Comments and API improvements of simplification (no functional changes)

- moved QgsVectorLayer::SimplifyHint enum to QgsVectorSimplifyMethod - use QFlags instead of int for hints - added few notes about simplification being added in 2.2
qgis · Feb 21, 2014 · da1ebc2 · ahuarte47 · Feb 22, 2014 · da1ebc2
1 parent 10f2ac9
commit da1ebc2
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Showing 17 changed files with 89 additions and 52 deletions.
diff --git a/python/core/qgsfeaturerequest.sip b/python/core/qgsfeaturerequest.sip
@@ -65,7 +65,10 @@ class QgsFeatureRequest
     QgsFeatureRequest& setSubsetOfAttributes( const QStringList& attrNames, const QgsFields& fields );
 
     //! Set a simplification method for geometries that will be fetched
+    //! @note added in 2.2
     QgsFeatureRequest& setSimplifyMethod( const QgsSimplifyMethod& simplifyMethod );
+    //! Get simplification method for geometries that will be fetched
+    //! @note added in 2.2
     const QgsSimplifyMethod& simplifyMethod() const;
 
     /**

diff --git a/python/core/qgssimplifymethod.sip b/python/core/qgssimplifymethod.sip
@@ -1,5 +1,7 @@
 
-/** This class contains information about how to simplify geometries fetched from a QgsFeatureIterator */
+/** This class contains information about how to simplify geometries fetched from a QgsFeatureIterator
+ * @note added in 2.2
+ */
 class QgsSimplifyMethod
 {
 %TypeHeaderCode

diff --git a/python/core/qgsvectorlayer.sip b/python/core/qgsvectorlayer.sip
@@ -1025,21 +1025,20 @@ class QgsVectorLayer : QgsMapLayer
     /** @note not available in python bindings */
     // inline QgsGeometryCache* cache();
 
-    /** Simplification flags for fast rendering of features */
-    enum SimplifyHint
-    {
-      NoSimplification           = 0, //!< No simplification can be applied
-      GeometrySimplification     = 1, //!< The geometries can be simplified using the current map2pixel context state
-      AntialiasingSimplification = 2, //!< The geometries can be rendered with 'AntiAliasing' disabled because of it is '1-pixel size'
-      FullSimplification         = 3, //!< All simplification hints can be applied ( Geometry + AA-disabling )
-    };
-    /** Set the simplification settings for fast rendering of features  */
+    /** Set the simplification settings for fast rendering of features
+     *  @note added in 2.2
+     */
     void setSimplifyMethod( const QgsVectorSimplifyMethod& simplifyMethod );
-    /** Returns the simplification settings for fast rendering of features  */
+    /** Returns the simplification settings for fast rendering of features
+     *  @note added in 2.2
+     */
     const QgsVectorSimplifyMethod& simplifyMethod() const;
 
-    /** Returns whether the VectorLayer can apply the specified simplification hint */
-    bool simplifyDrawingCanbeApplied( const QgsRenderContext& renderContext, int simplifyHint ) const;
+    /** Returns whether the VectorLayer can apply the specified simplification hint
+     *  @note Do not use in 3rd party code - may be removed in future version!
+     *  @note added in 2.2
+     */
+    bool simplifyDrawingCanbeApplied( const QgsRenderContext& renderContext, QgsVectorSimplifyMethod::SimplifyHint simplifyHint ) const;
 
   public slots:
     /**

diff --git a/python/core/qgsvectorsimplifymethod.sip b/python/core/qgsvectorsimplifymethod.sip
@@ -1,5 +1,7 @@
 
-/** This class contains information how to simplify geometries fetched from a vector layer */
+/** This class contains information how to simplify geometries fetched from a vector layer
+ * @note added in 2.2
+ */
 class QgsVectorSimplifyMethod
 {
 %TypeHeaderCode
@@ -12,10 +14,20 @@ class QgsVectorSimplifyMethod
     //! copy constructor
     QgsVectorSimplifyMethod( const QgsVectorSimplifyMethod& rh );
 
