[processing] restore Slope algorithm

Author: alexbruy

python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py

@@ -76,6 +76,7 @@
 from .SelectByAttribute import SelectByAttribute
 from .SelectByExpression import SelectByExpression
 from .SimplifyGeometries import SimplifyGeometries
+from .Slope import Slope
 from .Smooth import Smooth
 from .SnapGeometries import SnapGeometriesToLayer
 from .SpatialiteExecuteSQL import SpatialiteExecuteSQL
@@ -146,7 +147,6 @@
 # from .Translate import Translate
 # from .SingleSidedBuffer import SingleSidedBuffer
 # from .PointsAlongGeometry import PointsAlongGeometry
-# from .Slope import Slope
 # from .Ruggedness import Ruggedness
 # from .Hillshade import Hillshade
 # from .Relief import Relief
@@ -270,6 +270,7 @@ def getAlgs(self):
                 SelectByAttribute(),
                 SelectByExpression(),
                 SimplifyGeometries(),
+                Slope(),
                 Smooth(),
                 SnapGeometriesToLayer(),
                 SpatialiteExecuteSQL(),

python/plugins/processing/algs/qgis/Slope.py

@@ -30,21 +30,22 @@
 from qgis.PyQt.QtGui import QIcon
 
 from qgis.analysis import QgsSlopeFilter
-
+from qgis.core import (QgsProcessingParameterRasterLayer,
+                       QgsProcessingParameterNumber,
+                       QgsProcessingParameterRasterDestination)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.core.parameters import ParameterRaster
-from processing.core.parameters import ParameterNumber
-from processing.core.outputs import OutputRaster
 from processing.tools import raster
+from processing.tools.dataobjects import exportRasterLayer
+
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
 
 
 class Slope(QgisAlgorithm):
 
-    INPUT_LAYER = 'INPUT_LAYER'
+    INPUT = 'INPUT'
     Z_FACTOR = 'Z_FACTOR'
-    OUTPUT_LAYER = 'OUTPUT_LAYER'
+    OUTPUT = 'OUTPUT'
 
     def icon(self):
         return QIcon(os.path.join(pluginPath, 'images', 'dem.png'))
@@ -56,12 +57,12 @@ def __init__(self):
         super().__init__()
 
     def initAlgorithm(self, config=None):
-        self.addParameter(ParameterRaster(self.INPUT_LAYER,
-                                          self.tr('Elevation layer')))
-        self.addParameter(ParameterNumber(self.Z_FACTOR,
-                                          self.tr('Z factor'), 1.0, 999999.99, 1.0))
-        self.addOutput(OutputRaster(self.OUTPUT_LAYER,
-                                    self.tr('Slope')))
+        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT,
+                                                            self.tr('Elevation layer')))
+        self.addParameter(QgsProcessingParameterNumber(self.Z_FACTOR,
+                                                       self.tr('Z factor'), QgsProcessingParameterNumber.Double,
+                                                       1, False, 1, 999999.99))
+        self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT, self.tr('Slope')))
 
     def name(self):
         return 'slope'
@@ -70,12 +71,15 @@ def displayName(self):
         return self.tr('Slope')
 
     def processAlgorithm(self, parameters, context, feedback):
-        inputFile = self.getParameterValue(self.INPUT_LAYER)
-        zFactor = self.getParameterValue(self.Z_FACTOR)
-        outputFile = self.getOutputValue(self.OUTPUT_LAYER)
+        inputFile = exportRasterLayer(self.parameterAsRasterLayer(parameters, self.INPUT, context))
+        zFactor = self.parameterAsDouble(parameters, self.Z_FACTOR, context)
+
+        outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
 
         outputFormat = raster.formatShortNameFromFileName(outputFile)
 
         slope = QgsSlopeFilter(inputFile, outputFile, outputFormat)
         slope.setZFactor(zFactor)
-        slope.processRaster(None)
+        slope.processRaster(feedback)
+
+        return {self.OUTPUT: outputFile}

python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml

@@ -1044,18 +1044,18 @@ tests:
         hash: 762865ee485a6736d188402aa10e6fd38a812a9e45a7dd2d4885a63a
         type: rasterhash
 
-#  - algorithm: qgis:slope
-#    name: Slope from QGIS analysis library
-#    params:
-#      INPUT_LAYER:
-#        name: dem.tif
-#        type: raster
-#      Z_FACTOR: 1.0
-#    results:
-#      OUTPUT_LAYER:
-#        hash: 151ea76a21b286c16567eb6b4b692925a84145b65561a0017effb1a1
-#        type: rasterhash
-#
+  - algorithm: qgis:slope
+    name: Slope from QGIS analysis library
+    params:
+      INPUT_LAYER:
+        name: dem.tif
+        type: raster
+      Z_FACTOR: 1.0
+    results:
+      OUTPUT_LAYER:
+        hash: 151ea76a21b286c16567eb6b4b692925a84145b65561a0017effb1a1
+        type: rasterhash
+
 #  - algorithm: qgis:ruggednessindex
 #    name: Ruggedness index from QGIS analysis library
 #    params: