--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Layers/LayerSourceBase.h	Tue May 16 22:12:41 2017 +0200
@@ -0,0 +1,53 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017 Osimis, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include "ILayerSource.h"
+
+namespace OrthancStone
+{
+  class LayerSourceBase : public ILayerSource
+  {
+  private:
+    IObserver*  observer_;
+
+  protected:
+    void NotifySourceChange();
+
+    void NotifySliceChange(const SliceGeometry& slice);
+
+    // Takes ownership of "layer" (that cannot be "NULL")
+    void NotifyLayerReady(ILayerRenderer* layer,
+                          ILayerSource& source,
+                          const SliceGeometry& viewportSlice);
+    
+    void NotifyLayerError(ILayerSource& source,
+                          const SliceGeometry& viewportSlice);
+
+  public:
+    LayerSourceBase() : observer_(NULL)
+    {
+    }
+    
+    virtual void SetObserver(IObserver& observer);
+  };
+}