Merge pull request #21 from QGEP/inverseReaches

Add processing algorithm to reverse reaches

src/processing_provider/change_reach_direction.py

@@ -0,0 +1,91 @@
+# -*- coding: utf-8 -*-
+
+"""
+/***************************************************************************
+ QGEP processing provider
+                              -------------------
+        begin                : 18.11.2017
+        copyright            : (C) 2017 by OPENGIS.ch
+        email                : [email protected]
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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 qgis.core import (
+    QgsExpression,
+    QgsFeatureRequest,
+    QgsGeometry,
+    QgsProcessingAlgorithm,
+    QgsProcessingParameterNumber,
+    QgsProcessingParameterBoolean,
+    QgsProcessingParameterVectorLayer
+)
+
+from PyQt5.QtCore import QCoreApplication
+
+from .qgep_algorithm import QgepAlgorithm
+
+__author__ = 'Matthias Kuhn & Maxime Trolliet'
+__date__ = '2018-08-07'
+__copyright__ = '(C) 2018 by OPENGIS.ch'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+
+class ChangeReachDirection(QgepAlgorithm):
+    """
+	Change the direction of the selected reaches
+    """
+
+    REACH_LAYER = 'REACH_LAYER'
+
+
+    def name(self):
+        return 'change_direction'
+
+    def displayName(self):
+        return self.tr('Change reach direction')
+
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
+    def initAlgorithm(self, config=None):
+        """Here we define the inputs and output of the algorithm, along
+        with some other properties.
+        """
+
+        self.addParameter(QgsProcessingParameterVectorLayer(self.REACH_LAYER, description=self.tr(
+            'Selected features only - Reach layer, will be modified in place and its direction will be inverted')))
+
+    def processAlgorithm(self, parameters, context, feedback):
+        """Here is where the processing itself takes place."""
+        reach_layer = self.parameterAsVectorLayer(parameters, self.REACH_LAYER, context)
+
+        reach_layer.startEditing()
+
+        feature_count = 0
+
+        iterator = reach_layer.getSelectedFeatures()
+        feature_count = reach_layer.selectedFeatureCount()
+
+        # Loop through relevant reaches
+        reach_layer.beginEditCommand('change directions')
+        transaction = reach_layer.dataProvider().transaction()
+        #if not transaction:
+        #    raise Exception: if there is no transaction, complain to the user!
+        selected_obj_ids = [feature['obj_id'] for feature in iterator]
+        transaction.executeSql('SELECT qgep_od.reach_direction_change(\'{{{obj_ids}}}\');'.format(obj_ids=','.join(selected_obj_ids)))
+        reach_layer.endEditCommand()
+        feedback.setProgress(100)
+
+        return {}

src/processing_provider/provider.py

@@ -22,6 +22,7 @@
 from qgis.core import QgsProcessingProvider
 from .snap_reach import SnapReachAlgorithm
 from .flow_times import FlowTimesAlgorithm
+from .change_reach_direction import ChangeReachDirection
 
 from PyQt5.QtGui import QIcon
 import os
@@ -43,12 +44,12 @@ def __init__(self):
         self.activate = True
 
         # Load algorithms
-        self.alglist = [SnapReachAlgorithm(), FlowTimesAlgorithm()]
+        self.alglist = [SnapReachAlgorithm(), FlowTimesAlgorithm(), ChangeReachDirection()]
         for alg in self.alglist:
             alg.provider = self
 
     def getAlgs(self):
-        algs = [SnapReachAlgorithm(), FlowTimesAlgorithm()]
+        algs = [SnapReachAlgorithm(), FlowTimesAlgorithm(), ChangeReachDirection()]
         return algs
 
     def id(self):