bool QgsGeometryAnalyzer::convexHull( QgsVectorLayer* layer, const QString& shapefileName,
bool onlySelectedFeatures, int uniqueIdField, QProgressDialog* p )
{
if ( !layer )
{
return false;
}
QgsVectorDataProvider* dp = layer->dataProvider();
if ( !dp )
{
return false;
}
bool useField = false;
if ( uniqueIdField == -1 )
{
uniqueIdField = 0;
}
else
{
useField = true;
}
QgsFieldMap fields;
fields.insert( 0 , QgsField( QString( "UID" ), QVariant::String ) );
fields.insert( 1 , QgsField( QString( "AREA" ), QVariant::Double ) );
fields.insert( 2 , QgsField( QString( "PERIM" ), QVariant::Double ) );
QGis::WkbType outputType = QGis::WKBPolygon;
const QgsCoordinateReferenceSystem crs = layer->crs();
QgsVectorFileWriter vWriter( shapefileName, dp->encoding(), fields, outputType, &crs );
QgsFeature currentFeature;
QgsGeometry* dissolveGeometry = 0; //dissolve geometry
QMultiMap<QString, int> map;
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
QgsFeatureIds::const_iterator it = selection.constBegin();
for ( ; it != selection.constEnd(); ++it )
{
#if 0
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
// break; // it may be better to do something else here?
return false;
}
#endif
if ( !layer->featureAtId( *it, currentFeature, true, true ) )
{
continue;
}
map.insert( currentFeature.attributeMap()[ uniqueIdField ].toString(), currentFeature.id() );
}
}
else
{
layer->select( layer->pendingAllAttributesList(), QgsRectangle(), true, false );
while ( layer->nextFeature( currentFeature ) )
{
#if 0
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
// break; // it may be better to do something else here?
return false;
}
#endif
map.insert( currentFeature.attributeMap()[ uniqueIdField ].toString(), currentFeature.id() );
}
}
QMultiMap<QString, int>::const_iterator jt = map.constBegin();
while ( jt != map.constEnd() )
{
QString currentKey = jt.key();
int processedFeatures = 0;
//take only selection
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
if ( p )
{
p->setMaximum( selection.size() );
}
processedFeatures = 0;
while ( jt != map.constEnd() && ( jt.key() == currentKey || !useField ) )
{
if ( p && p->wasCanceled() )
{
break;
}
if ( selection.contains( jt.value() ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( !layer->featureAtId( jt.value(), currentFeature, true, true ) )
{
continue;
}
convexFeature( currentFeature, processedFeatures, &dissolveGeometry );
++processedFeatures;
}
++jt;
}
QList<double> values;
if ( !dissolveGeometry )
{
QgsDebugMsg( "no dissolved geometry - should not happen" );
return false;
}
dissolveGeometry = dissolveGeometry->convexHull();
values = simpleMeasure( dissolveGeometry );
QgsAttributeMap attributeMap;
attributeMap.insert( 0 , QVariant( currentKey ) );
attributeMap.insert( 1 , values[ 0 ] );
attributeMap.insert( 2 , values[ 1 ] );
QgsFeature dissolveFeature;
dissolveFeature.setAttributeMap( attributeMap );
dissolveFeature.setGeometry( dissolveGeometry );
vWriter.addFeature( dissolveFeature );
}
//take all features
else
{
int featureCount = layer->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
processedFeatures = 0;
while ( jt != map.constEnd() && ( jt.key() == currentKey || !useField ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
if ( !layer->featureAtId( jt.value(), currentFeature, true, true ) )
{
continue;
}
convexFeature( currentFeature, processedFeatures, &dissolveGeometry );
++processedFeatures;
++jt;
}
QList<double> values;
// QgsGeometry* tmpGeometry = 0;
if ( !dissolveGeometry )
{
