color individual points separately in QScatterSeries of Qt Charts

[sayan275]

Hi, am trying to color each points of QScatterSeries in Qt Chart separately when we click on each points.

//adding scatter series
for(int i = 0; i < CLUSTERSERIESCOUNT; ++i)//3 times
   {
        m_clusterseries[i] = new QScatterSeries();
        if(m_clusterseries[i])
        {
            m_clusterseries[i]->clear();
            connect(m_clusterseries[i], &QScatterSeries::clicked, this, &RadarGraphicsView::onClickedClusterScatterObject);
            connect(m_clusterseries[i], &QScatterSeries::hovered, this, &RadarGraphicsView::onHoverClusterObject);
        }
    }

for(int seriesIndex = 0; seriesIndex < CLUSTERSERIESCOUNT; ++seriesIndex)
    {
        if(seriesIndex == 0)
        {
            m_clusterseries[0]->setMarkerShape(QScatterSeries::MarkerShapeRectangle);
            m_clusterseries[0]->setPen(Qt::SolidLine);
            m_clusterseries[0]->setBorderColor(Qt::blue);
            m_clusterseries[0]->setColor(Qt::transparent);
            m_clusterseries[0]->setName(MOVING);
            m_clusterseries[0]->setMarkerSize(7.5);

            for(int i = 0; i < m_xValuesMCluster.count(); ++i)
            {
                m_clusterseries[0]->append(QPointF(m_xValuesMCluster.at(i), m_yValuesMCluster.at(i)));
            }
        }
        else if(seriesIndex == 1)
        {
            m_clusterseries[1]->setMarkerShape(QScatterSeries::MarkerShapeRectangle);
            m_clusterseries[1]->setPen(Qt::SolidLine);
            m_clusterseries[1]->setBorderColor(Qt::yellow);
            m_clusterseries[1]->setColor(Qt::transparent);
            m_clusterseries[1]->setName(STATIONARY);
            m_clusterseries[1]->setMarkerSize(7.5);

            for(int i = 0; i < m_xValuesSCluster.count(); ++i)
            {
                m_clusterseries[1]->append(QPointF(m_xValuesSCluster.at(i), m_yValuesSCluster.at(i)));
            }
        }
        else  if(seriesIndex == 2)
        {
            m_clusterseries[2]->setMarkerShape(QScatterSeries::MarkerShapeRectangle);
            m_clusterseries[2]->setPen(Qt::SolidLine);
            m_clusterseries[2]->setBorderColor(Qt::gray);
            m_clusterseries[2]->setColor(Qt::transparent);
            m_clusterseries[2]->setName(UNKNOWN);
            m_clusterseries[2]->setMarkerSize(7.5);

            for(int i = 0; i < m_xValuesUNCluster.count(); ++i)
            {
                m_clusterseries[2]->append(QPointF(m_xValuesUNCluster.at(i), m_yValuesUNCluster.at(i)));
            }
        }
    }

 //add series to the chart
    for(int i = 0; i < CLUSTERSERIESCOUNT; ++i)
    {
        m_chart->addSeries(m_clusterseries[i]);
        m_clusterseries[i]->attachAxis(m_axisX);
        m_clusterseries[i]->attachAxis(m_axisY);
    }

This is how am adding points and it looks as below.

on Clicking each point, I want that to color with a selected color.

void MyView::onClickedClusterScatterObject(const QPointF& point)
{
  //color the selected cluster
  QPointF p =  m_chart->mapToPosition(point);
  QGraphicsItem *it = itemAt(mapFromScene(p));
  it->setTransformOriginPoint(it->boundingRect().center());
//the below colors the whole series
//QGraphicsColorizeEffect* effect = new QGraphicsColorizeEffect(this);
//effect->setColor(QColor(m_CRLTColor));
//it->setGraphicsEffect(effect);

 QScatterSeries* series = qobject_cast<QScatterSeries*>(sender());
 qInfo()<<__FUNCTION__<<sender()<<series->markerShape();
 if(QGraphicsRectItem *rect = qgraphicsitem_cast<QGraphicsRectItem*>(it))
{
    rect->setBrush(QColor(m_CRLTColor));
}
 m_mainScene->update();
}

With above code, am able to color the selected points, only the Yellow series[ie, m_clusterseries[1]].

But on, clicking the Blue series points[ie, m_clusterseries[0]], it fails in the qgraphicsitem_cast<QGraphicsRectItem>(it) line. and rect->setBrush(color) doesn't execute*.
Why so? what wrong am doing?

Another issue, after new data is received, I clear the old series and perform the same initialization steps again. After the the nothing works, ie, the graphicsitem_cast fails for the yellow series also.

QGraphicsColorizeEffect code, colors the whole series, and some unexpected things, like on clicking the blue points, the yellow series is getting colored.

I suspect, there maybe in any issue in z-value with the blue series, so the GraphicsItem* It is picking something else than the cluster points.
Any suggestion to color individual points of a qscatterseries is appreciated.

QPointF p =  m_chart->mapToPosition(point);
QGraphicsItem *it = itemAt(mapFromScene(p));                
qInfo()<<"Flags"<<it->flags()<<"\tparent item "<<it->parentItem()
<<"\t childItems"<<it->childItems()<<"\t z value"<<it->zValue();

After some debugging I found, that the GraphicsItem retrived from the scene are different as below, so the graphicsitem_cast fails for QRectGraphicsItem.

Yellow Series
================
AnnotationViewerPlugins::RadarGraphicsView::onClickedClusterScatterObject QtCharts::QScatterSeries(0x1f454c3e1e0) 1 "Stationary"
Flags ( ItemIsSelectable ) 	parent item  QGraphicsItem(0x1f454c50f00, parent=0x1f454c50ea0, pos=0,0) 	 childItems () 	 z value 0
"#ff69b4"  color set to rect item 0

Blue Series
==============
AnnotationViewerPlugins::RadarGraphicsView::onClickedClusterScatterObject QtCharts::QScatterSeries(0x1f454c42230) 1 "Moving"
Flags ( ItemClipsChildrenToShape ) 	parent item  QtCharts::QChart(0x1f4434d1e10, pos=0,0, flags=(ItemUsesExtendedStyleOption|ItemSendsGeometryChanges)) 	 childItems (QGraphicsItem(0x1f454c50f00, parent=0x1f454c50ea0, pos=0,0)) 	 z value 4