[Paraview-developers] Updating view properties

[David Thompson]

> Alright, let's take a few steps back and see how to deal with this  
> issue.
>
> First try putting a cout or something in vtkPVContextView::Render().
> Is this method called every time the axis changes?

No. Interaction (panning/zooming) on the client does not result in  
Render() being called on either the client or the servers. I believe  
the pqContextView class uses the vtkPVContextView's vtkContextView  
object directly.

	Thanks,
	David

> On Thu, Feb 10, 2011 at 3:33 PM, David Thompson <dcthomp at sandia.gov>  
> wrote:
>>>> I'm not sure exactly which "change event" you mean I should  
>>>> listen to.
>>>> The
>>>> EndEvent signalling the end of a render? The Modified event  
>>>> signaling a
>>>> change in the vtkPVContextView subclass on the client? Or  
>>>> (certainly not)
>>>> the StateChangedEvent used by Undo/Redo?
>>>
>>> The event after which you wish to update the representations. I am  
>>> not
>>> sure what event the vtkAxis fires, if any when the limit changes,...
>>
>> It doesn't, but...
>>
>>> ... but that's what should trigger the change in properties on the
>>> representation, right?
>>
>> Yes. I was checking whether vtkAxis changed by observing the EndEvent
>> emitted by vtkContextView on the client. When it changed, I would
>> 1. use a vtkSMPropertyHelper to update the property of the  
>> vtkPVContextView
>> subclass,
>> 2. call UpdateProperty() on the proxy, and then
>> 3. invoke render() on the pqView subclass.
>> But on the server side, this results in a WrongTagEvent (it  
>> receives tag 16
>> instead of 1) followed by the server exiting.
>>
>> If I understand your suggestion, then instead of steps #1-2 above,  
>> I should
>> be using SendStream() to invoke a method on all the processes'
>> vtkPVContextView subclasses?
>>
>>        Thanks,
>>        David
>>
>