Using Qt::UserRole in the Model/View architecture

[wysota]

if you use setIndexWidget then the widget you set has no relation to the model-view architecture -- it is just a standalone widget positioned somewhere in the view widget.

if you want to display a plot in a view then a better solution is to implement a custom delegate that will (in its paint routine) use QwtPlot::print or something similar to render a plot in the item without explicitly showing any widgets.