Merge pull request #33987 from elpaso/bugfix-gh33840-loadstyle-render…

…ing-scalevisibility Fix scale visibility in style read/write
qgis · Jan 23, 2020 · 9c48368 · 9c48368
2 parents 09061d1 + 28ce3cd
commit 9c48368
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Showing 3 changed files with 81 additions and 2 deletions.
diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -2407,7 +2407,7 @@ bool QgsVectorLayer::readStyle( const QDomNode &node, QString &errorMessage,
       }
     }
 
-    // get and set the layer transparency if it exists
+    // get and set the layer transparency and scale visibility if they exists
     if ( categories.testFlag( Rendering ) )
     {
       QDomNode layerTransparencyNode = node.namedItem( QStringLiteral( "layerTransparency" ) );
@@ -2422,6 +2422,20 @@ bool QgsVectorLayer::readStyle( const QDomNode &node, QString &errorMessage,
         QDomElement e = layerOpacityNode.toElement();
         setOpacity( e.text().toDouble() );
       }
+
+      const bool hasScaleBasedVisibiliy { node.attributes().namedItem( QStringLiteral( "hasScaleBasedVisibilityFlag" ) ).nodeValue() == '1' };
+      setScaleBasedVisibility( hasScaleBasedVisibiliy );
+      bool ok;
+      const double maxScale { node.attributes().namedItem( QStringLiteral( "maxScale" ) ).nodeValue().toDouble( &ok ) };
+      if ( ok )
+      {
+        setMaximumScale( maxScale );
+      }
+      const double minScale { node.attributes().namedItem( QStringLiteral( "minScale" ) ).nodeValue().toDouble( &ok ) };
+      if ( ok )
+      {
+        setMinimumScale( minScale );
+      }
     }
 
     if ( categories.testFlag( Rendering ) )
@@ -2807,13 +2821,16 @@ bool QgsVectorLayer::writeStyle( QDomNode &node, QDomDocument &doc, QString &err
       node.appendChild( featureBlendModeElem );
     }
 
-    // add the layer opacity
+    // add the layer opacity and scale visibility
     if ( categories.testFlag( Rendering ) )
     {
       QDomElement layerOpacityElem  = doc.createElement( QStringLiteral( "layerOpacity" ) );
       QDomText layerOpacityText = doc.createTextNode( QString::number( opacity() ) );
       layerOpacityElem.appendChild( layerOpacityText );
       node.appendChild( layerOpacityElem );
+      mapLayerNode.setAttribute( QStringLiteral( "hasScaleBasedVisibilityFlag" ), hasScaleBasedVisibility() ? 1 : 0 );
+      mapLayerNode.setAttribute( QStringLiteral( "maxScale" ), maximumScale() );
+      mapLayerNode.setAttribute( QStringLiteral( "minScale" ), minimumScale() );
     }
 
     if ( categories.testFlag( Diagrams ) && mDiagramRenderer )

diff --git a/tests/src/python/CMakeLists.txt b/tests/src/python/CMakeLists.txt
@@ -248,6 +248,7 @@ ADD_PYTHON_TEST(PyQgsVectorFileWriterTask test_qgsvectorfilewritertask.py)
 ADD_PYTHON_TEST(PyQgsVectorLayer test_qgsvectorlayer.py)
 ADD_PYTHON_TEST(PyQgsVectorLayerCache test_qgsvectorlayercache.py)
 ADD_PYTHON_TEST(PyQgsVectorLayerEditBuffer test_qgsvectorlayereditbuffer.py)
+ADD_PYTHON_TEST(PyQgsVectorLayerNamedStyle test_qgsvectorlayer_namedstyle.py)
 ADD_PYTHON_TEST(PyQgsVectorLayerSelectedFeatureSource test_qgsvectorlayerselectedfeaturesource.py)
 ADD_PYTHON_TEST(PyQgsVectorLayerUtils test_qgsvectorlayerutils.py)
 ADD_PYTHON_TEST(PyQgsZonalStatistics test_qgszonalstatistics.py)

diff --git a/tests/src/python/test_qgsvectorlayer_namedstyle.py b/tests/src/python/test_qgsvectorlayer_namedstyle.py
@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsVectorLayer load/write named style.
+
+.. note:: 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.
+
+"""
+__author__ = 'Alessandro Pasotti'
+__date__ = '22/01/2020'
+__copyright__ = 'Copyright 2020, The QGIS Project'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+import tempfile
+from qgis.core import (
+    QgsVectorLayer,
+    QgsMapLayer,
+    QgsReadWriteContext,
+)
+from qgis.PyQt.QtXml import QDomDocument, QDomNode
+
+from qgis.testing import unittest
+
+
+class TestPyQgsVectorLayerNamedStyle(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        """Run before all tests"""
+        pass
+
+    def testLoadWriteRenderingScaleVisibility(self):
+        """Test write and load scale visibility, see GH #33840"""
+
+        vl = QgsVectorLayer("LineString?crs=epsg:4326", "result", "memory")
+        vl.setScaleBasedVisibility(True)
+        vl.setMinimumScale(125.0)
+        vl.setMaximumScale(1.25)
+        style = QDomDocument()
+        style.setContent("<!DOCTYPE qgis PUBLIC 'http://mrcc.com/qgis.dtd' 'SYSTEM'><qgis></qgis>")
+        node = style.firstChild()
+        self.assertTrue(vl.writeStyle(node, style, "Error writing style", QgsReadWriteContext(), QgsMapLayer.Rendering))
+
+        style_content = style.toString()
+        del(vl)
+
+        # Read
+        vl2 = QgsVectorLayer("LineString?crs=epsg:4326", "result", "memory")
+        self.assertFalse(vl2.hasScaleBasedVisibility())
+        style2 = QDomDocument()
+        style2.setContent(style_content)
+        self.assertTrue(vl2.readStyle(style.namedItem('qgis'), "Error reading style", QgsReadWriteContext(), QgsMapLayer.Rendering))
+        self.assertTrue(vl2.hasScaleBasedVisibility())
+        self.assertEqual(vl2.minimumScale(), 125.0)
+        self.assertEqual(vl2.maximumScale(), 1.25)
+
+
+if __name__ == '__main__':
+    unittest.main()