Connect line and point

"""
/***************************************************************************
Name			 	 : JH Plugin
Description          : Connects houses to rads
Date                 : 17/Jun/13
copyright            : (C) 2013 by Johan Holtby
email                : johan.holtby@gmail.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 PyQt4 import QtCore, QtGui
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *

import csv
import os.path
import operator

from Ui_JHPlugin import Ui_JHPlugin
from Ui_JHPlugin import *
# create the dialog for JHPlugin
class JHPluginDialog(QtGui.QDialog):

	def browse_outfile(self):
		newname = QFileDialog.getSaveFileName(None, QString.fromLocal8Bit("Output File"),
			self.ui.filename.displayText(), "*.csv")
		if newname != None:
			self.ui.filename.setText(QString(newname))

	def run(self):
		#This inform the user that this will take some time.
		#QMessageBox.critical(self.iface.mainWindow(), "Start processing", "The processing will start, this my take some time.")

		#Import the list of layers________________________________________________________
		self.canvas = self.iface.mapCanvas()


		#Get the layers selected to be processed _________________________________________
		self.HouseLayer=self.canvas.layer(self.ui.HouseLayer.currentIndex())
		self.RoadLayer=self.canvas.layer(self.ui.RoadLayer.currentIndex())


		#Add the columns___________________________________________________________________
		self.HouseLayer.startEditing()
		self.providerHouse=self.HouseLayer.dataProvider()
		self.providerRoad=self.RoadLayer.dataProvider()
		columns = self.providerHouse.fields()
		startColumn=len(columns)

		#Coordinates of the house
		self.providerHouse.addAttributes( [ QgsField('X', QVariant.Double) ] )
		self.providerHouse.addAttributes( [ QgsField('Y', QVariant.Double) ] )

		#Coordinates of the centroid of the road
		self.providerHouse.addAttributes( [ QgsField('R_ID', QVariant.Double) ] )
		self.providerHouse.addAttributes( [ QgsField('R_X', QVariant.Double) ] )
		self.providerHouse.addAttributes( [ QgsField('R_Y', QVariant.Double) ] )
		self.providerHouse.addAttributes( [ QgsField('(R_ID2)', QVariant.Double) ] )

		#Go through all of the roads attributes and add them to the House layer
		self.columnsRoad = self.providerRoad.fields()
		for key,value in self.columnsRoad.items():
			self.providerHouse.addAttributes( [ QgsField('R_' + value.name(), value.type()) ] )

		#Commit all changes
		self.HouseLayer.commitChanges()


		#Set up the spatial index___________________________________________________________
		self.spIndex = QgsSpatialIndex() #create spatial index object

		self.feat = QgsFeature()
		self.allAttrs = self.providerRoad.attributeIndexes()
		self.providerRoad.select(self.allAttrs)

		# insert features to index
		while self.providerRoad.nextFeature(self.feat):
			self.spIndex.insertFeature(self.feat)

		#Find all the closest roads__________________________________________________________
		self.feat2 = QgsFeature()
		self.feat3 = QgsFeature()

		self.allAttrs = self.providerHouse.attributeIndexes()
		self.providerHouse.select(self.allAttrs)

		self.HouseLayer.startEditing()

		#Go through all features and connect the house with the road
		while self.providerHouse.nextFeature(self.feat2):
			#House X&Y
			self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn, self.feat2.geometry().centroid().asPoint().x())
			self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn+1, self.feat2.geometry().centroid().asPoint().y())

			#Road ID
			nearestIds = self.spIndex.nearestNeighbor(self.feat2.geometry().centroid().asPoint(),1) # Get the closest neighbour
			self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn+2, nearestIds[0])

			#Road centroid X&Y
			self.RoadLayer.featureAtId(nearestIds[0], self.feat3, True, True)
			self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn+3, self.feat3.geometry().centroid().asPoint().x())
			self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn+4, self.feat3.geometry().centroid().asPoint().y())

			#The attributes of the road
			for key,value in self.columnsRoad.items():
				self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn+6+key, self.feat3[key])

			#If there is more then one closest get both
			if(len(nearestIds)>1):
				self.HouseLayer.changeAttributeValue(self.feat2.id(), startColumn+5, nearestIds[1])


		self.HouseLayer.commitChanges()
		QMessageBox.critical(self.iface.mainWindow(), "Done processing!", "The processing is done.")

	def __init__(self,iface):
		QtGui.QDialog.__init__(self)

		# Set up the user interface from Designer.
		self.iface = iface
		self.ui = Ui_JHPlugin ()
		self.ui.setupUi(self)

		#Add the browser functionality
		QtCore.QObject.connect(self.ui.browse, SIGNAL("clicked()"), self.browse_outfile)

		#Add the function to the OK button
		QtCore.QObject.connect(self.ui.buttonBox, QtCore.SIGNAL("accepted()"), self.run)

		#Set the file name
		self.ui.filename.setText(os.getcwd() + "/temp.csv")

		#Add the layers
		self.canvas=self.iface.mapCanvas()
		for layer in self.canvas.layers():
			if layer.type() == QgsMapLayer.VectorLayer:
				self.ui.HouseLayer.addItem(layer.name())
				self.ui.RoadLayer.addItem(layer.name())