void
PfPvDoubleClickPicker::widgetMouseDoubleClickEvent( QMouseEvent *me )
{
    QPointF p1 = invTransform(me->pos());
    QPoint p2 = pfPvTransform(p1);

    // emit the itemMoved signal
    Q_EMIT doubleClicked(p2.x(), p2.y());
}
QwtText
PfPvDoubleClickPicker::trackerTextF( const QPointF &pos ) const
{
    QPointF p = pfPvTransform(pos);

    //text.sprintf( tr("%.2f m/s (%.0f rpm), %.2f N (%.0f watts)"), pos.x(), p.x(), pos.y(), p.y() );
    QString text = QString(tr("%1 rpm, %2 watts")).arg(p.x()).arg(p.y());

    QwtText returning(text);
    returning.setColor(GColor(CPLOTMARKER));

    return returning;
}