Add QGIS plugin.

.gitignore

@@ -6,3 +6,6 @@
 *.pyc
 *.png
 *.osm
+*.egg
+
+resources.py

Readme.md

@@ -7,7 +7,7 @@ This is a Python program to solve the [Chinese postman problem](http://en.wikipe
 * Python2.7
 * [networkx](http://networkx.lanl.gov/)
 
-## Usage
+## Command-line Usage
 
 Input data file must be in CSV format, with each row containing the following columns:
 

__init__.py

@@ -0,0 +1,35 @@
+"""
+/***************************************************************************
+ ChinesePostman
+                                 A QGIS plugin
+ Chinese Postman Solver
+                             -------------------
+        begin                : 2013-05-11
+        copyright            : (C) 2013 by Ralf Kistner
+        email                : ralf.kistner@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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+ This script initializes the plugin, making it known to QGIS.
+"""
+def name():
+    return "Chinese Postman Solver"
+def description():
+    return "Chinese Postman Solver"
+def version():
+    return "Version 0.1"
+def icon():
+    return "icon.png"
+def qgisMinimumVersion():
+    return "1.7"
+def classFactory(iface):
+    # load ChinesePostman class from file ChinesePostman
+    from chinesepostman import ChinesePostman
+    return ChinesePostman(iface)

bundle.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+zip chinesepostman *.py lib/*.egg metadata.txt icon.png

chinesepostman.py

@@ -0,0 +1,122 @@
+"""
+/***************************************************************************
+ ChinesePostman
+                                 A QGIS plugin
+ Chinese Postman Solver
+                              -------------------
+        begin                : 2013-05-11
+        copyright            : (C) 2013 by Ralf Kistner
+        email                : ralf.kistner@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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+"""
+
+# To reload this plugin after modifying, run:
+# qgis.utils.reloadPlugin('chinesepostman')
+
+import postman
+
+# Import the PyQt and QGIS libraries
+from PyQt4.QtCore import *
+from PyQt4.QtGui import *
+from qgis.core import *
+import networkx as nx
+
+# We need to import resources, even though we don't use it directly
+import resources
+
+class ChinesePostman:
+
+    def __init__(self, iface):
+        # Save reference to the QGIS interface
+        self.iface = iface
+
+    def initGui(self):
+        # Create action that will start plugin configuration
+        self.action = QAction(QIcon(":/plugins/chinesepostman/icon.png"), \
+            "Chinese Postman", self.iface.mainWindow())
+        # connect the action to the run method
+        QObject.connect(self.action, SIGNAL("triggered()"), self.run)
+
+        # Add toolbar button and menu item
+        self.iface.addToolBarIcon(self.action)
+        self.iface.addPluginToMenu("&Chinese Postman", self.action)
+
+    def unload(self):
+        # Remove the plugin menu item and icon
+        self.iface.removePluginMenu("&Chinese Postman",self.action)
+        self.iface.removeToolBarIcon(self.action)
+
+    # run method that performs all the real work
+    def run(self):
+        layer = self.iface.mapCanvas().currentLayer()
+
+        graph = build_graph(layer.selectedFeatures())
+        graph = postman.validate_graph(graph)
+
+        paths = postman.chinese_postman_paths(graph, n=1)
+
+        for eulerian_graph, nodes in paths:
+
+            in_length = postman.edge_sum(graph)/1000.0
+            path_length = postman.edge_sum(eulerian_graph)/1000.0
+            duplicate_length = path_length - in_length
+
+            info = ""
+            info += "Total length of roads: %.3f km\n" % in_length
+            info += "Total length of path: %.3f km\n" % path_length
+            info += "Length of sections visited twice: %.3f km\n" % duplicate_length
+
+            QMessageBox.information(None, "Chinese Postman", "Done:\n%s" % info)
+            newlayer = build_layer(eulerian_graph, nodes, layer.crs())
+            QgsMapLayerRegistry.instance().addMapLayer(newlayer)
+
+
+def build_layer(graph, nodes, crs):
+    # create layer
+
+    # We want to set the CRS without prompting the user, so we disable prompting first
+    s = QSettings()
+    oldValidation = s.value("/Projections/defaultBehaviour", "useGlobal").toString()
+    s.setValue("/Projections/defaultBehaviour", "useGlobal")
+
+    vl = QgsVectorLayer("LineString", "chinese_postman", "memory")
+    vl.setCrs(crs)
+
+    s.setValue("/Projections/defaultBehaviour", oldValidation)
+
+    pr = vl.dataProvider()
+
+    # We use a single polyline to represent the route
+    points = []
+    for node in nodes:
+        points.append(QgsPoint(node[0], node[1]))
+
+    # add the feature
+    fet = QgsFeature()
+    fet.setGeometry(QgsGeometry.fromPolyline(points))
+
+    pr.addFeatures([fet])
+
+    # update layer's extent when new features have been added
+    # because change of extent in provider is not propagated to the layer
+    vl.updateExtents()
+    return vl
+
+def build_graph(features):
+    graph = nx.Graph()
+    for feature in features:
+        geom = feature.geometry()
+        nodes = geom.asPolyline()
+        for start, end in postman.pairs(nodes):
+            graph.add_edge((start[0], start[1]), (end[0], end[1]), weight=geom.length())
+    return graph
+

install.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+pyrcc4 -o resources.py  resources.qrc
+ln -sfn $PWD $HOME/.qgis/python/plugins/chinesepostman

metadata.txt

@@ -0,0 +1,17 @@
+# This file contains metadata for your plugin. Beginning
+# with version 1.8 this is the preferred way to supply information about a
+# plugin. The current method of embedding metadata in __init__.py will
+# be supported until version 2.0
+
+# This file should be included when you package your plugin.
+
+[general]
+name=Chinese Postman Solver
+description=Chinese Postman Solver
+version=0.1
+qgisMinimumVersion=1.7
+class_name=ChinesePostman
+website=
+[author]
+name=Ralf Kistner
+email=ralf.kistner@gmail.com

postman.py

@@ -1,14 +1,19 @@
 #!/usr/bin/env python2.7
 from __future__ import print_function
 import os
-from tempfile import mkstemp
+import sys
 import tempfile
 import subprocess
 
 __author__ = 'Ralf Kistner'
 
+# Use the bundled networkx egg
+if __name__ == '__main__':
+    nxegg = 'lib/networkx-1.7-py2.7.egg'
+else:
+    nxegg = os.path.join(os.path.dirname(__file__), 'lib/networkx-1.7-py2.7.egg')
+sys.path.append(nxegg)
 
-import sys
 import csv
 import networkx as nx
 import xml.dom.minidom as minidom
@@ -317,4 +322,3 @@ def chinese_postman_paths(graph, n=5):
     if args.png:
         specify_positions(eulerian_graph)
         make_png(eulerian_graph, args.png.name)
-

resources.qrc

@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/plugins/chinesepostman" >
+        <file>icon.png</file>
+    </qresource>
+</RCC>