0026961: Recover possibility to read files in old persistence format

[occt.git] / src / StdObjMgt / StdObjMgt_ContentTypes.hxx

diff --git a/src/StdObjMgt/StdObjMgt_ContentTypes.hxx b/src/StdObjMgt/StdObjMgt_ContentTypes.hxx
new file mode 100644 (file)
index 0000000..5455fe0
--- /dev/null
+++ b/src/StdObjMgt/StdObjMgt_ContentTypes.hxx
@@ -0,0 +1,102 @@
+// Copyright (c) 2015 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _StdObjMgt_ContentTypes_HeaderFile
+#define _StdObjMgt_ContentTypes_HeaderFile
+
+
+#include <StdObjMgt_ReadData.hxx>
+
+class StdObjMgt_Persistent;
+
+
+//! Root class for an object containing other obects.
+class StdObjMgt_ContentTypes
+{
+  template <typename Type>
+  class holder
+  {
+  public:
+    //! Return the value.
+    operator Type() const { return myValue; }
+
+  protected:
+    Type myValue;
+  };
+
+  template <typename Type>
+  struct enum_ : holder<Type>
+  {
+    //! Read the value from a file.
+    void Read (StdObjMgt_ReadData& theReadData)
+      { theReadData.ReadEnum (this->myValue); }
+  };
+
+  template <typename Type>
+  struct value : holder<Type>
+  {
+    //! Read the value from a file.
+    void Read (StdObjMgt_ReadData& theReadData)
+      { theReadData.ReadValue (this->myValue); }
+  };
+
+  template <class Class>
+  struct object : Class
+  {
+    //! Read object data from a file.
+    void Read (StdObjMgt_ReadData& theReadData)
+      { theReadData.ReadObject ((Class&)*this); }
+  };
+
+  template <class Persistent>
+  struct referenceT : Handle(Persistent)
+  {
+    //! Read object data from a file.
+    void Read (StdObjMgt_ReadData& theReadData)
+      { theReadData.ReadReference (*this); }
+  };
+
+  struct reference : Handle(StdObjMgt_Persistent)
+  {
+    //! Read object data from a file.
+    void Read (StdObjMgt_ReadData& theReadData)
+      { Handle(StdObjMgt_Persistent)::operator= (theReadData.ReadReference()); }
+
+    //! Cast the reference to a target type.
+    template <class Persistent>
+    bool Cast (Handle(Persistent)& theTarget) const
+    {
+      theTarget = Handle(Persistent)::DownCast(*this);
+      return ! theTarget.IsNull();
+    }
+  };
+
+public:
+  template <class Type>
+  struct Enum      : StdObjMgt_ReadData::Content <enum_<Type> > {};
+
+  template <class Type>
+  struct Value     : StdObjMgt_ReadData::Content <value<Type> > {};
+
+  template <class Class>
+  struct Object    : StdObjMgt_ReadData::Content <object<Class> > {};
+
+  template <class Persistent = StdObjMgt_Persistent>
+  struct Reference : StdObjMgt_ReadData::Content <referenceT<Persistent> > {};
+};
+
+template<>
+struct StdObjMgt_ContentTypes::Reference<StdObjMgt_Persistent>
+    : StdObjMgt_ReadData::Content <reference> {};
+
+#endif // _StdObjMgt_ContentTypes_HeaderFile