QgsDebugMsg( "no dissolved geometry - should not happen" );
return false;
}
dissolveGeometry = dissolveGeometry->convexHull();
// values = simpleMeasure( tmpGeometry );
values = simpleMeasure( dissolveGeometry );
QgsAttributeMap attributeMap;
attributeMap.insert( 0 , QVariant( currentKey ) );
attributeMap.insert( 1 , QVariant( values[ 0 ] ) );
attributeMap.insert( 2 , QVariant( values[ 1 ] ) );
QgsFeature dissolveFeature;
dissolveFeature.setAttributeMap( attributeMap );
dissolveFeature.setGeometry( dissolveGeometry );
vWriter.addFeature( dissolveFeature );
}
}
return true;
}
bool QgsGeometryAnalyzer::simplify( QgsVectorLayer* layer, const QString& shapefileName,
double tolerance, bool onlySelectedFeatures, QProgressDialog* p )
{
if ( !layer )
{
return false;
}
QgsVectorDataProvider* dp = layer->dataProvider();
if ( !dp )
{
return false;
}
QGis::WkbType outputType = dp->geometryType();
const QgsCoordinateReferenceSystem crs = layer->crs();
QgsVectorFileWriter vWriter( shapefileName, dp->encoding(), dp->fields(), outputType, &crs );
QgsFeature currentFeature;
//take only selection
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
if ( p )
{
p->setMaximum( selection.size() );
}
int processedFeatures = 0;
QgsFeatureIds::const_iterator it = selection.constBegin();
for ( ; it != selection.constEnd(); ++it )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
if ( !layer->featureAtId( *it, currentFeature, true, true ) )
{
continue;
}
simplifyFeature( currentFeature, &vWriter, tolerance );
++processedFeatures;
}
if ( p )
{
p->setValue( selection.size() );
}
}
//take all features
else
{
layer->select( layer->pendingAllAttributesList(), QgsRectangle(), true, false );
int featureCount = layer->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
int processedFeatures = 0;
while ( layer->nextFeature( currentFeature ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
simplifyFeature( currentFeature, &vWriter, tolerance );
++processedFeatures;
}
if ( p )
{
p->setValue( featureCount );
}
}
return true;
}
bool QgsGeometryAnalyzer::extent( QgsVectorLayer* layer, const QString& shapefileName,
bool onlySelectedFeatures, QProgressDialog* p )
{
if ( !layer )
{
return false;
}
QgsVectorDataProvider* dp = layer->dataProvider();
if ( !dp )
{
return false;
}
QGis::WkbType outputType = QGis::WKBPolygon;
const QgsCoordinateReferenceSystem crs = layer->crs();
QgsFieldMap fields;
fields.insert( 0 , QgsField( QString( "MINX" ), QVariant::Double ) );
fields.insert( 1 , QgsField( QString( "MINY" ), QVariant::Double ) );
fields.insert( 2 , QgsField( QString( "MAXX" ), QVariant::Double ) );
fields.insert( 3 , QgsField( QString( "MAXY" ), QVariant::Double ) );
fields.insert( 4 , QgsField( QString( "CNTX" ), QVariant::Double ) );
fields.insert( 5 , QgsField( QString( "CNTY" ), QVariant::Double ) );
fields.insert( 6 , QgsField( QString( "AREA" ), QVariant::Double ) );
fields.insert( 7 , QgsField( QString( "PERIM" ), QVariant::Double ) );
fields.insert( 8 , QgsField( QString( "HEIGHT" ), QVariant::Double ) );
fields.insert( 9 , QgsField( QString( "WIDTH" ), QVariant::Double ) );
QgsVectorFileWriter vWriter( shapefileName, dp->encoding(), fields, outputType, &crs );
QgsRectangle rect;
if ( onlySelectedFeatures ) // take only selection
{
rect = layer->boundingBoxOfSelected();
}
else
{
rect = layer->extent();
}
double minx = rect.xMinimum();
double miny = rect.yMinimum();
double maxx = rect.xMaximum();
double maxy = rect.yMaximum();
double height = rect.height();
double width = rect.width();
double cntx = minx + ( width / 2.0 );
