QGIS API Documentation  2.99.0-Master (b058df7)
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 "qgis_core.h"
20 #include "qgsfeature.h"
21 #include "qgsfeatureiterator.h"
22 
24 
32 {
33  public:
34 
41  QgsCachedFeatureIterator( QgsVectorLayerCache *vlCache, const QgsFeatureRequest &featureRequest );
42 
48  virtual bool rewind() override;
49 
55  virtual bool close() override;
56 
57  // QgsAbstractFeatureIterator interface
58  protected:
59 
68  virtual bool fetchFeature( QgsFeature &f ) override;
69 
76  virtual bool nextFeatureFilterFids( QgsFeature &f ) override { return fetchFeature( f ); }
77 
78  private:
79  QgsFeatureIds mFeatureIds;
80  QgsVectorLayerCache *mVectorLayerCache = nullptr;
81  QgsFeatureIds::ConstIterator mFeatureIdIterator;
82  QgsCoordinateTransform mTransform;
83  QgsRectangle mFilterRect;
84 };
85 
93 {
94  public:
95 
102  QgsCachedFeatureWriterIterator( QgsVectorLayerCache *vlCache, const QgsFeatureRequest &featureRequest );
103 
109  virtual bool rewind() override;
110 
116  virtual bool close() override;
117 
118  protected:
119 
128  virtual bool fetchFeature( QgsFeature &f ) override;
129 
130  private:
131  QgsFeatureIterator mFeatIt;
132  QgsVectorLayerCache *mVectorLayerCache = nullptr;
133  QgsFeatureIds mFids;
134  QgsCoordinateTransform mTransform;
135  QgsRectangle mFilterRect;
136 };
137 #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
A rectangle specified with double values.
Definition: qgsrectangle.h:39
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:544
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:62
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.
Class for doing transforms between two map coordinate systems.
Delivers features from the cache.