Port fixed distance buffer to new API

qgis · Jul 28, 2017 · 5763381 · 5763381
1 parent e53a14a
commit 5763381
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Showing 4 changed files with 188 additions and 175 deletions.
diff --git a/python/plugins/processing/algs/qgis/Buffer.py b/python/plugins/processing/algs/qgis/Buffer.py
@@ -25,25 +25,32 @@
 
 __revision__ = '$Format:%H$'
 
-from qgis.core import QgsFeature, QgsGeometry, QgsProcessingUtils
+from qgis.core import (QgsFeature,
+                       QgsGeometry,
+                       QgsFeatureRequest,
+                       QgsFeatureSink)
 
 
-def buffering(feedback, context, writer, distance, field, useField, layer, dissolve, segments, endCapStyle=1,
+def buffering(feedback, context, sink, distance, field, useField, source, dissolve, segments, endCapStyle=1,
               joinStyle=1, mitreLimit=2):
 
     if useField:
-        field = layer.fields().lookupField(field)
+        field = source.fields().lookupField(field)
 
     outFeat = QgsFeature()
 
     current = 0
-    features = QgsProcessingUtils.getFeatures(layer, context)
-    total = 100.0 / layer.featureCount() if layer.featureCount() else 0
+    total = 100.0 / source.featureCount() if source.featureCount() else 0
 
     # With dissolve
     if dissolve:
+
+        features = source.getFeatures(QgsFeatureRequest().setSubsetOfAttributes([]))
         buffered_geometries = []
         for inFeat in features:
+            if feedback.isCanceled():
+                break
+
             attrs = inFeat.attributes()
             if useField:
                 value = attrs[field]
@@ -60,10 +67,15 @@ def buffering(feedback, context, writer, distance, field, useField, layer, disso
         final_geometry = QgsGeometry.unaryUnion(buffered_geometries)
         outFeat.setGeometry(final_geometry)
         outFeat.setAttributes(attrs)
-        writer.addFeature(outFeat, QgsFeatureSink.FastInsert)
+        sink.addFeature(outFeat, QgsFeatureSink.FastInsert)
     else:
+
+        features = source.getFeatures()
+
         # Without dissolve
         for inFeat in features:
+            if feedback.isCanceled():
+                break
             attrs = inFeat.attributes()
             if useField:
                 value = attrs[field]
@@ -74,8 +86,6 @@ def buffering(feedback, context, writer, distance, field, useField, layer, disso
             outGeom = inGeom.buffer(float(value), segments, endCapStyle, joinStyle, mitreLimit)
             outFeat.setGeometry(outGeom)
             outFeat.setAttributes(attrs)
-            writer.addFeature(outFeat, QgsFeatureSink.FastInsert)
+            sink.addFeature(outFeat, QgsFeatureSink.FastInsert)
             current += 1
             feedback.setProgress(int(current * total))
-
-    del writer
diff --git a/python/plugins/processing/algs/qgis/FixedDistanceBuffer.py b/python/plugins/processing/algs/qgis/FixedDistanceBuffer.py
@@ -30,18 +30,16 @@
 from qgis.PyQt.QtGui import QIcon
 
 from qgis.core import (QgsWkbTypes,
-                       QgsFeatureSink,
-                       QgsProcessingUtils)
+                       QgsProcessing,
+                       QgsProcessingParameterFeatureSource,
+                       QgsProcessingParameterNumber,
+                       QgsProcessingParameterBoolean,
+                       QgsProcessingParameterEnum,
+                       QgsProcessingParameterFeatureSink)
 
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.core.parameters import ParameterVector
-from processing.core.parameters import ParameterBoolean
-from processing.core.parameters import ParameterNumber
-from processing.core.parameters import ParameterSelection
 
-from processing.core.outputs import OutputVector
 from . import Buffer as buff
-from processing.tools import dataobjects
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
 
@@ -68,31 +66,33 @@ def __init__(self):
         super().__init__()
 
