Make operations on the feature selection more memory friendly

src/app/qgsmaptoolmovefeature.cpp

@@ -120,7 +120,10 @@ void QgsMapToolMoveFeature::canvasPressEvent( QMouseEvent * e )
     mMovedFeatures = vlayer->selectedFeaturesIds();
 
     mRubberBand = createRubberBand( vlayer->geometryType() );
-    Q_FOREACH( const QgsFeature& feat, vlayer->selectedFeatures() )
+    QgsFeature feat;
+    QgsFeatureIterator it = vlayer->selectedFeaturesIterator( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
+
+    while ( it.nextFeature( feat ) )
     {
       mRubberBand->addGeometry( feat.geometry(), vlayer );
     }

src/app/qgsmaptoolrotatefeature.cpp

@@ -163,9 +163,12 @@ void QgsMapToolRotateFeature::canvasPressEvent( QMouseEvent * e )
     mRotatedFeatures = vlayer->selectedFeaturesIds();
 
     mRubberBand = createRubberBand( vlayer->geometryType() );
-    for ( int i = 0; i < vlayer->selectedFeatureCount(); i++ )
+
+    QgsFeature feat;
+    QgsFeatureIterator it = vlayer->selectedFeaturesIterator();
+    while ( it.nextFeature( feat ) )
     {
-      mRubberBand->addGeometry( vlayer->selectedFeatures()[i].geometry(), vlayer );
+      mRubberBand->addGeometry( feat.geometry(), vlayer );
     }
   }
 

src/core/qgsvectorlayer.cpp

@@ -2301,13 +2301,7 @@ QgsFeatureList QgsVectorLayer::selectedFeatures()
 {
   QgsFeatureList features;
 
-  QgsFeatureRequest req;
-  if ( geometryType() == QGis::NoGeometry )
-    req.setFlags( QgsFeatureRequest::NoGeometry );
-
-  req.setFilterFids( mSelectedFeatureIds );
-
-  QgsFeatureIterator it = getFeatures( req );
+  QgsFeatureIterator it = selectedFeaturesIterator();
 
   QgsFeature f;
   while ( it.nextFeature( f ) )
@@ -2318,6 +2312,16 @@ QgsFeatureList QgsVectorLayer::selectedFeatures()
   return features;
 }
 
+QgsFeatureIterator QgsVectorLayer::selectedFeaturesIterator( QgsFeatureRequest request )
+{
+  if ( geometryType() == QGis::NoGeometry )
+    request.setFlags( QgsFeatureRequest::NoGeometry );
+
+  request.setFilterFids( mSelectedFeatureIds );
+
+  return getFeatures( request );
+}
+
 bool QgsVectorLayer::addFeatures( QgsFeatureList features, bool makeSelected )
 {
   if ( !mEditBuffer || !mDataProvider )

src/core/qgsvectorlayer.h

@@ -734,6 +734,18 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      */
     QgsFeatureList selectedFeatures();
 
+    /**
+     * Get an iterator of the selected features
+     *
+     * @param request You may specify a request, e.g. to limit the set of requested attributes.
+     *                Any filter on the request will be discarded.
+     *
+     * @return Iterator over the selected features
+     *
+     * @see    selectedFeaturesIds()
+     */
+    QgsFeatureIterator selectedFeaturesIterator( QgsFeatureRequest request = QgsFeatureRequest() );
+
     /**
      * Return reference to identifiers of selected features
      *

src/core/qgsvectorlayereditutils.cpp

@@ -198,12 +198,12 @@ int QgsVectorLayerEditUtils::splitFeatures( const QList<QgsPoint>& splitLine, bo
   int splitFunctionReturn; //return code of QgsGeometry::splitGeometry
   int numberOfSplittedFeatures = 0;
 