+    /** Simplification flags for fast rendering of features */
+    enum SimplifyHint
+    {
+      NoSimplification           = 0, //!< No simplification can be applied
+      GeometrySimplification     = 1, //!< The geometries can be simplified using the current map2pixel context state
+      AntialiasingSimplification = 2, //!< The geometries can be rendered with 'AntiAliasing' disabled because of it is '1-pixel size'
+      FullSimplification         = 3, //!< All simplification hints can be applied ( Geometry + AA-disabling )
+    };
+    typedef QFlags<QgsVectorSimplifyMethod::SimplifyHint> SimplifyHints;
+
     /** Sets the simplification hints of the vector layer managed */
-    void setSimplifyHints( int simplifyHints );
+    void setSimplifyHints( QFlags<QgsVectorSimplifyMethod::SimplifyHint> simplifyHints );
     /** Gets the simplification hints of the vector layer managed */
-    int simplifyHints() const;
+    QFlags<QgsVectorSimplifyMethod::SimplifyHint> simplifyHints() const;
 
     /** Sets the simplification threshold of the vector layer managed */
     void setThreshold( float threshold );
@@ -32,3 +44,5 @@ class QgsVectorSimplifyMethod
     /** Gets the maximum scale at which the layer should be simplified */
     float maximumScale() const;
 };
+
+QFlags<QgsVectorSimplifyMethod::SimplifyHint> operator|( QgsVectorSimplifyMethod::SimplifyHint f1, QFlags<QgsVectorSimplifyMethod::SimplifyHint> f2 );
diff --git a/src/app/qgsoptions.cpp b/src/app/qgsoptions.cpp
@@ -569,7 +569,7 @@ QgsOptions::QgsOptions( QWidget *parent, Qt::WFlags fl ) :
   chkUseRenderCaching->setChecked( settings.value( "/qgis/enable_render_caching", false ).toBool() );
 
   // Default simplify drawing configuration
-  mSimplifyDrawingGroupBox->setChecked( settings.value( "/qgis/simplifyDrawingHints", ( int )QgsVectorLayer::GeometrySimplification ).toInt() != QgsVectorLayer::NoSimplification );
+  mSimplifyDrawingGroupBox->setChecked( settings.value( "/qgis/simplifyDrawingHints", ( int )QgsVectorSimplifyMethod::GeometrySimplification ).toInt() != QgsVectorSimplifyMethod::NoSimplification );
   mSimplifyDrawingSpinBox->setValue( settings.value( "/qgis/simplifyDrawingTol", QGis::DEFAULT_MAPTOPIXEL_THRESHOLD ).toFloat() );
   mSimplifyDrawingAtProvider->setChecked( !settings.value( "/qgis/simplifyLocal", true ).toBool() );
 
@@ -1110,13 +1110,13 @@ void QgsOptions::saveOptions()
   settings.setValue( "/qgis/capitaliseLayerName", capitaliseCheckBox->isChecked() );
 
   // Default simplify drawing configuration
-  int simplifyHints = QgsVectorLayer::NoSimplification;
+  QgsVectorSimplifyMethod::SimplifyHints simplifyHints = QgsVectorSimplifyMethod::NoSimplification;
   if ( mSimplifyDrawingGroupBox->isChecked() )
   {
-    simplifyHints |= QgsVectorLayer::GeometrySimplification;
-    if ( mSimplifyDrawingSpinBox->value() > 1 ) simplifyHints |= QgsVectorLayer::AntialiasingSimplification;
+    simplifyHints |= QgsVectorSimplifyMethod::GeometrySimplification;
+    if ( mSimplifyDrawingSpinBox->value() > 1 ) simplifyHints |= QgsVectorSimplifyMethod::AntialiasingSimplification;
   }
-  settings.setValue( "/qgis/simplifyDrawingHints", simplifyHints );
+  settings.setValue( "/qgis/simplifyDrawingHints", ( int ) simplifyHints );
   settings.setValue( "/qgis/simplifyDrawingTol", mSimplifyDrawingSpinBox->value() );
   settings.setValue( "/qgis/simplifyLocal", !mSimplifyDrawingAtProvider->isChecked() );
   settings.setValue( "/qgis/simplifyMaxScale", 1.0 / mSimplifyMaximumScaleComboBox->scale() );

diff --git a/src/app/qgsvectorlayerproperties.cpp b/src/app/qgsvectorlayerproperties.cpp
@@ -393,7 +393,7 @@ void QgsVectorLayerProperties::syncToLayer( void )
 
