# -*- coding: utf-8 -*- """ *************************************************************************** PolygonCentroids.py --------------------- Date : August 2012 Copyright : (C) 2012 by Victor Olaya Email : volayaf at gmail dot com *************************************************************************** * * * 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__ = 'Victor Olaya' __date__ = 'August 2012' __copyright__ = '(C) 2012, Victor Olaya' # This will get replaced with a git SHA1 when you do a git archive323 __revision__ = '$Format:%H$' import os from qgis.PyQt.QtGui import QIcon from qgis.core import (QgsProcessingAlgorithm, QgsGeometry, QgsFeature, QgsWkbTypes, QgsProcessingUtils) from processing.algs.qgis import QgisAlgorithm from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException from processing.core.parameters import ParameterVector from processing.core.outputs import OutputVector from processing.tools import dataobjects pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class PolygonCentroids(QgisAlgorithm): INPUT_LAYER = 'INPUT_LAYER' OUTPUT_LAYER = 'OUTPUT_LAYER' def flags(self): # this algorithm is deprecated - use Centroids instead return QgsProcessingAlgorithm.FlagDeprecated def icon(self): return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'centroids.png')) def group(self): return self.tr('Vector geometry tools') def __init__(self): super().__init__() self.addParameter(ParameterVector(self.INPUT_LAYER, self.tr('Input layer'), [dataobjects.TYPE_VECTOR_POLYGON])) self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Centroids'))) def name(self): return 'polygoncentroids' def displayName(self): return self.tr('Polygon centroids') def processAlgorithm(self, parameters, context, feedback): layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context) writer = self.getOutputFromName( self.OUTPUT_LAYER).getVectorWriter(layer.fields(), QgsWkbTypes.Point, layer.crs(), context) outFeat = QgsFeature() features = QgsProcessingUtils.getFeatures(layer, context) total = 100.0 / QgsProcessingUtils.featureCount(layer, context) for current, feat in enumerate(features): inGeom = feat.geometry() attrs = feat.attributes() if inGeom.isNull(): outGeom = QgsGeometry(None) else: outGeom = QgsGeometry(inGeom.centroid()) if not outGeom: raise GeoAlgorithmExecutionException( self.tr('Error calculating centroid')) outFeat.setGeometry(outGeom) outFeat.setAttributes(attrs) writer.addFeature(outFeat) feedback.setProgress(int(current * total)) del writer