-  QgsFeatureList featureList;
+  QgsFeatureIterator features;
   const QgsFeatureIds selectedIds = L->selectedFeaturesIds();
 
   if ( selectedIds.size() > 0 ) //consider only the selected features if there is a selection
   {
-    featureList = L->selectedFeatures();
+    features = L->selectedFeaturesIterator();
   }
   else //else consider all the feature that intersect the bounding box of the split line
   {
@@ -243,28 +243,24 @@ int QgsVectorLayerEditUtils::splitFeatures( const QList<QgsPoint>& splitLine, bo
       }
     }
 
-    QgsFeatureIterator fit = L->getFeatures( QgsFeatureRequest().setFilterRect( bBox ).setFlags( QgsFeatureRequest::ExactIntersect ) );
-
-    QgsFeature f;
-    while ( fit.nextFeature( f ) )
-      featureList << QgsFeature( f );
+    features = L->getFeatures( QgsFeatureRequest().setFilterRect( bBox ).setFlags( QgsFeatureRequest::ExactIntersect ) );
   }
 
-  QgsFeatureList::iterator select_it = featureList.begin();
-  for ( ; select_it != featureList.end(); ++select_it )
+  QgsFeature feat;
+  while ( features.nextFeature( feat ) )
   {
-    if ( !select_it->geometry() )
+    if ( !feat.geometry() )
     {
       continue;
     }
     QList<QgsGeometry*> newGeometries;
     QList<QgsPoint> topologyTestPoints;
     QgsGeometry* newGeometry = 0;
-    splitFunctionReturn = select_it->geometry()->splitGeometry( splitLine, newGeometries, topologicalEditing, topologyTestPoints );
+    splitFunctionReturn = feat.geometry()->splitGeometry( splitLine, newGeometries, topologicalEditing, topologyTestPoints );
     if ( splitFunctionReturn == 0 )
     {
       //change this geometry
-      L->editBuffer()->changeGeometry( select_it->id(), select_it->geometry() );
+      L->editBuffer()->changeGeometry( feat.id(), feat.geometry() );
 
       //insert new features
       for ( int i = 0; i < newGeometries.size(); ++i )
@@ -275,7 +271,7 @@ int QgsVectorLayerEditUtils::splitFeatures( const QList<QgsPoint>& splitLine, bo
 
         //use default value where possible for primary key (e.g. autoincrement),
         //and use the value from the original (split) feature if not primary key
-        QgsAttributes newAttributes = select_it->attributes();
+        QgsAttributes newAttributes = feat.attributes();
         foreach ( int pkIdx, L->dataProvider()->pkAttributeIndexes() )
         {
           const QVariant defaultValue = L->dataProvider()->defaultValue( pkIdx );
@@ -335,12 +331,11 @@ int QgsVectorLayerEditUtils::splitParts( const QList<QgsPoint>& splitLine, bool
   int splitFunctionReturn; //return code of QgsGeometry::splitGeometry
   int numberOfSplittedParts = 0;
 
-  QgsFeatureList featureList;
-  const QgsFeatureIds selectedIds = L->selectedFeaturesIds();
+  QgsFeatureIterator fit;
 
-  if ( selectedIds.size() > 0 ) //consider only the selected features if there is a selection
+  if ( L->selectedFeatureCount() > 0 ) //consider only the selected features if there is a selection
   {
-    featureList = L->selectedFeatures();
+    fit = L->selectedFeaturesIterator();
   }
   else //else consider all the feature that intersect the bounding box of the split line
   {
@@ -380,15 +375,13 @@ int QgsVectorLayerEditUtils::splitParts( const QList<QgsPoint>& splitLine, bool
       }
     }
 
-    QgsFeatureIterator fit = L->getFeatures( QgsFeatureRequest().setFilterRect( bBox ).setFlags( QgsFeatureRequest::ExactIntersect ) );
-
-    QgsFeature f;
-    while ( fit.nextFeature( f ) )
-      featureList << QgsFeature( f );
+    fit = L->getFeatures( QgsFeatureRequest().setFilterRect( bBox ).setFlags( QgsFeatureRequest::ExactIntersect ) );
   }
 
   int addPartRet = 0;
-  foreach ( const QgsFeature& feat, featureList )
+
+  QgsFeature feat;
+  while ( fit.nextFeature( feat ) )
   {
     QList<QgsGeometry*> newGeometries;
     QList<QgsPoint> topologyTestPoints;
@@ -448,7 +441,7 @@ int QgsVectorLayerEditUtils::splitParts( const QList<QgsPoint>& splitLine, bool
     qDeleteAll( newGeometries );
   }
 