     def initAlgorithm(self, config=None):
-        self.addParameter(ParameterVector(self.INPUT,
-                                          self.tr('Input layer')))
-        self.addParameter(ParameterNumber(self.DISTANCE,
-                                          self.tr('Distance'), default=10.0))
-        self.addParameter(ParameterNumber(self.SEGMENTS,
-                                          self.tr('Segments'), 1, default=5))
-        self.addParameter(ParameterBoolean(self.DISSOLVE,
-                                           self.tr('Dissolve result'), False))
+        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
+                                                              self.tr('Input layer')))
+
+        self.addParameter(QgsProcessingParameterNumber(self.DISTANCE,
+                                                       self.tr('Distance'), defaultValue=10.0))
+        self.addParameter(QgsProcessingParameterNumber(self.SEGMENTS,
+                                                       self.tr('Segments'), type=QgsProcessingParameterNumber.Integer, minValue=1, defaultValue=5))
+        self.addParameter(QgsProcessingParameterBoolean(self.DISSOLVE,
+                                                        self.tr('Dissolve result'), defaultValue=False))
         self.end_cap_styles = [self.tr('Round'),
                                'Flat',
                                'Square']
-        self.addParameter(ParameterSelection(
+        self.addParameter(QgsProcessingParameterEnum(
             self.END_CAP_STYLE,
             self.tr('End cap style'),
-            self.end_cap_styles, default=0))
+            options=self.end_cap_styles, defaultValue=0))
         self.join_styles = [self.tr('Round'),
                             'Mitre',
                             'Bevel']
-        self.addParameter(ParameterSelection(
+        self.addParameter(QgsProcessingParameterEnum(
             self.JOIN_STYLE,
             self.tr('Join style'),
-            self.join_styles, default=0))
-        self.addParameter(ParameterNumber(self.MITRE_LIMIT,
-                                          self.tr('Mitre limit'), 1, default=2))
-        self.addOutput(OutputVector(self.OUTPUT, self.tr('Buffer'), datatype=[dataobjects.TYPE_VECTOR_POLYGON]))
+            options=self.join_styles, defaultValue=0))
+        self.addParameter(QgsProcessingParameterNumber(self.MITRE_LIMIT,
+                                                       self.tr('Mitre limit'), minValue=0, defaultValue=2))
+
+        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Buffer'), QgsProcessing.TypeVectorPolygon))
 
     def name(self):
         return 'fixeddistancebuffer'
@@ -101,16 +101,19 @@ def displayName(self):
         return self.tr('Fixed distance buffer')
 
     def processAlgorithm(self, parameters, context, feedback):
-        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
-        distance = self.getParameterValue(self.DISTANCE)
-        dissolve = self.getParameterValue(self.DISSOLVE)
-        segments = int(self.getParameterValue(self.SEGMENTS))
-        end_cap_style = self.getParameterValue(self.END_CAP_STYLE) + 1
-        join_style = self.getParameterValue(self.JOIN_STYLE) + 1
-        miter_limit = self.getParameterValue(self.MITRE_LIMIT)
-
-        writer = self.getOutputFromName(
-            self.OUTPUT).getVectorWriter(layer.fields(), QgsWkbTypes.Polygon, layer.crs(), context)
-
-        buff.buffering(feedback, context, writer, distance, None, False, layer, dissolve, segments, end_cap_style,
+        source = self.parameterAsSource(parameters, self.INPUT, context)
+
+        distance = self.parameterAsDouble(parameters, self.DISTANCE, context)
+        dissolve = self.parameterAsBool(parameters, self.DISSOLVE, context)
+        segments = self.parameterAsInt(parameters, self.SEGMENTS, context)
+        end_cap_style = self.parameterAsEnum(parameters, self.END_CAP_STYLE, context) + 1
+        join_style = self.parameterAsEnum(parameters, self.JOIN_STYLE, context) + 1
+        miter_limit = self.parameterAsDouble(parameters, self.MITRE_LIMIT, context)
+
+        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
+                                               source.fields(), QgsWkbTypes.Polygon, source.sourceCrs())
+
+        buff.buffering(feedback, context, sink, distance, None, False, source, dissolve, segments, end_cap_style,
                        join_style, miter_limit)
+
+        return {self.OUTPUT: dest_id}
diff --git a/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
@@ -67,6 +67,7 @@
 from .ExtentFromLayer import ExtentFromLayer
 from .ExtractNodes import ExtractNodes
 from .ExtractSpecificNodes import ExtractSpecificNodes
+from .FixedDistanceBuffer import FixedDistanceBuffer
 from .FixGeometry import FixGeometry
 from .GeometryByExpression import GeometryByExpression
 from .GridPolygon import GridPolygon
@@ -132,7 +133,6 @@
 from .ZonalStatistics import ZonalStatistics
 
 # from .ExtractByLocation import ExtractByLocation
-# from .FixedDistanceBuffer import FixedDistanceBuffer
 # from .VariableDistanceBuffer import VariableDistanceBuffer
 # from .RandomSelection import RandomSelection
 # from .RandomSelectionWithinSubsets import RandomSelectionWithinSubsets
@@ -185,7 +185,6 @@ def __init__(self):
 
     def getAlgs(self):
         # algs = [
-        #         FixedDistanceBuffer(),
         #         VariableDistanceBuffer(),
         #         RandomSelection(), RandomSelectionWithinSubsets(),
         #         SelectByLocation(),
@@ -240,6 +239,7 @@ def getAlgs(self):
                 ExtentFromLayer(),
                 ExtractNodes(),
                 ExtractSpecificNodes(),
+                FixedDistanceBuffer(),
                 FixGeometry(),
                 GeometryByExpression(),
                 GridPolygon(),