I have a QCustomPlot with 2 QCPAxisRects in a grid layout. I want to draw a vertical line in both plots at the same x-coordinate. Since both plots have completely different areas and are zoomable, I only manage to display the two lines in the respective plot. But they are both connected to the upper QCPAxisRect. If I zoom or move something in the upper plot, the line in the lower plot is moved accordingly.
Is there a way to register or connect the lower QCPItem line with the lower layout/QCPAxisRect?