diff --git a/DestinationGLCanvas.cpp b/DestinationGLCanvas.cpp
index e92b1ee..05c507d 100644
--- a/DestinationGLCanvas.cpp
+++ b/DestinationGLCanvas.cpp
@@ -26,21 +26,20 @@ DestinationGLCanvas::DestinationGLCanvas(MainWindow* mainWindow, QWidget* parent
 {
 }
 
-MShape* DestinationGLCanvas::getShapeFromMappingId(uid mappingId) const
+MShape::ptr DestinationGLCanvas::getShapeFromMappingId(uid mappingId) const
 {
   if (mappingId == NULL_UID)
-    return NULL;
+    return MShape::ptr();
   else
-    return getMainWindow()->getMappingManager().getMappingById(mappingId)->getShape().data();
+    return getMainWindow()->getMappingManager().getMappingById(mappingId)->getShape();
 }
 
-ShapeGraphicsItem* DestinationGLCanvas::getShapeGraphicsItemFromMappingId(uid mappingId) const
+QSharedPointer<ShapeGraphicsItem> DestinationGLCanvas::getShapeGraphicsItemFromMappingId(uid mappingId) const
 {
   if (mappingId == NULL_UID)
-    return NULL;
-
+    return QSharedPointer<ShapeGraphicsItem>();
   else
   {
-    return MainWindow::instance()->getMapperByMappingId(mappingId)->getGraphicsItem().data();
+    return MainWindow::instance()->getMapperByMappingId(mappingId)->getGraphicsItem();
   }
 }
diff --git a/DestinationGLCanvas.h b/DestinationGLCanvas.h
index ef5b443..df51cb8 100644
--- a/DestinationGLCanvas.h
+++ b/DestinationGLCanvas.h
@@ -35,8 +35,8 @@ public:
   virtual ~DestinationGLCanvas() {}
 
   virtual bool isOutput() const { return true; }
-  virtual MShape* getShapeFromMappingId(uid mappingId) const;
-  virtual ShapeGraphicsItem* getShapeGraphicsItemFromMappingId(uid mappingId) const;
+  virtual MShape::ptr getShapeFromMappingId(uid mappingId) const;
+  virtual QSharedPointer<ShapeGraphicsItem> getShapeGraphicsItemFromMappingId(uid mappingId) const;
 };
 
 #endif /* DESTINATIONGLCANVAS_H_ */
diff --git a/MapperGLCanvas.cpp b/MapperGLCanvas.cpp
index a559013..958f423 100644
--- a/MapperGLCanvas.cpp
+++ b/MapperGLCanvas.cpp
@@ -61,12 +61,12 @@ MapperGLCanvas::MapperGLCanvas(MainWindow* mainWindow, QWidget* parent, const QG
   this->scene()->setBackgroundBrush(Qt::black);
 }
 
-MShape* MapperGLCanvas::getCurrentShape()
+MShape::ptr MapperGLCanvas::getCurrentShape()
 {
   return getShapeFromMappingId(MainWindow::instance()->getCurrentMappingId());
 }
 
-ShapeGraphicsItem* MapperGLCanvas::getCurrentShapeGraphicsItem()
+QSharedPointer<ShapeGraphicsItem> MapperGLCanvas::getCurrentShapeGraphicsItem()
 {
   return getShapeGraphicsItemFromMappingId(MainWindow::instance()->getCurrentMappingId());
 }
@@ -81,7 +81,7 @@ void MapperGLCanvas::drawForeground(QPainter *painter , const QRectF &rect)
     if (mid != NULL_UID)
     {
       // Use current shape graphics item to draw controls.
-      ShapeGraphicsItem* item = getCurrentShapeGraphicsItem();
+      ShapeGraphicsItem::ptr item = getCurrentShapeGraphicsItem();
       if (item)
       {
         QList<int> selected;
@@ -118,7 +118,7 @@ void MapperGLCanvas::mousePressEvent(QMouseEvent* event)
   // Check for vertex selection first.
   else if (event->buttons() & Qt::LeftButton)
   {
-    MShape* shape = getCurrentShape();
+    MShape::ptr shape = getCurrentShape();
     if (shape)
     {
       // Note: we compare with the square value for fastest computation of the distance
@@ -148,14 +148,14 @@ void MapperGLCanvas::mousePressEvent(QMouseEvent* event)
   // Check for shape selection.
   if (event->buttons() & (Qt::LeftButton | Qt::RightButton)) // Add Right click for context menu
   {
-    MShape* selectedShape = getCurrentShape();
+    MShape::ptr selectedShape = getCurrentShape();
 
     // Possibility of changing shape in output by clicking on it.
     MappingManager manager = getMainWindow()->getMappingManager();
     QVector<Mapping::ptr> mappings = manager.getVisibleMappings();
     for (QVector<Mapping::ptr>::const_iterator it = mappings.end() - 1; it >= mappings.begin(); --it)
     {
-      MShape *shape = getShapeFromMappingId((*it)->getId());
+      MShape::ptr shape = getShapeFromMappingId((*it)->getId());
 
