QGIS API Documentation  3.26.3-Buenos Aires (65e4edfdad)
qgsalgorithmspatialindex.cpp
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1 /***************************************************************************
2  qgsalgorithmspatialindex.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 #include "qgsvectordataprovider.h"
21 
23 
24 QString QgsSpatialIndexAlgorithm::name() const
25 {
26  return QStringLiteral( "createspatialindex" );
27 }
28 
29 QString QgsSpatialIndexAlgorithm::displayName() const
30 {
31  return QObject::tr( "Create spatial index" );
32 }
33 
34 QStringList QgsSpatialIndexAlgorithm::tags() const
35 {
36  return QObject::tr( "table,spatial,geometry,index,create,vector" ).split( ',' );
37 }
38 
39 QString QgsSpatialIndexAlgorithm::group() const
40 {
41  return QObject::tr( "Vector general" );
42 }
43 
44 QString QgsSpatialIndexAlgorithm::groupId() const
45 {
46  return QStringLiteral( "vectorgeneral" );
47 }
48 
49 QgsProcessingAlgorithm::Flags QgsSpatialIndexAlgorithm::flags() const
50 {
52 }
53 
54 
55 QString QgsSpatialIndexAlgorithm::shortHelpString() const
56 {
57  return QObject::tr( "Creates an index to speed up access to the features "
58  "in a layer based on their spatial location. Support "
59  "for spatial index creation is dependent on the layer's "
60  "data provider." );
61 }
62 
63 QgsSpatialIndexAlgorithm *QgsSpatialIndexAlgorithm::createInstance() const
64 {
65  return new QgsSpatialIndexAlgorithm();
66 }
67 
68 void QgsSpatialIndexAlgorithm::initAlgorithm( const QVariantMap & )
69 {
70  addParameter( new QgsProcessingParameterVectorLayer( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ) ) );
71 
72  addOutput( new QgsProcessingOutputVectorLayer( QStringLiteral( "OUTPUT" ), QObject::tr( "Indexed layer" ) ) );
73 }
74 
75 QVariantMap QgsSpatialIndexAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
76 {
77  QgsVectorLayer *layer = parameterAsVectorLayer( parameters, QStringLiteral( "INPUT" ), context );
78 
79  if ( !layer )
80  throw QgsProcessingException( QObject::tr( "Could not load source layer for %1." ).arg( QLatin1String( "INPUT" ) ) );
81 
82  QgsVectorDataProvider *provider = layer->dataProvider();
83 
85  {
86  if ( !provider->createSpatialIndex() )
87  {
88  feedback->pushInfo( QObject::tr( "Could not create spatial index" ) );
89  }
90  }
91  else
92  {
93  feedback->pushInfo( QObject::tr( "Layer's data provider does not support spatial indexes" ) );
94  }
95 
96  QVariantMap outputs;
97  outputs.insert( QStringLiteral( "OUTPUT" ), layer->id() );
98  return outputs;
99 }
100 
QgsVectorDataProvider::createSpatialIndex
virtual bool createSpatialIndex()
Creates a spatial index on the datasource (if supported by the provider type).
Definition: qgsvectordataprovider.cpp:197
QgsVectorLayer::dataProvider
QgsVectorDataProvider * dataProvider() FINAL
Returns the layer's data provider, it may be nullptr.
Definition: qgsvectorlayer.cpp:676
QgsProcessingFeedback
Base class for providing feedback from a processing algorithm.
Definition: qgsprocessingfeedback.h:37
QgsVectorDataProvider::CreateSpatialIndex
@ CreateSpatialIndex
Allows creation of spatial index.
Definition: qgsvectordataprovider.h:80
QgsProcessingFeedback::pushInfo
virtual void pushInfo(const QString &info)
Pushes a general informational message from the algorithm.
Definition: qgsprocessingfeedback.cpp:77
QgsProcessingOutputVectorLayer
A vector layer output for processing algorithms.
Definition: qgsprocessingoutputs.h:179
QgsVectorDataProvider::capabilities
virtual Q_INVOKABLE QgsVectorDataProvider::Capabilities capabilities() const
Returns flags containing the supported capabilities.
Definition: qgsvectordataprovider.cpp:208
QgsProcessingContext
Contains information about the context in which a processing algorithm is executed.
Definition: qgsprocessingcontext.h:46
qgsalgorithmspatialindex.h
qgsvectordataprovider.h
QgsMapLayer::id
QString id() const
Returns the layer's unique ID, which is used to access this layer from QgsProject.
Definition: qgsmaplayer.cpp:169
QgsProcessingParameterVectorLayer
A vector layer (with or without geometry) parameter for processing algorithms. Consider using the mor...
Definition: qgsprocessingparameters.h:2827
qgsvectorlayer.h
QgsProcessingAlgorithm::FlagNoThreading
@ FlagNoThreading
Algorithm is not thread safe and cannot be run in a background thread, e.g. for algorithms which mani...
Definition: qgsprocessingalgorithm.h:76
QgsVectorLayer
Represents a vector layer which manages a vector based data sets.
Definition: qgsvectorlayer.h:391
QgsVectorDataProvider
This is the base class for vector data providers.
Definition: qgsvectordataprovider.h:58
QgsProcessingAlgorithm::flags
virtual Flags flags() const
Returns the flags indicating how and when the algorithm operates and should be exposed to users.
Definition: qgsprocessingalgorithm.cpp:90
QgsProcessingException
Custom exception class for processing related exceptions.
Definition: qgsexception.h:82