   // get simplify drawing configuration
   const QgsVectorSimplifyMethod& simplifyMethod = layer->simplifyMethod();
-  mSimplifyDrawingGroupBox->setChecked( simplifyMethod.simplifyHints() != QgsVectorLayer::NoSimplification );
+  mSimplifyDrawingGroupBox->setChecked( simplifyMethod.simplifyHints() != QgsVectorSimplifyMethod::NoSimplification );
   mSimplifyDrawingSpinBox->setValue( simplifyMethod.threshold() );
 
   if ( !( layer->dataProvider()->capabilities() & QgsVectorDataProvider::SimplifyGeometries ) )
@@ -558,11 +558,11 @@ void QgsVectorLayerProperties::apply()
   layer->setMetadataUrlFormat( mLayerMetadataUrlFormatComboBox->currentText() );
 
   //layer simplify drawing configuration
-  int simplifyHints = QgsVectorLayer::NoSimplification;
+  QgsVectorSimplifyMethod::SimplifyHints simplifyHints = QgsVectorSimplifyMethod::NoSimplification;
   if ( mSimplifyDrawingGroupBox->isChecked() )
   {
-    simplifyHints |= QgsVectorLayer::GeometrySimplification;
-    if ( mSimplifyDrawingSpinBox->value() > 1 ) simplifyHints |= QgsVectorLayer::AntialiasingSimplification;
+    simplifyHints |= QgsVectorSimplifyMethod::GeometrySimplification;
+    if ( mSimplifyDrawingSpinBox->value() > 1 ) simplifyHints |= QgsVectorSimplifyMethod::AntialiasingSimplification;
   }
   QgsVectorSimplifyMethod simplifyMethod = layer->simplifyMethod();
   simplifyMethod.setSimplifyHints( simplifyHints );

diff --git a/src/core/qgsfeaturerequest.h b/src/core/qgsfeaturerequest.h
@@ -123,7 +123,10 @@ class CORE_EXPORT QgsFeatureRequest
     QgsFeatureRequest& setSubsetOfAttributes( const QStringList& attrNames, const QgsFields& fields );
 
     //! Set a simplification method for geometries that will be fetched
+    //! @note added in 2.2
     QgsFeatureRequest& setSimplifyMethod( const QgsSimplifyMethod& simplifyMethod );
+    //! Get simplification method for geometries that will be fetched
+    //! @note added in 2.2
     const QgsSimplifyMethod& simplifyMethod() const { return mSimplifyMethod; }
 
     /**

diff --git a/src/core/qgssimplifymethod.h b/src/core/qgssimplifymethod.h
@@ -20,6 +20,7 @@ class QgsAbstractGeometrySimplifier;
 
 /**
  * This class contains information about how to simplify geometries fetched from a QgsFeatureIterator
+ * @note added in 2.2
  */
 class CORE_EXPORT QgsSimplifyMethod
 {

diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -186,7 +186,7 @@ QgsVectorLayer::QgsVectorLayer( QString vectorLayerPath,
 
   // Default simplify drawing settings
   QSettings settings;
-  mSimplifyMethod.setSimplifyHints( settings.value( "/qgis/simplifyDrawingHints", mSimplifyMethod.simplifyHints() ).toInt() );
+  mSimplifyMethod.setSimplifyHints( ( QgsVectorSimplifyMethod::SimplifyHints ) settings.value( "/qgis/simplifyDrawingHints", ( int ) mSimplifyMethod.simplifyHints() ).toInt() );
   mSimplifyMethod.setThreshold( settings.value( "/qgis/simplifyDrawingTol", mSimplifyMethod.threshold() ).toFloat() );
   mSimplifyMethod.setForceLocalOptimization( settings.value( "/qgis/simplifyLocal", mSimplifyMethod.forceLocalOptimization() ).toBool() );
   mSimplifyMethod.setMaximumScale( settings.value( "/qgis/simplifyMaxScale", mSimplifyMethod.maximumScale() ).toFloat() );
@@ -704,7 +704,7 @@ bool QgsVectorLayer::draw( QgsRenderContext& rendererContext )
                                      .setSubsetOfAttributes( attributes );
 