double cnty = miny + ( height / 2.0 );
double area = width * height;
double perim = ( 2 * width ) + ( 2 * height );
QgsFeature feat;
QgsAttributeMap map;
map.insert( 0 , QVariant( minx ) );
map.insert( 1 , QVariant( miny ) );
map.insert( 2 , QVariant( maxx ) );
map.insert( 3 , QVariant( maxy ) );
map.insert( 4 , QVariant( cntx ) );
map.insert( 5 , QVariant( cnty ) );
map.insert( 6 , QVariant( area ) );
map.insert( 7 , QVariant( perim ) );
map.insert( 8 , QVariant( height ) );
map.insert( 9 , QVariant( width ) );
feat.setAttributeMap( map );
feat.setGeometry( QgsGeometry::fromRect( rect ) );
vWriter.addFeature( feat );
return true;
}
bool QgsGeometryAnalyzer::buffer( QgsVectorLayer* layer, const QString& shapefileName, double bufferDistance,
bool onlySelectedFeatures, bool dissolve, int bufferDistanceField, QProgressDialog* p )
{
if ( !layer )
{
return false;
}
QgsVectorDataProvider* dp = layer->dataProvider();
if ( !dp )
{
return false;
}
QGis::WkbType outputType = QGis::WKBPolygon;
if ( dissolve )
{
outputType = QGis::WKBMultiPolygon;
}
QgsCoordinateReferenceSystem crs = layer->crs();
QgsVectorFileWriter vWriter( shapefileName, dp->encoding(), layer->fields(), outputType, &crs );
QgsFeature currentFeature;
QgsGeometry *dissolveGeometry = nullptr; //dissolve geometry (if dissolve enabled)
//take only selection
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
if ( p )
{
p->setMaximum( selection.size() );
}
int processedFeatures = 0;
QgsFeatureIds::const_iterator it = selection.constBegin();
for ( ; it != selection.constEnd(); ++it )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
if ( !layer->getFeatures( QgsFeatureRequest().setFilterFid( *it ) ).nextFeature( currentFeature ) )
{
continue;
}
bufferFeature( currentFeature, processedFeatures, &vWriter, dissolve, &dissolveGeometry, bufferDistance, bufferDistanceField );
++processedFeatures;
}
if ( p )
{
p->setValue( selection.size() );
}
}
//take all features
else
{
QgsFeatureIterator fit = layer->getFeatures();
int featureCount = layer->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
int processedFeatures = 0;
while ( fit.nextFeature( currentFeature ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
bufferFeature( currentFeature, processedFeatures, &vWriter, dissolve, &dissolveGeometry, bufferDistance, bufferDistanceField );
++processedFeatures;
}
if ( p )
{
p->setValue( featureCount );
}
}
if ( dissolve )
{
QgsFeature dissolveFeature;
if ( !dissolveGeometry )
{
QgsDebugMsg( "no dissolved geometry - should not happen" );
return false;
}
dissolveFeature.setGeometry( dissolveGeometry );
vWriter.addFeature( dissolveFeature );
}
return true;
}
bool QgsGeometryAnalyzer::dissolve( QgsVectorLayer* layer, const QString& shapefileName,
bool onlySelectedFeatures, int uniqueIdField, QProgressDialog* p )
{
if ( !layer )
{
return false;
}
QgsVectorDataProvider* dp = layer->dataProvider();
if ( !dp )
{
return false;
}
bool useField = false;
if ( uniqueIdField == -1 )
{
uniqueIdField = 0;
}
else
{
useField = true;
}
QGis::WkbType outputType = dp->geometryType();
QgsCoordinateReferenceSystem crs = layer->crs();
QgsVectorFileWriter vWriter( shapefileName, dp->encoding(), layer->fields(), outputType, &crs );
QgsFeature currentFeature;
QMultiMap<QString, QgsFeatureId> map;
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
QgsFeatureIds::const_iterator it = selection.constBegin();
for ( ; it != selection.constEnd(); ++it )
{
if ( !layer->getFeatures( QgsFeatureRequest().setFilterFid( *it ) ).nextFeature( currentFeature ) )
