bool QgsOverlayAnalyzer::intersection( QgsVectorLayer* layerA, QgsVectorLayer* layerB,
const QString& shapefileName, bool onlySelectedFeatures,
QProgressDialog* p )
{
if ( !layerA && !layerB )
{
return false;
}
QgsVectorDataProvider* dpA = layerA->dataProvider();
QgsVectorDataProvider* dpB = layerB->dataProvider();
if ( !dpA && !dpB )
{
return false;
}
QGis::WkbType outputType = dpA->geometryType();
const QgsCoordinateReferenceSystem crs = layerA->srs();
QgsFieldMap fieldsA = dpA->fields();
QgsFieldMap fieldsB = dpB->fields();
combineFieldLists( fieldsA, fieldsB );
QgsVectorFileWriter vWriter( shapefileName, dpA->encoding(), fieldsA, outputType, &crs );
QgsFeature currentFeature;
QgsSpatialIndex index;
//take only selection
if ( onlySelectedFeatures )
{
const QgsFeatureIds selectionB = layerB->selectedFeaturesIds();
QgsFeatureIds::const_iterator it = selectionB.constBegin();
for ( ; it != selectionB.constEnd(); ++it )
{
if ( !layerB->featureAtId( *it, currentFeature, true, true ) )
{
continue;
}
index.insertFeature( currentFeature );
}
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selectionA = layerA->selectedFeaturesIds();
if ( p )
{
p->setMaximum( selectionA.size() );
}
QgsFeature currentFeature;
int processedFeatures = 0;
it = selectionA.constBegin();
for ( ; it != selectionA.constEnd(); ++it )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
if ( !layerA->featureAtId( *it, currentFeature, true, true ) )
{
continue;
}
intersectFeature( currentFeature, &vWriter, layerB, &index );
++processedFeatures;
}
if ( p )
{
p->setValue( selectionA.size() );
}
}
//take all features
else
{
layerB->select( layerB->pendingAllAttributesList(), QgsRectangle(), true, false );
while ( layerB->nextFeature( currentFeature ) )
{
index.insertFeature( currentFeature );
}
QgsFeature currentFeature;
layerA->select( layerA->pendingAllAttributesList(), QgsRectangle(), true, false );
int featureCount = layerA->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
int processedFeatures = 0;
while ( layerA->nextFeature( currentFeature ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
intersectFeature( currentFeature, &vWriter, layerB, &index );
++processedFeatures;
}
if ( p )
{
p->setValue( featureCount );
}
}
return true;
}
bool QgsOverlayAnalyzer::intersection( QgsVectorLayer *layerA, QgsVectorLayer *layerB,
const QString &shapefileName, bool onlySelectedFeatures,
QProgressDialog *p )
{
if ( !layerA || !layerB )
{
return false;
}
QgsVectorDataProvider *dpA = layerA->dataProvider();
QgsVectorDataProvider *dpB = layerB->dataProvider();
if ( !dpA || !dpB )
{
return false;
}
QgsWkbTypes::Type outputType = dpA->wkbType();
QgsCoordinateReferenceSystem crs = layerA->crs();
QgsFields fieldsA = layerA->fields();
QgsFields fieldsB = layerB->fields();
combineFieldLists( fieldsA, fieldsB );
QgsVectorFileWriter vWriter( shapefileName, dpA->encoding(), fieldsA, outputType, crs );
QgsFeature currentFeature;
//take only selection
if ( onlySelectedFeatures )
{
QgsFeatureIds selectionB = layerB->selectedFeatureIds();
QgsFeatureRequest req = QgsFeatureRequest().setFilterFids( selectionB ).setSubsetOfAttributes( QgsAttributeList() );
QgsSpatialIndex index = QgsSpatialIndex( layerB->getFeatures( req ) );
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selectionA = layerA->selectedFeatureIds();
if ( p )
{
p->setMaximum( selectionA.size() );
}
req = QgsFeatureRequest().setFilterFids( selectionA );
QgsFeatureIterator selectionAIt = layerA->getFeatures( req );
QgsFeature currentFeature;
int processedFeatures = 0;
while ( selectionAIt.nextFeature( currentFeature ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
intersectFeature( currentFeature, &vWriter, layerB, &index );
++processedFeatures;
}
if ( p )
{
p->setValue( selectionA.size() );
}
}
//take all features
else
{
QgsFeatureRequest req = QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() );
QgsSpatialIndex index = QgsSpatialIndex( layerB->getFeatures( req ) );
int featureCount = layerA->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
int processedFeatures = 0;
QgsFeatureIterator fit = layerA->getFeatures();
QgsFeature currentFeature;
while ( fit.nextFeature( currentFeature ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
intersectFeature( currentFeature, &vWriter, layerB, &index );
++processedFeatures;
}
if ( p )
{
p->setValue( featureCount );
}
}
return true;
}
