review Clip tool

qgis · Mar 21, 2013 · aa4f70c · aa4f70c
1 parent 48e9f42
commit aa4f70c
Showing 1 changed file with 71 additions and 76 deletions.
diff --git a/python/plugins/sextante/algs/ftools/Clip.py b/python/plugins/sextante/algs/ftools/Clip.py
@@ -23,113 +23,108 @@
 # This will get replaced with a git SHA1 when you do a git archive
 __revision__ = '$Format:%H$'
 
-from sextante.core.GeoAlgorithm import GeoAlgorithm
 from PyQt4.QtCore import *
-from PyQt4.QtGui import *
+
 from qgis.core import *
-from sextante.parameters.ParameterVector import ParameterVector
+
+from sextante.core.GeoAlgorithm import GeoAlgorithm
 from sextante.core.QGisLayers import QGisLayers
+from sextante.core.SextanteLog import SextanteLog
+
+from sextante.parameters.ParameterVector import ParameterVector
+
 from sextante.outputs.OutputVector import OutputVector
+
 from sextante.algs.ftools import FToolsUtils as utils
-from sextante.core.SextanteLog import SextanteLog
 
 class Clip(GeoAlgorithm):
 
     INPUT = "INPUT"
-    INPUT2 = "INPUT2"
+    OVERLAY = "OVERLAY"
     OUTPUT = "OUTPUT"
 
     #===========================================================================
     # def getIcon(self):
     #    return QtGui.QIcon(os.path.dirname(__file__) + "/icons/clip.png")
     #===========================================================================
 
+    def defineCharacteristics(self):
+        self.name = "Clip"
+        self.group = "Vector overlay tools"
+        self.addParameter(ParameterVector(Clip.INPUT, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
+        self.addParameter(ParameterVector(Clip.OVERLAY, "Clip layer", ParameterVector.VECTOR_TYPE_ANY))
+        self.addOutput(OutputVector(Clip.OUTPUT, "Clipped"))
+
     def processAlgorithm(self, progress):
-        settings = QSettings()
-        systemEncoding = settings.value( "/UI/encoding", "System" ).toString()
-        output = self.getOutputValue(Clip.OUTPUT)
-        vlayerA = QGisLayers.getObjectFromUri(self.getParameterValue(Clip.INPUT))
-        vlayerB = QGisLayers.getObjectFromUri(self.getParameterValue(Clip.INPUT2))
+        layerA = QGisLayers.getObjectFromUri(self.getParameterValue(Clip.INPUT))
+        layerB = QGisLayers.getObjectFromUri(self.getParameterValue(Clip.OVERLAY))
+
         GEOS_EXCEPT = True
         FEATURE_EXCEPT = True
-        vproviderA = vlayerA.dataProvider()
-        #allAttrsA = vproviderA.attributeIndexes()
-        #vproviderA.select( allAttrsA )
-        vproviderB = vlayerB.dataProvider()
-        #allAttrsB = vproviderB.attributeIndexes()
-        #vproviderB.select( allAttrsB )
-
-        # check for crs compatibility
-        crsA = vproviderA.crs()
-        crsB = vproviderB.crs()
-        if not crsA.isValid() or not crsB.isValid():
-            SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Intersection. Invalid CRS. Results might be unexpected")
-        else:
-            if crsA != crsB:
-                SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Intersection. Non-matching CRSs. Results might be unexpected")
-        fields = vproviderA.fields()
-        writer = QgsVectorFileWriter( output, systemEncoding,fields, vproviderA.geometryType(), vproviderA.crs() )
+
+        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layerA.pendingFields(),
+                     layerA.dataProvider().geometryType(), layerA.dataProvider().crs())
 