{
continue;
}
map.insert( currentFeature.attribute( uniqueIdField ).toString(), currentFeature.id() );
}
}
else
{
QgsFeatureIterator fit = layer->getFeatures();
while ( fit.nextFeature( currentFeature ) )
{
map.insert( currentFeature.attribute( uniqueIdField ).toString(), currentFeature.id() );
}
}
QgsGeometry *dissolveGeometry = nullptr; //dissolve geometry
QMultiMap<QString, QgsFeatureId>::const_iterator jt = map.constBegin();
QgsFeature outputFeature;
while ( jt != map.constEnd() )
{
QString currentKey = jt.key();
int processedFeatures = 0;
bool first = true;
//take only selection
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
if ( p )
{
p->setMaximum( selection.size() );
}
while ( jt != map.constEnd() && ( jt.key() == currentKey || !useField ) )
{
if ( p && p->wasCanceled() )
{
break;
}
if ( selection.contains( jt.value() ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( !layer->getFeatures( QgsFeatureRequest().setFilterFid( jt.value() ) ).nextFeature( currentFeature ) )
{
continue;
}
if ( first )
{
outputFeature.setAttributes( currentFeature.attributes() );
first = false;
}
dissolveFeature( currentFeature, processedFeatures, &dissolveGeometry );
++processedFeatures;
}
++jt;
}
}
//take all features
else
{
int featureCount = layer->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
while ( jt != map.constEnd() && ( jt.key() == currentKey || !useField ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
if ( !layer->getFeatures( QgsFeatureRequest().setFilterFid( jt.value() ) ).nextFeature( currentFeature ) )
{
continue;
}
{
outputFeature.setAttributes( currentFeature.attributes() );
first = false;
}
dissolveFeature( currentFeature, processedFeatures, &dissolveGeometry );
++processedFeatures;
++jt;
}
}
outputFeature.setGeometry( dissolveGeometry );
vWriter.addFeature( outputFeature );
}
return true;
}
bool QgsGeometryAnalyzer::centroids( QgsVectorLayer* layer, const QString& shapefileName,
bool onlySelectedFeatures, QProgressDialog* p )
{
if ( !layer )
{
QgsDebugMsg( "No layer passed to centroids" );
return false;
}
QgsVectorDataProvider* dp = layer->dataProvider();
if ( !dp )
{
QgsDebugMsg( "No data provider for layer passed to centroids" );
return false;
}
QGis::WkbType outputType = QGis::WKBPoint;
QgsCoordinateReferenceSystem crs = layer->crs();
QgsVectorFileWriter vWriter( shapefileName, dp->encoding(), layer->fields(), outputType, &crs );
QgsFeature currentFeature;
//take only selection
if ( onlySelectedFeatures )
{
//use QgsVectorLayer::featureAtId
const QgsFeatureIds selection = layer->selectedFeaturesIds();
if ( p )
{
p->setMaximum( selection.size() );
}
int processedFeatures = 0;
QgsFeatureIds::const_iterator it = selection.constBegin();
for ( ; it != selection.constEnd(); ++it )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
if ( !layer->getFeatures( QgsFeatureRequest().setFilterFid( *it ) ).nextFeature( currentFeature ) )
{
continue;
}
centroidFeature( currentFeature, &vWriter );
++processedFeatures;
}
if ( p )
{
p->setValue( selection.size() );
}
}
//take all features
else
{
QgsFeatureIterator fit = layer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
int featureCount = layer->featureCount();
if ( p )
{
p->setMaximum( featureCount );
}
int processedFeatures = 0;
while ( fit.nextFeature( currentFeature ) )
{
if ( p )
{
p->setValue( processedFeatures );
}
if ( p && p->wasCanceled() )
{
break;
}
centroidFeature( currentFeature, &vWriter );
++processedFeatures;
}
if ( p )
{
p->setValue( featureCount );
}
}
return true;
}
