Hello,

I want to drag my QwtPlotMarker on the plot and thus I have writen the following functions:
Qt Code: 
  1. void Plot::cursorSelected(const QwtDoublePoint &Point)
  2. {
  3. 	std::cout << "in Plot::cursorSelected" << std::endl;
  4. 	const QwtPlotItemList& List = itemList();
  5. 	QwtPlotItemIterator Iter = List.begin();
  6.  
  7. 	selectedPoint = NULL;
  8. 	std::cout << "selectedPoint = " << selectedPoint << std::endl;
  9. 	std::cout << "Point = " << Point.x() << ", " << Point.y()<< std::endl;
  10.   while(Iter != List.end())
  11.   {
  12.      QwtPlotItem *pItem = (QwtPlotItem *)(*Iter);
  13.  
  14.      if(pItem->rtti() == QwtPlotItem::Rtti_PlotMarker)
  15.         if(pItem->boundingRect().contains(Point)){
  16.         	std::cout << "MATCH"  << std::endl;
  17. 			 selectedPoint = dynamic_cast<QwtPlotMarker*>(pItem);
  18. 			 std::cout << "selectedPoint = " << selectedPoint << std::endl;
  19.         }
  20.      Iter++;
  21.   }
  22. }
  23.  
  24. void Plot::cursorMoved( const QPoint& Point){
  25. 	std::cout << "in Plot::cursorMoved" << std::endl;
  26. 	if(selectedPoint){
  27. 		double xData = this->invTransform(selectedPoint->xAxis(), Point.x());;
  28. 		double  yData =this->invTransform(selectedPoint->yAxis(), Point.y());;
  29.  
  30. 		    std::cout << "xData: " << xData <<"yData: " << yData<< std::endl;
  31. 		    selectedPoint->setXValue(xData);
  32. 		    selectedPoint->setYValue(yData);
  33.  
  34. 		    std::cout << "selectedPoint->xValue(): " << selectedPoint->xValue() <<"selectedPoint->yValue(): " << selectedPoint->yValue()<< std::endl;
  35. 		    this->replot();
  36. 	}
  37. }
To copy to clipboard, switch view to plain text mode 

and I get the following output if I drag the Marker:
in Plot::cursorMoved
xData: 0.38022yData: -0.00858369
selectedPoint->xValue(): 0.38022selectedPoint->yValue(): -0.00858369
in Plot::cursorMoved
xData: 0.410989yData: -0.0343348
selectedPoint->xValue(): 0.410989selectedPoint->yValue(): -0.0343348
in Plot::cursorMoved
xData: 0.481319yData: -0.0772532
selectedPoint->xValue(): 0.481319selectedPoint->yValue(): -0.0772532
in Plot::cursorSelected
selectedPoint = 0
Point = 0.481319, -0.0772532

That means the coordinates of the marker are changed, but the command this->replot() does not work because the marker is still on its last position.
Or does I have to repaint/ redraw the marker at new position by calling its member function "draw"?

Help me please.

Thank you