QGIS API Documentation  2.99.0-Master (8ec3eaf)
qgscachedfeatureiterator.h
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1 /***************************************************************************
2  qgscachedfeatureiterator.h
3  --------------------------------------
4  Date : 12.2.2013
5  Copyright : (C) 2013 Matthias Kuhn
6  Email : matthias at opengis dot ch
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
16 #ifndef QGSCACHEDFEATUREITERATOR_H
17 #define QGSCACHEDFEATUREITERATOR_H
18 
19 #include "qgsfeature.h"
20 #include "qgsfeatureiterator.h"
21 
23 
30 {
31  public:
32 
39  QgsCachedFeatureIterator( QgsVectorLayerCache* vlCache, const QgsFeatureRequest& featureRequest );
40 
46  virtual bool rewind() override;
47 
53  virtual bool close() override;
54 
55  // QgsAbstractFeatureIterator interface
56  protected:
57 
66  virtual bool fetchFeature( QgsFeature& f ) override;
67 
74  virtual bool nextFeatureFilterFids( QgsFeature& f ) override { return fetchFeature( f ); }
75 
76  private:
77  QgsFeatureIds mFeatureIds;
78  QgsVectorLayerCache* mVectorLayerCache;
79  QgsFeatureIds::ConstIterator mFeatureIdIterator;
80 };
81 
88 {
89  public:
90 
97  QgsCachedFeatureWriterIterator( QgsVectorLayerCache* vlCache, const QgsFeatureRequest& featureRequest );
98 
104  virtual bool rewind() override;
105 
111  virtual bool close() override;
112 
113  protected:
114 
123  virtual bool fetchFeature( QgsFeature& f ) override;
124 
125  private:
126  QgsFeatureIterator mFeatIt;
127  QgsVectorLayerCache* mVectorLayerCache;
128  QgsFeatureIds mFids;
129 };
130 #endif // QGSCACHEDFEATUREITERATOR_H
Wrapper for iterator of features from vector data provider or vector layer.
virtual bool close()=0
end of iterating: free the resources / lock
virtual bool fetchFeature(QgsFeature &f)=0
If you write a feature iterator for your provider, this is the method you need to implement!! ...
QSet< QgsFeatureId > QgsFeatureIds
Definition: qgsfeature.h:355
virtual bool rewind()=0
reset the iterator to the starting position
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:135
Uses another iterator as backend and writes features to the cache.
Internal feature iterator to be implemented within data providers.
This class wraps a request for features to a vector layer (or directly its vector data provider)...
This class caches features of a given QgsVectorLayer.
virtual bool nextFeatureFilterFids(QgsFeature &f) override
We have a local special iterator for FilterFids, no need to run the generic.
Delivers features from the cache.