   // enable the simplification of the geometries (Using the current map2pixel context) before send it to renderer engine.
-  if ( simplifyDrawingCanbeApplied( rendererContext, QgsVectorLayer::GeometrySimplification ) )
+  if ( simplifyDrawingCanbeApplied( rendererContext, QgsVectorSimplifyMethod::GeometrySimplification ) )
   {
     QPainter* p = rendererContext.painter();
     double dpi = ( p->device()->logicalDpiX() + p->device()->logicalDpiY() ) / 2;
@@ -1290,7 +1290,7 @@ bool QgsVectorLayer::setSubsetString( QString subset )
   return res;
 }
 
-bool QgsVectorLayer::simplifyDrawingCanbeApplied( const QgsRenderContext& renderContext, int simplifyHint ) const
+bool QgsVectorLayer::simplifyDrawingCanbeApplied( const QgsRenderContext& renderContext, QgsVectorSimplifyMethod::SimplifyHint simplifyHint ) const
 {
   if ( mDataProvider && !mEditBuffer && ( hasGeometryType() && geometryType() != QGis::Point ) && ( mSimplifyMethod.simplifyHints() & simplifyHint ) && renderContext.useRenderingOptimization() )
   {
@@ -1907,7 +1907,7 @@ bool QgsVectorLayer::readSymbology( const QDomNode& node, QString& errorMessage
     }
 
     // get the simplification drawing settings
-    mSimplifyMethod.setSimplifyHints( e.attribute( "simplifyDrawingHints", "1" ).toInt() );
+    mSimplifyMethod.setSimplifyHints( ( QgsVectorSimplifyMethod::SimplifyHints ) e.attribute( "simplifyDrawingHints", "1" ).toInt() );
     mSimplifyMethod.setThreshold( e.attribute( "simplifyDrawingTol", "1" ).toFloat() );
     mSimplifyMethod.setForceLocalOptimization( e.attribute( "simplifyLocal", "1" ).toInt() );
     mSimplifyMethod.setMaximumScale( e.attribute( "simplifyMaxScale", "1" ).toFloat() );

diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
@@ -1376,21 +1376,20 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     /** @note not available in python bindings */
     inline QgsGeometryCache* cache() { return mCache; }
 
-    /** Simplification flags for fast rendering of features */
-    enum SimplifyHint
-    {
-      NoSimplification           = 0, //!< No simplification can be applied
-      GeometrySimplification     = 1, //!< The geometries can be simplified using the current map2pixel context state
-      AntialiasingSimplification = 2, //!< The geometries can be rendered with 'AntiAliasing' disabled because of it is '1-pixel size'
-      FullSimplification         = 3, //!< All simplification hints can be applied ( Geometry + AA-disabling )
-    };
-    /** Set the simplification settings for fast rendering of features  */
+    /** Set the simplification settings for fast rendering of features
+     *  @note added in 2.2
+     */
     void setSimplifyMethod( const QgsVectorSimplifyMethod& simplifyMethod ) { mSimplifyMethod = simplifyMethod; }
-    /** Returns the simplification settings for fast rendering of features  */
+    /** Returns the simplification settings for fast rendering of features
+     *  @note added in 2.2
+     */
     inline const QgsVectorSimplifyMethod& simplifyMethod() const { return mSimplifyMethod; }
 
-    /** Returns whether the VectorLayer can apply the specified simplification hint */
-    bool simplifyDrawingCanbeApplied( const QgsRenderContext& renderContext, int simplifyHint ) const;
+    /** Returns whether the VectorLayer can apply the specified simplification hint
+     *  @note Do not use in 3rd party code - may be removed in future version!
+     *  @note added in 2.2
+     */
+    bool simplifyDrawingCanbeApplied( const QgsRenderContext& renderContext, QgsVectorSimplifyMethod::SimplifyHint simplifyHint ) const;
 
   public slots:
     /**

diff --git a/src/core/qgsvectorsimplifymethod.cpp b/src/core/qgsvectorsimplifymethod.cpp
@@ -18,7 +18,7 @@
 #include "qgsvectorlayer.h"
 
