--- a/Framework/Layers/ILayerSource.h	Tue Nov 06 14:21:02 2018 +0100
+++ b/Framework/Layers/ILayerSource.h	Tue Nov 06 14:41:36 2018 +0100
@@ -33,37 +33,69 @@
   class ILayerSource : public IObservable
   {
   public:
-
-    typedef OriginMessage<MessageType_LayerSource_GeometryReady, ILayerSource> GeometryReadyMessage;
-    typedef OriginMessage<MessageType_LayerSource_GeometryError, ILayerSource> GeometryErrorMessage;
+    typedef OriginMessage<MessageType_LayerSource_GeometryReady, ILayerSource>  GeometryReadyMessage;
+    typedef OriginMessage<MessageType_LayerSource_GeometryError, ILayerSource>  GeometryErrorMessage;
     typedef OriginMessage<MessageType_LayerSource_ContentChanged, ILayerSource> ContentChangedMessage;
 
-    struct SliceChangedMessage : public OriginMessage<MessageType_LayerSource_SliceChanged, ILayerSource>
+    class SliceChangedMessage : public OriginMessage<MessageType_LayerSource_SliceChanged, ILayerSource>
     {
+    private:
       const Slice& slice_;
-      SliceChangedMessage(ILayerSource& origin, const Slice& slice)
-        : OriginMessage(origin),
-          slice_(slice)
+
+    public:
+      SliceChangedMessage(ILayerSource& origin,
+                          const Slice& slice) :
+        OriginMessage(origin),
+        slice_(slice)
       {
       }
-    };
 
-    struct LayerReadyMessage : public OriginMessage<MessageType_LayerSource_LayerReady, ILayerSource>
+      const Slice& GetSlice() const
+      {
+        return slice_;
+      }
+    };
+    
+
+    class LayerReadyMessage : public OriginMessage<MessageType_LayerSource_LayerReady, ILayerSource>
     {
-      std::auto_ptr<ILayerRenderer>& renderer_;
+    private:
+      std::auto_ptr<ILayerRenderer> renderer_;
       const CoordinateSystem3D& slice_;
       bool isError_;
 
+    public:
       LayerReadyMessage(ILayerSource& origin,
-                        std::auto_ptr<ILayerRenderer>& layer,
+                        ILayerRenderer* renderer,  // Takes ownership => TODO Remove this!
                         const CoordinateSystem3D& slice,
-                        bool isError  // TODO Shouldn't this be separate as NotifyLayerError?
-                        )
-        : OriginMessage(origin),
-          renderer_(layer),
-          slice_(slice),
-          isError_(isError)
+                        bool isError  // TODO => create NotifyLayerError
+                        ) :
+        OriginMessage(origin),
+        renderer_(renderer),
+        slice_(slice),
+        isError_(isError)
+      {
+      }
+
+      // TODO - Remove this function
+      std::auto_ptr<ILayerRenderer>& GetRendererRaw()
       {
+        return renderer_;
+      }
+
+      const ILayerRenderer& GetRenderer() const
+      {
+        return *renderer_;
+      }
+
+      const CoordinateSystem3D& GetSlice() const
+      {
+        return slice_;
+      }
+
+      bool IsError() const
+      {
+        return isError_;
       }
     };
 

--- a/Framework/Layers/LayerSourceBase.cpp	Tue Nov 06 14:21:02 2018 +0100
+++ b/Framework/Layers/LayerSourceBase.cpp	Tue Nov 06 14:41:36 2018 +0100
@@ -49,8 +49,7 @@
                                          const CoordinateSystem3D& slice,
                                          bool isError)
   {
-    std::auto_ptr<ILayerRenderer> renderer(layer);
-    EmitMessage(ILayerSource::LayerReadyMessage(*this, renderer, slice, isError));
+    EmitMessage(ILayerSource::LayerReadyMessage(*this, layer, slice, isError));
   }
 
   void LayerSourceBase::NotifyImageReady(const Orthanc::ImageAccessor& image,
@@ -59,5 +58,4 @@
   {
     EmitMessage(ILayerSource::ImageReadyMessage(*this, image, imageQuality, slice));
   }
-
 }

--- a/Framework/Widgets/LayerWidget.cpp	Tue Nov 06 14:21:02 2018 +0100
+++ b/Framework/Widgets/LayerWidget.cpp	Tue Nov 06 14:41:36 2018 +0100
@@ -562,13 +562,14 @@
     {
       InvalidateLayer(index);
     }
+    
     EmitMessage(LayerWidget::ContentChangedMessage(*this));
   }
   
 
   void LayerWidget::OnSliceChanged(const ILayerSource::SliceChangedMessage& message)
   {
-    if (message.slice_.ContainsPlane(slice_))
+    if (message.GetSlice().ContainsPlane(slice_))
     {
       size_t index;
       if (LookupLayer(index, message.GetOrigin()))
@@ -576,6 +577,7 @@
         InvalidateLayer(index);
       }
     }
+    
     EmitMessage(LayerWidget::ContentChangedMessage(*this));
   }
   
@@ -585,7 +587,7 @@
     size_t index;
     if (LookupLayer(index, message.GetOrigin()))
     {
-      if (message.isError_)
+      if (message.IsError())
       {
         LOG(ERROR) << "Using error renderer on layer " << index;
       }
@@ -594,11 +596,14 @@
         LOG(INFO) << "Renderer ready for layer " << index;
       }
 
-      if (message.renderer_.get() != NULL)
+      // TODO -- REMOVE THIS UGLY STUFF
+      ILayerSource::LayerReadyMessage& ugly = const_cast<ILayerSource::LayerReadyMessage&>(message);
+      
+      if (ugly.GetRendererRaw().get() != NULL)
       {
-        UpdateLayer(index, message.renderer_.release(), message.slice_);
+        UpdateLayer(index, ugly.GetRendererRaw().release(), message.GetSlice());
       }
-      else if (message.isError_)
+      else if (message.IsError())
       {
         // TODO
         //UpdateLayer(index, new SliceOutlineRenderer(slice), slice);