84 lines
3.1 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
ExtendLines.py
--------------------
Date : October 2016
Copyright : (C) 2016 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__ = 'October 2016'
__copyright__ = '(C) 2016, Nyall Dawson'
# This will get replaced with a git SHA1 when you do a git archive323
__revision__ = '$Format:%H$'
from qgis.core import (QgsProcessingParameterNumber,
QgsProcessingException,
QgsProcessing)
from processing.algs.qgis.QgisAlgorithm import QgisFeatureBasedAlgorithm
class ExtendLines(QgisFeatureBasedAlgorithm):
START_DISTANCE = 'START_DISTANCE'
END_DISTANCE = 'END_DISTANCE'
def group(self):
return self.tr('Vector geometry')
def groupId(self):
return 'vectorgeometry'
def __init__(self):
super().__init__()
self.start_distance = None
self.end_distance = None
def initParameters(self, config=None):
self.addParameter(QgsProcessingParameterNumber(self.START_DISTANCE,
self.tr('Start distance'), type=QgsProcessingParameterNumber.Double, defaultValue=0.0))
self.addParameter(QgsProcessingParameterNumber(self.END_DISTANCE,
self.tr('End distance'), type=QgsProcessingParameterNumber.Double, defaultValue=0.0))
def name(self):
return 'extendlines'
def displayName(self):
return self.tr('Extend lines')
def outputName(self):
return self.tr('Extended')
def inputLayerTypes(self):
return [QgsProcessing.TypeVectorLine]
def prepareAlgorithm(self, parameters, context, feedback):
self.start_distance = self.parameterAsDouble(parameters, self.START_DISTANCE, context)
self.end_distance = self.parameterAsDouble(parameters, self.END_DISTANCE, context)
return True
def processFeature(self, feature, context, feedback):
input_geometry = feature.geometry()
if input_geometry:
output_geometry = input_geometry.extendLine(self.start_distance, self.end_distance)
if not output_geometry:
raise QgsProcessingException(
self.tr('Error calculating extended line'))
feature.setGeometry(output_geometry)
return feature