Merge pull request #9908 from raymondnijssen/roundextent

Round values in ExtentFromLayer processing algorithm
qgis · May 13, 2019 · 6a3cd82 · 6a3cd82
2 parents 84a9891 + 6e62c02
commit 6a3cd82
Show file tree

Hide file tree

Showing 5 changed files with 163 additions and 2 deletions.
diff --git a/python/plugins/processing/algs/help/qgis.yaml b/python/plugins/processing/algs/help/qgis.yaml
@@ -334,7 +334,7 @@ qgis:polygoncentroids: >
   NOTE: This algorithm is deprecated and the generic "centroids" algorithm (which works for line and multi geometry layers) should be used instead.
 
 qgis:polygonfromlayerextent: >
-  This algorithm takes a map layer and generates a new vector layer with the minimum bounding box (rectangle with N-S orientation) that covers the input layer.
+  This algorithm takes a map layer and generates a new vector layer with the minimum bounding box (rectangle polygon with N-S orientation) that covers the input layer. Optionally, the extent can be enlarged to a rounded value.
 
 qgis:polygonize:  >
   This algorithm takes a lines layer and creates a polygon layer, with polygons generated from the lines in the input layer.

diff --git a/python/plugins/processing/algs/qgis/ExtentFromLayer.py b/python/plugins/processing/algs/qgis/ExtentFromLayer.py
@@ -26,6 +26,7 @@
 __revision__ = '$Format:%H$'
 
 import os
+from math import floor, ceil
 
 from qgis.PyQt.QtGui import QIcon
 from qgis.PyQt.QtCore import QVariant
@@ -39,6 +40,8 @@
                        QgsProcessing,
                        QgsProcessingException,
                        QgsProcessingParameterMapLayer,
+                       QgsProcessingParameterDistance,
+                       QgsProcessingParameterDefinition,
                        QgsProcessingParameterFeatureSink,
                        QgsFields)
 
@@ -51,6 +54,7 @@ class ExtentFromLayer(QgisAlgorithm):
 
     INPUT = 'INPUT'
     BY_FEATURE = 'BY_FEATURE'
+    ROUND_TO = 'ROUND_TO'
 
     OUTPUT = 'OUTPUT'
 
@@ -61,7 +65,7 @@ def svgIconPath(self):
         return QgsApplication.iconPath("/algorithms/mAlgorithmExtractLayerExtent.svg")
 
     def tags(self):
-        return self.tr('polygon,from,vector,raster,extent,envelope,bounds,bounding,boundary,layer').split(',')
+        return self.tr('polygon,vector,raster,extent,envelope,bounds,bounding,boundary,layer,round,rounded').split(',')
 
     def group(self):
         return self.tr('Layer tools')
@@ -74,6 +78,15 @@ def __init__(self):
 
     def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterMapLayer(self.INPUT, self.tr('Input layer')))
+
+        round_to_parameter = QgsProcessingParameterDistance(self.ROUND_TO,
+                                                            self.tr('Round values to'),
+                                                            parentParameterName=self.INPUT,
+                                                            minValue=0,
+                                                            defaultValue=0)
+        round_to_parameter.setFlags(round_to_parameter.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
+        self.addParameter(round_to_parameter)
+
         self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Extent'), type=QgsProcessing.TypeVectorPolygon))
 
     def name(self):
@@ -85,6 +98,8 @@ def displayName(self):
     def processAlgorithm(self, parameters, context, feedback):
         layer = self.parameterAsLayer(parameters, self.INPUT, context)
 
