QGIS API Documentation  3.14.0-Pi (9f7028fd23)
qgsalgorithmgeometrybyexpression.h
Go to the documentation of this file.
1 /***************************************************************************
2  qgsalgorithmgeometrybyexpression.h
3  ----------------------
4  begin : November 2019
5  copyright : (C) 2019 by Alexander Bruy
6  email : alexander dot bruy at gmail dot com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #ifndef QGSALGORITHMGEOMETRYBYEXPRESSION_H
19 #define QGSALGORITHMGEOMETRYBYEXPRESSION_H
20 
21 #define SIP_NO_FILE
22 
23 #include "qgis_sip.h"
24 #include "qgsprocessingalgorithm.h"
25 #include "qgsapplication.h"
26 
28 
32 class QgsGeometryByExpressionAlgorithm : public QgsProcessingFeatureBasedAlgorithm
33 {
34 
35  public:
36 
37  QgsGeometryByExpressionAlgorithm() = default;
38  QIcon icon() const override { return QgsApplication::getThemeIcon( QStringLiteral( "/algorithms/mAlgorithmCentroids.svg" ) ); }
39  QString svgIconPath() const override { return QgsApplication::iconPath( QStringLiteral( "/algorithms/mAlgorithmCentroids.svg" ) ); }
40  QString name() const override;
41  QString displayName() const override;
42  QStringList tags() const override;
43  QString group() const override;
44  QString groupId() const override;
45  QString shortHelpString() const override;
46  QList<int> inputLayerTypes() const override;
47  QgsGeometryByExpressionAlgorithm *createInstance() const override SIP_FACTORY;
48  void initParameters( const QVariantMap &configuration = QVariantMap() ) override;
49 
50  protected:
51 
52  QString outputName() const override;
55  bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
56  QgsFeatureList processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
57 
58  private:
59 
60  QgsWkbTypes::Type mWkbType;
61  QgsExpression mExpression;
62  QgsExpressionContext mExpressionContext;
63 };
64 
66 
67 #endif // QGSALGORITHMGEOMETRYBYEXPRESSION_H
QgsExpressionContext
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Definition: qgsexpressioncontext.h:369
QgsApplication::getThemeIcon
static QIcon getThemeIcon(const QString &name)
Helper to get a theme icon.
Definition: qgsapplication.cpp:605
QgsProcessingAlgorithm::displayName
virtual QString displayName() const =0
Returns the translated algorithm name, which should be used for any user-visible display of the algor...
QgsProcessingFeedback
Definition: qgsprocessingfeedback.h:37
QgsProcessingFeatureBasedAlgorithm::outputWkbType
virtual QgsWkbTypes::Type outputWkbType(QgsWkbTypes::Type inputWkbType) const
Maps the input WKB geometry type (inputWkbType) to the corresponding output WKB type generated by the...
Definition: qgsprocessingalgorithm.cpp:920
QgsProcessingFeatureBasedAlgorithm::initParameters
virtual void initParameters(const QVariantMap &configuration=QVariantMap())
Initializes any extra parameters added by the algorithm subclass.
Definition: qgsprocessingalgorithm.cpp:935
QgsProcessingAlgorithm::groupId
virtual QString groupId() const
Returns the unique ID of the group this algorithm belongs to.
Definition: qgsprocessingalgorithm.h:231
QgsProcessingAlgorithm::createInstance
virtual QgsProcessingAlgorithm * createInstance() const =0
Creates a new instance of the algorithm class.
QgsProcessingAlgorithm::svgIconPath
virtual QString svgIconPath() const
Returns a path to an SVG version of the algorithm's icon.
Definition: qgsprocessingalgorithm.cpp:83
QgsWkbTypes::Type
Type
The WKB type describes the number of dimensions a geometry has.
Definition: qgswkbtypes.h:68
QgsProcessingAlgorithm::prepareAlgorithm
virtual bool prepareAlgorithm(const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback) SIP_THROW(QgsProcessingException)
Prepares the algorithm to run using the specified parameters.
Definition: qgsprocessingalgorithm.cpp:359
QgsApplication::iconPath
static QString iconPath(const QString &iconFile)
Returns path to the desired icon file.
Definition: qgsapplication.cpp:594
QgsProcessingFeatureBasedAlgorithm
Definition: qgsprocessingalgorithm.h:1042
QgsProcessingFeatureBasedAlgorithm::sourceFlags
virtual QgsProcessingFeatureSource::Flag sourceFlags() const
Returns the processing feature source flags to be used in the algorithm.
Definition: qgsprocessingalgorithm.cpp:910
SIP_FACTORY
#define SIP_FACTORY
Definition: qgis_sip.h:76
qgsapplication.h
QgsProcessingAlgorithm::name
virtual QString name() const =0
Returns the algorithm name, used for identifying the algorithm.
QgsProcessingFeatureBasedAlgorithm::processFeature
virtual QgsFeatureList processFeature(const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback) SIP_THROW(QgsProcessingException)=0
Processes an individual input feature from the source.
QgsProcessingContext
Definition: qgsprocessingcontext.h:43
qgsprocessingalgorithm.h
qgis_sip.h
QgsFeatureList
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:572
QgsProcessingAlgorithm::shortHelpString
virtual QString shortHelpString() const
Returns a localised short helper string for the algorithm.
Definition: qgsprocessingalgorithm.cpp:63
QgsProcessingFeatureBasedAlgorithm::outputName
virtual QString outputName() const =0
Returns the translated, user visible name for any layers created by this algorithm.
QgsProcessingFeatureSource::Flag
Flag
Flags controlling how QgsProcessingFeatureSource fetches features.
Definition: qgsprocessingutils.h:473
QgsProcessingAlgorithm::icon
virtual QIcon icon() const
Returns an icon for the algorithm.
Definition: qgsprocessingalgorithm.cpp:78
QgsProcessingAlgorithm::group
virtual QString group() const
Returns the name of the group this algorithm belongs to.
Definition: qgsprocessingalgorithm.h:222
QgsFeature
Definition: qgsfeature.h:55
QgsExpression
Definition: qgsexpression.h:113
QgsProcessingFeatureBasedAlgorithm::inputLayerTypes
virtual QList< int > inputLayerTypes() const
Returns the valid input layer types for the source layer for this algorithm.
Definition: qgsprocessingalgorithm.cpp:900
QgsProcessingAlgorithm::tags
virtual QStringList tags() const
Returns a list of tags which relate to the algorithm, and are used to assist users in searching for s...
Definition: qgsprocessingalgorithm.h:178