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"""
***************************************************************************
Buffer.py
---------------------
Date : Janaury 2015
Copyright : (C) 2015 by Giovanni Manghi
Email : giovanni dot manghi at naturalgis dot pt
***************************************************************************
* *
* 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__ = "Giovanni Manghi"
__date__ = "January 2015"
__copyright__ = "(C) 2015, Giovanni Manghi"
from qgis.core import (
QgsProcessing,
QgsProcessingParameterDistance,
QgsProcessingParameterDefinition,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterField,
QgsProcessingParameterString,
QgsProcessingParameterNumber,
QgsProcessingException,
QgsProcessingParameterBoolean,
QgsProcessingParameterVectorDestination,
)
from processing.algs.gdal.GdalAlgorithm import GdalAlgorithm
from processing.algs.gdal.GdalUtils import GdalUtils
class Buffer(GdalAlgorithm):
INPUT = "INPUT"
FIELD = "FIELD"
GEOMETRY = "GEOMETRY"
DISTANCE = "DISTANCE"
DISSOLVE = "DISSOLVE"
EXPLODE_COLLECTIONS = "EXPLODE_COLLECTIONS"
OPTIONS = "OPTIONS"
OUTPUT = "OUTPUT"
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(
QgsProcessingParameterFeatureSource(self.INPUT, self.tr("Input layer"))
)
self.addParameter(
QgsProcessingParameterString(
self.GEOMETRY, self.tr("Geometry column name"), defaultValue="geometry"
)
)
self.addParameter(
QgsProcessingParameterDistance(
self.DISTANCE,
self.tr("Buffer distance"),
parentParameterName=self.INPUT,
defaultValue=10.0,
)
)
self.addParameter(
QgsProcessingParameterField(
self.FIELD,
self.tr("Dissolve by attribute"),
None,
self.INPUT,
QgsProcessingParameterField.DataType.Any,
optional=True,
)
)
self.addParameter(
QgsProcessingParameterBoolean(
self.DISSOLVE, self.tr("Dissolve all results"), defaultValue=False
)
)
self.addParameter(
QgsProcessingParameterBoolean(
self.EXPLODE_COLLECTIONS,
self.tr(
"Produce one feature for each geometry in any kind of geometry collection in the source file"
),
defaultValue=False,
)
)
options_param = QgsProcessingParameterString(
self.OPTIONS,
self.tr("Additional creation options"),
defaultValue="",
optional=True,
)
options_param.setFlags(
options_param.flags() | QgsProcessingParameterDefinition.Flag.FlagAdvanced
)
self.addParameter(options_param)
self.addParameter(
QgsProcessingParameterVectorDestination(
self.OUTPUT,
self.tr("Buffer"),
QgsProcessing.SourceType.TypeVectorPolygon,
)
)
def name(self):
return "buffervectors"
def displayName(self):
return self.tr("Buffer vectors")
def group(self):
return self.tr("Vector geoprocessing")
def groupId(self):
return "vectorgeoprocessing"
def commandName(self):
return "ogr2ogr"
def getConsoleCommands(self, parameters, context, feedback, executing=True):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, self.INPUT)
)
fields = source.fields()
source_details = self.getOgrCompatibleSource(
self.INPUT, parameters, context, feedback, executing
)
geometry = self.parameterAsString(parameters, self.GEOMETRY, context)
if source_details.geometry_column_name:
geometry = source_details.geometry_column_name
distance = self.parameterAsDouble(parameters, self.DISTANCE, context)
fieldName = self.parameterAsString(parameters, self.FIELD, context)
dissolve = self.parameterAsBoolean(parameters, self.DISSOLVE, context)
options = self.parameterAsString(parameters, self.OPTIONS, context)
outFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
self.setOutputValue(self.OUTPUT, outFile)
output_details = GdalUtils.gdal_connection_details_from_uri(outFile, context)
other_fields_exist = any(True for f in fields if f.name() != geometry)
other_fields = ",*" if other_fields_exist else ""
arguments = [
output_details.connection_string,
source_details.connection_string,
"-dialect",
"sqlite",
"-sql",
]
if dissolve or fieldName:
sql = f'SELECT ST_Union(ST_Buffer({geometry}, {distance})) AS {geometry}{other_fields} FROM "{source_details.layer_name}"'
else:
sql = f'SELECT ST_Buffer({geometry}, {distance}) AS {geometry}{other_fields} FROM "{source_details.layer_name}"'
if fieldName:
sql = f'{sql} GROUP BY "{fieldName}"'
arguments.append(sql)
if self.parameterAsBoolean(parameters, self.EXPLODE_COLLECTIONS, context):
arguments.append("-explodecollections")
if source_details.open_options:
arguments.extend(source_details.open_options_as_arguments())
if source_details.credential_options:
arguments.extend(source_details.credential_options_as_arguments())
if options:
arguments.append(options)
if output_details.format:
arguments.append(f"-f {output_details.format}")
return [self.commandName(), GdalUtils.escapeAndJoin(arguments)]
|
