setPointConfiguration does nothing

nekkceb

I am using Qt ver 6.2.8 (64-bit) in Windows 10 (latest). I have a QLineSeries that I am trying to implement a way for the user to select a point with the mouse, and have that point highlighted with a larger symbol, and possible label the point. Though the code is pretty large at this point here are relevant snippets:
I have an over-loaded QChart classe that defines a QLineSeries:

  m_avgSeries= new QLineSeries(this);
  m_avgSeries->setName("Avg");
  QPen avgCol(Qt::blue);
  m_avgSeries->setUseOpenGL(true);
  avgCol.setWidth(3);
  // m_avgSeries->setMarkerSize(8.0);
  m_avgSeries->setPointsVisible(true);
  m_avgSeries->setPen(avgCol);
  m_avgSeries->append(m_x, m_y);
  QObject::connect(m_avgSeries, SIGNAL(clicked(QPointF)), this,
                   SLOT(handleAvgPtSelect(QPointF)));

I also define a pointConfiguration member variable:

// from header: QHash<QXYSeries::PointConfiguration, QVariant> ptconf;
  m_ptConf[QXYSeries::PointConfiguration::Color]= QColor(Qt::magenta);
  m_ptConf[QXYSeries::PointConfiguration::Size]= 8;
  m_ptConf[QXYSeries::PointConfiguration::LabelVisibility]= true;

Then in the slot handleAvgPtSelect I first find the index of the mouse-selected point (the m_avgSeries is pretty large at this point...), then try to highlight it with this code:

      m_avgSeries->setPointConfiguration(index, m_ptConf);
      m_avgSeries->setPointSelected(index, true);

But this does nothing to the appearance on the graph. I have set breakpoints at various places in this code, and it is all getting hit at appropriate times. Any suggestions for what might be wrong are appreciated.

JonB

@nekkceb
To me your code looks reasonable. I would spend the 5 minutes to set up a brand new project and just paste in the code from https://doc.qt.io/qt-6/qxyseries.html#setPointConfiguration. Does that work for you?

nekkceb

@JonB Thanks for quick response and suggestion. And, yes that simple example works fine!

JonB

@nekkceb
Then it's your job to find out how they differ! Check your value for index. Maybe when " (the m_avgSeries is pretty large at this point...)" it doesn't plot one point or it's hard tp see? Try calling the setPointConfiguration() on lots/every point in the series, is that visible?

nekkceb

@JonB Well, it may be trying to use OpenGL, which I had turned on because other documentation suggested it would give me faster refreshes using large series. I juist turned that off:

m_series->setUseOpenGL(false)
m_avgSeries->setUseOpenGL(false);

Not only do the PointConfigurations work, but I had also turned on pointsVisible for the series, and the points were not showing, only the lines.

nekkceb

@JonB I should ask, is this an oversight or bug? Should turning on OpenGL de-activate certain features of QLineseries?