bool JsonParser::read( QIODevice* device )
{
// Assert previous document got released.
delete m_document;
m_document = new GeoDataDocument;
Q_ASSERT( m_document );
// Read file data
QJsonParseError error;
const QJsonDocument jsonDoc = QJsonDocument::fromJson(device->readAll(), &error);
if (jsonDoc.isNull()) {
qDebug() << "Error parsing GeoJSON : " << error.errorString();
return false;
}
// Start parsing
const QJsonValue featuresValue = jsonDoc.object().value(QStringLiteral("features"));
// In GeoJSON format, geometries are stored in features, so we iterate on features
if (featuresValue.isArray()) {
const QJsonArray featureArray = featuresValue.toArray();
// Parse each feature
for (int featureIndex = 0; featureIndex < featureArray.size(); ++featureIndex) {
const QJsonObject featureObject = featureArray[featureIndex].toObject();
// Check if the feature contains a geometry
const QJsonValue geometryValue = featureObject.value(QStringLiteral("geometry"));
if (geometryValue.isObject()) {
const QJsonObject geometryObject = geometryValue.toObject();
// Variables for creating the geometry
QList<GeoDataGeometry*> geometryList;
QList<GeoDataPlacemark*> placemarkList;
// Create the different geometry types
const QString geometryType = geometryObject.value(QStringLiteral("type")).toString().toUpper();
if (geometryType == QLatin1String("POLYGON")) {
// Check first that there are coordinates
const QJsonValue coordinatesValue = geometryObject.value(QStringLiteral("coordinates"));
if (coordinatesValue.isArray()) {
const QJsonArray coordinateArray = coordinatesValue.toArray();
GeoDataPolygon * geom = new GeoDataPolygon( RespectLatitudeCircle | Tessellate );
// Coordinates first array will be the outer boundary, if there are more
// positions those will be inner holes
for (int ringIndex = 0 ; ringIndex < coordinateArray.size(); ++ringIndex) {
const QJsonArray ringArray = coordinateArray[ringIndex].toArray();
GeoDataLinearRing linearRing;
for (int coordinatePairIndex = 0; coordinatePairIndex < ringArray.size(); ++coordinatePairIndex) {
const QJsonArray coordinatePairArray = ringArray[coordinatePairIndex].toArray();
const qreal longitude = coordinatePairArray.at(0).toDouble();
const qreal latitude = coordinatePairArray.at(1).toDouble();
linearRing.append( GeoDataCoordinates( longitude , latitude , 0 , GeoDataCoordinates::Degree ) );
}
// Outer ring
if (ringIndex == 0) {
geom->setOuterBoundary( linearRing );
}
// Inner holes
else {
geom->appendInnerBoundary( linearRing );
}
}
geometryList.append( geom );
}
} else if (geometryType == QLatin1String("MULTIPOLYGON")) {
// Check first that there are coordinates
const QJsonValue coordinatesValue = geometryObject.value(QStringLiteral("coordinates"));
if (coordinatesValue.isArray()) {
const QJsonArray coordinateArray = coordinatesValue.toArray();
for (int polygonIndex = 0; polygonIndex < coordinateArray.size(); ++polygonIndex) {
const QJsonArray polygonArray = coordinateArray[polygonIndex].toArray();
GeoDataPolygon * geom = new GeoDataPolygon( RespectLatitudeCircle | Tessellate );
// Coordinates first array will be the outer boundary, if there are more
// positions those will be inner holes
for (int ringIndex = 0 ; ringIndex < polygonArray.size(); ++ringIndex) {
const QJsonArray ringArray = polygonArray[ringIndex].toArray();
GeoDataLinearRing linearRing;
for (int coordinatePairIndex = 0; coordinatePairIndex < ringArray.size(); ++coordinatePairIndex) {
const QJsonArray coordinatePairArray = ringArray[coordinatePairIndex].toArray();
const qreal longitude = coordinatePairArray.at(0).toDouble();
const qreal latitude = coordinatePairArray.at(1).toDouble();
linearRing.append( GeoDataCoordinates( longitude , latitude , 0 , GeoDataCoordinates::Degree ) );
}
// Outer ring
if (ringIndex == 0) {
geom->setOuterBoundary( linearRing );
}
// Inner holes
else {
geom->appendInnerBoundary( linearRing );
}
}
geometryList.append( geom );
}
}
} else if (geometryType == QLatin1String("LINESTRING")) {
// Check first that there are coordinates
const QJsonValue coordinatesValue = geometryObject.value(QStringLiteral("coordinates"));
if (coordinatesValue.isArray()) {
const QJsonArray coordinateArray = coordinatesValue.toArray();
GeoDataLineString * geom = new GeoDataLineString( RespectLatitudeCircle | Tessellate );
for (int coordinatePairIndex = 0; coordinatePairIndex < coordinateArray.size(); ++coordinatePairIndex) {
const QJsonArray coordinatePairArray = coordinateArray[coordinatePairIndex].toArray();
const qreal longitude = coordinatePairArray.at(0).toDouble();
const qreal latitude = coordinatePairArray.at(1).toDouble();
geom->append( GeoDataCoordinates( longitude , latitude , 0 , GeoDataCoordinates::Degree ) );
