Disable feature fetching for symbol selector widget preview

It's just too expensive for any remote provider, e.g. wfs, and causes many ui lockups. Revisit when support for iterator timeouts is more mature.
qgis · Aug 16, 2018 · b422504 · b422504
1 parent 291224e
commit b422504
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/src/gui/symbology/qgssymbolselectordialog.cpp b/src/gui/symbology/qgssymbolselectordialog.cpp
@@ -253,11 +253,15 @@ QgsSymbolSelectorWidget::QgsSymbolSelectorWidget( QgsSymbol *symbol, QgsStyle *s
   //get first feature from layer for previews
   if ( mVectorLayer )
   {
+#if 0 // this is too expensive to do for many providers. TODO revisit when support for connection timeouts is complete across all providers
     // short timeout for request - it doesn't really matter if we don't get the feature, and this call is blocking UI
     QgsFeatureIterator it = mVectorLayer->getFeatures( QgsFeatureRequest().setLimit( 1 ).setConnectionTimeout( 100 ) );
     it.nextFeature( mPreviewFeature );
+#endif
     mPreviewExpressionContext.appendScopes( QgsExpressionContextUtils::globalProjectLayerScopes( mVectorLayer ) );
+#if 0
     mPreviewExpressionContext.setFeature( mPreviewFeature );
+#endif
   }
   else
   {