2017-10-26 07:06:34 +10:00

158 lines
6.5 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
SumLines.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.PyQt.QtCore import QVariant
from qgis.core import (QgsFeature,
QgsFeatureSink,
QgsField,
QgsGeometry,
QgsFeatureRequest,
QgsDistanceArea,
QgsProject,
QgsProcessing,
QgsProcessingParameterString,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterFeatureSink,
QgsSpatialIndex)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class SumLines(QgisAlgorithm):
LINES = 'LINES'
POLYGONS = 'POLYGONS'
LEN_FIELD = 'LEN_FIELD'
COUNT_FIELD = 'COUNT_FIELD'
OUTPUT = 'OUTPUT'
def icon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'sum_lines.png'))
def group(self):
return self.tr('Vector analysis')
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(QgsProcessingParameterFeatureSource(self.LINES,
self.tr('Lines'), [QgsProcessing.TypeVectorLine]))
self.addParameter(QgsProcessingParameterFeatureSource(self.POLYGONS,
self.tr('Polygons'), [QgsProcessing.TypeVectorPolygon]))
self.addParameter(QgsProcessingParameterString(self.LEN_FIELD,
self.tr('Lines length field name'), defaultValue='LENGTH'))
self.addParameter(QgsProcessingParameterString(self.COUNT_FIELD,
self.tr('Lines count field name'), defaultValue='COUNT'))
self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Line length'), QgsProcessing.TypeVectorPolygon))
def name(self):
return 'sumlinelengths'
def displayName(self):
return self.tr('Sum line lengths')
def processAlgorithm(self, parameters, context, feedback):
line_source = self.parameterAsSource(parameters, self.LINES, context)
poly_source = self.parameterAsSource(parameters, self.POLYGONS, context)
length_field_name = self.parameterAsString(parameters, self.LEN_FIELD, context)
count_field_name = self.parameterAsString(parameters, self.COUNT_FIELD, context)
fields = poly_source.fields()
if fields.lookupField(length_field_name) < 0:
fields.append(QgsField(length_field_name, QVariant.Double))
length_field_index = fields.lookupField(length_field_name)
if fields.lookupField(count_field_name) < 0:
fields.append(QgsField(count_field_name, QVariant.Int))
count_field_index = fields.lookupField(count_field_name)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, poly_source.wkbType(), poly_source.sourceCrs())
spatialIndex = QgsSpatialIndex(line_source.getFeatures(
QgsFeatureRequest().setSubsetOfAttributes([]).setDestinationCrs(poly_source.sourceCrs())), feedback)
distArea = QgsDistanceArea()
distArea.setSourceCrs(poly_source.sourceCrs())
distArea.setEllipsoid(context.project().ellipsoid())
features = poly_source.getFeatures()
total = 100.0 / poly_source.featureCount() if poly_source.featureCount() else 0
for current, poly_feature in enumerate(features):
if feedback.isCanceled():
break
output_feature = QgsFeature()
count = 0
length = 0
if poly_feature.hasGeometry():
poly_geom = poly_feature.geometry()
has_intersections = False
lines = spatialIndex.intersects(poly_geom.boundingBox())
engine = None
if len(lines) > 0:
has_intersections = True
# use prepared geometries for faster intersection tests
engine = QgsGeometry.createGeometryEngine(poly_geom.constGet())
engine.prepareGeometry()
if has_intersections:
request = QgsFeatureRequest().setFilterFids(lines).setSubsetOfAttributes([]).setDestinationCrs(poly_source.sourceCrs())
for line_feature in line_source.getFeatures(request):
if feedback.isCanceled():
break
if engine.intersects(line_feature.geometry().constGet()):
outGeom = poly_geom.intersection(line_feature.geometry())
length += distArea.measureLength(outGeom)
count += 1
output_feature.setGeometry(poly_geom)
attrs = poly_feature.attributes()
if length_field_index == len(attrs):
attrs.append(length)
else:
attrs[length_field_index] = length
if count_field_index == len(attrs):
attrs.append(count)
else:
attrs[count_field_index] = count
output_feature.setAttributes(attrs)
sink.addFeature(output_feature, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}