Use checkboxes for Extract/Select by Location algs

src/core/processing/qgsnativealgorithms.cpp

@@ -1356,12 +1356,7 @@ void QgsSelectByLocationAlgorithm::initAlgorithm( const QVariantMap & )
 
   addParameter( new QgsProcessingParameterVectorLayer( QStringLiteral( "INPUT" ), QObject::tr( "Select features from" ),
                 QList< int >() << QgsProcessing::TypeVectorAnyGeometry ) );
-
-
-  addParameter( new QgsProcessingParameterEnum( QStringLiteral( "PREDICATE" ),
-                QObject::tr( "Where the features are (geometric predicate)" ),
-                predicateOptionsList(), true, QVariant::fromValue( QList< int >() << 0 ) ) );
-
+  addPredicateParameter();
   addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INTERSECT" ),
                 QObject::tr( "By comparing to the features from" ),
                 QList< int >() << QgsProcessing::TypeVectorAnyGeometry ) );
@@ -1529,6 +1524,23 @@ void QgsLocationBasedAlgorithm::process( QgsFeatureSource *targetSource,
   }
 }
 
+void QgsLocationBasedAlgorithm::addPredicateParameter()
+{
+  std::unique_ptr< QgsProcessingParameterEnum > predicateParam( new QgsProcessingParameterEnum( QStringLiteral( "PREDICATE" ),
+      QObject::tr( "Where the features are (geometric predicate)" ),
+      predicateOptionsList(), true, QVariant::fromValue( QList< int >() << 0 ) ) );
+
+  QVariantMap predicateMetadata;
+  QVariantMap widgetMetadata;
+  widgetMetadata.insert( QStringLiteral( "class" ), QStringLiteral( "processing.gui.wrappers.EnumWidgetWrapper" ) );
+  widgetMetadata.insert( QStringLiteral( "useCheckBoxes" ), true );
+  widgetMetadata.insert( QStringLiteral( "columns" ), 2 );
+  predicateMetadata.insert( QStringLiteral( "widget_wrapper" ), widgetMetadata );
+  predicateParam->setMetadata( predicateMetadata );
+
+  addParameter( predicateParam.release() );
+}
+
 QgsLocationBasedAlgorithm::Predicate QgsLocationBasedAlgorithm::reversePredicate( QgsLocationBasedAlgorithm::Predicate predicate ) const
 {
   switch ( predicate )
@@ -1572,11 +1584,7 @@ void QgsExtractByLocationAlgorithm::initAlgorithm( const QVariantMap & )
 {
   addParameter( new QgsProcessingParameterVectorLayer( QStringLiteral( "INPUT" ), QObject::tr( "Extract features from" ),
                 QList< int >() << QgsProcessing::TypeVectorAnyGeometry ) );
-
-  addParameter( new QgsProcessingParameterEnum( QStringLiteral( "PREDICATE" ),
-                QObject::tr( "Where the features are (geometric predicate)" ),
-                predicateOptionsList(), true, QVariant::fromValue( QList< int >() << 0 ) ) );
-
+  addPredicateParameter();
   addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INTERSECT" ),
                 QObject::tr( "By comparing to the features from" ),
                 QList< int >() << QgsProcessing::TypeVectorAnyGeometry ) );

src/core/processing/qgsnativealgorithms.h

@@ -504,6 +504,7 @@ class QgsLocationBasedAlgorithm : public QgsProcessingAlgorithm
       Crosses,
     };
 
+    void addPredicateParameter();
     Predicate reversePredicate( Predicate predicate ) const;
     QStringList predicateOptionsList() const;
     void process( QgsFeatureSource *targetSource, QgsFeatureSource *intersectSource, const QList<int> &selectedPredicates, const std::function< void( const QgsFeature & )> &handleFeatureFunction, bool onlyRequireTargetIds, QgsFeedback *feedback );