[Paraview] Example of displaying information

[Bryn Lloyd]

Hi

I have been looking for an example, which would help me understand how  
I can get some information about a dataset and display it in a GUI  
element (e.g. in a QLabel).

E.g. as an example, I would like to have a panel or some other gui  
element, which displays certain values which it gets from a data set  
(e.g. number of lines in a polydata, or total volume of a unstructured  
grid, or ...)

Can you please suggest how I could achieve this?

Thanks,
Bryn