oldFontSize;
        r_font.setPointSizeF(newFontSize);
        painter.setFont(r_font);
        oldFontSize = newFontSize;
        //qDebug() << "OldFontSize=" << oldFontSize << "HtoFitIn=" << _heightToFitIn << "  fontHeight=" << oldHeight << "  newFontSize=" << newFontSize;
    }

    // End
    r_font.setPointSizeF(newFontSize);
    painter.setFont(r_font);
}