# -*- coding: utf-8 -*-
"""
***************************************************************************
vector.py
---------------------
Date : February 2013
Copyright : (C) 2013 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. *
* *
***************************************************************************
"""
from processing.algs.qgis import postgis_utils
__author__ = 'Victor Olaya'
__date__ = 'February 2013'
__copyright__ = '(C) 2013, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import csv
import uuid
import codecs
import cStringIO
from PyQt4.QtCore import QVariant, QSettings
from qgis.core import QGis, QgsFields, QgsField, QgsGeometry, QgsRectangle, QgsSpatialIndex, QgsMapLayerRegistry, QgsMapLayer, QgsVectorLayer, QgsVectorFileWriter, QgsDistanceArea
from processing.core.ProcessingConfig import ProcessingConfig
from PyQt4 import QtSql
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from qgis.core import *
GEOM_TYPE_MAP = {
QGis.WKBPoint: 'Point',
QGis.WKBLineString: 'LineString',
QGis.WKBPolygon: 'Polygon',
QGis.WKBMultiPoint: 'MultiPoint',
QGis.WKBMultiLineString: 'MultiLineString',
QGis.WKBMultiPolygon: 'MultiPolygon',
}
TYPE_MAP = {
str: QVariant.String,
float: QVariant.Double,
int: QVariant.Int,
bool: QVariant.Bool
}
TYPE_MAP_MEMORY_LAYER = {
QVariant.String: "string",
QVariant.Double: "double",
QVariant.Int: "integer"
}
TYPE_MAP_POSTGIS_LAYER = {
QVariant.String: "VARCHAR",
QVariant.Double: "REAL",
QVariant.Int: "INTEGER",
QVariant.Bool: "BOOLEAN"
}
def features(layer):
"""This returns an iterator over features in a vector layer,
considering the selection that might exist in the layer, and the
configuration that indicates whether to use only selected feature
or all of them.
This should be used by algorithms instead of calling the QGis API
directly, to ensure a consistent behaviour across algorithms.
"""
class Features:
def __init__(self, layer):
self.layer = layer
self.selection = False
self.iter = layer.getFeatures()
if ProcessingConfig.getSetting(ProcessingConfig.USE_SELECTED):
selected = layer.selectedFeatures()
if len(selected) > 0:
self.selection = True
self.iter = iter(selected)
def __iter__(self):
return self.iter
def __len__(self):
if self.selection:
return int(self.layer.selectedFeatureCount())
else:
return int(self.layer.featureCount())
return Features(layer)
def uniqueValues(layer, attribute):
"""Returns a list of unique values for a given attribute.
Attribute can be defined using a field names or a zero-based
field index. It considers the existing selection.
"""
values = []
fieldIndex = resolveFieldIndex(layer, attribute)
feats = features(layer)
for feat in feats:
if feat.attributes()[fieldIndex] not in values:
values.append(feat.attributes()[fieldIndex])
return values
def resolveFieldIndex(layer, attr):
"""This method takes an object and returns the index field it
refers to in a layer. If the passed object is an integer, it
returns the same integer value. If the passed value is not an
integer, it returns the field whose name is the string
representation of the passed object.
Ir raises an exception if the int value is larger than the number
of fields, or if the passed object does not correspond to any
field.
"""
if isinstance(attr, int):
return attr
else:
index = layer.fieldNameIndex(unicode(attr))
if index == -1:
raise ValueError('Wrong field name')
return index
def values(layer, *attributes):
"""Returns the values in the attributes table of a vector layer,
for the passed fields.
Field can be passed as field names or as zero-based field indices.
Returns a dict of lists, with the passed field identifiers as keys.
It considers the existing selection.
It assummes fields are numeric or contain values that can be parsed
to a number.
