QGIS API Documentation  3.16.0-Hannover (43b64b13f3)
qgsalgorithmsumlinelength.h
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1 /***************************************************************************
2  qgsalgorithmsumlinelength.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 QGSALGORITHMSUMLINELENGTH_H
19 #define QGSALGORITHMSUMLINELENGTH_H
20 
21 #define SIP_NO_FILE
22 
23 #include "qgis.h"
24 #include "qgsprocessingalgorithm.h"
25 
27 
31 class QgsSumLineLengthAlgorithm : public QgsProcessingFeatureBasedAlgorithm
32 {
33 
34  public:
35 
36  QgsSumLineLengthAlgorithm() = default;
37  QString name() const override;
38  QString displayName() const override;
39  QStringList tags() const override;
40  QString svgIconPath() const override;
41  QIcon icon() const override;
42  QString group() const override;
43  QString groupId() const override;
44  QString shortHelpString() const override;
45  QgsSumLineLengthAlgorithm *createInstance() const override SIP_FACTORY;
46  void initParameters( const QVariantMap &configuration = QVariantMap() ) override;
47  QList<int> inputLayerTypes() const override;
50 
51 
52  protected:
53  QString inputParameterName() const override;
54  QString inputParameterDescription() const override;
55  QString outputName() const override;
56  bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
57  QgsFeatureList processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
58  QgsFields outputFields( const QgsFields &inputFields ) const override;
59 
60  private:
61 
62  QString mLengthFieldName;
63  QString mCountFieldName;
64  mutable int mLengthFieldIndex = -1;
65  mutable int mCountFieldIndex = -1;
66  mutable QgsFields mFields;
67  mutable QgsCoordinateReferenceSystem mCrs;
68  mutable QgsDistanceArea mDa;
69  QgsCoordinateTransformContext mTransformContext;
70  std::unique_ptr< QgsProcessingFeatureSource > mLinesSource;
71 };
72 
74 
75 #endif // QGSALGORITHMSUMLINELENGTH_H
QgsCoordinateTransformContext
Contains information about the context in which a coordinate transform is executed.
Definition: qgscoordinatetransformcontext.h:58
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
Base class for providing feedback from a processing algorithm.
Definition: qgsprocessingfeedback.h:38
QgsFields
Container of fields for a vector layer.
Definition: qgsfields.h:45
QgsProcessingFeatureBasedAlgorithm::inputParameterDescription
virtual QString inputParameterDescription() const
Returns the translated description of the parameter corresponding to the input layer.
Definition: qgsprocessingalgorithm.cpp:922
QgsProcessingFeatureBasedAlgorithm::initParameters
virtual void initParameters(const QVariantMap &configuration=QVariantMap())
Initializes any extra parameters added by the algorithm subclass.
Definition: qgsprocessingalgorithm.cpp:962
qgis.h
QgsProcessingAlgorithm::groupId
virtual QString groupId() const
Returns the unique ID of the group this algorithm belongs to.
Definition: qgsprocessingalgorithm.h:233
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
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:373
QgsProcessingFeatureBasedAlgorithm
An abstract QgsProcessingAlgorithm base class for processing algorithms which operate "feature-by-fea...
Definition: qgsprocessingalgorithm.h:1073
SIP_FACTORY
#define SIP_FACTORY
Definition: qgis_sip.h:76
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
Contains information about the context in which a processing algorithm is executed.
Definition: qgsprocessingcontext.h:44
qgsprocessingalgorithm.h
QgsProcessingFeatureBasedAlgorithm::outputCrs
virtual QgsCoordinateReferenceSystem outputCrs(const QgsCoordinateReferenceSystem &inputCrs) const
Maps the input source coordinate reference system (inputCrs) to a corresponding output CRS generated ...
Definition: qgsprocessingalgorithm.cpp:957
QgsFeatureList
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:583
QgsProcessingAlgorithm::shortHelpString
virtual QString shortHelpString() const
Returns a localised short helper string for the algorithm.
Definition: qgsprocessingalgorithm.cpp:63
QgsCoordinateReferenceSystem
This class represents a coordinate reference system (CRS).
Definition: qgscoordinatereferencesystem.h:206
QgsProcessingFeatureBasedAlgorithm::outputLayerType
virtual QgsProcessing::SourceType outputLayerType() const
Returns the layer type for layers generated by this algorithm, if this is possible to determine in ad...
Definition: qgsprocessingalgorithm.cpp:932
QgsProcessingFeatureBasedAlgorithm::outputName
virtual QString outputName() const =0
Returns the translated, user visible name for any layers created by this algorithm.
QgsProcessingFeatureBasedAlgorithm::outputFields
virtual QgsFields outputFields(const QgsFields &inputFields) const
Maps the input source fields (inputFields) to corresponding output fields generated by the algorithm.
Definition: qgsprocessingalgorithm.cpp:952
QgsProcessingAlgorithm::icon
virtual QIcon icon() const
Returns an icon for the algorithm.
Definition: qgsprocessingalgorithm.cpp:78
QgsProcessingFeatureBasedAlgorithm::inputParameterName
virtual QString inputParameterName() const
Returns the name of the parameter corresponding to the input layer.
Definition: qgsprocessingalgorithm.cpp:917
QgsDistanceArea
A general purpose distance and area calculator, capable of performing ellipsoid based calculations.
Definition: qgsdistancearea.h:50
QgsProcessingAlgorithm::group
virtual QString group() const
Returns the name of the group this algorithm belongs to.
Definition: qgsprocessingalgorithm.h:224
QgsFeature
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:56
QgsProcessing::SourceType
SourceType
Data source types enum.
Definition: qgsprocessing.h:45
QgsProcessingFeatureBasedAlgorithm::inputLayerTypes
virtual QList< int > inputLayerTypes() const
Returns the valid input layer types for the source layer for this algorithm.
Definition: qgsprocessingalgorithm.cpp:927
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:180