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91 lines
3.1 KiB
Python
91 lines
3.1 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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PolygonsToLines.py
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---------------------
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Date : August 2012
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Copyright : (C) 2012 by Victor Olaya
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Email : volayaf at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Victor Olaya'
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__date__ = 'August 2012'
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__copyright__ = '(C) 2012, Victor Olaya'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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from qgis.core import QGis, QgsFeature, QgsGeometry
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.parameters import ParameterVector
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from processing.core.outputs import OutputVector
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from processing.tools import dataobjects, vector
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class PolygonsToLines(GeoAlgorithm):
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INPUT = 'INPUT'
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OUTPUT = 'OUTPUT'
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def defineCharacteristics(self):
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self.name, self.i18n_name = self.trAlgorithm('Polygons to lines')
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self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
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self.addParameter(ParameterVector(self.INPUT,
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self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POLYGON]))
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self.addOutput(OutputVector(self.OUTPUT, self.tr('Lines from polygons')))
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def processAlgorithm(self, progress):
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layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT))
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
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layer.pendingFields().toList(), QGis.WKBLineString, layer.crs())
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outFeat = QgsFeature()
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inGeom = QgsGeometry()
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outGeom = QgsGeometry()
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current = 0
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features = vector.features(layer)
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total = 100.0 / float(len(features))
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for f in features:
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inGeom = f.geometry()
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attrs = f.attributes()
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lineList = self.extractAsLine(inGeom)
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outFeat.setAttributes(attrs)
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for h in lineList:
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outFeat.setGeometry(outGeom.fromPolyline(h))
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writer.addFeature(outFeat)
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current += 1
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progress.setPercentage(int(current * total))
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del writer
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def extractAsLine(self, geom):
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multiGeom = QgsGeometry()
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lines = []
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if geom.type() == QGis.Polygon:
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if geom.isMultipart():
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multiGeom = geom.asMultiPolygon()
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for i in multiGeom:
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lines.extend(i)
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else:
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multiGeom = geom.asPolygon()
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lines = multiGeom
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return lines
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else:
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return []
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