         inFeatA = QgsFeature()
         inFeatB = QgsFeature()
         outFeat = QgsFeature()
-        index = utils.createSpatialIndex(vlayerB)
-        #vproviderA.rewind()
-        nElement = 0
-        selectionA = QGisLayers.features(vlayerA)
-        nFeat = len(selectionA)
+
+        index = utils.createSpatialIndex(layerB)
+
+        selectionA = QGisLayers.features(layerA)
+
+        current = 0
+        total = 100.0 / float(len(selectionA))
+
         for inFeatA in selectionA:
-            nElement += 1
-            progress.setPercentage(nElement/float(nFeat) * 100)
-            geom = QgsGeometry( inFeatA.geometry() )
-            int_geom = QgsGeometry( geom )
-            atMap = inFeatA.attributes()
-            intersects = index.intersects(geom.boundingBox())
-            found = False
+            geom = QgsGeometry(inFeatA.geometry())
+            attrs = inFeatA.attributes()
+            intersections = index.intersects(geom.boundingBox())
             first = True
-            for id in intersects:
-                vlayerB.featureAtId(int(id), inFeatB)
-                tmpGeom = QgsGeometry(inFeatB.geometry())
-                if tmpGeom.intersects(geom):
-                    found = True
-                    if first:
-                        outFeat.setGeometry(QgsGeometry(tmpGeom))
-                        first = False
-                    else:
+            found = False
+            if len(intersections) > 0:
+                for i in intersections:
+                    request = QgsFeatureRequest().setFilterFid(i)
+                    inFeatB = layerB.getFeatures(request).next()
+                    tmpGeom = QgsGeometry(inFeatB.geometry())
+                    if tmpGeom.intersects(geom):
+                        found = True
+                        if first:
+                            outFeat.setGeometry(QgsGeometry(tmpGeom))
+                            first = False
+                        else:
+                            try:
+                                cur_geom = QgsGeometry(outFeat.geometry())
+                                new_geom = QgsGeometry(cur_geom.combine(tmpGeom))
+                                outFeat.setGeometry(QgsGeometry(new_geom))
+                            except:
+                                GEOS_EXCEPT = False
+                                break
+                if found:
+                    try:
+                        cur_geom = QgsGeometry(outFeat.geometry())
+                        new_geom = QgsGeometry(geom.intersection(cur_geom))
+                        if new_geom.wkbType() == QGis.WKBNoGeometry :
+                            int_com = QgsGeometry(geom.combine(cur_geom))
+                            int_sym = QgsGeometry(geom.symDifference(cur_geom))
+                            new_geom = QgsGeometry(int_com.difference(int_sym))
                         try:
-                            cur_geom = QgsGeometry( outFeat.geometry() )
-                            new_geom = QgsGeometry( cur_geom.combine( tmpGeom ) )
-                            outFeat.setGeometry( QgsGeometry( new_geom ) )
+                            outFeat.setGeometry(new_geom)
+                            outFeat.setAttributes(attrs)
+                            writer.addFeature(outFeat)
                         except:
-                            GEOS_EXCEPT = False
-                            break
-            if found:
-                try:
-                    cur_geom = QgsGeometry( outFeat.geometry() )
-                    new_geom = QgsGeometry( geom.intersection( cur_geom ) )
-                    if new_geom.wkbType() == 7:
-                        int_com = QgsGeometry( geom.combine( cur_geom ) )
-                        int_sym = QgsGeometry( geom.symDifference( cur_geom ) )
-                        new_geom = QgsGeometry( int_com.difference( int_sym ) )
-                    try:
-                        outFeat.setGeometry( new_geom )
-                        outFeat.setAttributes( atMap )
-                        writer.addFeature( outFeat )
+                            FEAT_EXCEPT = False
+                            continue
                     except:
-                        FEATURE_EXCEPT = False
+                        GEOS_EXCEPT = False
                         continue
-                except:
-                    GEOS_EXCEPT = False
-                    continue
+
+            current += 1
+            progress.setPercentage(int(current * total))
+
+        del writer
 
         if not GEOS_EXCEPT:
             SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Geometry exception while computing clip")
         if not FEATURE_EXCEPT:
             SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Feature exception while computing clip")
-
-    def defineCharacteristics(self):
-        self.name = "Clip"
-        self.group = "Vector overlay tools"
-        self.addParameter(ParameterVector(Clip.INPUT, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
-        self.addParameter(ParameterVector(Clip.INPUT2, "Clip layer", ParameterVector.VECTOR_TYPE_ANY))
-        self.addOutput(OutputVector(Clip.OUTPUT, "Clipped"))