2015-08-22 14:29:41 +02:00

124 lines
4.8 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Difference.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__ = '$Format:%H$'
from qgis.core import QgsFeatureRequest, QgsFeature, QgsGeometry
from processing.core.ProcessingLog import ProcessingLog
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector
class Difference(GeoAlgorithm):
INPUT = 'INPUT'
OVERLAY = 'OVERLAY'
OUTPUT = 'OUTPUT'
#==========================================================================
#def getIcon(self):
# return QtGui.QIcon(os.path.dirname(__file__) + "/icons/difference.png")
#==========================================================================
def defineCharacteristics(self):
self.name, self.i18n_name = self.trAlgorithm('Difference')
self.group, self.i18n_group = self.trAlgorithm('Vector overlay tools')
self.addParameter(ParameterVector(Difference.INPUT,
self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_ANY]))
self.addParameter(ParameterVector(Difference.OVERLAY,
self.tr('Difference layer'), [ParameterVector.VECTOR_TYPE_ANY]))
self.addOutput(OutputVector(Difference.OUTPUT, self.tr('Difference')))
def processAlgorithm(self, progress):
layerA = dataobjects.getObjectFromUri(
self.getParameterValue(Difference.INPUT))
layerB = dataobjects.getObjectFromUri(
self.getParameterValue(Difference.OVERLAY))
GEOS_EXCEPT = True
FEATURE_EXCEPT = True
writer = self.getOutputFromName(
Difference.OUTPUT).getVectorWriter(layerA.pendingFields(),
layerA.dataProvider().geometryType(),
layerA.dataProvider().crs())
inFeatA = QgsFeature()
inFeatB = QgsFeature()
outFeat = QgsFeature()
index = vector.spatialindex(layerB)
selectionA = vector.features(layerA)
current = 0
total = 100.0 / float(len(selectionA))
for inFeatA in selectionA:
add = True
geom = QgsGeometry(inFeatA.geometry())
diff_geom = QgsGeometry(geom)
attrs = inFeatA.attributes()
intersections = index.intersects(geom.boundingBox())
for i in intersections:
request = QgsFeatureRequest().setFilterFid(i)
inFeatB = layerB.getFeatures(request).next()
tmpGeom = QgsGeometry(inFeatB.geometry())
try:
if diff_geom.intersects(tmpGeom):
diff_geom = QgsGeometry(diff_geom.difference(tmpGeom))
if diff_geom.isGeosEmpty():
GEOS_EXCEPT = False
add = False
break
except:
GEOS_EXCEPT = False
add = False
break
if add:
try:
outFeat.setGeometry(diff_geom)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
except:
FEATURE_EXCEPT = False
continue
current += 1
progress.setPercentage(int(current * total))
del writer
if not GEOS_EXCEPT:
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING,
self.tr('Geometry exception while computing difference'))
if not FEATURE_EXCEPT:
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING,
self.tr('Feature exception while computing difference'))