QGIS API Documentation 3.39.0-Master (be2050b798e)
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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 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"
23#include "qgsvectorlayercache.h"
24#include <QPointer>
25
27
35{
36 public:
37
44 QgsCachedFeatureIterator( QgsVectorLayerCache *vlCache, const QgsFeatureRequest &featureRequest );
45
47
53 bool rewind() override;
54
60 bool close() override;
61
62 // QgsAbstractFeatureIterator interface
63 protected:
64
73 bool fetchFeature( QgsFeature &f ) override;
74
81 bool nextFeatureFilterFids( QgsFeature &f ) override { return fetchFeature( f ); }
82
83 private:
84#ifdef SIP_RUN
86#endif
87
88 QList< QgsFeatureId > mFeatureIds;
89 QPointer< QgsVectorLayerCache > mVectorLayerCache = nullptr;
90 QList< QgsFeatureId >::ConstIterator mFeatureIdIterator;
91 QgsCoordinateTransform mTransform;
92 QgsRectangle mFilterRect;
93
94 QgsGeometry mDistanceWithinGeom;
95 std::unique_ptr< QgsGeometryEngine > mDistanceWithinEngine;
96 double mDistanceWithin = 0;
97};
98
106{
107 public:
108
116
122 bool rewind() override;
123
129 bool close() override;
130
131 protected:
132
141 bool fetchFeature( QgsFeature &f ) override;
142
143 private:
144 QgsFeatureIterator mFeatIt;
145 QPointer< QgsVectorLayerCache > mVectorLayerCache;
146 QgsFeatureIds mFids;
147 QgsCoordinateTransform mTransform;
148 QgsRectangle mFilterRect;
149
150};
151#endif // QGSCACHEDFEATUREITERATOR_H
Internal feature iterator to be implemented within data providers.
virtual bool rewind()=0
Resets the iterator to the starting position.
virtual bool fetchFeature(QgsFeature &f)=0
If you write a feature iterator for your provider, this is the method you need to implement!...
virtual bool close()=0
Call to end the iteration.
Delivers features from the cache.
~QgsCachedFeatureIterator() override
bool nextFeatureFilterFids(QgsFeature &f) override
We have a local special iterator for FilterFids, no need to run the generic.
Uses another iterator as backend and writes features to the cache.
Class for doing transforms between two map coordinate systems.
Wrapper for iterator of features from vector data provider or vector layer.
This class wraps a request for features to a vector layer (or directly its vector data provider).
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition qgsfeature.h:58
A geometry is the spatial representation of a feature.
A rectangle specified with double values.
This class caches features of a given QgsVectorLayer.
QSet< QgsFeatureId > QgsFeatureIds