       // Check if mouse was pressed on that shape.
       if (shape && shape->includesPoint(pos))
@@ -240,7 +240,7 @@ void MapperGLCanvas::mouseMoveEvent(QMouseEvent* event)
   if (_vertexGrabbed)
   {
     // std::cout << "Move event " << std::endl;
-    MShape* shape = getCurrentShape();
+    MShape::ptr shape = getCurrentShape();
     if (shape && hasActiveVertex())
     {
 //      QPointF p = shape->getVertex(_activeVertex);
@@ -262,7 +262,7 @@ void MapperGLCanvas::mouseMoveEvent(QMouseEvent* event)
   else if (_shapeGrabbed)
   {
     // std::cout << "Move event " << std::endl;
-    MShape* shape = getCurrentShape();
+    MShape::ptr shape = getCurrentShape();
     if (shape)
     {
       if (_shapeFirstGrab)
@@ -301,7 +301,7 @@ void MapperGLCanvas::keyPressEvent(QKeyEvent* event)
   // Active vertex selected.
   if (hasActiveVertex())
   {
-    MShape* shape = getCurrentShape();
+    MShape::ptr shape = getCurrentShape();
     QPointF p = shape->getVertex(_activeVertex);
     handledKey = true;
 
diff --git a/MapperGLCanvas.h b/MapperGLCanvas.h
index 12f5dc5..f21ace4 100644
--- a/MapperGLCanvas.h
+++ b/MapperGLCanvas.h
@@ -47,7 +47,6 @@ class ShapeGraphicsItem;
 class MapperGLCanvas: public QGraphicsView
 {
   Q_OBJECT
-
 public:
   /// Constructor.
   MapperGLCanvas(MainWindow* mainWindow, QWidget* parent = 0, const QGLWidget* shareWidget = 0, QGraphicsScene* scene = 0);
@@ -55,11 +54,11 @@ public:
 
   /// Returns shape associated with mapping id.
   virtual bool isOutput() const = 0;
-  virtual MShape* getShapeFromMappingId(uid mappingId) const = 0;
-  virtual ShapeGraphicsItem* getShapeGraphicsItemFromMappingId(uid mappingId) const = 0;
+  virtual MShape::ptr getShapeFromMappingId(uid mappingId) const = 0;
+  virtual QSharedPointer<ShapeGraphicsItem> getShapeGraphicsItemFromMappingId(uid mappingId) const = 0;
 
-  MShape* getCurrentShape();
-  ShapeGraphicsItem* getCurrentShapeGraphicsItem();
+  MShape::ptr getCurrentShape();
+  QSharedPointer<ShapeGraphicsItem> getCurrentShapeGraphicsItem();
 
 //  QSize sizeHint() const;
 //  QSize minimumSizeHint() const;
diff --git a/SourceGLCanvas.cpp b/SourceGLCanvas.cpp
index 9a57277..5af3f0a 100644
--- a/SourceGLCanvas.cpp
+++ b/SourceGLCanvas.cpp
@@ -28,27 +28,27 @@ SourceGLCanvas::SourceGLCanvas(MainWindow* mainWindow, QWidget* parent)
 {
 }
 
-MShape* SourceGLCanvas::getShapeFromMappingId(uid mappingId) const
+MShape::ptr SourceGLCanvas::getShapeFromMappingId(uid mappingId) const
 {
   if (mappingId == NULL_UID)
-    return NULL;
+    return MShape::ptr();
 
   else
   {
     Mapping::ptr mapping = getMainWindow()->getMappingManager().getMappingById(mappingId);
     Q_CHECK_PTR(mapping);
-    return mapping->getInputShape().data();
+    return mapping->getInputShape();
   }
 }
 
-ShapeGraphicsItem* SourceGLCanvas::getShapeGraphicsItemFromMappingId(uid mappingId) const
+QSharedPointer<ShapeGraphicsItem> SourceGLCanvas::getShapeGraphicsItemFromMappingId(uid mappingId) const
 {
   if (mappingId == NULL_UID)
-    return NULL;
+    return QSharedPointer<ShapeGraphicsItem>();
 
   else
   {
-    return MainWindow::instance()->getMapperByMappingId(mappingId)->getInputGraphicsItem().data();
+    return MainWindow::instance()->getMapperByMappingId(mappingId)->getInputGraphicsItem();
   }
 }
 
diff --git a/SourceGLCanvas.h b/SourceGLCanvas.h
index 09c581c..c0f0119 100644
--- a/SourceGLCanvas.h
+++ b/SourceGLCanvas.h
@@ -36,8 +36,8 @@ public:
   virtual ~SourceGLCanvas() {}
 
   virtual bool isOutput() const { return false; }
-  virtual MShape* getShapeFromMappingId(uid mappingId) const;
-  virtual ShapeGraphicsItem* getShapeGraphicsItemFromMappingId(uid mappingId) const;
+  virtual MShape::ptr getShapeFromMappingId(uid mappingId) const;
+  virtual QSharedPointer<ShapeGraphicsItem> getShapeGraphicsItemFromMappingId(uid mappingId) const;
 
 private:
 //  virtual void doDraw(QPainter* painter);