[slicer-users] Syncing widgets with MRML scene

Steve Pieper pieper at bwh.harvard.edu
Fri Mar 19 17:41:06 EDT 2010

Hi Ali -

Good bug!  I had to really dig to understand this one.  The issue is the 
extra arguments to the SetNodeClass need to be strings, like so:

 >     self.my_selector.SetNodeClass('vtkMRMLFiducialListNode', "", "", "")

This is probably due to a subtle difference between 'slicerpython' and 
'vktpython' in the way it coerces datatypes - this method expects 
strings so it turned the 0s into "0"s
.  Hopefully there aren't too many of those gotcha's hiding.  I'll add a 
pointer to this email in the bug tracker.  We'll be reworking all the 
python stuff in the not too distant future so I hope this issue will 

I checked in a standalone example that works for me in case you neede it 
for anything:



On M/19/10 2:40 PM, Ali Uneri wrote:
> Hello,
> This mail-list has been very helpful in the past, and I'm in need of
> help once again.
> I'm having a problem with my Slicer Interactive module in Python. I've
> created a vtkSlicerNodeSelectorWidget and I want the nodes to be in sync
> with my MRMLScene, i.e. if the nodes are of type
> vtkMRMLFiducialListNode, I would like to see them in my widget just as
> in the Fiducials Module. Below is how I currently instantiate my widget:
> from Slicer import slicer
> class MyModule(ScriptedModuleGUI):
>     ...
>     self.my_selector = slicer.vtkSlicerNodeSelectorWidget()
>     self.my_selector.SetParent(parent_frame)
>     self.my_selector.SetNodeClass('vtkMRMLFiducialListNode', 0, 0, 0)
>     self.my_selector.Create()
>     self.my_selector.SetMRMLScene(slicer.MRMLScene)
>     self.my_selector.UpdateMenu()
>     self.my_selector.SetLabelText('My Fiducials')
>     slicer.TkCall('pack %s -side top -fill x -padx 5 -pady 5' %
> self.my_selector.GetWidgetName())
> In the C++ version, .SetMRMLScene() was enough to establish a link
> between the widget and the scene, however this is not the case in
> Python. Do I need to handle an event, or update something periodically
> to ensure that my selector widget displays the correct nodes in the
> current scene.
> I also noticed there are multiple ways to obtain a scene, i.e.
> slicer.MRMLScene, self.GetApplicationGUI().GetMRMLScene(),
> self.GetLogic().GetMRMLScene(), what is the preferred way of getting the
> current scene?
> Thank you,
> Ali
> _______________________________________________
> slicer-users mailing list
> slicer-users at bwh.harvard.edu
> http://massmail.spl.harvard.edu/mailman/listinfo/slicer-users
> To unsubscribe: send email to slicer-users-request at massmail.spl.harvard.edu with unsubscribe as the subject

More information about the slicer-users mailing list