QGIS API Documentation 3.34.0-Prizren (ffbdd678812)
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qgsalgorithmsetmvalue.cpp
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1/***************************************************************************
2 qgsalgorithmsetmvalue.cpp
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
19#include "qgsvectorlayer.h"
20
22
23QString QgsSetMValueAlgorithm::name() const
24{
25 return QStringLiteral( "setmvalue" );
26}
27
28QString QgsSetMValueAlgorithm::displayName() const
29{
30 return QObject::tr( "Set M value" );
31}
32
33QStringList QgsSetMValueAlgorithm::tags() const
34{
35 return QObject::tr( "set,add,m,measure,values" ).split( ',' );
36}
37
38QString QgsSetMValueAlgorithm::group() const
39{
40 return QObject::tr( "Vector geometry" );
41}
42
43QString QgsSetMValueAlgorithm::groupId() const
44{
45 return QStringLiteral( "vectorgeometry" );
46}
47
48QString QgsSetMValueAlgorithm::shortHelpString() const
49{
50 return QObject::tr( "This algorithm sets the M value for geometries in a layer.\n\n"
51 "If M values already exist in the layer, they will be overwritten "
52 "with the new value. If no M values exist, the geometry will be "
53 "upgraded to include M values and the specified value used as "
54 "the initial M value for all geometries." );
55}
56
57QString QgsSetMValueAlgorithm::outputName() const
58{
59 return QObject::tr( "M Added" );
60}
61
62QgsSetMValueAlgorithm *QgsSetMValueAlgorithm::createInstance() const
63{
64 return new QgsSetMValueAlgorithm();
65}
66
67bool QgsSetMValueAlgorithm::supportInPlaceEdit( const QgsMapLayer *l ) const
68{
69 const QgsVectorLayer *layer = qobject_cast< const QgsVectorLayer * >( l );
70 if ( !layer )
71 return false;
72
74}
75
76QgsProcessingFeatureSource::Flag QgsSetMValueAlgorithm::sourceFlags() const
77{
79}
80
81Qgis::WkbType QgsSetMValueAlgorithm::outputWkbType( Qgis::WkbType type ) const
82{
83 return QgsWkbTypes::addM( type );
84}
85
86void QgsSetMValueAlgorithm::initParameters( const QVariantMap & )
87{
88 auto mValueParam = std::make_unique < QgsProcessingParameterNumber >( QStringLiteral( "M_VALUE" ), QObject::tr( "M Value" ), QgsProcessingParameterNumber::Double, 0.0 );
89 mValueParam->setIsDynamic( true );
90 mValueParam->setDynamicPropertyDefinition( QgsPropertyDefinition( QStringLiteral( "M_VALUE" ), QObject::tr( "M Value" ), QgsPropertyDefinition::Double ) );
91 mValueParam->setDynamicLayerParameterName( QStringLiteral( "INPUT" ) );
92 addParameter( mValueParam.release() );
93}
94
95bool QgsSetMValueAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * )
96{
97 mMValue = parameterAsDouble( parameters, QStringLiteral( "M_VALUE" ), context );
98 mDynamicMValue = QgsProcessingParameters::isDynamic( parameters, QStringLiteral( "M_VALUE" ) );
99 if ( mDynamicMValue )
100 mMValueProperty = parameters.value( QStringLiteral( "M_VALUE" ) ).value< QgsProperty >();
101
102 return true;
103}
104
105QgsFeatureList QgsSetMValueAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback * )
106{
107 QgsFeature f = feature;
108
109 if ( f.hasGeometry() )
110 {
111 std::unique_ptr< QgsAbstractGeometry > newGeometry( f.geometry().constGet()->clone() );
112 // addMValue won't alter existing M values, so drop them first
113 if ( QgsWkbTypes::hasM( newGeometry->wkbType() ) )
114 newGeometry->dropMValue();
115
116 double m = mMValue;
117 if ( mDynamicMValue )
118 m = mMValueProperty.valueAsDouble( context.expressionContext(), m );
119
120 newGeometry->addMValue( m );
121
122 f.setGeometry( QgsGeometry( std::move( newGeometry ) ) );
123 }
124
125 return QgsFeatureList() << f;
126}
127
WkbType
The WKB type describes the number of dimensions a geometry has.
Definition qgis.h:182
virtual QgsAbstractGeometry * clone() const =0
Clones the geometry by performing a deep copy.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition qgsfeature.h:56
QgsGeometry geometry
Definition qgsfeature.h:67
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:74
Contains information about the context in which a processing algorithm is executed.
QgsExpressionContext & expressionContext()
Returns the expression context.
bool supportInPlaceEdit(const QgsMapLayer *layer) const override
Checks whether this algorithm supports in-place editing on the given layer Default implementation for...
Flag
Flags controlling how QgsProcessingFeatureSource fetches features.
@ FlagSkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
Base class for providing feedback from a processing algorithm.
static bool isDynamic(const QVariantMap &parameters, const QString &name)
Returns true if the parameter with matching name is a dynamic parameter, and must be evaluated once f...
Definition for a property.
Definition qgsproperty.h:46
@ Double
Double value (including negative values)
Definition qgsproperty.h:56
A store for object properties.
Represents a vector layer which manages a vector based data sets.
Q_INVOKABLE Qgis::WkbType wkbType() const FINAL
Returns the WKBType or WKBUnknown in case of error.
static Qgis::WkbType addM(Qgis::WkbType type)
Adds the m dimension to a WKB type and returns the new type.
static bool hasM(Qgis::WkbType type)
Tests whether a WKB type contains m values.
QList< QgsFeature > QgsFeatureList
Definition qgsfeature.h:920