"""
ret = {}
for attr in attributes:
index = resolveFieldIndex(layer, attr)
values = []
feats = features(layer)
for feature in feats:
try:
v = float(feature.attributes()[index])
values.append(v)
except:
values.append(None)
ret[attr] = values
return ret
def testForUniqueness(fieldList1, fieldList2):
'''Returns a modified version of fieldList2, removing naming
collisions with fieldList1.'''
changed = True
while changed:
changed = False
for i in range(0, len(fieldList1)):
for j in range(0, len(fieldList2)):
if fieldList1[i].name() == fieldList2[j].name():
field = fieldList2[j]
name = createUniqueFieldName(field.name(), fieldList1)
fieldList2[j] = QgsField(name, field.type(), len=field.length(), prec=field.precision(), comment=field.comment())
changed = True
return fieldList2
def spatialindex(layer):
"""Creates a spatial index for the passed vector layer.
"""
idx = QgsSpatialIndex()
feats = features(layer)
for ft in feats:
idx.insertFeature(ft)
return idx
def createUniqueFieldName(fieldName, fieldList):
def nextname(name):
num = 1
while True:
returnname = '{name}_{num}'.format(name=name[:8], num=num)
yield returnname
num += 1
def found(name):
return any(f.name() == name for f in fieldList)
shortName = fieldName[:10]
if not fieldList:
return shortName
if not found(shortName):
return shortName
for newname in nextname(shortName):
if not found(newname):
return newname
def findOrCreateField(layer, fieldList, fieldName, fieldLen=24, fieldPrec=15):
idx = layer.fieldNameIndex(fieldName)
if idx == -1:
fn = createUniqueFieldName(fieldName, fieldList)
field = QgsField(fn, QVariant.Double, '', fieldLen, fieldPrec)
idx = len(fieldList)
fieldList.append(field)
return (idx, fieldList)
def extractPoints(geom):
points = []
if geom.type() == QGis.Point:
if geom.isMultipart():
points = geom.asMultiPoint()
else:
points.append(geom.asPoint())
elif geom.type() == QGis.Line:
if geom.isMultipart():
lines = geom.asMultiPolyline()
for line in lines:
points.extend(line)
else:
points = geom.asPolyline()
elif geom.type() == QGis.Polygon:
if geom.isMultipart():
polygons = geom.asMultiPolygon()
for poly in polygons:
for line in poly:
points.extend(line)
else:
polygon = geom.asPolygon()
for line in polygon:
points.extend(line)
return points
def simpleMeasure(geom, method=0, ellips=None, crs=None):
# Method defines calculation type:
# 0 - layer CRS
# 1 - project CRS
# 2 - ellipsoidal
if geom.wkbType() in [QGis.WKBPoint, QGis.WKBPoint25D]:
pt = geom.asPoint()
attr1 = pt.x()
attr2 = pt.y()
elif geom.wkbType() in [QGis.WKBMultiPoint, QGis.WKBMultiPoint25D]:
pt = geom.asMultiPoint()
attr1 = pt[0].x()
attr2 = pt[0].y()
else:
measure = QgsDistanceArea()
if method == 2:
measure.setSourceCrs(crs)
measure.setEllipsoid(ellips)
measure.setEllipsoidalMode(True)
attr1 = measure.measure(geom)
if geom.type() == QGis.Polygon:
attr2 = measure.measurePerimeter(geom)
else:
attr2 = None
return (attr1, attr2)
def getUniqueValues(layer, fieldIndex):
values = []
feats = features(layer)
for feat in feats:
if feat.attributes()[fieldIndex] not in values:
values.append(feat.attributes()[fieldIndex])
return values
def getUniqueValuesCount(layer, fieldIndex):
return len(getUniqueValues(layer, fieldIndex))
def combineVectorFields(layerA, layerB):
"""Create single field map from two input field maps.
"""
fields = []
fieldsA = layerA.pendingFields()
fields.extend(fieldsA)
namesA = [unicode(f.name()).lower() for f in fieldsA]
fieldsB = layerB.pendingFields()
for field in fieldsB:
name = unicode(field.name()).lower()
if name in namesA:
idx = 2
newName = name + '_' + unicode(idx)
while newName in namesA:
idx += 1
newName = name + '_' + unicode(idx)
field = QgsField(newName, field.type(), field.typeName())
fields.append(field)
return fields
def duplicateInMemory(layer, newName='', addToRegistry=False):
"""Return a memory copy of a layer
layer: QgsVectorLayer that shall be copied to memory.
new_name: The name of the copied layer.
add_to_registry: if True, the new layer will be added to the QgsMapRegistry
Returns an in-memory copy of a layer.
