1 /***************************************************************************
2 qgsalgorithmboundary.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
18 #include "qgsalgorithmboundary.h"
19 #include "qgsvectorlayer.h"
20
21 ///@cond PRIVATE
22
name() const23 QString QgsBoundaryAlgorithm::name() const
24 {
25 return QStringLiteral( "boundary" );
26 }
27
displayName() const28 QString QgsBoundaryAlgorithm::displayName() const
29 {
30 return QObject::tr( "Boundary" );
31 }
32
tags() const33 QStringList QgsBoundaryAlgorithm::tags() const
34 {
35 return QObject::tr( "boundary,ring,border,exterior" ).split( ',' );
36 }
37
group() const38 QString QgsBoundaryAlgorithm::group() const
39 {
40 return QObject::tr( "Vector geometry" );
41 }
42
groupId() const43 QString QgsBoundaryAlgorithm::groupId() const
44 {
45 return QStringLiteral( "vectorgeometry" );
46 }
47
outputName() const48 QString QgsBoundaryAlgorithm::outputName() const
49 {
50 return QObject::tr( "Boundary" );
51 }
52
shortHelpString() const53 QString QgsBoundaryAlgorithm::shortHelpString() const
54 {
55 return QObject::tr( "Returns the closure of the combinatorial boundary of the input geometries (ie the "
56 "topological boundary of the geometry). For instance, a polygon geometry will have a "
57 "boundary consisting of the linestrings for each ring in the polygon. Only valid for "
58 "polygon or line layers." );
59 }
60
inputLayerTypes() const61 QList<int> QgsBoundaryAlgorithm::inputLayerTypes() const
62 {
63 return QList<int>() << QgsProcessing::TypeVectorLine << QgsProcessing::TypeVectorPolygon;
64 }
65
supportInPlaceEdit(const QgsMapLayer *) const66 bool QgsBoundaryAlgorithm::supportInPlaceEdit( const QgsMapLayer * ) const
67 {
68 return false;
69 }
70
createInstance() const71 QgsBoundaryAlgorithm *QgsBoundaryAlgorithm::createInstance() const
72 {
73 return new QgsBoundaryAlgorithm();
74 }
75
sourceFlags() const76 QgsProcessingFeatureSource::Flag QgsBoundaryAlgorithm::sourceFlags() const
77 {
78 return QgsProcessingFeatureSource::FlagSkipGeometryValidityChecks;
79 }
80
outputWkbType(QgsWkbTypes::Type inputWkbType) const81 QgsWkbTypes::Type QgsBoundaryAlgorithm::outputWkbType( QgsWkbTypes::Type inputWkbType ) const
82 {
83 QgsWkbTypes::Type outputWkb = QgsWkbTypes::Unknown;
84 switch ( QgsWkbTypes::geometryType( inputWkbType ) )
85 {
86 case QgsWkbTypes::LineGeometry:
87 outputWkb = QgsWkbTypes::MultiPoint;
88 break;
89
90 case QgsWkbTypes::PolygonGeometry:
91 outputWkb = QgsWkbTypes::MultiLineString;
92 break;
93
94 case QgsWkbTypes::PointGeometry:
95 case QgsWkbTypes::UnknownGeometry:
96 case QgsWkbTypes::NullGeometry:
97 outputWkb = QgsWkbTypes::NoGeometry;
98 break;
99 }
100
101 if ( QgsWkbTypes::hasZ( inputWkbType ) )
102 outputWkb = QgsWkbTypes::addZ( outputWkb );
103 if ( QgsWkbTypes::hasM( inputWkbType ) )
104 outputWkb = QgsWkbTypes::addM( outputWkb );
105
106 return outputWkb;
107 }
108
processFeature(const QgsFeature & feature,QgsProcessingContext &,QgsProcessingFeedback * feedback)109 QgsFeatureList QgsBoundaryAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &, QgsProcessingFeedback *feedback )
110 {
111 QgsFeature outFeature = feature;
112
113 if ( feature.hasGeometry() )
114 {
115 const QgsGeometry inputGeometry = feature.geometry();
116 const QgsGeometry outputGeometry = QgsGeometry( inputGeometry.constGet()->boundary() );
117 if ( outputGeometry.isNull() )
118 {
119 feedback->reportError( QObject::tr( "No boundary for feature %1 (possibly a closed linestring?)'" ).arg( feature.id() ) );
120 outFeature.clearGeometry();
121 }
122 else
123 {
124 outFeature.setGeometry( outputGeometry );
125 }
126 }
127 return QgsFeatureList() << outFeature;
128 }
129
130 ///@endcond
131