107 lines
4.2 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
OffsetLine.py
--------------
Date : July 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__ = 'July 2016'
__copyright__ = '(C) 2016, Nyall Dawson'
# This will get replaced with a git SHA1 when you do a git archive323
__revision__ = '$Format:%H$'
import os
from qgis.core import QgsGeometry, QgsWkbTypes
from qgis.PyQt.QtGui import QIcon
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector, ParameterSelection, ParameterNumber
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 OffsetLine(GeoAlgorithm):
INPUT_LAYER = 'INPUT_LAYER'
OUTPUT_LAYER = 'OUTPUT_LAYER'
DISTANCE = 'DISTANCE'
SEGMENTS = 'SEGMENTS'
JOIN_STYLE = 'JOIN_STYLE'
MITRE_LIMIT = 'MITRE_LIMIT'
def defineCharacteristics(self):
self.name, self.i18n_name = self.trAlgorithm('Offset line')
self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
self.addParameter(ParameterVector(self.INPUT_LAYER,
self.tr('Input layer'), [dataobjects.TYPE_VECTOR_LINE]))
self.addParameter(ParameterNumber(self.DISTANCE,
self.tr('Distance'), default=10.0))
self.addParameter(ParameterNumber(self.SEGMENTS,
self.tr('Segments'), 1, default=8))
self.join_styles = [self.tr('Round'),
'Mitre',
'Bevel']
self.addParameter(ParameterSelection(
self.JOIN_STYLE,
self.tr('Join style'),
self.join_styles))
self.addParameter(ParameterNumber(self.MITRE_LIMIT,
self.tr('Mitre limit'), 1, default=2))
self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Offset'), datatype=[dataobjects.TYPE_VECTOR_LINE]))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT_LAYER))
writer = self.getOutputFromName(
self.OUTPUT_LAYER).getVectorWriter(
layer.fields().toList(),
QgsWkbTypes.LineString,
layer.crs())
distance = self.getParameterValue(self.DISTANCE)
segments = int(self.getParameterValue(self.SEGMENTS))
join_style = self.getParameterValue(self.JOIN_STYLE) + 1
miter_limit = self.getParameterValue(self.MITRE_LIMIT)
features = vector.features(layer)
total = 100.0 / len(features)
for current, input_feature in enumerate(features):
output_feature = input_feature
input_geometry = input_feature.geometry()
if input_geometry:
output_geometry = input_geometry.offsetCurve(distance, segments, join_style, miter_limit)
if not output_geometry:
raise GeoAlgorithmExecutionException(
self.tr('Error calculating line offset'))
output_feature.setGeometry(output_geometry)
writer.addFeature(output_feature)
progress.setPercentage(int(current * total))
del writer