"""
if newName is '':
newName = layer.name() + ' (Memory)'
if layer.type() == QgsMapLayer.VectorLayer:
geomType = layer.geometryType()
if geomType == QGis.Point:
strType = 'Point'
elif geomType == QGis.Line:
strType = 'Line'
elif geomType == QGis.Polygon:
strType = 'Polygon'
else:
raise RuntimeError('Layer is whether Point nor Line nor Polygon')
else:
raise RuntimeError('Layer is not a VectorLayer')
crs = layer.crs().authid().lower()
myUuid = unicode(uuid.uuid4())
uri = '%s?crs=%s&index=yes&uuid=%s' % (strType, crs, myUuid)
memLayer = QgsVectorLayer(uri, newName, 'memory')
memProvider = memLayer.dataProvider()
provider = layer.dataProvider()
fields = provider.fields().toList()
memProvider.addAttributes(fields)
memLayer.updateFields()
for ft in provider.getFeatures():
memProvider.addFeatures([ft])
if addToRegistry:
if memLayer.isValid():
QgsMapLayerRegistry.instance().addMapLayer(memLayer)
else:
raise RuntimeError('Layer invalid')
return memLayer
def checkMinDistance(point, index, distance, points):
"""Check if distance from given point to all other points is greater
than given value.
"""
if distance == 0:
return True
neighbors = index.nearestNeighbor(point, 1)
if len(neighbors) == 0:
return True
if neighbors[0] in points:
np = points[neighbors[0]]
if np.sqrDist(point) < (distance * distance):
return False
return True
def _toQgsField(f):
if isinstance(f, QgsField):
return f
return QgsField(f[0], TYPE_MAP.get(f[1], QVariant.String))
def snapToPrecision(geom, precision):
snapped = QgsGeometry(geom)
if precision == 0.0:
return snapped
i = 0
p = snapped.vertexAt(i)
while p.x() != 0.0 and p.y() != 0.0:
x = round(p.x() / precision, 0) * precision
y = round(p.y() / precision, 0) * precision
snapped.moveVertex(x, y, i)
i = i + 1
p = snapped.vertexAt(i)
return snapped
def bufferedBoundingBox(bbox, buffer_size):
if buffer_size == 0.0:
return QgsRectangle(bbox)
return QgsRectangle(
bbox.xMinimum() - buffer_size,
bbox.yMinimum() - buffer_size,
bbox.xMaximum() + buffer_size,
bbox.yMaximum() + buffer_size)
class VectorWriter:
MEMORY_LAYER_PREFIX = 'memory:'
POSTGIS_LAYER_PREFIX = 'postgis:'
def __init__(self, destination, encoding, fields, geometryType,
crs, options=None):
self.destination = destination
self.isNotFileBased = False
self.layer = None
self.writer = None
if encoding is None:
settings = QSettings()
encoding = settings.value('/Processing/encoding', 'System', type=str)
if self.destination.startswith(self.MEMORY_LAYER_PREFIX):
self.isNotFileBased = True
uri = GEOM_TYPE_MAP[geometryType] + "?uuid=" + unicode(uuid.uuid4())
if crs.isValid():
uri += '&crs=' + crs.authid()
fieldsdesc = []
for f in fields:
qgsfield = _toQgsField(f)
fieldsdesc.append('field=%s:%s' % (qgsfield.name(),
TYPE_MAP_MEMORY_LAYER.get(qgsfield.type(), "string")))
if fieldsdesc:
uri += '&' + '&'.join(fieldsdesc)
self.layer = QgsVectorLayer(uri, self.destination, 'memory')
self.writer = self.layer.dataProvider()
elif self.destination.startswith(self.POSTGIS_LAYER_PREFIX):
self.isNotFileBased = True
uri = QgsDataSourceURI(self.destination[len(self.POSTGIS_LAYER_PREFIX):])
connInfo = uri.connectionInfo()
(success, user, passwd ) = QgsCredentials.instance().get(connInfo, None, None)
if success:
