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Changes from review comments

- Shorten algorithm names (KNearestNeighbour and ConcaveHull)
- Check for feedback cancellation
- remove unnecessary try/except blocks
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rudivs committed Sep 14, 2018
1 parent 5076fb6 commit f4cab1780a1897baf79f942bc509611659d104b9
@@ -75,7 +75,10 @@ def name(self):
return 'concavehull'

def displayName(self):
return self.tr('Concave hull (using alpha shapes algorithm)')
return self.tr('Concave hull (alpha shapes)')

def shortDescription(self):
return self.tr('Creates a concave hull using the alpha shapes algorithm.')

def icon(self):
return QgsApplication.getThemeIcon("/algorithms/mAlgorithmConcaveHull.svg")
@@ -63,7 +63,10 @@ def name(self):
return 'knearestconcavehull'

def displayName(self):
return self.tr('Concave hull (using k-nearest neighbour algorithm)')
return self.tr('Concave hull (k-nearest neighbour)')

def shortDescription(self):
return self.tr('Creates a concave hull using the k-nearest neighbour algorithm.')

def icon(self):
return QgsApplication.getThemeIcon("/algorithms/mAlgorithmConcaveHull.svg")
@@ -134,28 +137,28 @@ def processAlgorithm(self, parameters, context, feedback):
filter = QgsExpression.createFieldEqualityExpression(field_name, unique)
request = QgsFeatureRequest().setFilterExpression(filter)
request.setSubsetOfAttributes([])
features = source.getFeatures(request) # Get features with the grouping attribute equal to the current grouping value
# Get features with the grouping attribute equal to the current grouping value
features = source.getFeatures(request)
for in_feature in features:
points.extend(extract_points(in_feature.geometry())) # Either points or vertices of more complex geometry
if feedback.isCanceled():
break
# Add points or vertices of more complex geometry
points.extend(extract_points(in_feature.geometry()))
current += 1
feedback.setProgress(int(current * total))

# A minimum of 3 points is necessary to proceed
if len(points) >= 3:
out_feature = QgsFeature()
try:
the_hull = concave_hull(points, kneighbors)
if the_hull:
vertex = [QgsPointXY(point[0], point[1]) for point in the_hull]
poly = QgsGeometry().fromPolygonXY([vertex])

out_feature.setGeometry(poly)
out_feature.setAttributes([fid, unique]) # Give the polygon the same attribute as the point grouping attribute
sink.addFeature(out_feature, QgsFeatureSink.FastInsert)
success = True # at least one polygon created
except:
feedback.reportError('Exception while computing concave hull.')
raise QgsProcessingException('Exception while computing concave hull.')
the_hull = concave_hull(points, kneighbors)
if the_hull:
vertex = [QgsPointXY(point[0], point[1]) for point in the_hull]
poly = QgsGeometry().fromPolygonXY([vertex])

out_feature.setGeometry(poly)
# Give the polygon the same attribute as the point grouping attribute
out_feature.setAttributes([fid, unique])
sink.addFeature(out_feature, QgsFeatureSink.FastInsert)
success = True # at least one polygon created
fid += 1
if not success:
raise QgsProcessingException('No hulls could be created. Most likely there were not at least three unique points in any of the groups.')
@@ -178,25 +181,26 @@ def processAlgorithm(self, parameters, context, feedback):
features = source.getFeatures(request) # Get all features
total = 100.0 / source.featureCount() if source.featureCount() else 0
for in_feature in features:
points.extend(extract_points(in_feature.geometry())) # Either points or vertices of more complex geometry
if feedback.isCanceled():
break
# Add points or vertices of more complex geometry
points.extend(extract_points(in_feature.geometry()))
current += 1
feedback.setProgress(int(current * total))

# A minimum of 3 points is necessary to proceed
if len(points) >= 3:
out_feature = QgsFeature()
try:
the_hull = concave_hull(points, kneighbors)
if the_hull:
vertex = [QgsPointXY(point[0], point[1]) for point in the_hull]
poly = QgsGeometry().fromPolygonXY([vertex])

out_feature.setGeometry(poly)
out_feature.setAttributes([0])
sink.addFeature(out_feature, QgsFeatureSink.FastInsert)
except:
feedback.reportError('Exception while computing concave hull.')
raise QgsProcessingException('Exception while computing concave hull.')
the_hull = concave_hull(points, kneighbors)
if the_hull:
vertex = [QgsPointXY(point[0], point[1]) for point in the_hull]
poly = QgsGeometry().fromPolygonXY([vertex])

out_feature.setGeometry(poly)
out_feature.setAttributes([0])
sink.addFeature(out_feature, QgsFeatureSink.FastInsert)
else:
raise QgsProcessingException('Error while creating concave hull.')
else:
raise QgsProcessingException('At least three unique points are required to create a concave hull.')

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