#8725-R: FeatureIterator and other minor changes

Author: ahuarte47

src/app/qgsvectorlayerproperties.cpp

@@ -396,10 +396,21 @@ void QgsVectorLayerProperties::syncToLayer( void )
   const QgsVectorSimplifyMethod& simplifyMethod = layer->simplifyMethod();
   mSimplifyDrawingGroupBox->setChecked( simplifyMethod.simplifyHints() != QgsVectorLayer::NoSimplification );
   mSimplifyDrawingSlider->setValue(( int )( 5.0f * ( simplifyMethod.threshold() - 1 ) ) );
-  mSimplifyDrawingAtProvider->setChecked( !simplifyMethod.forceLocalOptimization() );
   mSimplifyDrawingPanel->setVisible( mSimplifyDrawingSlider->value() > 0 );
   mSimplifyDrawingPx->setText( QString( "(%1 px)" ).arg( 1.0f + 0.2f * mSimplifyDrawingSlider->value() ) );
 
+  if ( !( layer->dataProvider()->capabilities() & QgsVectorDataProvider::SimplifyGeometries ) )
+  {
+    mSimplifyDrawingAtProvider->setChecked( false );
+    mSimplifyDrawingAtProvider->setEnabled( false );
+    mSimplifyDrawingAtProvider->setText( QString( "%1 (%2)" ).arg( mSimplifyDrawingAtProvider->text(), tr( "Not supported" ) ) );
+  }
+  else
+  {
+    mSimplifyDrawingAtProvider->setChecked( !simplifyMethod.forceLocalOptimization() );
+    mSimplifyDrawingAtProvider->setEnabled( mSimplifyDrawingGroupBox->isChecked() );
+  }
+
   // load appropriate symbology page (V1 or V2)
   updateSymbologyPage();
 
@@ -1094,3 +1105,15 @@ void QgsVectorLayerProperties::on_mSimplifyDrawingSlider_valueChanged( int value
   mSimplifyDrawingPanel->setVisible( value > 0 );
   mSimplifyDrawingPx->setText( QString( "(%1 px)" ).arg( 1.0f + 0.2f * value ) );
 }
+
+void QgsVectorLayerProperties::on_mSimplifyDrawingGroupBox_toggled( bool checked )
+{
+  if ( !( layer->dataProvider()->capabilities() & QgsVectorDataProvider::SimplifyGeometries ) )
+  {
+    mSimplifyDrawingAtProvider->setEnabled( false );
+  }
+  else
+  {
+    mSimplifyDrawingAtProvider->setEnabled( mSimplifyDrawingGroupBox->isChecked() );
+  }
+}

src/app/qgsvectorlayerproperties.h

@@ -120,6 +120,7 @@ class APP_EXPORT QgsVectorLayerProperties : public QgsOptionsDialogBase, private
     void on_mMaximumScaleSetCurrentPushButton_clicked();
 
     void on_mSimplifyDrawingSlider_valueChanged( int value );
+    void on_mSimplifyDrawingGroupBox_toggled( bool checked );
 
   signals:
 

src/core/qgsfeatureiterator.cpp

@@ -25,27 +25,6 @@ QgsAbstractFeatureIterator::QgsAbstractFeatureIterator( const QgsFeatureRequest&
     , refs( 0 )
     , mGeometrySimplifier( NULL )
 {
-  const QgsSimplifyMethod& simplifyMethod = request.simplifyMethod();
-
-  if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && simplifyMethod.forceLocalOptimization() )
-  {
-    QgsSimplifyMethod::MethodType methodType = simplifyMethod.methodType();
-
-    if ( methodType == QgsSimplifyMethod::OptimizeForRendering )
-    {
-      int simplifyFlags = QgsMapToPixelSimplifier::SimplifyGeometry | QgsMapToPixelSimplifier::SimplifyEnvelope;
-      mGeometrySimplifier = new QgsMapToPixelSimplifier( simplifyFlags, simplifyMethod.tolerance() );
-    }
-    else
-    if ( methodType == QgsSimplifyMethod::PreserveTopology )
-    {
-      mGeometrySimplifier = new QgsTopologyPreservingSimplifier( simplifyMethod.tolerance() );
-    }
-    else
-    {
-      QgsDebugMsg( QString( "Simplification method type (%1) is not recognised" ).arg( methodType ) );
-    }
-  }
 }
 
