Check if feature is rendered before displaying its map tips #38861
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pblottiere
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| renderer.reset( vlayer->renderer()->clone() ); | ||
| renderer->startRender( renderCtx, vlayer->fields() ); | ||
| } | ||
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| QgsFeatureIterator it = vlayer->getFeatures( request ); |
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It's possible to optimise this request based on the renderer's visible features -- if the layer has a renderer, you can use QgsFeatureRenderer::filter to set a filter expression on the request to avoid fetching and testing some invisible features, which should speed this functionality up
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Indeed! I take a look. Thanks for your input Nyall 👍.
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@nyalldawson I think I took into account your comment. Let me know if it's not what you had in mind.
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Actually we also need:
request.setFilterExpression( renderer->filter( vlayer->fields() ));
in order to delegate the filter to the provider
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Mmm... In my use case with a graduated renderer and a SHP, the renderer->filter( vlayer->fields() ) call returns an empty string so I get an "empty" iterator from vlayer->getFeatures( request ). So map tips are never displayed.
I can write a unit test to highlight this behavior if you want?
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It's not implemented for the graduated renderer -- so if filter() returns an empty string, you don't set a filter expression on the iterator. It's implemented for categorized, rule based renderers only.
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OK good to know. The code is now updated.
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I'll merge this PR in the coming days if I don't have more comments in the meantime. |
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Description
Fixes #37066