-  if ( numberOfSplittedParts == 0 && selectedIds.size() > 0  && returnCode == 0 )
+  if ( numberOfSplittedParts == 0 && L->selectedFeatureCount() > 0  && returnCode == 0 )
   {
     //There is a selection but no feature has been split.
     //Maybe user forgot that only the selected features are split

src/plugins/spatialquery/qgsreaderfeatures.cpp

@@ -28,49 +28,19 @@ QgsReaderFeatures::QgsReaderFeatures( QgsVectorLayer *layer, bool useSelection )
 
 } // QgsReaderFeatures::QgsReaderFeatures(QgsVectorLayer *layer, bool useSelection)
 
-QgsReaderFeatures::~QgsReaderFeatures()
-{
-  if ( mListSelectedFeature.count() > 0 )
-  {
-    mListSelectedFeature.clear();
-  }
-
-} // QgsReaderFeatures::~QgsReaderFeatures()
-
 bool QgsReaderFeatures::nextFeature( QgsFeature & feature )
 {
-  return ( this->*mFuncNextFeature )( feature );
-
+  return mFit.nextFeature( feature );
 } // bool QgsReaderFeatures::nextFeature(QgsFeature & feature)
 
 void QgsReaderFeatures::initReader( bool useSelection )
 {
   if ( useSelection )
   {
-    mListSelectedFeature = mLayer->selectedFeatures();
-    mIterSelectedFeature = mListSelectedFeature.begin();
-    mFuncNextFeature = &QgsReaderFeatures::nextFeatureSelected;
+    mFit = mLayer->selectedFeaturesIterator( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
   }
   else
   {
     mFit = mLayer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
-    mFuncNextFeature = &QgsReaderFeatures::nextFeatureTotal;
   }
-
 } // void QgsReaderFeatures::initReader()
-
-bool QgsReaderFeatures::nextFeatureTotal( QgsFeature & feature )
-{
-  return mFit.nextFeature( feature );
-} // bool QgsReaderFeatures::nextFeatureTotal ( QgsFeature & feature )
-
-bool QgsReaderFeatures::nextFeatureSelected( QgsFeature & feature )
-{
-  if ( mIterSelectedFeature == mListSelectedFeature.end() )
-    return false;
-
-  feature = *mIterSelectedFeature;
-  ++mIterSelectedFeature;
-
-  return true;
-} // bool QgsReaderFeatures::nextFeatureSelected( QgsFeature &feature )

src/plugins/spatialquery/qgsreaderfeatures.h

@@ -35,11 +35,6 @@ class QgsReaderFeatures
     */
     QgsReaderFeatures( QgsVectorLayer *layer, bool useSelection );
 
-    /**
-    * \brief Destructor
-    */
-    ~QgsReaderFeatures();
-
     /**
     * \brief Next feature
     * \param feature reference to next Feature.
@@ -54,24 +49,7 @@ class QgsReaderFeatures
     */
     void initReader( bool useSelection );
 
-    /**
-    * \brief Next feature, not using the features selected
-    * \param feature reference to next Feature.
-    * \returns True if has next feature.
-    */
-    bool nextFeatureTotal( QgsFeature & feature );
-
-    /**
-    * \brief Next feature, using the features selected
-    * \param feature reference to next Feature.
-    * \returns True if has next feature.
-    */
-    bool nextFeatureSelected( QgsFeature & feature );
-
     QgsVectorLayer * mLayer;
-    QgsFeatureList   mListSelectedFeature;
-    QList<QgsFeature>::iterator mIterSelectedFeature;
-    bool ( QgsReaderFeatures::* mFuncNextFeature )( QgsFeature & );
     QgsFeatureIterator mFit;
 };