Hello,

I have got the same problem, because of size 0 of the boundingRect() the item cannot be found:

Qt Code: 
  1. void Plot::cursorSelected(const QwtDoublePoint &Point)
  2. {
  3. 	//selectedPoint = NULL;
  4. 	std::cout << "in Plot::cursorSelected, selectedPoint = " << selectedPoint << std::endl;
  5. 	const QwtPlotItemList& List = itemList();
  6. 	QwtPlotItemIterator Iter = List.begin();
  7. 	for ( QwtPlotItemIterator it = List.begin();it != List.end(); ++it )
  8. 	    {
  9. 	    	std::cout << "(*it) "<< (*it) << std::endl;
  10. 	        if ( (*it)->rtti() == QwtPlotItem::Rtti_PlotMarker )
  11. 	        {
  12. 	            QwtPlotMarker *mark = ((QwtPlotMarker*)(*it));
  13. 	            QwtDoubleRect rec = mark->boundingRect();
  14. 	            std::cout << "mark->boundingRect()"  <<rec.width()<<rec.height()<< std::endl;
  15. 	            if(mark->boundingRect().contains(Point)){
  16. 	                    	std::cout << "MATCH"  << std::endl;
  17. 	            			 selectedPoint = dynamic_cast<QwtPlotMarker*>(mark);
  18. 	            			 std::cout << "selectedPoint = " << selectedPoint << std::endl;
  19. 	                    }
  20. 	            else selectedPoint = NULL;
  21. 	        }
  22. 	    }
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What do you mean by using Pixel coordinates? Di you mean I have to transform them like that? :
Qt Code: 
  1. double x = this->transform(mark->xAxis(),Point.x());
  2.      	double y = this->transform(mark->yAxis(),Point.y());
  3.      	QwtDoublePoint trPoint = QwtDoublePoint(x,y);
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I also uses this, but it does not work too. Perhaps because I did not expansed the size of boundingRect. How can I do it?