basic scenery data export in legacy text format

MemCell.h

@@ -13,10 +13,11 @@ http://mozilla.org/MPL/2.0/.
 #include "scenenode.h"
 #include "names.h"
 
-class TMemCell : public editor::basic_node {
+class TMemCell : public scene::basic_node {
 
 public:
     std::string asTrackName; // McZapkie-100302 - zeby nazwe toru na ktory jest Putcommand wysylane pamietac
+    bool is_exportable { true }; // export helper; autogenerated cells don't need to be exported
 
     explicit TMemCell( scene::node_data const &Nodedata );
 
@@ -49,6 +50,15 @@ public:
     void AssignEvents(TEvent *e);
 
 private:
+// methods
+    // serialize() subclass details, sends content of the subclass to provided stream
+    void serialize_( std::ostream &Output ) const;
+    // deserialize() subclass details, restores content of the subclass from provided stream
+    void deserialize_( std::istream &Input );
+    // export() subclass details, sends basic content of the class in legacy (text) format to provided stream
+    void export_as_text_( std::ostream &Output ) const;
+
+// members
     // content
     std::string szText;
     double fValue1 { 0.0 };