QGIS/python/plugins/processing/algs/qgis/PolygonCentroids.py

105 lines
3.5 KiB
Python

# -*- 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)
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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 PolygonCentroids(GeoAlgorithm):
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 name(self):
return 'polygoncentroids'
def displayName(self):
return self.tr('Polygon centroids')
def defineCharacteristics(self):
self.addParameter(ParameterVector(self.INPUT_LAYER,
self.tr('Input layer'), [dataobjects.TYPE_VECTOR_POLYGON]))
self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Centroids')))
def processAlgorithm(self, context, feedback):
layer = dataobjects.getLayerFromString(
self.getParameterValue(self.INPUT_LAYER))
writer = self.getOutputFromName(
self.OUTPUT_LAYER).getVectorWriter(
layer.fields(),
QgsWkbTypes.Point,
layer.crs())
outFeat = QgsFeature()
features = vector.features(layer)
total = 100.0 / len(features)
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