# -*- coding: utf-8 -*- """ *************************************************************************** Polygonize.py --------------------- Date : March 2013 Copyright : (C) 2013 by Piotr Pociask Email : ppociask at o2 dot pl *************************************************************************** * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. * * * *************************************************************************** """ __author__ = 'Piotr Pociask' __date__ = 'March 2013' __copyright__ = '(C) 2013, Piotr Pociask' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' from PyQt4.QtCore import QVariant from qgis.core import QGis, QgsFields, QgsField, QgsFeature, QgsGeometry from processing.core.GeoAlgorithm import GeoAlgorithm from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException from processing.core.parameters import ParameterVector from processing.core.parameters import ParameterBoolean from processing.core.outputs import OutputVector from processing.tools import dataobjects, vector class Polygonize(GeoAlgorithm): INPUT = 'INPUT' OUTPUT = 'OUTPUT' FIELDS = 'FIELDS' GEOMETRY = 'GEOMETRY' def processAlgorithm(self, progress): try: from shapely.ops import polygonize from shapely.geometry import Point, MultiLineString except ImportError: raise GeoAlgorithmExecutionException( self.tr('Polygonize algorithm requires shapely module!')) vlayer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT)) output = self.getOutputFromName(self.OUTPUT) vprovider = vlayer.dataProvider() if self.getParameterValue(self.FIELDS): fields = vprovider.fields() else: fields = QgsFields() if self.getParameterValue(self.GEOMETRY): fieldsCount = fields.count() fields.append(QgsField('area', QVariant.Double, 'double', 16, 2)) fields.append(QgsField('perimeter', QVariant.Double, 'double', 16, 2)) allLinesList = [] features = vector.features(vlayer) current = 0 progress.setInfo(self.tr('Processing lines...')) total = 40.0 / float(len(features)) for inFeat in features: inGeom = inFeat.geometry() if inGeom.isMultipart(): allLinesList.extend(inGeom.asMultiPolyline()) else: allLinesList.append(inGeom.asPolyline()) current += 1 progress.setPercentage(int(current * total)) progress.setPercentage(40) allLines = MultiLineString(allLinesList) progress.setInfo(self.tr('Noding lines...')) try: from shapely.ops import unary_union allLines = unary_union(allLines) except ImportError: allLines = allLines.union(Point(0, 0)) progress.setPercentage(45) progress.setInfo(self.tr('Polygonizing...')) polygons = list(polygonize([allLines])) if not polygons: raise GeoAlgorithmExecutionException(self.tr('No polygons were created!')) progress.setPercentage(50) progress.setInfo('Saving polygons...') writer = output.getVectorWriter(fields, QGis.WKBPolygon, vlayer.crs()) outFeat = QgsFeature() current = 0 total = 50.0 / float(len(polygons)) for polygon in polygons: outFeat.setGeometry(QgsGeometry.fromWkt(polygon.wkt)) if self.getParameterValue(self.GEOMETRY): outFeat.setAttributes([None] * fieldsCount + [polygon.area, polygon.length]) writer.addFeature(outFeat) current += 1 progress.setPercentage(50 + int(current * total)) progress.setInfo(self.tr('Finished')) del writer def defineCharacteristics(self): self.name = 'Polygonize' self.group = 'Vector geometry tools' self.addParameter(ParameterVector(self.INPUT, self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_LINE])) self.addParameter(ParameterBoolean(self.FIELDS, self.tr('Keep table structure of line layer'), False)) self.addParameter(ParameterBoolean(self.GEOMETRY, self.tr('Create geometry columns'), True)) self.addOutput(OutputVector(self.OUTPUT, self.tr('Output layer')))