bool QgsMapRendererJob::prepareLabelCache() const
{
bool canCache = mCache;
// calculate which layers will be labeled
QSet< QgsMapLayer * > labeledLayers;
Q_FOREACH ( const QgsMapLayer *ml, mSettings.layers() )
{
QgsVectorLayer *vl = const_cast< QgsVectorLayer * >( qobject_cast<const QgsVectorLayer *>( ml ) );
if ( vl && QgsPalLabeling::staticWillUseLayer( vl ) )
labeledLayers << vl;
if ( vl && vl->labelsEnabled() && vl->labeling()->requiresAdvancedEffects() )
{
canCache = false;
break;
}
}
if ( mCache && mCache->hasCacheImage( LABEL_CACHE_ID ) )
{
// we may need to clear label cache and re-register labeled features - check for that here
// can we reuse the cached label solution?
bool canUseCache = canCache && mCache->dependentLayers( LABEL_CACHE_ID ).toSet() == labeledLayers;
if ( !canUseCache )
{
// no - participating layers have changed
mCache->clearCacheImage( LABEL_CACHE_ID );
}
}
return canCache;
}
bool QgsMapToolLabel::createAuxiliaryFields( LabelDetails &details, QgsPalIndexes &indexes ) const
{
bool newAuxiliaryLayer = false;
QgsVectorLayer *vlayer = details.layer;
QString providerId = details.pos.providerID;
if ( !vlayer || !vlayer->labelsEnabled() )
return false;
if ( !vlayer->auxiliaryLayer() )
{
QgsNewAuxiliaryLayerDialog dlg( vlayer );
dlg.exec();
newAuxiliaryLayer = true;
}
if ( !vlayer->auxiliaryLayer() )
return false;
for ( const QgsPalLayerSettings::Property &p : qgis::as_const( mPalProperties ) )
{
int index = -1;
// always use the default activated property
QgsProperty prop = details.settings.dataDefinedProperties().property( p );
if ( prop.propertyType() == QgsProperty::FieldBasedProperty && prop.isActive() )
{
index = vlayer->fields().lookupField( prop.field() );
}
else
{
index = QgsAuxiliaryLayer::createProperty( p, vlayer );
}
indexes[p] = index;
}
details.settings = vlayer->labeling()->settings( providerId );
return newAuxiliaryLayer;
}