[SerializableAttribute]
[PersistenceVersionAttribute(3, 0)]
public abstract class CalculationSettings : DocumentNode

    internal class MyCalculationSettings : CalculationSettings
    {
    #region Classes for property names

    public new abstract class PropertyNames : CalculationSettings.PropertyNames
    {
            //empty
    }

    #endregion // Classes for property names

    #region Classes for calculation dependency identifiers

    public new abstract class CalculationDependencyIdentifiers 
        : CalculationSettings.CalculationDependencyIdentifiers
    {
        internal static readonly CalculationDependencyIdentifier XColumns = CreateIdentifier("XColumns");

        internal static readonly CalculationDependencyIdentifier YColumns = CreateIdentifier("YColumns");

        internal static readonly CalculationDependencyIdentifier DataFilteringSelection = CreateIdentifier("DataFilteringSelection"); 
    }

    #endregion

    #region Properties

    public override CalculationUpdateBehavior UpdateBehavior
    {
        get { return CalculationUpdateBehavior.Invalidate; }
    }

    public DataTable XColumnsSourceDataTable
    {
        get
        {
            DataColumnCalculationDependencyCollection dep = GetColumnDependencies(CalculationDependencyIdentifiers.XColumns);
            if (dep != null)
            {
                //unlike asking the columns for their ancestor table this will always work even if the user has deleted all columns
                //in the table and is thus preferable
                return dep.DataTable;
            }
            return null;            
        }
    }

    public IEnumerable<DataColumn> XColumns
    {
        get 
        {     
            DataColumnCalculationDependencyCollection dep =  GetColumnDependencies(CalculationDependencyIdentifiers.XColumns);
            if (dep != null)
            {
                return dep.Columns;
            }
            return new List<DataColumn>();
        }
        set 
        { 
            AddDependency(CalculationDependencyIdentifiers.XColumns, value);
        }
    }

    public IEnumerable<DataColumn> YColumns
    {
        get
        {
            DataColumnCalculationDependencyCollection dep = GetColumnDependencies(CalculationDependencyIdentifiers.YColumns);
            if (dep != null)
            {
                return dep.Columns;
            }
            return new List<DataColumn>();
        }
        set 
        { 
            AddDependency(CalculationDependencyIdentifiers.YColumns, value);
        }
    }

    //the steps for a dependency on marking are exactly the same
    public DataFilteringSelection DataFilteringSelection
    {
         get
         {
             DataSelectionCalculationDependency dep = GetDataSelectionDependency(CalculationDependencyIdentifiers.DataFilteringSelection);
             if(dep!=null)
             {
                 return dep.DataSelection;
             }
             return null;
         }
         set
         {
             AddDependency(CalculationDependencyIdentifiers.DataFilteringSelection, value);
         }
    }

    #endregion

    #region Construction

    public MyCalculationSettings()
    {
    }

    #endregion

    #region ISerializable Members

    protected MyCalculationSettings(SerializationInfo info, StreamingContext context)
       : base(info, context)
    {
    }

    protected override void GetObjectData(SerializationInfo info, StreamingContext context)
    {
        base.GetObjectData(info, context);
    }

    #endregion 
}