 QgsAbstractFeatureIterator::~QgsAbstractFeatureIterator()
@@ -122,6 +101,41 @@ void QgsAbstractFeatureIterator::deref()
     delete this;
 }
 
+bool QgsAbstractFeatureIterator::prepareLocalSimplification()
+{
+  const QgsSimplifyMethod& simplifyMethod = mRequest.simplifyMethod();
+
+  if ( mGeometrySimplifier )
+  {
+    delete mGeometrySimplifier;
+    mGeometrySimplifier = NULL;
+  }
+
+  // setup the local simplification of geometries to fetch, it uses the settings of current FeatureRequest
+  if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && simplifyMethod.forceLocalOptimization() && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) )
+  {
+    QgsSimplifyMethod::MethodType methodType = simplifyMethod.methodType();
+
+    if ( methodType == QgsSimplifyMethod::OptimizeForRendering )
+    {
+      int simplifyFlags = QgsMapToPixelSimplifier::SimplifyGeometry | QgsMapToPixelSimplifier::SimplifyEnvelope;
+      mGeometrySimplifier = new QgsMapToPixelSimplifier( simplifyFlags, simplifyMethod.tolerance() );
+      return true;
+    }
+    else
+    if ( methodType == QgsSimplifyMethod::PreserveTopology )
+    {
+      mGeometrySimplifier = new QgsTopologyPreservingSimplifier( simplifyMethod.tolerance() );
+      return true;
+    }
+    else
+    {
+      QgsDebugMsg( QString( "Simplification method type (%1) is not recognised" ).arg( methodType ) );
+    }
+  }
+  return false;
+}
+
 ///////
 
 QgsFeatureIterator& QgsFeatureIterator::operator=( const QgsFeatureIterator & other )

src/core/qgsfeatureiterator.h

@@ -87,6 +87,9 @@ class CORE_EXPORT QgsAbstractFeatureIterator
     void deref(); //!< remove reference, delete if refs == 0
     friend class QgsFeatureIterator;
 
+    //! setup if required the local simplification of geometries to fetch, it uses the settings of current FeatureRequest
+    virtual bool prepareLocalSimplification();
+
   private:
     //! optional object to locally simplify geometries fetched by this feature iterator
     QgsAbstractGeometrySimplifier* mGeometrySimplifier;

src/core/qgsgeometrysimplifier.h

@@ -53,7 +53,7 @@ class CORE_EXPORT QgsTopologyPreservingSimplifier : public QgsAbstractGeometrySi
     QgsTopologyPreservingSimplifier( double tolerance );
     virtual ~QgsTopologyPreservingSimplifier();
 
-  private:
+  protected:
     //! Distance tolerance for the simplification
     double mTolerance;
 

src/core/qgsvectordataprovider.cpp

@@ -194,6 +194,12 @@ QString QgsVectorDataProvider::capabilitiesString() const
     QgsDebugMsg( "Capability: Change Geometries" );
   }
 
+  if ( abilities & QgsVectorDataProvider::SimplifyGeometries )
+  {
+    abilitiesList += tr( "Simplify Geometries" );
+    QgsDebugMsg( "Capability: Simplify Geometries before fetch the feature" );
+  }
+
   return abilitiesList.join( ", " );
 
 }

src/core/qgsvectorlayerfeatureiterator.cpp

@@ -77,6 +77,9 @@ QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayer* la
       mProviderIterator = L->dataProvider()->getFeatures( mProviderRequest );
     }
 
+    // setup if required the local simplification of geometries to fetch
+    prepareLocalSimplification();
+
     rewindEditBuffer();
   }