[Paraview] Access on widget properties

[Stephan Rogge]

Hello,

I want to have access on the "HandlePositions" property of a spline widget
(proxygroup="3d_widget_representations" proxyname="SplineRepresentation").
So I tried to search proxies and its properties via vtkSMProxyManager which
is similar to the way of the VR-Plugin. 

To try this approach I've create a new scene with a single Spline widget and
saved the state file. The widget representation is named as
"DataRepresentation1". I thought I can now have access on certain properties
- let's say "HandlePositions" - and change the values as I desire.
Unfortunately, this does not work:  

vtkSMProxy* Proxy = 
       vtkSMProxyManager::GetProxyManager()->
            GetActiveSessionProxyManager()->
            GetProxy( " DataRepresentation1" );

if(Proxy)
  {
  vtkSMDoubleVectorProperty* Property =
           vtkSMDoubleVectorProperty::SafeDownCast( 
              Proxy->GetProperty( " HandlePositions " ));	
  }

The property would be NULL.

Can someone help me please?

Thanks.