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Move expression preparation to prepare step

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m-kuhn committed Mar 11, 2019
1 parent c8333d5 commit da7b4892020dc25b645a6d3cfd7f55ed0d352114
Showing with 103 additions and 7 deletions.
  1. +103 −7 src/core/qgspallabeling.cpp
@@ -389,6 +389,109 @@ QgsPalLayerSettings &QgsPalLayerSettings::operator=( const QgsPalLayerSettings &
return *this;
}

bool QgsPalLayerSettings::prepare( const QgsRenderContext &context, QSet<QString> &attributeNames, const QgsFields &fields, const QgsMapSettings &mapSettings, const QgsCoordinateReferenceSystem &crs )
{
if ( drawLabels )
{
if ( fieldName.isEmpty() )
{
return false;
}

if ( isExpression )
{
QgsExpression exp( fieldName );
if ( exp.hasEvalError() )
{
QgsDebugMsgLevel( "Prepare error:" + exp.evalErrorString(), 4 );
return false;
}
}
else
{
// If we aren't an expression, we check to see if we can find the column.
if ( fields.lookupField( fieldName ) == -1 )
{
return false;
}
}
}

mCurFields = fields;

if ( drawLabels || obstacle )
{
if ( drawLabels )
{
// add field indices for label's text, from expression or field
if ( isExpression )
{
// prepare expression for use in QgsPalLayerSettings::registerFeature()
QgsExpression *exp = getLabelExpression();
exp->prepare( &context.expressionContext() );
if ( exp->hasEvalError() )
{
QgsDebugMsgLevel( "Prepare error:" + exp->evalErrorString(), 4 );
}
const auto referencedColumns = exp->referencedColumns();
for ( const QString &name : referencedColumns )
{
attributeNames.insert( name );
}
}
else
{
attributeNames.insert( fieldName );
}
}

mDataDefinedProperties.prepare( context.expressionContext() );
// add field indices of data defined expression or field
attributeNames.unite( dataDefinedProperties().referencedFields( context.expressionContext() ) );
}

// NOW INITIALIZE QgsPalLayerSettings

// TODO: ideally these (non-configuration) members should get out of QgsPalLayerSettings to QgsVectorLayerLabelProvider::prepare
// (together with registerFeature() & related methods) and QgsPalLayerSettings just stores config

// save the pal layer to our layer context (with some additional info)
fieldIndex = fields.lookupField( fieldName );

xform = &mapSettings.mapToPixel();
ct = QgsCoordinateTransform();
if ( context.coordinateTransform().isValid() )
// this is context for layer rendering
ct = context.coordinateTransform();
else
{
// otherwise fall back to creating our own CT
ct = QgsCoordinateTransform( crs, mapSettings.destinationCrs(), mapSettings.transformContext() );
}
ptZero = xform->toMapCoordinates( 0, 0 );
ptOne = xform->toMapCoordinates( 1, 0 );

// rect for clipping
extentGeom = QgsGeometry::fromRect( mapSettings.visibleExtent() );
if ( !qgsDoubleNear( mapSettings.rotation(), 0.0 ) )
{
//PAL features are prerotated, so extent also needs to be unrotated
extentGeom.rotate( -mapSettings.rotation(), mapSettings.visibleExtent().center() );
}

mFeatsSendingToPal = 0;

if ( !mGeometryGeneratorExpression.isValid() )
{
mGeometryGeneratorExpression = QgsExpression( geometryGenerator );
mGeometryGeneratorExpression.prepare( &context.expressionContext() );
if ( mGeometryGeneratorExpression.hasParserError() )
QgsMessageLog::logMessage( QObject::tr( "Labeling" ), mGeometryGeneratorExpression.parserErrorString() );
}

return true;
}


QgsPalLayerSettings::~QgsPalLayerSettings()
{
@@ -1222,13 +1325,6 @@ void QgsPalLayerSettings::registerFeature( const QgsFeature &f, QgsRenderContext
QgsFeature feature = f;
if ( geometryGeneratorEnabled )
{
if ( !mGeometryGeneratorExpression.isValid() )
{
mGeometryGeneratorExpression = QgsExpression( geometryGenerator );
mGeometryGeneratorExpression.prepare( &context.expressionContext() );
if ( mGeometryGeneratorExpression.hasParserError() )
QgsMessageLog::logMessage( QObject::tr( "Labeling" ), mGeometryGeneratorExpression.parserErrorString() );
}
const QgsGeometry geometry = mGeometryGeneratorExpression.evaluate( &context.expressionContext() ).value<QgsGeometry>();
if ( mGeometryGeneratorExpression.hasEvalError() )
QgsMessageLog::logMessage( QObject::tr( "Labeling" ), mGeometryGeneratorExpression.evalErrorString() );

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