src/core/qgsvectorlayerfeatureiterator.h

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/***************************************************************************
    qgsvectorlayerfeatureiterator.h
    ---------------------
    begin                : Dezember 2012
    copyright            : (C) 2012 by Martin Dobias
    email                : wonder dot sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
#ifndef QGSVECTORLAYERFEATUREITERATOR_H
#define QGSVECTORLAYERFEATUREITERATOR_H

#include "qgsfeatureiterator.h"

#include <QSet>

typedef QMap<QgsFeatureId, QgsFeature> QgsFeatureMap;

class QgsVectorLayer;
struct QgsVectorJoinInfo;

class CORE_EXPORT QgsVectorLayerFeatureIterator : public QgsAbstractFeatureIterator
{
  public:
    QgsVectorLayerFeatureIterator( QgsVectorLayer* layer, const QgsFeatureRequest& request );

    ~QgsVectorLayerFeatureIterator();

    virtual bool nextFeature( QgsFeature& feature );

    virtual bool rewind();

    virtual bool close();

  protected:
    QgsVectorLayer* L;

    QgsFeatureRequest mProviderRequest;
    QgsFeatureIterator mProviderIterator;

    // general stuff
    //bool mFetching;
    //QgsRectangle mFetchRect;
    //QgsAttributeList mFetchAttributes;
    //QgsAttributeList mFetchProvAttributes;
    //bool mFetchGeometry;

    // only related to editing
    QSet<QgsFeatureId> mFetchConsidered;
    QgsGeometryMap::iterator mFetchChangedGeomIt;
    QgsFeatureMap::iterator mFetchAddedFeaturesIt;

    bool mFetchedFid; // when iterating by FID: indicator whether it has been fetched yet or not

    void rewindEditBuffer();
    void prepareJoins();
    bool fetchNextAddedFeature( QgsFeature& f );
    bool fetchNextChangedGeomFeature( QgsFeature& f );
    void useAddedFeature( const QgsFeature& src, QgsFeature& f );
    void useChangedAttributeFeature( QgsFeatureId fid, const QgsGeometry& geom, QgsFeature& f );
    bool nextFeatureFid( QgsFeature& f );
    void addJoinedAttributes( QgsFeature &f );

    struct FetchJoinInfo
    {
      const QgsVectorJoinInfo* joinInfo;
      QgsAttributeList attributes;      
      int indexOffset;                  
      QgsVectorLayer* joinLayer;        
      int targetField;                  
      int joinField;                    

      void addJoinedAttributesCached( QgsFeature& f, const QVariant& joinValue ) const;
      void addJoinedAttributesDirect( QgsFeature& f, const QVariant& joinValue ) const;
    };


    QMap<QgsVectorLayer*, FetchJoinInfo> mFetchJoinInfo;

};

#endif // QGSVECTORLAYERFEATUREITERATOR_H