QCustomPlot - show item on QCPAxisRect below customPlot

Question

In a project resembling the QCustomPlot financial demo I want to draw a QCPItemRect not only into the chart area, but also to the area below the chart.

Having

Answer 1

Found the answer (thanks to the author of QCustomPlot). The missing components were

1. Settings the clipAxisRect of the rectangle (already contained in the last update of question)
2. Settings the axes, which the rectangle obeys.

Specifically,

 xRectItem->setClipAxisRect     ( xRect );

and

 xRectItem->topLeft     ->setAxes( xRect->axis(QCPAxis::atBottom), xRect->axis(QCPAxis::atLeft) );
 xRectItem->bottomRight ->setAxes( xRect->axis(QCPAxis::atBottom), xRect->axis(QCPAxis::atLeft) );