QGIS API Documentation  3.4.3-Madeira (2f64a3c)
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 
32 class CORE_EXPORT QgsVectorLayerFeatureCounter : public QgsTask
33 {
34  Q_OBJECT
35 
36  public:
37 
42 
43  bool run() override;
44 
51  QHash<QString, long> symbolFeatureCountMap() const SIP_SKIP;
52 
57  long featureCount( const QString &legendKey ) const;
58 
59  signals:
60 
64  void symbolsCounted();
65 
66  private:
67  std::unique_ptr<QgsVectorLayerFeatureSource> mSource;
68  std::unique_ptr<QgsFeatureRenderer> mRenderer;
69  QgsExpressionContext mExpressionContext;
70  QHash<QString, long> mSymbolFeatureCountMap;
71  int mFeatureCount;
72 
73 };
74 
75 #endif // QGSVECTORLAYERFEATURECOUNTER_H
Counts the features in a QgsVectorLayer in task.
#define SIP_SKIP
Definition: qgis_sip.h:119
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.