2013-02-07 23:40:43 +01:00

112 lines
4.7 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 PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from sextante.parameters.ParameterVector import ParameterVector
from sextante.core.QGisLayers import QGisLayers
from sextante.outputs.OutputVector import OutputVector
from sextante.algs.ftools import FToolsUtils as utils
from sextante.core.SextanteLog import SextanteLog
from sextante.core.GeoAlgorithm import GeoAlgorithm
class Difference(GeoAlgorithm):
INPUT = "INPUT"
INPUT2 = "INPUT2"
OUTPUT = "OUTPUT"
#===========================================================================
# def getIcon(self):
# return QtGui.QIcon(os.path.dirname(__file__) + "/icons/difference.png")
#===========================================================================
def processAlgorithm(self, progress):
vlayerA = QGisLayers.getObjectFromUri(self.getParameterValue(Difference.INPUT))
vlayerB = QGisLayers.getObjectFromUri(self.getParameterValue(Difference.INPUT2))
GEOS_EXCEPT = True
FEATURE_EXCEPT = True
vproviderA = vlayerA.dataProvider()
vproviderB = vlayerB.dataProvider()
fields = vproviderA.fields()
# check for crs compatibility
crsA = vproviderA.crs()
crsB = vproviderB.crs()
if not crsA.isValid() or not crsB.isValid():
SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Difference. Invalid CRS. Results might be unexpected")
else:
if crsA != crsB:
SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Difference. Non-matching CRSs. Results might be unexpected")
writer = self.getOutputFromName(Difference.OUTPUT).getVectorWriter(fields, vproviderA.geometryType(), vproviderA.crs() )
inFeatA = QgsFeature()
inFeatB = QgsFeature()
outFeat = QgsFeature()
index = utils.createSpatialIndex(vlayerB)
nElement = 0
selectionA = QGisLayers.features(vlayerA)
nFeat = len(selectionA)
for inFeatA in selectionA:
nElement += 1
progress.setPercentage(nElement/float(nFeat) * 100)
add = True
geom = QgsGeometry( inFeatA.geometry() )
diff_geom = QgsGeometry( geom )
atMap = inFeatA.attributes()
intersects = index.intersects( geom.boundingBox() )
for id in intersects:
vlayerB.featureAtId( int( id ), inFeatB , True)
tmpGeom = QgsGeometry( inFeatB.geometry() )
try:
if diff_geom.intersects( tmpGeom ):
diff_geom = QgsGeometry( diff_geom.difference( tmpGeom ) )
except:
GEOS_EXCEPT = False
add = False
break
if add:
try:
outFeat.setGeometry( diff_geom )
outFeat.setAttributes( atMap )
writer.addFeature( outFeat )
except:
FEATURE_EXCEPT = False
continue
del writer
if not GEOS_EXCEPT:
SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Geometry exception while computing difference")
if not FEATURE_EXCEPT:
SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Feature exception while computing difference")
def defineCharacteristics(self):
self.name = "Difference"
self.group = "Vector overlay tools"
self.addParameter(ParameterVector(Difference.INPUT, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
self.addParameter(ParameterVector(Difference.INPUT2, "Difference layer", ParameterVector.VECTOR_TYPE_ANY))
self.addOutput(OutputVector(Difference.OUTPUT, "Difference"))