QGIS API Documentation  3.2.0-Bonn (bc43194)
qgsalgorithmmultiparttosinglepart.cpp
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1 /***************************************************************************
2  qgsalgorithmmultiparttosinglepart.cpp
3  ---------------------
4  begin : April 2017
5  copyright : (C) 2017 by Nyall Dawson
6  email : nyall dot dawson 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 
19 
21 
22 QString QgsMultipartToSinglepartAlgorithm::name() const
23 {
24  return QStringLiteral( "multiparttosingleparts" );
25 }
26 
27 QString QgsMultipartToSinglepartAlgorithm::displayName() const
28 {
29  return QObject::tr( "Multipart to singleparts" );
30 }
31 
32 QString QgsMultipartToSinglepartAlgorithm::outputName() const
33 {
34  return QObject::tr( "Single parts" );
35 }
36 
37 QgsWkbTypes::Type QgsMultipartToSinglepartAlgorithm::outputWkbType( QgsWkbTypes::Type inputWkbType ) const
38 {
39  return QgsWkbTypes::singleType( inputWkbType );
40 }
41 
42 QStringList QgsMultipartToSinglepartAlgorithm::tags() const
43 {
44  return QObject::tr( "multi,single,multiple,split,dump" ).split( ',' );
45 }
46 
47 QString QgsMultipartToSinglepartAlgorithm::group() const
48 {
49  return QObject::tr( "Vector geometry" );
50 }
51 
52 QString QgsMultipartToSinglepartAlgorithm::groupId() const
53 {
54  return QStringLiteral( "vectorgeometry" );
55 }
56 
57 QString QgsMultipartToSinglepartAlgorithm::shortHelpString() const
58 {
59  return QObject::tr( "This algorithm takes a vector layer with multipart geometries and generates a new one in which all geometries contain "
60  "a single part. Features with multipart geometries are divided in as many different features as parts the geometry "
61  "contain, and the same attributes are used for each of them." );
62 }
63 
64 QgsMultipartToSinglepartAlgorithm *QgsMultipartToSinglepartAlgorithm::createInstance() const
65 {
66  return new QgsMultipartToSinglepartAlgorithm();
67 }
68 
69 QgsProcessingFeatureSource::Flag QgsMultipartToSinglepartAlgorithm::sourceFlags() const
70 {
71  // skip geometry checks - this algorithm can be used to repair geometries
73 }
74 
75 QgsFeatureList QgsMultipartToSinglepartAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &, QgsProcessingFeedback * )
76 {
77  if ( !feature.hasGeometry() )
78  return QgsFeatureList() << feature;
79 
80  QgsGeometry inputGeometry = feature.geometry();
81  QgsFeatureList outputs;
82  if ( inputGeometry.isMultipart() )
83  {
84  const QVector<QgsGeometry> parts = inputGeometry.asGeometryCollection();
85  for ( const QgsGeometry &g : parts )
86  {
87  QgsFeature out;
88  out.setAttributes( feature.attributes() );
89  out.setGeometry( g );
90  outputs.append( out );
91  }
92  }
93  else
94  {
95  outputs.append( feature );
96  }
97  return outputs;
98 }
99 
100 
102 
103 
static Type singleType(Type type)
Returns the single type for a WKB type.
Definition: qgswkbtypes.h:152
Base class for providing feedback from a processing algorithm.
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
bool isMultipart() const
Returns true if WKB of the geometry is of WKBMulti* type.
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:549
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:104
void setAttributes(const QgsAttributes &attrs)
Sets the feature&#39;s attributes.
Definition: qgsfeature.cpp:127
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:62
bool hasGeometry() const
Returns true if the feature has an associated geometry.
Definition: qgsfeature.cpp:190
QVector< QgsGeometry > asGeometryCollection() const
Returns contents of the geometry as a list of geometries.
Type
The WKB type describes the number of dimensions a geometry has.
Definition: qgswkbtypes.h:67
QgsGeometry geometry() const
Returns the geometry associated with this feature.
Definition: qgsfeature.cpp:101
Flag
Flags controlling how QgsProcessingFeatureSource fetches features.
void setGeometry(const QgsGeometry &geometry)
Set the feature&#39;s geometry.
Definition: qgsfeature.cpp:137
Contains information about the context in which a processing algorithm is executed.
QgsAttributes attributes
Definition: qgsfeature.h:72