73 lines
2.7 KiB
Python

from sextante.core.GeoAlgorithm import GeoAlgorithm
import os.path
from PyQt4 import QtGui
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
class Explode(GeoAlgorithm):
INPUT = "INPUT"
OUTPUT = "OUTPUT"
def getIcon(self):
return QtGui.QIcon(os.path.dirname(__file__) + "/../images/toolbox.png")
def processAlgorithm(self, progress):
settings = QSettings()
systemEncoding = settings.value( "/UI/encoding", "System" ).toString()
vlayer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT))
output = self.getOutputValue(self.OUTPUT)
vprovider = vlayer.dataProvider()
allAttrs = vprovider.attributeIndexes()
vprovider.select( allAttrs )
fields = vprovider.fields()
writer = QgsVectorFileWriter( output, systemEncoding,
fields, QGis.WKBLineString, vprovider.crs() )
inFeat = QgsFeature()
outFeat = QgsFeature()
inGeom = QgsGeometry()
nFeat = vprovider.featureCount()
nElement = 0
while vprovider.nextFeature( inFeat ):
nElement += 1
progress.setPercentage((nElement*100)/nFeat)
inGeom = inFeat.geometry()
atMap = inFeat.attributeMap()
segments = self.extractAsSingleSegments( inGeom )
outFeat.setAttributeMap( atMap )
for segment in segments:
outFeat.setGeometry(segment)
writer.addFeature(outFeat)
del writer
def extractAsSingleSegments( self, geom ):
segments = []
if geom.isMultipart():
multi = geom.asMultiPolyline()
for polyline in multi:
segments.extend( self.getPolylineAsSingleSegments(polyline))
else:
segments.extend( self.getPolylineAsSingleSegments(geom.asPolyline()))
return segments
def getPolylineAsSingleSegments(self, polyline):
segments = []
for i in range(len(polyline)-1):
ptA = polyline[i]
ptB = polyline[i+1]
segment = QgsGeometry.fromPolyline([ptA, ptB])
segments.append(segment)
return segments
def defineCharacteristics(self):
self.name = "Explode lines"
self.group = "Algorithms for vector layers"
self.addParameter(ParameterVector(self.INPUT, "Input layer",ParameterVector.VECTOR_TYPE_LINE))
self.addOutput(OutputVector(self.OUTPUT, "Output layer"))