 QgsVectorSimplifyMethod::QgsVectorSimplifyMethod()
-    : mSimplifyHints( QGis::DEFAULT_MAPTOPIXEL_THRESHOLD > 1 ? QgsVectorLayer::FullSimplification : QgsVectorLayer::GeometrySimplification )
+    : mSimplifyHints( QGis::DEFAULT_MAPTOPIXEL_THRESHOLD > 1 ? QgsVectorSimplifyMethod::FullSimplification : QgsVectorSimplifyMethod::GeometrySimplification )
     , mThreshold( QGis::DEFAULT_MAPTOPIXEL_THRESHOLD )
     , mLocalOptimization( true )
     , mMaximumScale( 1 )

diff --git a/src/core/qgsvectorsimplifymethod.h b/src/core/qgsvectorsimplifymethod.h
@@ -16,7 +16,11 @@
 #ifndef QGSVECTORSIMPLIFYMETHOD_H
 #define QGSVECTORSIMPLIFYMETHOD_H
 
-/** This class contains information how to simplify geometries fetched from a vector layer */
+#include <QFlags>
+
+/** This class contains information how to simplify geometries fetched from a vector layer
+ * @note added in 2.2
+ */
 class CORE_EXPORT QgsVectorSimplifyMethod
 {
   public:
@@ -27,10 +31,20 @@ class CORE_EXPORT QgsVectorSimplifyMethod
     //! assignment operator
     QgsVectorSimplifyMethod& operator=( const QgsVectorSimplifyMethod& rh );
 
+    /** Simplification flags for fast rendering of features */
+    enum SimplifyHint
+    {
+      NoSimplification           = 0, //!< No simplification can be applied
+      GeometrySimplification     = 1, //!< The geometries can be simplified using the current map2pixel context state
+      AntialiasingSimplification = 2, //!< The geometries can be rendered with 'AntiAliasing' disabled because of it is '1-pixel size'
+      FullSimplification         = 3, //!< All simplification hints can be applied ( Geometry + AA-disabling )
+    };
+    Q_DECLARE_FLAGS( SimplifyHints, SimplifyHint )
+
     /** Sets the simplification hints of the vector layer managed */
-    void setSimplifyHints( int simplifyHints ) { mSimplifyHints = simplifyHints; }
+    void setSimplifyHints( SimplifyHints simplifyHints ) { mSimplifyHints = simplifyHints; }
     /** Gets the simplification hints of the vector layer managed */
-    inline int simplifyHints() const { return mSimplifyHints; }
+    inline SimplifyHints simplifyHints() const { return mSimplifyHints; }
 
     /** Sets the simplification threshold of the vector layer managed */
     void setThreshold( float threshold ) { mThreshold = threshold; }
@@ -49,7 +63,7 @@ class CORE_EXPORT QgsVectorSimplifyMethod
 
   private:
     /** Simplification hints for fast rendering of features of the vector layer managed */
-    int mSimplifyHints;
+    SimplifyHints mSimplifyHints;
     /** Simplification threshold */
     float mThreshold;
     /** Simplification executes after fetch the geometries from provider, otherwise it executes, when supported, in provider before fetch the geometries */
@@ -58,4 +72,6 @@ class CORE_EXPORT QgsVectorSimplifyMethod
     float mMaximumScale;
 };
 
+Q_DECLARE_OPERATORS_FOR_FLAGS( QgsVectorSimplifyMethod::SimplifyHints )
+
 #endif // QGSVECTORSIMPLIFYMETHOD_H
diff --git a/src/core/symbology-ng/qgslinesymbollayerv2.cpp b/src/core/symbology-ng/qgslinesymbollayerv2.cpp
@@ -188,7 +188,7 @@ void QgsSimpleLineSymbolLayerV2::renderPolyline( const QPolygonF& points, QgsSym
   p->setPen( context.selected() ? mSelPen : mPen );
 
   // Disable 'Antialiasing' if the geometry was generalized in the current RenderContext (We known that it must have least #2 points).
-  if ( points.size() <= 2 && context.layer() && context.layer()->simplifyDrawingCanbeApplied( context.renderContext(), QgsVectorLayer::AntialiasingSimplification ) && QgsAbstractGeometrySimplifier::canbeGeneralizedByDeviceBoundingBox( points, context.layer()->simplifyMethod().threshold() ) && ( p->renderHints() & QPainter::Antialiasing ) )
+  if ( points.size() <= 2 && context.layer() && context.layer()->simplifyDrawingCanbeApplied( context.renderContext(), QgsVectorSimplifyMethod::AntialiasingSimplification ) && QgsAbstractGeometrySimplifier::canbeGeneralizedByDeviceBoundingBox( points, context.layer()->simplifyMethod().threshold() ) && ( p->renderHints() & QPainter::Antialiasing ) )
   {
     p->setRenderHint( QPainter::Antialiasing, false );
     p->drawPolyline( points );

diff --git a/src/core/symbology-ng/qgssymbollayerv2.cpp b/src/core/symbology-ng/qgssymbollayerv2.cpp
@@ -388,7 +388,7 @@ void QgsFillSymbolLayerV2::_renderPolygon( QPainter* p, const QPolygonF& points,
   }
 
