1 /*************************************************************************** 2 qgsfeaturefilterprovider.h 3 -------------------------- 4 begin : 22-05-2015 5 copyright : (C) 2008 by Stéphane Brunner 6 email : stephane dot brunner at camptocamp dot com 7 ***************************************************************************/ 8 9 /*************************************************************************** 10 * * 11 * This program is free software; you can redistribute it and/or modify * 12 * it under the terms of the GNU General Public License as published by * 13 * the Free Software Foundation; either version 2 of the License, or * 14 * (at your option) any later version. * 15 * * 16 ***************************************************************************/ 17 18 #ifndef QGSFEATUREFILTERPROVIDER_H 19 #define QGSFEATUREFILTERPROVIDER_H 20 21 #include <QtGlobal> 22 #include <QStringList> 23 #include "qgis_sip.h" 24 25 #include "qgis_core.h" 26 #include "qgsfeaturerequest.h" 27 28 class QString; 29 class QgsVectorLayer; 30 31 32 /** 33 * \ingroup core 34 * \class QgsFeatureFilterProvider 35 * \brief Abstract interface for use by classes that filter the features or attributes of a layer. 36 * 37 * A QgsFeatureFilterProvider provides a method for modifying a QgsFeatureRequest in place to apply 38 * additional filters to the request, since QGIS 3.18 a method to filter allowed attributes is also available. 39 * 40 * \since QGIS 2.14 41 */ 42 43 class CORE_EXPORT QgsFeatureFilterProvider 44 { 45 public: 46 47 #ifndef SIP_RUN 48 49 //! Constructor 50 QgsFeatureFilterProvider() = default; 51 52 virtual ~QgsFeatureFilterProvider() = default; 53 54 #endif 55 56 /** 57 * Add additional filters to the feature request to further restrict the features returned by the request. 58 * Derived classes must implement this method. 59 * \param layer the layer to filter 60 * \param featureRequest the feature request to update 61 */ 62 virtual void filterFeatures( const QgsVectorLayer *layer, QgsFeatureRequest &featureRequest ) const = 0; 63 64 /** 65 * Returns the list of visible attribute names from a list of \a attributes names for the given \a layer 66 * \since QGIS 3.18 67 */ 68 virtual QStringList layerAttributes( const QgsVectorLayer *layer, const QStringList &attributes ) const = 0; 69 70 /** 71 * Create a clone of the feature filter provider 72 * \returns a new clone 73 */ 74 virtual QgsFeatureFilterProvider *clone() const = 0 SIP_FACTORY; 75 }; 76 77 #endif 78