#8725-R: refactoring of simplification API in FeatureIterators

qgis · Jan 15, 2014 · 4cc82e6 · 4cc82e6
1 parent 1e781ff
commit 4cc82e6
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Showing 7 changed files with 51 additions and 30 deletions.
diff --git a/src/core/qgsfeatureiterator.cpp b/src/core/qgsfeatureiterator.cpp
@@ -55,16 +55,11 @@ bool QgsAbstractFeatureIterator::nextFeature( QgsFeature& f )
       break;
   }
 
-  // simplify locally the geometry using the simplifier defined in constructor
-  if ( dataOk && mGeometrySimplifier )
+  // simplify the geometry using the simplifier configured
+  if ( dataOk )
   {
     QgsGeometry* geometry = f.geometry();
-
-    if ( geometry ) 
-    {
-      QGis::GeometryType geometryType = geometry->type();
-      if ( geometryType == QGis::Line || geometryType == QGis::Polygon ) mGeometrySimplifier->simplifyGeometry( geometry );
-    }
+    if ( geometry ) simplify( f );
   }
   return dataOk;
 }
@@ -101,10 +96,8 @@ void QgsAbstractFeatureIterator::deref()
     delete this;
 }
 
-bool QgsAbstractFeatureIterator::prepareLocalSimplification()
+bool QgsAbstractFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simplifyMethod )
 {
-  const QgsSimplifyMethod& simplifyMethod = mRequest.simplifyMethod();
-
   if ( mGeometrySimplifier )
   {
     delete mGeometrySimplifier;
@@ -136,6 +129,22 @@ bool QgsAbstractFeatureIterator::prepareLocalSimplification()
   return false;
 }
 
+bool QgsAbstractFeatureIterator::simplify( QgsFeature& feature )
+{
+  // simplify locally the geometry using the configured simplifier
+  if ( mGeometrySimplifier )
+  {
+    QgsGeometry* geometry = feature.geometry();
+
+    if ( geometry ) 
+    {
+      QGis::GeometryType geometryType = geometry->type();
+      if ( geometryType == QGis::Line || geometryType == QGis::Polygon ) return mGeometrySimplifier->simplifyGeometry( geometry );
+    }
+  }
+  return false;
+}
+
 ///////
 
 QgsFeatureIterator& QgsFeatureIterator::operator=( const QgsFeatureIterator & other )

diff --git a/src/core/qgsfeatureiterator.h b/src/core/qgsfeatureiterator.h
@@ -87,12 +87,15 @@ 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();
+    //! Setup the simplification of geometries to fetch using the specified simplify method
+    virtual bool prepareSimplification( const QgsSimplifyMethod& simplifyMethod );
 
   private:
     //! optional object to locally simplify geometries fetched by this feature iterator
     QgsAbstractGeometrySimplifier* mGeometrySimplifier;
+
+    //! simplify the specified geometry if it was configured
+    virtual bool simplify( QgsFeature& feature );
 };
 
 

diff --git a/src/core/qgsvectorlayerfeatureiterator.cpp b/src/core/qgsvectorlayerfeatureiterator.cpp
@@ -68,6 +68,15 @@ QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayer* la
   }
   else // no filter or filter by rect
   {
+    QgsSimplifyMethod simplifyMethod = request.simplifyMethod();
+
+    // if required, local simplification will be configured for all providers, then avoid simplify twice (this iterator and provider iterator)
+    if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && simplifyMethod.forceLocalOptimization() )
+    {
+      simplifyMethod.setMethodType( QgsSimplifyMethod::NoSimplification );
+      if ( L->editBuffer() ) mChangedFeaturesRequest.setSimplifyMethod( simplifyMethod ); else mProviderRequest.setSimplifyMethod( simplifyMethod );
+    }
+
     if ( L->editBuffer() )
     {
       mChangedFeaturesIterator = L->dataProvider()->getFeatures( mChangedFeaturesRequest );
@@ -77,8 +86,8 @@ QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayer* la
       mProviderIterator = L->dataProvider()->getFeatures( mProviderRequest );
     }
 
-    // setup if required the local simplification of geometries to fetch
-    prepareLocalSimplification();
+    // prepare if required the local simplification of geometries to fetch
+    prepareSimplification( request.simplifyMethod() );
 
     rewindEditBuffer();
   }

diff --git a/src/providers/ogr/qgsogrfeatureiterator.cpp b/src/providers/ogr/qgsogrfeatureiterator.cpp
@@ -81,7 +81,7 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrProvider* p, const QgsFeatur
   }
 
   //setup if required the simplification of OGR-geometries fetched
-  prepareProviderSimplification();
+  prepareSimplification( request.simplifyMethod() );
 
