bool QgsVectorDataProvider::empty() const
{
QgsFeature f;
QgsFeatureRequest request;
request.setNoAttributes();
request.setFlags( QgsFeatureRequest::NoGeometry );
request.setLimit( 1 );
if ( getFeatures( request ).nextFeature( f ) )
return false;
else
return true;
}
QgsFeatureList QgsQuickIdentifyKit::identifyVectorLayer( QgsVectorLayer *layer, const QgsPointXY &point ) const
{
QgsFeatureList results;
if ( !layer || !layer->isSpatial() )
return results;
if ( !layer->isInScaleRange( mMapSettings->mapSettings().scale() ) )
return results;
QgsFeatureList featureList;
// toLayerCoordinates will throw an exception for an 'invalid' point.
// For example, if you project a world map onto a globe using EPSG 2163
// and then click somewhere off the globe, an exception will be thrown.
try
{
// create the search rectangle
double searchRadius = searchRadiusMU();
QgsRectangle r;
r.setXMinimum( point.x() - searchRadius );
r.setXMaximum( point.x() + searchRadius );
r.setYMinimum( point.y() - searchRadius );
r.setYMaximum( point.y() + searchRadius );
r = toLayerCoordinates( layer, r );
QgsFeatureRequest req;
req.setFilterRect( r );
req.setLimit( mFeaturesLimit );
req.setFlags( QgsFeatureRequest::ExactIntersect );
QgsFeatureIterator fit = layer->getFeatures( req );
QgsFeature f;
while ( fit.nextFeature( f ) )
featureList << QgsFeature( f );
}
catch ( QgsCsException &cse )
{
QgsDebugMsg( QStringLiteral( "Invalid point, proceed without a found features." ) );
Q_UNUSED( cse );
}
bool filter = false;
QgsRenderContext context( QgsRenderContext::fromMapSettings( mMapSettings->mapSettings() ) );
context.expressionContext() << QgsExpressionContextUtils::layerScope( layer );
QgsFeatureRenderer *renderer = layer->renderer();
if ( renderer && renderer->capabilities() & QgsFeatureRenderer::ScaleDependent )
{
// setup scale for scale dependent visibility (rule based)
renderer->startRender( context, layer->fields() );
filter = renderer->capabilities() & QgsFeatureRenderer::Filter;
}
for ( const QgsFeature &feature : featureList )
{
context.expressionContext().setFeature( feature );
if ( filter && !renderer->willRenderFeature( const_cast<QgsFeature &>( feature ), context ) )
continue;
results.append( feature );
}
if ( renderer && renderer->capabilities() & QgsFeatureRenderer::ScaleDependent )
{
renderer->stopRender( context );
}
return results;
}
