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       1                 :            : /***************************************************************************
       2                 :            :   qgsalgorithmunion.cpp
       3                 :            :   ---------------------
       4                 :            :   Date                 : April 2018
       5                 :            :   Copyright            : (C) 2018 by Martin Dobias
       6                 :            :   Email                : wonder dot sk at gmail dot com
       7                 :            :  ***************************************************************************
       8                 :            :  *                                                                         *
       9                 :            :  *   This program is free software; you can redistribute it and/or modify  *
      10                 :            :  *   it under the terms of the GNU General Public License as published by  *
      11                 :            :  *   the Free Software Foundation; either version 2 of the License, or     *
      12                 :            :  *   (at your option) any later version.                                   *
      13                 :            :  *                                                                         *
      14                 :            :  ***************************************************************************/
      15                 :            : 
      16                 :            : #include "qgsalgorithmunion.h"
      17                 :            : 
      18                 :            : #include "qgsoverlayutils.h"
      19                 :            : 
      20                 :            : ///@cond PRIVATE
      21                 :            : 
      22                 :            : 
      23                 :          0 : QString QgsUnionAlgorithm::name() const
      24                 :            : {
      25                 :          0 :   return QStringLiteral( "union" );
      26                 :            : }
      27                 :            : 
      28                 :          0 : QString QgsUnionAlgorithm::displayName() const
      29                 :            : {
      30                 :          0 :   return QObject::tr( "Union" );
      31                 :            : }
      32                 :            : 
      33                 :          0 : QString QgsUnionAlgorithm::group() const
      34                 :            : {
      35                 :          0 :   return QObject::tr( "Vector overlay" );
      36                 :            : }
      37                 :            : 
      38                 :          0 : QString QgsUnionAlgorithm::groupId() const
      39                 :            : {
      40                 :          0 :   return QStringLiteral( "vectoroverlay" );
      41                 :            : }
      42                 :            : 
      43                 :          0 : QString QgsUnionAlgorithm::shortHelpString() const
      44                 :            : {
      45                 :          0 :   return QObject::tr( "This algorithm checks overlaps between features within the Input layer and creates separate features for overlapping "
      46                 :            :                       "and non-overlapping parts. The area of overlap will create as many identical overlapping features as there are "
      47                 :            :                       "features that participate in that overlap." )
      48                 :          0 :          + QStringLiteral( "\n\n" )
      49                 :          0 :          + QObject::tr( "An Overlay layer can also be used, in which case features from each layer are split at their overlap with features from "
      50                 :            :                         "the other one, creating a layer containing all the portions from both Input and Overlay layers. "
      51                 :            :                         "The attribute table of the Union layer is filled with attribute values from the respective original layer "
      52                 :            :                         "for non-overlapping features, and attribute values from both layers for overlapping features." );
      53                 :          0 : }
      54                 :            : 
      55                 :          0 : QgsProcessingAlgorithm *QgsUnionAlgorithm::createInstance() const
      56                 :            : {
      57                 :          0 :   return new QgsUnionAlgorithm();
      58                 :            : }
      59                 :            : 
      60                 :          0 : void QgsUnionAlgorithm::initAlgorithm( const QVariantMap & )
      61                 :            : {
      62                 :          0 :   addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ) ) );
      63                 :          0 :   addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "OVERLAY" ), QObject::tr( "Overlay layer" ), QList< int >(), QVariant(), true ) );
      64                 :            : 
      65                 :          0 :   std::unique_ptr< QgsProcessingParameterString > prefix = std::make_unique< QgsProcessingParameterString >( QStringLiteral( "OVERLAY_FIELDS_PREFIX" ), QObject::tr( "Overlay fields prefix" ), QString(), false, true );
      66                 :          0 :   prefix->setFlags( prefix->flags() | QgsProcessingParameterDefinition::FlagAdvanced );
      67                 :          0 :   addParameter( prefix.release() );
      68                 :            : 
      69                 :          0 :   addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Union" ) ) );
      70                 :          0 : }
      71                 :            : 
      72                 :          0 : QVariantMap QgsUnionAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
      73                 :            : {
      74                 :          0 :   std::unique_ptr< QgsFeatureSource > sourceA( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
      75                 :          0 :   if ( !sourceA )
      76                 :          0 :     throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
      77                 :            : 
      78                 :          0 :   std::unique_ptr< QgsFeatureSource > sourceB( parameterAsSource( parameters, QStringLiteral( "OVERLAY" ), context ) );
      79                 :          0 :   if ( parameters.value( QStringLiteral( "OVERLAY" ) ).isValid() && !sourceB )
      80                 :          0 :     throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "OVERLAY" ) ) );
      81                 :            : 
      82                 :          0 :   QgsWkbTypes::Type geomType = QgsWkbTypes::multiType( sourceA->wkbType() );
      83                 :            : 
      84                 :          0 :   QString overlayFieldsPrefix = parameterAsString( parameters, QStringLiteral( "OVERLAY_FIELDS_PREFIX" ), context );
      85                 :          0 :   QgsFields fields = sourceB ? QgsProcessingUtils::combineFields( sourceA->fields(), sourceB->fields(), overlayFieldsPrefix ) : sourceA->fields();
      86                 :            : 
      87                 :          0 :   QString dest;
      88                 :          0 :   std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields, geomType, sourceA->sourceCrs(), QgsFeatureSink::RegeneratePrimaryKey ) );
      89                 :          0 :   if ( !sink )
      90                 :          0 :     throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
      91                 :            : 
      92                 :          0 :   QVariantMap outputs;
      93                 :          0 :   outputs.insert( QStringLiteral( "OUTPUT" ), dest );
      94                 :            : 
      95                 :          0 :   if ( !sourceB )
      96                 :            :   {
      97                 :            :     // we are doing single layer union
      98                 :          0 :     QgsOverlayUtils::resolveOverlaps( *sourceA, *sink, feedback );
      99                 :          0 :     return outputs;
     100                 :            :   }
     101                 :            : 
     102                 :          0 :   QList<int> fieldIndicesA = QgsProcessingUtils::fieldNamesToIndices( QStringList(), sourceA->fields() );
     103                 :          0 :   QList<int> fieldIndicesB = QgsProcessingUtils::fieldNamesToIndices( QStringList(), sourceB->fields() );
     104                 :            : 
     105                 :          0 :   int count = 0;
     106                 :          0 :   int total = sourceA->featureCount() * 2 + sourceB->featureCount();
     107                 :            : 
     108                 :          0 :   QgsOverlayUtils::intersection( *sourceA, *sourceB, *sink, context, feedback, count, total, fieldIndicesA, fieldIndicesB );
     109                 :            : 
     110                 :          0 :   QgsOverlayUtils::difference( *sourceA, *sourceB, *sink, context, feedback, count, total, QgsOverlayUtils::OutputAB );
     111                 :            : 
     112                 :          0 :   QgsOverlayUtils::difference( *sourceB, *sourceA, *sink, context, feedback, count, total, QgsOverlayUtils::OutputBA );
     113                 :            : 
     114                 :          0 :   return outputs;
     115                 :          0 : }
     116                 :            : 
     117                 :            : ///@endcond