QGIS/python/plugins/sextante/ftools/ExtentFromLayer.py
2012-10-11 20:27:47 +03:00

211 lines
8.3 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
ExtentFromLayer.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.path
from PyQt4 import QtGui
from PyQt4.QtCore import *
from qgis.core import *
from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.core.QGisLayers import QGisLayers
from sextante.parameters.ParameterVector import ParameterVector
from sextante.parameters.ParameterBoolean import ParameterBoolean
from sextante.outputs.OutputVector import OutputVector
class ExtentFromLayer(GeoAlgorithm):
INPUT_LAYER = "INPUT_LAYER"
USE_SELECTION = "USE_SELECTION"
BY_FEATURE = "BY_FEATURE"
OUTPUT = "OUTPUT"
def getIcon(self):
return QtGui.QIcon(os.path.dirname(__file__) + "/icons/layer_extent.png")
def defineCharacteristics(self):
self.name = "Polygon from layer extent"
self.group = "Research tools"
self.addParameter(ParameterVector(self.INPUT_LAYER, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
self.addParameter(ParameterBoolean(self.USE_SELECTION, "Use selection", False))
self.addParameter(ParameterBoolean(self.BY_FEATURE, "Calculate extent for each feature separately", False))
self.addOutput(OutputVector(self.OUTPUT, "Output layer"))
def processAlgorithm(self, progress):
layer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER))
useSelection = self.getParameterValue(self.USE_SELECTION)
byFeature = self.getParameterValue(self.BY_FEATURE)
output = self.getOutputValue(self.OUTPUT)
fields = {0 : QgsField("MINX", QVariant.Double),
1 : QgsField("MINY", QVariant.Double),
2 : QgsField("MAXX", QVariant.Double),
3 : QgsField("MAXY", QVariant.Double),
4 : QgsField("CNTX", QVariant.Double),
5 : QgsField("CNTY", QVariant.Double),
6 : QgsField("AREA", QVariant.Double),
7 : QgsField("PERIM", QVariant.Double),
8 : QgsField("HEIGHT", QVariant.Double),
9 : QgsField("WIDTH", QVariant.Double)
}
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields,
QGis.WKBPolygon, layer.crs())
if byFeature:
self.featureExtent(layer, writer, useSelection, progress)
else:
self.layerExtent(layer, writer, progress)
del writer
def layerExtent(self, layer, writer, progress):
rect = layer.extent()
minx = rect.xMinimum()
miny = rect.yMinimum()
maxx = rect.xMaximum()
maxy = rect.yMaximum()
height = rect.height()
width = rect.width()
cntx = minx + (width / 2.0)
cnty = miny + (height / 2.0)
area = width * height
perim = (2 * width) + (2 * height)
rect = [QgsPoint(minx, miny),
QgsPoint(minx, maxy),
QgsPoint(maxx, maxy),
QgsPoint(maxx, miny),
QgsPoint(minx, miny)
]
geometry = QgsGeometry().fromPolygon([rect])
feat = QgsFeature()
feat.setGeometry(geometry)
feat.setAttributeMap({0 : QVariant(minx),
1 : QVariant(miny),
2 : QVariant(maxx),
3 : QVariant(maxy),
4 : QVariant(cntx),
5 : QVariant(cnty),
6 : QVariant(area),
7 : QVariant(perim),
8 : QVariant(height),
9 : QVariant(width)
})
writer.addFeature(feat)
def featureExtent(self, layer, writer, useSelection, progress):
current = 0
inFeat = QgsFeature()
outFeat = QgsFeature()
provider = layer.dataProvider()
provider.select()
if useSelection:
total = 100.0 / float(layer.selectedFeatureCount())
for inFeat in layer.selectedFeatures():
rect = inFeat.geometry().boundingBox()
minx = rect.xMinimum()
miny = rect.yMinimum()
maxx = rect.xMaximum()
maxy = rect.yMaximum()
height = rect.height()
width = rect.width()
cntx = minx + (width / 2.0)
cnty = miny + (height / 2.0)
area = width * height
perim = (2 * width) + (2 * height)
rect = [QgsPoint(minx, miny),
QgsPoint(minx, maxy),
QgsPoint(maxx, maxy),
QgsPoint(maxx, miny),
QgsPoint(minx, miny)
]
geometry = QgsGeometry().fromPolygon([rect])
outFeat.setGeometry(geometry)
outFeat.setAttributeMap({0 : QVariant(minx),
1 : QVariant(miny),
2 : QVariant(maxx),
3 : QVariant(maxy),
4 : QVariant(cntx),
5 : QVariant(cnty),
6 : QVariant(area),
7 : QVariant(perim),
8 : QVariant(height),
9 : QVariant(width)
})
writer.addFeature(outFeat)
current += 1
progress.setPercentage(int(current * total))
else:
total = 100.0 / float(provider.featureCount())
while provider.nextFeature(inFeat):
rect = inFeat.geometry().boundingBox()
minx = rect.xMinimum()
miny = rect.yMinimum()
maxx = rect.xMaximum()
maxy = rect.yMaximum()
height = rect.height()
width = rect.width()
cntx = minx + (width / 2.0)
cnty = miny + (height / 2.0)
area = width * height
perim = (2 * width) + (2 * height)
rect = [QgsPoint(minx, miny),
QgsPoint(minx, maxy),
QgsPoint(maxx, maxy),
QgsPoint(maxx, miny),
QgsPoint(minx, miny)
]
geometry = QgsGeometry().fromPolygon([rect])
outFeat.setGeometry(geometry)
outFeat.setAttributeMap({0 : QVariant(minx),
1 : QVariant(miny),
2 : QVariant(maxx),
3 : QVariant(maxy),
4 : QVariant(cntx),
5 : QVariant(cnty),
6 : QVariant(area),
7 : QVariant(perim),
8 : QVariant(height),
9 : QVariant(width)
})
writer.addFeature(outFeat)
current += 1
progress.setPercentage(int(current * total))