QGIS/python/plugins/processing/algs/qgis/PolygonsToLines.py
2014-10-03 15:47:44 +03:00

99 lines
3.4 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
PolygonsToLines.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 archive
__revision__ = '$Format:%H$'
from PyQt4.QtCore import *
from qgis.core import *
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector
class PolygonsToLines(GeoAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
# =========================================================================
# def getIcon(self):
# return QIcon(os.path.dirname(__file__) + "/icons/to_lines.png")
# =========================================================================
def defineCharacteristics(self):
self.name = 'Polygons to lines'
self.group = 'Vector geometry tools'
self.addParameter(ParameterVector(self.INPUT, 'Input layer',
[ParameterVector.VECTOR_TYPE_POLYGON]))
self.addOutput(OutputVector(self.OUTPUT, 'Output layer'))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT))
writer = self.getOutputFromName(
self.OUTPUT).getVectorWriter(layer.pendingFields().toList(),
QGis.WKBLineString, layer.crs())
outFeat = QgsFeature()
inGeom = QgsGeometry()
outGeom = QgsGeometry()
current = 0
features = vector.features(layer)
total = 100.0 / float(len(features))
for f in features:
inGeom = f.geometry()
attrs = f.attributes()
lineList = self.extractAsLine(inGeom)
outFeat.setAttributes(attrs)
for h in lineList:
outFeat.setGeometry(outGeom.fromPolyline(h))
writer.addFeature(outFeat)
current += 1
progress.setPercentage(int(current * total))
del writer
def extractAsLine(self, geom):
multiGeom = QgsGeometry()
lines = []
if geom.type() == QGis.Polygon:
if geom.isMultipart():
multiGeom = geom.asMultiPolygon()
for i in multiGeom:
lines.extend(i)
else:
multiGeom = geom.asPolygon()
lines = multiGeom
return lines
else:
return []