ScaRecordColDesc.h

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// # ScaRecordColDesc.h: Class for description of table scalar record columns
// # Copyright (C) 1998,2000
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library 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 Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef TABLES_SCARECORDCOLDESC_H
#define TABLES_SCARECORDCOLDESC_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/Tables/BaseColDesc.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class PlainColumn;
class ColumnSet;
 
// <summary>
// Class to define columns of scalar records in tables
// </summary>
 
// <reviewed reviewer="Wim Brouw" date="1998/12/09" tests="tTableDesc">
// </reviewed>
 
// <use visibility=export>
 
// <prerequisite>
//   <li> <linkto class=ColumnDesc>ColumnDesc</linkto>
//   <li> <linkto class=TableDesc>TableDesc</linkto>
//   <li> <linkto class=TableRecord>TableRecord</linkto>
// </prerequisite>
 
// <etymology>
//  This class builds descriptions of table columns where each cell (which
//  may also be called a row) will hold a scalar record value.
// </etymology>
 
// <synopsis>
// ScalarRecordColumnDesc is the class for defining a
// table column containing scalar record values. The only record class
// supported is <linkto class=TableRecord>TableRecord</linkto>.
// <br>
// This class is similar to the templated class
// <linkto class=ScalarColumnDesc>ScalarColumnDesc</linkto> used
// to define column descriptions for scalars with a standard data type.
// <p>
// The data managers handle a record as an indirect Vector of uChar,
// because class
// <linkto class=ScalarRecordColumnData>ScalarRecordColumnData</linkto>
// converts a record to such a vector before passing it to the data manager.
// <p>
// This class is derived from
// <linkto class=BaseColumnDesc>BaseColumnDesc</linkto>, thus the functions
// in there also apply to this class.
// <br>
// Once a column description is setup satisfactorily, it must be added
// to a table description before it can be used by the table system.
// </synopsis>
 
// <example>
// <srcblock>
//     TableDesc tabDesc("tTableDesc", "1", TableDesc::New);
//
//     // Add a scalar integer column ac, define keywords for it
//     // and define a default value 0.
//     ScalarRecordColumnDesc<Int> acColumn("ac");
//     acColumn.rwKeywordSet().define ("scale", Complex(0));
//     acColumn.rwKeywordSet().define ("unit", "");
//     acColumn.setDefault (0);
//     tabDesc.addColumn (acColumn);
//
//     // Add another column, now with data type String..
//     // This can be added directly, because no special things like
//     // keywords or default values have to be set.
//     tabDesc.addColumn (ScalarRecordColumnDesc<String>("name", "comments"));
// </srcblock>
// </example>
 
// <motivation>
// This class resembles the templated class
// <linkto class=ScalarColumnDesc>ScalarColumnDesc</linkto>
// a lot, but is different enough to make that templated class not usable
// for records.
// <br>In principle it could have been a template specialization,
// but not all compilers support specializations so well.
// </motivation>
 
// <todo asof="$DATE:$">
// # A List of bugs, limitations, extensions or planned refinements.
//  <li> Introduce a class ArrayRecordColumnDesc to support arrays of records.
// </todo>
 
class ScalarRecordColumnDesc : public BaseColumnDesc {
  friend class ColumnDesc;
 
 public:
  // Construct the column with the given name.
  // The data manager type defaults to the StandardStMan storage manager.
  // The data manager group defaults to the data manager type.
  explicit ScalarRecordColumnDesc(const String& name);
 
  // Construct the column with the given name and comment.
  // The data manager type defaults to the StandardStMan storage manager.
  // The data manager group defaults to the data manager type.
  ScalarRecordColumnDesc(const String& name, const String& comment);
 
  // Construct the column with the given name, comment, and
  // default data manager type and group.
  // A blank data manager group defaults to the data manager type.
  ScalarRecordColumnDesc(const String& name, const String& comment, const String& dataManName,
                         const String& dataManGroup);
 
  // Copy constructor (copy semantics);
  ScalarRecordColumnDesc(const ScalarRecordColumnDesc&);
 
  ~ScalarRecordColumnDesc();
 
  // Assignment (copy semantics);
  ScalarRecordColumnDesc& operator=(const ScalarRecordColumnDesc&);
 
  // Clone this column description.
  virtual BaseColumnDesc* clone() const;
 
  // Get the name of this class. It is used by the registration process.
  virtual String className() const;
 
  // Create a Column object out of this.
  // This is used by class ColumnSet to construct a table column object.
  virtual PlainColumn* makeColumn(ColumnSet*) const;
 
  // Show the column.
  virtual void show(ostream& os) const;
 
  // Create the object from AipsIO (this function is registered
  // by ColumnDesc.cc).
  static BaseColumnDesc* makeDesc(const String& name);
 
 private:
  // Put the object.
  virtual void putDesc(AipsIO&) const;
 
  // Get the object.
  virtual void getDesc(AipsIO&);
};
 
}  // namespace casacore
 
#endif