QGIS/python/plugins/processing/algs/qgis/SelectByLocation.py
Nyall Dawson 99cfb8faf3 Fix processing algs crash when no source features exist
Instead we output an empty layer - this may be critical for
multi-step models where there is validly no features present
in a source layer
2017-06-23 13:49:32 +10:00

155 lines
6.2 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
SelectByLocation.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__ = '$Format:%H$'
import os
from qgis.PyQt.QtGui import QIcon
from qgis.core import QgsGeometry, QgsFeatureRequest, QgsProcessingUtils
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from processing.core.parameters import ParameterSelection
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterNumber
from processing.core.outputs import OutputVector
from processing.tools import vector
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class SelectByLocation(QgisAlgorithm):
INPUT = 'INPUT'
INTERSECT = 'INTERSECT'
PREDICATE = 'PREDICATE'
PRECISION = 'PRECISION'
METHOD = 'METHOD'
OUTPUT = 'OUTPUT'
def icon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'select_location.png'))
def group(self):
return self.tr('Vector selection tools')
def __init__(self):
super().__init__()
self.predicates = (
('intersects', self.tr('intersects')),
('contains', self.tr('contains')),
('disjoint', self.tr('disjoint')),
('equals', self.tr('equals')),
('touches', self.tr('touches')),
('overlaps', self.tr('overlaps')),
('within', self.tr('within')),
('crosses', self.tr('crosses')))
self.methods = [self.tr('creating new selection'),
self.tr('adding to current selection'),
self.tr('removing from current selection')]
self.addParameter(ParameterVector(self.INPUT,
self.tr('Layer to select from')))
self.addParameter(ParameterVector(self.INTERSECT,
self.tr('Additional layer (intersection layer)')))
self.addParameter(ParameterSelection(self.PREDICATE,
self.tr('Geometric predicate'),
self.predicates,
multiple=True))
self.addParameter(ParameterNumber(self.PRECISION,
self.tr('Precision'),
0.0, None, 0.0))
self.addParameter(ParameterSelection(self.METHOD,
self.tr('Modify current selection by'),
self.methods, 0))
self.addOutput(OutputVector(self.OUTPUT, self.tr('Selected (location)'), True))
def name(self):
return 'selectbylocation'
def displayName(self):
return self.tr('Select by location')
def processAlgorithm(self, parameters, context, feedback):
filename = self.getParameterValue(self.INPUT)
inputLayer = QgsProcessingUtils.mapLayerFromString(filename, context)
method = self.getParameterValue(self.METHOD)
filename2 = self.getParameterValue(self.INTERSECT)
selectLayer = QgsProcessingUtils.mapLayerFromString(filename2, context)
predicates = self.getParameterValue(self.PREDICATE)
precision = self.getParameterValue(self.PRECISION)
oldSelection = set(inputLayer.selectedFeatureIds())
inputLayer.removeSelection()
index = QgsProcessingUtils.createSpatialIndex(inputLayer, context)
if 'disjoint' in predicates:
disjoinSet = []
for feat in QgsProcessingUtils.getFeatures(inputLayer, context):
disjoinSet.append(feat.id())
geom = QgsGeometry()
selectedSet = []
features = QgsProcessingUtils.getFeatures(selectLayer, context)
total = 100.0 / selectLayer.featureCount() if selectLayer.featureCount() else 0
for current, f in enumerate(features):
geom = vector.snapToPrecision(f.geometry(), precision)
bbox = geom.boundingBox()
bbox.grow(0.51 * precision)
intersects = index.intersects(bbox)
request = QgsFeatureRequest().setFilterFids(intersects).setSubsetOfAttributes([])
for feat in inputLayer.getFeatures(request):
tmpGeom = vector.snapToPrecision(feat.geometry(), precision)
res = False
for predicate in predicates:
if predicate == 'disjoint':
if tmpGeom.intersects(geom):
try:
disjoinSet.remove(feat.id())
except:
pass # already removed
else:
res = getattr(tmpGeom, predicate)(geom)
if res:
selectedSet.append(feat.id())
break
feedback.setProgress(int(current * total))
if 'disjoint' in predicates:
selectedSet = selectedSet + disjoinSet
if method == 1:
selectedSet = list(oldSelection.union(selectedSet))
elif method == 2:
selectedSet = list(oldSelection.difference(selectedSet))
inputLayer.selectByIds(selectedSet)
self.setOutputValue(self.OUTPUT, filename)