   //start with first feature
   rewind();
@@ -105,9 +105,9 @@ void QgsOgrFeatureIterator::ensureRelevantFields()
   P->mRelevantFieldsForNextFeature = true;
 }
 
-bool QgsOgrFeatureIterator::prepareProviderSimplification()
+bool QgsOgrFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simplifyMethod )
 {
-  const QgsSimplifyMethod& simplifyMethod = mRequest.simplifyMethod();
+  bool providerSimplification = false;
 
   if ( mGeometrySimplifier )
   {
@@ -124,20 +124,20 @@ bool QgsOgrFeatureIterator::prepareProviderSimplification()
     {
       int simplifyFlags = QgsMapToPixelSimplifier::SimplifyGeometry | QgsMapToPixelSimplifier::SimplifyEnvelope;
       mGeometrySimplifier = new QgsOgrMapToPixelSimplifier( simplifyFlags, simplifyMethod.tolerance() );
-      return true;
+      providerSimplification = true;
     }
     else
     if ( methodType == QgsSimplifyMethod::PreserveTopology )
     {
       mGeometrySimplifier = new QgsOgrTopologyPreservingSimplifier( simplifyMethod.tolerance() );
-      return true;
+      providerSimplification = true;
     }
     else
     {
       QgsDebugMsg( QString( "Simplification method type (%1) is not recognised by OgrFeatureIterator class" ).arg( methodType ) );
     }
   }
-  return false;
+  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod ) || providerSimplification;
 }
 
 bool QgsOgrFeatureIterator::fetchFeature( QgsFeature& feature )

diff --git a/src/providers/ogr/qgsogrfeatureiterator.h b/src/providers/ogr/qgsogrfeatureiterator.h
@@ -39,8 +39,8 @@ class QgsOgrFeatureIterator : public QgsAbstractFeatureIterator
     //! fetch next feature, return true on success
     virtual bool fetchFeature( QgsFeature& feature );
 
-    //! setup if required the simplification of OGR-geometries fetched, it uses the settings of current FeatureRequest
-    virtual bool prepareProviderSimplification();
+    //! Setup the simplification of geometries to fetch using the specified simplify method
+    virtual bool prepareSimplification( const QgsSimplifyMethod& simplifyMethod );
 
     QgsOgrProvider* P;
 

diff --git a/src/providers/postgres/qgspostgresfeatureiterator.cpp b/src/providers/postgres/qgspostgresfeatureiterator.cpp
@@ -81,7 +81,7 @@ QgsPostgresFeatureIterator::QgsPostgresFeatureIterator( QgsPostgresProvider* p,
   }
 
   //setup if required the simplification of geometries to fetch
-  prepareProviderSimplification();
+  prepareSimplification( request.simplifyMethod() );
 
   mFetched = 0;
 }
@@ -173,9 +173,9 @@ bool QgsPostgresFeatureIterator::fetchFeature( QgsFeature& feature )
   return true;
 }
 
-bool QgsPostgresFeatureIterator::prepareProviderSimplification()
+bool QgsPostgresFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simplifyMethod )
 {
-  const QgsSimplifyMethod& simplifyMethod = mRequest.simplifyMethod();
+  bool providerSimplification = false;
 
   // validate settings of simplification of geometries to fetch
   if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && !simplifyMethod.forceLocalOptimization() && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) )
@@ -184,14 +184,14 @@ bool QgsPostgresFeatureIterator::prepareProviderSimplification()
 
     if ( methodType == QgsSimplifyMethod::OptimizeForRendering || methodType == QgsSimplifyMethod::PreserveTopology )
     {
-      return true;
+      providerSimplification = true;
     }
     else
     {
       QgsDebugMsg( QString( "Simplification method type (%1) is not recognised by PostgresFeatureIterator" ).arg( methodType ) );
     }
   }
-  return false;
+  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod ) || providerSimplification;
 }
 
 bool QgsPostgresFeatureIterator::rewind()

diff --git a/src/providers/postgres/qgspostgresfeatureiterator.h b/src/providers/postgres/qgspostgresfeatureiterator.h
@@ -40,8 +40,8 @@ class QgsPostgresFeatureIterator : public QgsAbstractFeatureIterator
     //! fetch next feature, return true on success
     virtual bool fetchFeature( QgsFeature& feature );
 
-    //! setup if required the simplification of geometries to fetch, it uses the settings of current FeatureRequest
-    virtual bool prepareProviderSimplification();
+    //! Setup the simplification of geometries to fetch using the specified simplify method
+    virtual bool prepareSimplification( const QgsSimplifyMethod& simplifyMethod );
 
     QgsPostgresProvider* P;