qgridder_dialog_export.py

# -*- coding: utf-8 -*-
"""
/***************************************************************************
 qgridderdialog.py
                                 Qgridder - A QGIS plugin

 This file handles Qgridder graphical user interface                           

 Qgridder Builds 2D regular and unstructured grids and comes together with 
 pre- and post-processing capabilities for spatially distributed modeling.

			     -------------------
        begin                : 2013-04-08
        copyright            : (C) 2013 by Pryet
        email                : alexandre.pryet@ensegid.fr
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *

from qgridder_dialog_base import QGridderDialog
from ui_qgridder_export import Ui_QGridderExport

import ftools_utils
import qgridder_utils

class QGridderDialogExport(QGridderDialog, Ui_QGridderExport):
    """
    Qgridder settings dialog class
    """
    def __init__(self,iface, settings):
	"""
	Description
	-----------
	Initialize export window

	"""
	# Set up the user interface
     	QDialog.__init__(self)
	self.iface = iface
	self.settings = settings		
	self.setupUi(self)
	self.proj = QgsProject.instance()

	# Connect buttons
	QObject.connect(self.buttonExportTextFile, SIGNAL("clicked()"), self.export_geometry)
	QObject.connect(self.buttonBrowseOutputFile, SIGNAL("clicked()"), self.out_text_file)

	# Populate layer list
	self.populate_layer_list(self.listGridLayer)


    def out_text_file(self):
	"""
	Description
	-----------
	Choose output shape file

	"""

        self.textOutTextFileName.clear()
        fileName, self.encoding  = ftools_utils.saveDialog( self )
        if fileName is None or self.encoding is None:
            return
        self.textOutTextFileName.setText( fileName  )


    def export_geometry(self) :
	"""
	Description
	-----------
	Export grid to text file

	"""

	gridLayerName = self.listGridLayer.currentText()

	outTextFileName = self.textOutTextFileName.text()
	
	# settings	
	delimiter = ','
	lineterminator = '\r'
	max_decimals = 2

	# Error checks
	if len(outTextFileName) <= 0:
		return "No output file given"

	gridLayer = ftools_utils.getMapLayerByName( unicode( gridLayerName ) )

	if gridLayer == None:
		return "Layer " + gridLayerName + " not found"

	# Create the CSV file
	try:
		txtfile = open(outTextFileName, 'w')
	except ValueError:
	    print "Writing Error.  Try again..."

	# Iterate through each feature in the source layer
	feature_count = gridLayer.dataProvider().featureCount()

	# Initialize progress bar
	progress=QProgressDialog("Exporting attributes...", "Abort Export", 0, feature_count);
	progress.setWindowModality(Qt.WindowModal)

	# Select all features along with their attributes
	allAttrs = gridLayer.pendingAllAttributesList()
	gridLayer.select(allAttrs)

	# Iterate over grid cells
	for feat in gridLayer.getFeatures():
	    p0, p1, p2, p3 = ftools_utils.extractPoints(feat.geometry())[:4]
	    txtfile.write(str(feat.id()) + ' AUTO' + lineterminator)
	    for point in [p0,p1,p2,p3,p0]:
		xcoor = round(point.x(), max_decimals)
		ycoor = round(point.y(), max_decimals)
		txtfile.write('\t' + str(xcoor) + delimiter + str(ycoor) + lineterminator)
	    txtfile.write('END' + lineterminator)
	    progress.setValue(feat.id())
	    if (progress.wasCanceled()):
		   return "Export canceled "

	txtfile.write('END' + lineterminator)
	
	progress.close()
	txtfile.close()