QGIS API Documentation 3.39.0-Master (67e056379ed)
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qgsalgorithmboundary.cpp
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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
19#include "qgsvectorlayer.h"
20
22
23QString QgsBoundaryAlgorithm::name() const
24{
25 return QStringLiteral( "boundary" );
26}
27
28QString QgsBoundaryAlgorithm::displayName() const
29{
30 return QObject::tr( "Boundary" );
31}
32
33QStringList QgsBoundaryAlgorithm::tags() const
34{
35 return QObject::tr( "boundary,ring,border,exterior" ).split( ',' );
36}
37
38QString QgsBoundaryAlgorithm::group() const
39{
40 return QObject::tr( "Vector geometry" );
41}
42
43QString QgsBoundaryAlgorithm::groupId() const
44{
45 return QStringLiteral( "vectorgeometry" );
46}
47
48QString QgsBoundaryAlgorithm::outputName() const
49{
50 return QObject::tr( "Boundary" );
51}
52
53QString 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
61QList<int> QgsBoundaryAlgorithm::inputLayerTypes() const
62{
63 return QList<int>() << static_cast< int >( Qgis::ProcessingSourceType::VectorLine ) << static_cast< int >( Qgis::ProcessingSourceType::VectorPolygon );
64}
65
66bool QgsBoundaryAlgorithm::supportInPlaceEdit( const QgsMapLayer * ) const
67{
68 return false;
69}
70
71QgsBoundaryAlgorithm *QgsBoundaryAlgorithm::createInstance() const
72{
73 return new QgsBoundaryAlgorithm();
74}
75
76Qgis::ProcessingFeatureSourceFlags QgsBoundaryAlgorithm::sourceFlags() const
77{
79}
80
81Qgis::WkbType QgsBoundaryAlgorithm::outputWkbType( Qgis::WkbType inputWkbType ) const
82{
84 switch ( QgsWkbTypes::geometryType( inputWkbType ) )
85 {
87 outputWkb = Qgis::WkbType::MultiPoint;
88 break;
89
92 break;
93
97 outputWkb = Qgis::WkbType::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
109QgsFeatureList 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
@ VectorPolygon
Vector polygon layers.
@ VectorLine
Vector line layers.
@ Polygon
Polygons.
@ Unknown
Unknown types.
@ Null
No geometry.
@ SkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
WkbType
The WKB type describes the number of dimensions a geometry has.
Definition qgis.h:201
@ MultiPoint
MultiPoint.
@ NoGeometry
No geometry.
@ MultiLineString
MultiLineString.
@ Unknown
Unknown.
QFlags< ProcessingFeatureSourceFlag > ProcessingFeatureSourceFlags
Flags which control how QgsProcessingFeatureSource fetches features.
Definition qgis.h:3153
virtual QgsAbstractGeometry * boundary() const =0
Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the...
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition qgsfeature.h:58
QgsFeatureId id
Definition qgsfeature.h:66
QgsGeometry geometry
Definition qgsfeature.h:69
void clearGeometry()
Removes any geometry associated with the feature.
bool hasGeometry() const
Returns true if the feature has an associated geometry.
void setGeometry(const QgsGeometry &geometry)
Set the feature's geometry.
A geometry is the spatial representation of a feature.
const QgsAbstractGeometry * constGet() const
Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
Base class for all map layer types.
Definition qgsmaplayer.h:75
Contains information about the context in which a processing algorithm is executed.
Base class for providing feedback from a processing algorithm.
virtual void reportError(const QString &error, bool fatalError=false)
Reports that the algorithm encountered an error while executing.
static Qgis::GeometryType geometryType(Qgis::WkbType type)
Returns the geometry type for a WKB type, e.g., both MultiPolygon and CurvePolygon would have a Polyg...
static Qgis::WkbType addM(Qgis::WkbType type)
Adds the m dimension to a WKB type and returns the new type.
static Qgis::WkbType addZ(Qgis::WkbType type)
Adds the z dimension to a WKB type and returns the new type.
static bool hasZ(Qgis::WkbType type)
Tests whether a WKB type contains the z-dimension.
static bool hasM(Qgis::WkbType type)
Tests whether a WKB type contains m values.
QList< QgsFeature > QgsFeatureList