QgsFeatureIds QgsMapToolSelectUtils::getMatchingFeatures( QgsMapCanvas *canvas, const QgsGeometry &selectGeometry, bool doContains, bool singleSelect )
{
QgsFeatureIds newSelectedFeatures;
if ( selectGeometry.type() != QgsWkbTypes::PolygonGeometry )
return newSelectedFeatures;
QgsVectorLayer *vlayer = QgsMapToolSelectUtils::getCurrentVectorLayer( canvas );
if ( !vlayer )
return newSelectedFeatures;
// toLayerCoordinates will throw an exception for any 'invalid' points in
// the rubber band.
// For example, if you project a world map onto a globe using EPSG 2163
// and then click somewhere off the globe, an exception will be thrown.
QgsGeometry selectGeomTrans = selectGeometry;
try
{
QgsCoordinateTransform ct( canvas->mapSettings().destinationCrs(), vlayer->crs(), QgsProject::instance() );
if ( !ct.isShortCircuited() && selectGeomTrans.type() == QgsWkbTypes::PolygonGeometry )
{
// convert add more points to the edges of the rectangle
// improve transformation result
QgsPolygonXY poly( selectGeomTrans.asPolygon() );
if ( poly.size() == 1 && poly.at( 0 ).size() == 5 )
{
const QgsPolylineXY &ringIn = poly.at( 0 );
QgsPolygonXY newpoly( 1 );
newpoly[0].resize( 41 );
QgsPolylineXY &ringOut = newpoly[0];
ringOut[ 0 ] = ringIn.at( 0 );
int i = 1;
for ( int j = 1; j < 5; j++ )
{
QgsVector v( ( ringIn.at( j ) - ringIn.at( j - 1 ) ) / 10.0 );
for ( int k = 0; k < 9; k++ )
{
ringOut[ i ] = ringOut[ i - 1 ] + v;
i++;
}
ringOut[ i++ ] = ringIn.at( j );
}
selectGeomTrans = QgsGeometry::fromPolygonXY( newpoly );
}
}
selectGeomTrans.transform( ct );
}
catch ( QgsCsException &cse )
{
Q_UNUSED( cse );
// catch exception for 'invalid' point and leave existing selection unchanged
QgsDebugMsg( QStringLiteral( "Caught CRS exception " ) );
QgisApp::instance()->messageBar()->pushMessage(
QObject::tr( "CRS Exception" ),
QObject::tr( "Selection extends beyond layer's coordinate system" ),
Qgis::Warning,
QgisApp::instance()->messageTimeout() );
return newSelectedFeatures;
}
QgsDebugMsgLevel( "Selection layer: " + vlayer->name(), 3 );
QgsDebugMsgLevel( "Selection polygon: " + selectGeomTrans.asWkt(), 3 );
QgsDebugMsgLevel( "doContains: " + QString( doContains ? "T" : "F" ), 3 );
QgsRenderContext context = QgsRenderContext::fromMapSettings( canvas->mapSettings() );
context.expressionContext() << QgsExpressionContextUtils::layerScope( vlayer );
std::unique_ptr< QgsFeatureRenderer > r;
if ( vlayer->renderer() )
{
r.reset( vlayer->renderer()->clone() );
r->startRender( context, vlayer->fields() );
}
QgsFeatureRequest request;
request.setFilterRect( selectGeomTrans.boundingBox() );
request.setFlags( QgsFeatureRequest::ExactIntersect );
if ( r )
request.setSubsetOfAttributes( r->usedAttributes( context ), vlayer->fields() );
else
request.setNoAttributes();
QgsFeatureIterator fit = vlayer->getFeatures( request );
QgsFeature f;
QgsFeatureId closestFeatureId = 0;
bool foundSingleFeature = false;
double closestFeatureDist = std::numeric_limits<double>::max();
while ( fit.nextFeature( f ) )
{
context.expressionContext().setFeature( f );
// make sure to only use features that are visible
if ( r && !r->willRenderFeature( f, context ) )
continue;
QgsGeometry g = f.geometry();
if ( doContains )
{
if ( !selectGeomTrans.contains( g ) )
continue;
}
else
{
if ( !selectGeomTrans.intersects( g ) )
continue;
}
if ( singleSelect )
{
foundSingleFeature = true;
double distance = g.distance( selectGeomTrans );
if ( distance <= closestFeatureDist )
{
closestFeatureDist = distance;
closestFeatureId = f.id();
}
}
else
{
newSelectedFeatures.insert( f.id() );
}
}
if ( singleSelect && foundSingleFeature )
{
newSelectedFeatures.insert( closestFeatureId );
}
if ( r )
r->stopRender( context );
QgsDebugMsg( "Number of new selected features: " + QString::number( newSelectedFeatures.size() ) );
return newSelectedFeatures;
}
QDomElement QgsXmlUtils::writeVariant( const QVariant &value, QDomDocument &doc )
{
QDomElement element = doc.createElement( QStringLiteral( "Option" ) );
switch ( value.type() )
{
case QVariant::Invalid:
{
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "invalid" ) );
break;
}
case QVariant::Map:
{
QVariantMap map = value.toMap();
for ( auto option = map.constBegin(); option != map.constEnd(); ++option )
{
QDomElement optionElement = writeVariant( option.value(), doc );
optionElement.setAttribute( QStringLiteral( "name" ), option.key() );
element.appendChild( optionElement );
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "Map" ) );
}
break;
}
case QVariant::List:
{
QVariantList list = value.toList();
const auto constList = list;
for ( const QVariant &value : constList )
{
QDomElement valueElement = writeVariant( value, doc );
element.appendChild( valueElement );
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "List" ) );
}
break;
}
case QVariant::StringList:
{
QStringList list = value.toStringList();
const auto constList = list;
for ( const QString &value : constList )
{
QDomElement valueElement = writeVariant( value, doc );
element.appendChild( valueElement );
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "StringList" ) );
}
break;
}
case QVariant::Int:
case QVariant::UInt:
case QVariant::Bool:
case QVariant::Double:
case QVariant::LongLong:
case QVariant::ULongLong:
case QVariant::String:
element.setAttribute( QStringLiteral( "type" ), QVariant::typeToName( value.type() ) );
element.setAttribute( QStringLiteral( "value" ), value.toString() );
break;
case QVariant::UserType:
{
if ( value.canConvert< QgsProperty >() )
{
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "QgsProperty" ) );
const QDomElement propertyElem = QgsXmlUtils::writeVariant( value.value< QgsProperty >().toVariant(), doc );
element.appendChild( propertyElem );
break;
}
else if ( value.canConvert< QgsCoordinateReferenceSystem >() )
{
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "QgsCoordinateReferenceSystem" ) );
const QgsCoordinateReferenceSystem crs = value.value< QgsCoordinateReferenceSystem >();
crs.writeXml( element, doc );
break;
}
else if ( value.canConvert< QgsGeometry >() )
{
element.setAttribute( QStringLiteral( "type" ), QStringLiteral( "QgsGeometry" ) );
const QgsGeometry geom = value.value< QgsGeometry >();
element.setAttribute( QStringLiteral( "value" ), geom.asWkt() );
break;
}
FALLTHROUGH
}
default:
Q_ASSERT_X( false, "QgsXmlUtils::writeVariant", QStringLiteral( "unsupported variant type %1" ).arg( QVariant::typeToName( value.type() ) ).toLocal8Bit() );
break;
}
return element;
}