}
geometryList.append( geom );
}
} else if (geometryType == QLatin1String("MULTILINESTRING")) {
// Check first that there are coordinates
const QJsonValue coordinatesValue = geometryObject.value(QStringLiteral("coordinates"));
if (coordinatesValue.isArray()) {
const QJsonArray coordinateArray = coordinatesValue.toArray();
for (int lineStringIndex = 0; lineStringIndex < coordinateArray.size(); ++lineStringIndex) {
const QJsonArray lineStringArray = coordinateArray[lineStringIndex].toArray();
GeoDataLineString * geom = new GeoDataLineString( RespectLatitudeCircle | Tessellate );
for (int coordinatePairIndex = 0; coordinatePairIndex < lineStringArray.size(); ++coordinatePairIndex) {
const QJsonArray coordinatePairArray = lineStringArray[coordinatePairIndex].toArray();
const qreal longitude = coordinatePairArray.at(0).toDouble();
const qreal latitude = coordinatePairArray.at(1).toDouble();
geom->append( GeoDataCoordinates( longitude , latitude , 0 , GeoDataCoordinates::Degree ) );
}
geometryList.append( geom );
}
}
} else if (geometryType == QLatin1String("POINT")) {
// Check first that there are coordinates
const QJsonValue coordinatesValue = geometryObject.value(QStringLiteral("coordinates"));
if (coordinatesValue.isArray()) {
const QJsonArray coordinatePairArray = coordinatesValue.toArray();
GeoDataPoint * geom = new GeoDataPoint();
const qreal longitude = coordinatePairArray.at(0).toDouble();
const qreal latitude = coordinatePairArray.at(1).toDouble();
geom->setCoordinates( GeoDataCoordinates( longitude , latitude , 0 , GeoDataCoordinates::Degree ) );
geometryList.append( geom );
}
} else if (geometryType == QLatin1String("MULTIPOINT")) {
// Check first that there are coordinates
const QJsonValue coordinatesValue = geometryObject.value(QStringLiteral("coordinates"));
if (coordinatesValue.isArray()) {
const QJsonArray coordinateArray = coordinatesValue.toArray();
for (int pointIndex = 0; pointIndex < coordinateArray.size(); ++pointIndex) {
const QJsonArray coordinatePairArray = coordinateArray[pointIndex].toArray();
GeoDataPoint * geom = new GeoDataPoint();
const qreal longitude = coordinatePairArray.at(0).toDouble();
const qreal latitude = coordinatePairArray.at(1).toDouble();
geom->setCoordinates( GeoDataCoordinates( longitude , latitude , 0 , GeoDataCoordinates::Degree ) );
geometryList.append( geom );
}
}
}
// Parse the features properties
const QJsonValue propertiesValue = featureObject.value(QStringLiteral("properties"));
if (!geometryList.isEmpty() && propertiesValue.isObject()) {
const QJsonObject propertiesObject = propertiesValue.toObject();
// First create a placemark for each geometry, there could be multi geometries
// that are translated into more than one geometry/placemark
for ( int numberGeometries = 0 ; numberGeometries < geometryList.length() ; numberGeometries++ ) {
GeoDataPlacemark * placemark = new GeoDataPlacemark();
placemarkList.append( placemark );
}
OsmPlacemarkData osmData;
QJsonObject::ConstIterator it = propertiesObject.begin();
const QJsonObject::ConstIterator end = propertiesObject.end();
for ( ; it != end; ++it) {
if (it.value().isObject() || it.value().isArray()) {
qDebug() << "Skipping property, values of type arrays and objects not supported:" << it.key();
continue;
}
// pass value through QVariant to also get bool & numbers
osmData.addTag(it.key(), it.value().toVariant().toString());
}
// If the property read, is the features name
const auto tagIter = osmData.findTag(QStringLiteral("name"));
if (tagIter != osmData.tagsEnd()) {
const QString& name = tagIter.value();
for (int pl = 0 ; pl < placemarkList.length(); ++pl) {
placemarkList.at(pl)->setName(name);
}
}
const GeoDataPlacemark::GeoDataVisualCategory category = StyleBuilder::determineVisualCategory(osmData);
if (category != GeoDataPlacemark::None) {
// Add the visual category to all the placemarks
for (int pl = 0 ; pl < placemarkList.length(); ++pl) {
placemarkList.at(pl)->setVisualCategory(category);
placemarkList.at(pl)->setOsmData(osmData);
}
}
}
// Add the geometry to the document
if ( geometryList.length() == placemarkList.length() ) {
while( placemarkList.length() > 0 ) {
GeoDataPlacemark * placemark = placemarkList.last();
placemarkList.pop_back();
GeoDataGeometry * geom = geometryList.last();
geometryList.pop_back();
placemark->setGeometry( geom );
placemark->setVisible( true );
m_document->append( placemark );
}
}
// If geometries or placemarks missing inside the lists, delete them
qDeleteAll( geometryList.begin(), geometryList.end() );
geometryList.clear();
qDeleteAll( placemarkList.begin(), placemarkList.end() );
placemarkList.clear();
}
}
}
return true;
}
