QGIS/python/plugins/processing/algs/qgis/PolygonsToLines.py
2017-05-02 13:40:49 +10:00

88 lines
3.1 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__ = '$Format:%H$'
import os
from qgis.PyQt.QtGui import QIcon
from qgis.core import QgsGeometry, QgsWkbTypes, QgsProcessingUtils
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class PolygonsToLines(GeoAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
def icon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'to_lines.png'))
def tags(self):
return self.tr('line,polygon,convert').split(',')
def group(self):
return self.tr('Vector geometry tools')
def name(self):
return 'polygonstolines'
def displayName(self):
return self.tr('Polygons to lines')
def defineCharacteristics(self):
self.addParameter(ParameterVector(self.INPUT,
self.tr('Input layer'), [dataobjects.TYPE_VECTOR_POLYGON]))
self.addOutput(OutputVector(self.OUTPUT, self.tr('Lines from polygons'), datatype=[dataobjects.TYPE_VECTOR_LINE]))
def processAlgorithm(self, context, feedback):
layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.fields().toList(), QgsWkbTypes.LineString,
layer.crs(), context)
features = QgsProcessingUtils.getFeatures(layer, context)
total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
for current, f in enumerate(features):
if f.hasGeometry():
lines = QgsGeometry(f.geometry().geometry().boundary()).asGeometryCollection()
for line in lines:
f.setGeometry(line)
writer.addFeature(f)
else:
writer.addFeature(f)
feedback.setProgress(int(current * total))
del writer