diff --git a/src/simitembase.h b/src/simitembase.h
new file mode 100644
--- /dev/null
+++ b/src/simitembase.h
@@ -0,0 +1,67 @@
+/*
+ *
+ *  $Id$
+ *
+ *  This file is part of the Virtual Leaf.
+ *
+ *  The Virtual Leaf is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The Virtual Leaf 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with the Virtual Leaf.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Copyright 2010 Roeland Merks.
+ *
+ */
+
+
+#ifndef _SIMITEMBASE_H_
+#define _SIMITEMBASE_H_
+
+#include <QGraphicsScene>
+#include <QBrush>
+#include <assert.h>
+class Vector;
+
+
+template<class TYPE> 
+TYPE class_cast(void * symbol)
+{
+  assert(sizeof(void *) == sizeof(TYPE));
+  union
+  {
+    void * symbol;
+    TYPE unknownclass;
+  } cast;
+  
+  cast.symbol = symbol;
+  return cast.unknownclass;
+}
+
+class SimItemBase
+{
+public:
+  SimItemBase( void *v, QGraphicsScene *canvas );
+  virtual ~SimItemBase(void);
+  virtual void userMove(double dx, double dy);
+  
+
+ protected:
+
+  // I know which simulation object I represent, so if I am moved around
+  // the canvas, the real object can be moved as well
+  
+  // (both Cell and Node have Vector as base class...)
+  // Not proper design... sorry.
+ 
+  void *obj; 
+  };
+
+#endif