[QGIS-Developer] QGIS3: Python QgsFeatureRenderer subclass problem

[Chris Crook]

Hi Nyall

The code is on github ..

https://github.com/ccrook/QGIS-VectorFieldRenderer-Plugin/tree/qgis3_wip

I've documented this in issue 8 at:

https://github.com/ccrook/QGIS-VectorFieldRenderer-Plugin/issues/8

Any thoughts would be greatly appreciated :-)

Chris

________________________________________
From: Nyall Dawson [nyall.dawson at gmail.com]
Sent: 08 February 2018 10:53
To: Chris Crook
Cc: qgis-developer at lists.osgeo.org
Subject: Re: [QGIS-Developer] QGIS3: Python QgsFeatureRenderer subclass problem

On 8 February 2018 at 05:44, Chris Crook <ccrook at linz.govt.nz> wrote:
> I am converting a python  plugin the implements a subclass of QgsFeatureRenderer.  At the moment the plugin is dying on the startRender function with the message (from the base class)
>
> "ASSERT failure in QgsFeatureRenderer::renderFeature: \"renderFeature called in a different thread - use a cloned renderer instead\"
>
> I can't see where I should be creating the cloned renderer for the rendering.  I had a look at the QgsSingleSymbolRenderer C++ code and I can't see anything there, so I'm wondering if the python implementation in some way corrupts the multiprocessing implementation.  Can anyone offer any suggestions
>

Interesting - is your code public anywhere? I'll take a look.

Nyall

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