Getting consistency of QwtPlotMultiBarChart item value from QwtPicker trackerText

How to make QwtPicker to work with QwtPlotMultiBarChart, is it possible?
My current code is like these one:

Code:

---

#include "barchart.h"
#include <qwt_plot_renderer.h>
#include <qwt_plot_canvas.h>
#include <qwt_plot_multi_barchart.h>
#include <qwt_column_symbol.h>
#include <qwt_plot_layout.h>
#include <qwt_legend.h>
#include <qwt_scale_draw.h>
#include <qwt_picker.h>
#include <QDebug>
 
class Picker:public  QwtPicker
{
public:
	Picker(QWidget *canvas):QwtPicker(canvas){
		 setRubberBandPen( QColor( Qt::darkGreen ) );
        setTrackerMode( QwtPicker::AlwaysOn );
	}
	~Picker(){}
 
	QwtText trackerText(const QPoint &  pos	) 	const
	{
		QString s;
		s+=QString("x: %1, y:%2").arg(pos.x()).arg(pos.y());
		qDebug()<<s;
		QwtText text;
		text.setColor( Qt::white );
		 QColor c = rubberBandPen().color();
        text.setBorderPen( QPen( c ) );
        text.setBorderRadius( 6 );
        c.setAlpha( 170 );
        text.setBackgroundBrush( c );
		return text;
	}
 
private:
 
 
};
 
BarChart::BarChart( QWidget *parent ):
    QwtPlot( parent )
{
    setAutoFillBackground( true );
 
    setPalette( Qt::white );
    canvas()->setPalette( QColor( "LemonChiffon" ) );
	Picker *pick=new Picker(canvas());
 
    setTitle( "Bar Chart" );
 
    setAxisTitle( QwtPlot::yLeft, "Whatever" );
    setAxisTitle( QwtPlot::xBottom, "Whatever" );
 
    d_barChartItem = new QwtPlotMultiBarChart( "Bar Chart " );
    d_barChartItem->setLayoutPolicy( QwtPlotMultiBarChart::AutoAdjustSamples );
    d_barChartItem->setSpacing( 20 );
    d_barChartItem->setMargin( 3 );
 
    d_barChartItem->attach( this );
 
    insertLegend( new QwtLegend() );
 
    populate();
    setOrientation( 0 );
 
    setAutoReplot( true );
}
 
void BarChart::populate()
{
    static const char *colors[] = { "DarkOrchid", "SteelBlue", "Gold" };
 
    const int numSamples = 5;
    const int numBars = sizeof( colors ) / sizeof( colors[0] );
 
    QList<QwtText> titles;
    for ( int i = 0; i < numBars; i++ )
    {
        QString title("Bar %1");
        titles += title.arg( i );
    }
    d_barChartItem->setBarTitles( titles );
    d_barChartItem->setLegendIconSize( QSize( 10, 14 ) );
 
    for ( int i = 0; i < numBars; i++ )
    {
        QwtColumnSymbol *symbol = new QwtColumnSymbol( QwtColumnSymbol::Box );
        symbol->setLineWidth( 2 );
        symbol->setFrameStyle( QwtColumnSymbol::Raised );
        symbol->setPalette( QPalette( colors[i] ) );
 
        d_barChartItem->setSymbol( i, symbol );
    }
 
    QVector< QVector<double> > series;
    for ( int i = 0; i < numSamples; i++ )
    {
        QVector<double> values;
        for ( int j = 0; j < numBars; j++ )
            values += ( 2 + qrand() % 8 );
 
        series += values;
    }
 
    d_barChartItem->setSamples( series );
}
 
void BarChart::setMode( int mode )
{
    if ( mode == 0 )
    {
        d_barChartItem->setStyle( QwtPlotMultiBarChart::Grouped );
    }
    else
    {
        d_barChartItem->setStyle( QwtPlotMultiBarChart::Stacked );
    }
}
 
void BarChart::setOrientation( int orientation )
{
    QwtPlot::Axis axis1, axis2;
 
    if ( orientation == 0 )
    {
        axis1 = QwtPlot::xBottom;
        axis2 = QwtPlot::yLeft;
 
        d_barChartItem->setOrientation( Qt::Vertical );
    }
    else
    {
        axis1 = QwtPlot::yLeft;
        axis2 = QwtPlot::xBottom;
 
        d_barChartItem->setOrientation( Qt::Horizontal );
    }
 
    setAxisScale( axis1, 0, d_barChartItem->dataSize() - 1, 1.0 );
    setAxisAutoScale( axis2 );
 
    QwtScaleDraw *scaleDraw1 = axisScaleDraw( axis1 );
    scaleDraw1->enableComponent( QwtScaleDraw::Backbone, false );
    scaleDraw1->enableComponent( QwtScaleDraw::Ticks, false );
 
    QwtScaleDraw *scaleDraw2 = axisScaleDraw( axis2 );
    scaleDraw2->enableComponent( QwtScaleDraw::Backbone, true );
    scaleDraw2->enableComponent( QwtScaleDraw::Ticks, true );
 
    plotLayout()->setAlignCanvasToScale( axis1, true );
    plotLayout()->setAlignCanvasToScale( axis2, false );
 
    plotLayout()->setCanvasMargin( 0 );
    updateCanvasMargins();
 
    replot();
}
 
void BarChart::exportChart()
{
    QwtPlotRenderer renderer;
    renderer.exportTo( this, "barchart.pdf" );
}

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Above code is taken from barchart example with addition of QwtPicker for use.

Note that what I want is to retrieve current hovered barchart item vertical y values from trackerText overloaded function.

Also the tooltip textmarker is not showing as is stockchart demo doing. How to do that ?

Maybe the easiest solution might be to overload QwtPlotMultiBarChart::drawBar, where you can store the geometries of each bar. Then you can use QRectF::contains() to identify, where the mouse is.

Uwe