+        round_to = self.parameterAsDouble(parameters, self.ROUND_TO, context)
+
         fields = QgsFields()
         fields.append(QgsField('MINX', QVariant.Double))
         fields.append(QgsField('MINY', QVariant.Double))
@@ -109,7 +124,15 @@ def processAlgorithm(self, parameters, context, feedback):
             pass
 
         rect = layer.extent()
+
+        if round_to > 0:
+            rect.setXMinimum(floor(rect.xMinimum() / round_to) * round_to)
+            rect.setYMinimum(floor(rect.yMinimum() / round_to) * round_to)
+            rect.setXMaximum(ceil(rect.xMaximum() / round_to) * round_to)
+            rect.setYMaximum(ceil(rect.yMaximum() / round_to) * round_to)
+
         geometry = QgsGeometry.fromRect(rect)
+
         minx = rect.xMinimum()
         miny = rect.yMinimum()
         maxx = rect.xMaximum()

diff --git a/python/plugins/processing/tests/testdata/expected/polygon_from_extent_rounded_2.gml b/python/plugins/processing/tests/testdata/expected/polygon_from_extent_rounded_2.gml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ polygon_from_extent_rounded_2.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>-2</gml:X><gml:Y>-4</gml:Y></gml:coord>
+      <gml:coord><gml:X>12</gml:X><gml:Y>6</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:polygon_from_extent_rounded_2 fid="polygon_from_extent_rounded_2.0">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>-2,-4 12,-4 12,6 -2,6 -2,-4</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:MINX>-2</ogr:MINX>
+      <ogr:MINY>-4</ogr:MINY>
+      <ogr:MAXX>12</ogr:MAXX>
+      <ogr:MAXY>6</ogr:MAXY>
+      <ogr:CNTX>5</ogr:CNTX>
+      <ogr:CNTY>1</ogr:CNTY>
+      <ogr:AREA>140</ogr:AREA>
+      <ogr:PERIM>48</ogr:PERIM>
+      <ogr:HEIGHT>10</ogr:HEIGHT>
+      <ogr:WIDTH>14</ogr:WIDTH>
+    </ogr:polygon_from_extent_rounded_2>
+  </gml:featureMember>
+</ogr:FeatureCollection>
diff --git a/python/plugins/processing/tests/testdata/expected/polygon_from_extent_rounded_2.xsd b/python/plugins/processing/tests/testdata/expected/polygon_from_extent_rounded_2.xsd
@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xs:schema targetNamespace="http://ogr.maptools.org/" xmlns:ogr="http://ogr.maptools.org/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" version="1.0">
+<xs:import namespace="http://www.opengis.net/gml" schemaLocation="http://schemas.opengis.net/gml/2.1.2/feature.xsd"/>
+<xs:element name="FeatureCollection" type="ogr:FeatureCollectionType" substitutionGroup="gml:_FeatureCollection"/>
+<xs:complexType name="FeatureCollectionType">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureCollectionType">
+      <xs:attribute name="lockId" type="xs:string" use="optional"/>
+      <xs:attribute name="scope" type="xs:string" use="optional"/>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+<xs:element name="polygon_from_extent_rounded_2" type="ogr:polygon_from_extent_rounded_2_Type" substitutionGroup="gml:_Feature"/>
+<xs:complexType name="polygon_from_extent_rounded_2_Type">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureType">
+      <xs:sequence>
+        <xs:element name="geometryProperty" type="gml:PolygonPropertyType" nillable="true" minOccurs="0" maxOccurs="1"/>
+        <xs:element name="MINX" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="MINY" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="MAXX" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="MAXY" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="CNTX" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="CNTY" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="AREA" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="PERIM" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="HEIGHT" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="WIDTH" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+      </xs:sequence>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+</xs:schema>
diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -1801,4 +1801,30 @@ tests:
         name: expected/multipoint_delaunay.gml
         type: vector
 
+  - algorithm: qgis:polygonfromlayerextent
+    name: Polygon from layer extent rounded to 0
+    params:
+      BY_FEATURE: false
+      INPUT:
+        name: polys.gml
+        type: vector
+      ROUND_TO: 0.0
+    results:
+      OUTPUT:
+        name: expected/polygon_from_extent.gml
+        type: vector
+
+  - algorithm: qgis:polygonfromlayerextent
+    name: Polygon from layer extent rounded to 2
+    params:
+      BY_FEATURE: false
+      INPUT:
+        name: lines.gml
+        type: vector
+      ROUND_TO: 2.0
+    results:
+      OUTPUT:
+        name: expected/polygon_from_extent_rounded_2.gml
+        type: vector
+
 # See ../README.md for a description of the file format