QGIS API Documentation  3.17.0-Master (a035f434f4)
qgsvectorlayerfeaturecounter.h
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1 /***************************************************************************
2  qgsvectorlayerfeaturecounter.h
3  ---------------------
4  begin : May 2017
5  copyright : (C) 2017 by 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 #ifndef QGSVECTORLAYERFEATURECOUNTER_H
16 #define QGSVECTORLAYERFEATURECOUNTER_H
17 
19 #include "qgsrenderer.h"
20 #include "qgstaskmanager.h"
21 #include "qgsfeatureid.h"
22 
33 class CORE_EXPORT QgsVectorLayerFeatureCounter : public QgsTask
34 {
35  Q_OBJECT
36 
37  public:
38 
45  QgsVectorLayerFeatureCounter( QgsVectorLayer *layer, const QgsExpressionContext &context = QgsExpressionContext(), bool storeSymbolFids = false );
46 
47 
51  bool run() override;
52 
59  QHash<QString, long> symbolFeatureCountMap() const SIP_SKIP;
60 
65  long featureCount( const QString &legendKey ) const;
66 
75  QHash<QString, QgsFeatureIds> symbolFeatureIdMap() const SIP_SKIP;
76 
83  QgsFeatureIds featureIds( const QString &symbolkey ) const;
84 
85  signals:
86 
90  void symbolsCounted();
91 
92  private:
93  std::unique_ptr<QgsVectorLayerFeatureSource> mSource;
94  std::unique_ptr<QgsFeatureRenderer> mRenderer;
95  QgsExpressionContext mExpressionContext;
96  QHash<QString, long> mSymbolFeatureCountMap;
97  QHash<QString, QgsFeatureIds> mSymbolFeatureIdMap;
98  bool mWithFids = false;
99  int mFeatureCount;
100 
101 };
102 
103 #endif // QGSVECTORLAYERFEATURECOUNTER_H
QSet< QgsFeatureId > QgsFeatureIds
Definition: qgsfeatureid.h:37
Counts the features in a QgsVectorLayer in task.
#define SIP_SKIP
Definition: qgis_sip.h:126
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Abstract base class for long running background tasks.
virtual bool run()=0
Performs the task&#39;s operation.
Represents a vector layer which manages a vector based data sets.