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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 dot kuhn at gmx 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:
43  QgsCachedFeatureIterator( QgsVectorLayerCache* vlCache, QgsFeatureRequest featureRequest, QgsFeatureIds featureIds );
44 
52 
58  virtual bool rewind();
59 
65  virtual bool close();
66 
67  // QgsAbstractFeatureIterator interface
68  protected:
77  virtual bool fetchFeature( QgsFeature& f );
78 
85  virtual bool nextFeatureFilterFids( QgsFeature& f ) { return fetchFeature( f ); }
86 
87  private:
90  QgsFeatureIds::ConstIterator mFeatureIdIterator;
91 };
92 
99 {
100  public:
108 
114  virtual bool rewind();
115 
121  virtual bool close();
122 
123  protected:
124 
133  virtual bool fetchFeature( QgsFeature& f );
134 
135  private:
139 };
140 #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:325
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:113
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)
We have a local special iterator for FilterFids, no need to run the generic.
QgsVectorLayerCache * mVectorLayerCache
Delivers features from the cache.
QgsFeatureIds::ConstIterator mFeatureIdIterator