QGIS/python/plugins/processing/algs/qgis/ReverseLineDirection.py
Nyall Dawson b1cadb1822 Use generic algorithm icon for qgis algorithms which do not
have specific icons, instead of generic qgis icon

We consider these 'top level' algorithms, and using the
standard algorithm icon should help reflect this and
differentiate them from 3rd party algorithms.
2017-06-24 12:01:20 +10:00

88 lines
3.4 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
ReverseLineDirection.py
-----------------------
Date : November 2015
Copyright : (C) 2015 by Nyall Dawson
Email : nyall dot dawson 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__ = 'Nyall Dawson'
__date__ = 'November 2015'
__copyright__ = '(C) 2015, Nyall Dawson'
# This will get replaced with a git SHA1 when you do a git archive323
__revision__ = '$Format:%H$'
from qgis.core import (QgsApplication,
QgsGeometry,
QgsFeature,
QgsFeatureSink,
QgsProcessingUtils)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects
class ReverseLineDirection(QgisAlgorithm):
INPUT_LAYER = 'INPUT_LAYER'
OUTPUT_LAYER = 'OUTPUT_LAYER'
def group(self):
return self.tr('Vector geometry tools')
def __init__(self):
super().__init__()
self.addParameter(ParameterVector(self.INPUT_LAYER,
self.tr('Input layer'), [dataobjects.TYPE_VECTOR_LINE]))
self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Reversed'), datatype=[dataobjects.TYPE_VECTOR_LINE]))
def name(self):
return 'reverselinedirection'
def displayName(self):
return self.tr('Reverse line direction')
def processAlgorithm(self, parameters, context, feedback):
layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
writer = self.getOutputFromName(
self.OUTPUT_LAYER).getVectorWriter(layer.fields(), layer.wkbType(), layer.crs(), context)
outFeat = QgsFeature()
features = QgsProcessingUtils.getFeatures(layer, context)
total = 100.0 / layer.featureCount() if layer.featureCount() else 0
for current, inFeat in enumerate(features):
inGeom = inFeat.geometry()
attrs = inFeat.attributes()
outGeom = None
if not inGeom.isNull():
reversedLine = inGeom.geometry().reversed()
if not reversedLine:
raise GeoAlgorithmExecutionException(
self.tr('Error reversing line'))
outGeom = QgsGeometry(reversedLine)
outFeat.setGeometry(outGeom)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
del writer