   // Disable 'Antialiasing' if the geometry was generalized in the current RenderContext (We known that it must have least #5 points).
-  if ( points.size() <= 5 && context.layer() && context.layer()->simplifyDrawingCanbeApplied( context.renderContext(), QgsVectorLayer::AntialiasingSimplification ) && QgsAbstractGeometrySimplifier::canbeGeneralizedByDeviceBoundingBox( points, context.layer()->simplifyMethod().threshold() ) && ( p->renderHints() & QPainter::Antialiasing ) )
+  if ( points.size() <= 5 && context.layer() && context.layer()->simplifyDrawingCanbeApplied( context.renderContext(), QgsVectorSimplifyMethod::AntialiasingSimplification ) && QgsAbstractGeometrySimplifier::canbeGeneralizedByDeviceBoundingBox( points, context.layer()->simplifyMethod().threshold() ) && ( p->renderHints() & QPainter::Antialiasing ) )
   {
     p->setRenderHint( QPainter::Antialiasing, false );
     p->drawRect( points.boundingRect() );

diff --git a/tests/src/core/testqgsatlascomposition.cpp b/tests/src/core/testqgsatlascomposition.cpp
@@ -81,7 +81,7 @@ void TestQgsAtlasComposition::initTestCase()
                                      "ogr" );
 
   QgsVectorSimplifyMethod simplifyMethod;
-  simplifyMethod.setSimplifyHints( QgsVectorLayer::NoSimplification );
+  simplifyMethod.setSimplifyHints( QgsVectorSimplifyMethod::NoSimplification );
   mVectorLayer->setSimplifyMethod( simplifyMethod );
 
   QgsMapLayerRegistry::instance()->addMapLayers( QList<QgsMapLayer*>() << mVectorLayer );

diff --git a/tests/src/core/testqgsblendmodes.cpp b/tests/src/core/testqgsblendmodes.cpp
@@ -89,7 +89,7 @@ void TestQgsBlendModes::initTestCase()
                                      myPolyFileInfo.completeBaseName(), "ogr" );
 
   QgsVectorSimplifyMethod simplifyMethod;
-  simplifyMethod.setSimplifyHints( QgsVectorLayer::NoSimplification );
+  simplifyMethod.setSimplifyHints( QgsVectorSimplifyMethod::NoSimplification );
 
   mpPolysLayer->setSimplifyMethod( simplifyMethod );
   QgsMapLayerRegistry::instance()->addMapLayers(

diff --git a/tests/src/core/testqgsgradients.cpp b/tests/src/core/testqgsgradients.cpp
@@ -96,7 +96,7 @@ void TestQgsGradients::initTestCase()
                                      myPolyFileInfo.completeBaseName(), "ogr" );
 
   QgsVectorSimplifyMethod simplifyMethod;
-  simplifyMethod.setSimplifyHints( QgsVectorLayer::NoSimplification );
+  simplifyMethod.setSimplifyHints( QgsVectorSimplifyMethod::NoSimplification );
   mpPolysLayer->setSimplifyMethod( simplifyMethod );
 
   // Register the layer with the registry
@@ -250,7 +250,7 @@ void TestQgsGradients::gradientSymbolFromQml()
   mReport += "<h2>Gradient symbol from QML test</h2>\n";
   QVERIFY( setQml( "gradient" ) );
   QgsVectorSimplifyMethod simplifyMethod;
-  simplifyMethod.setSimplifyHints( QgsVectorLayer::NoSimplification );
+  simplifyMethod.setSimplifyHints( QgsVectorSimplifyMethod::NoSimplification );
   mpPolysLayer->setSimplifyMethod( simplifyMethod );
   QVERIFY( imageCheck( "gradient_from_qml" ) );
 }