QgsCredentials.instance().put(connInfo, user, passwd)
else:
raise GeoAlgorithmExecutionException("Couldn't connect to database")
print uri.uri()
try:
db = postgis_utils.GeoDB(host=uri.host(), port=int(uri.port()),
dbname=uri.database(), user=user, passwd=passwd)
except postgis_utils.DbError as e:
raise GeoAlgorithmExecutionException(
"Couldn't connect to database:\n%s" % e.message)
def _runSQL(sql):
try:
db._exec_sql_and_commit(unicode(sql))
except postgis_utils.DbError as e:
raise GeoAlgorithmExecutionException(
'Error creating output PostGIS table:\n%s' % e.message)
fields = [_toQgsField(f) for f in fields]
fieldsdesc = ",".join('%s %s' % (f.name(),
TYPE_MAP_POSTGIS_LAYER.get(f.type(), "VARCHAR"))
for f in fields)
_runSQL("CREATE TABLE %s.%s (%s)" % (uri.schema(), uri.table().lower(), fieldsdesc))
_runSQL("SELECT AddGeometryColumn('{schema}', '{table}', 'the_geom', {srid}, '{typmod}', 2)".format(
table=uri.table().lower(), schema=uri.schema(), srid=crs.authid().split(":")[-1],
typmod=GEOM_TYPE_MAP[geometryType].upper()))
self.layer = QgsVectorLayer(uri.uri(), uri.table(), "postgres")
self.writer = self.layer.dataProvider()
else:
formats = QgsVectorFileWriter.supportedFiltersAndFormats()
OGRCodes = {}
for (key, value) in formats.items():
extension = unicode(key)
extension = extension[extension.find('*.') + 2:]
extension = extension[:extension.find(' ')]
OGRCodes[extension] = value
extension = self.destination[self.destination.rfind('.') + 1:]
if extension not in OGRCodes:
extension = 'shp'
self.destination = self.destination + '.shp'
qgsfields = QgsFields()
for field in fields:
qgsfields.append(_toQgsField(field))
self.writer = QgsVectorFileWriter(self.destination, encoding,
qgsfields, geometryType, crs, OGRCodes[extension])
def addFeature(self, feature):
if self.isNotFileBased:
self.writer.addFeatures([feature])
else:
self.writer.addFeature(feature)
class TableWriter:
def __init__(self, fileName, encoding, fields):
self.fileName = fileName
if not self.fileName.lower().endswith('csv'):
self.fileName += '.csv'
self.encoding = encoding
if self.encoding is None or encoding == 'System':
self.encoding = 'utf-8'
with open(self.fileName, 'wb') as csvFile:
self.writer = UnicodeWriter(csvFile, encoding=self.encoding)
if len(fields) != 0:
self.writer.writerow(fields)
def addRecord(self, values):
with open(self.fileName, 'ab') as csvFile:
self.writer = UnicodeWriter(csvFile, encoding=self.encoding)
self.writer.writerow(values)
def addRecords(self, records):
with open(self.fileName, 'ab') as csvFile:
self.writer = UnicodeWriter(csvFile, encoding=self.encoding)
self.writer.writerows(records)
class UnicodeWriter:
def __init__(self, f, dialect=csv.excel, encoding='utf-8', **kwds):
self.queue = cStringIO.StringIO()
self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
self.stream = f
self.encoder = codecs.getincrementalencoder(encoding)()
def writerow(self, row):
row = map(unicode, row)
try:
self.writer.writerow([s.encode('utf-8') for s in row])
except:
self.writer.writerow(row)
data = self.queue.getvalue()
data = data.decode('utf-8')
data = self.encoder.encode(data)
self.stream.write(data)
self.queue.truncate(0)
def writerows(self, rows):
for row in rows:
self.writerow(row)