source: branches/RemoveBackwardsCompatibility/HeuristicLab.ExtLibs/HeuristicLab.EPPlus/4.0.3/EPPlus-4.0.3/FormulaParsing/ExcelDataProvider.cs.orig

using OfficeOpenXml.FormulaParsing.LexicalAnalysis;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace OfficeOpenXml.FormulaParsing
{
    /// <summary>
    /// This class should be implemented to be able to deliver excel data
    /// to the formula parser.
    /// </summary>
    public abstract class ExcelDataProvider : IDisposable
    {
        public interface ICellInfo : IEnumerator<ICellInfo>, IEnumerable<ICellInfo>
        {
            string Address { get; }
            int Row { get; }
            int Column { get; }
            string Formula { get;  }
            object Value { get; }
            double ValueDouble { get; }
            double ValueDoubleLogical { get; }
            bool IsHiddenRow { get; }
            bool IsEmpty { get; }
            bool IsMulti { get; }
            bool NextCell();
            IList<Token> Tokens { get; }
            int GetNCells();
        }
        public interface INameInfo
        {
            ulong Id { get; set; }
            string Name { get; set; }
            string Formula { get; set; }
            IList<Token> Tokens { get; }
            object Value { get; set; }
        }
        /// <summary>
        /// Returns the names of all worksheet names
        /// </summary>
        /// <returns></returns>
        public abstract ExcelNamedRangeCollection GetWorksheetNames();
        /// <summary>
        /// Returns all defined names in a workbook
        /// </summary>
        /// <returns></returns>
        public abstract ExcelNamedRangeCollection GetWorkbookNameValues();
        /// <summary>
        /// Returns values from the required range.
        /// </summary>
        /// <param name="address">An Excel address</param>
        /// <returns>values from the required cells</returns>
        public abstract ICellInfo GetRange(string worksheetName, int row, int column, string address);
        public abstract INameInfo GetName(string worksheet, string name);

        public abstract IEnumerable<object> GetRangeValues(string address);

        public abstract string GetRangeFormula(string worksheetName, int row, int column);
        public abstract List<Token> GetRangeFormulaTokens(string worksheetName, int row, int column);
        public abstract bool IsRowHidden(string worksheetName, int row);
        ///// <summary>
        ///// Returns a single cell value
        ///// </summary>
        ///// <param name="address"></param>
        ///// <returns></returns>
        //public abstract object GetCellValue(int sheetID, string address);

        /// <summary>
        /// Returns a single cell value
        /// </summary>
        /// <param name="row"></param>
        /// <param name="col"></param>
        /// <returns></returns>
        public abstract object GetCellValue(string sheetName, int row, int col);

        ///// <summary>
        ///// Sets the value on the cell
        ///// </summary>
        ///// <param name="address"></param>
        ///// <param name="value"></param>
        //public abstract void SetCellValue(string address, object value);

        /// <summary>
        /// Use this method to free unmanaged resources.
        /// </summary>
        public abstract void Dispose();

        /// <summary>
        /// Max number of columns in a worksheet that the Excel data provider can handle.
        /// </summary>
        public abstract int ExcelMaxColumns { get; }

        /// <summary>
        /// Max number of rows in a worksheet that the Excel data provider can handle
        /// </summary>
        public abstract int ExcelMaxRows { get; }

        public abstract object GetRangeValue(string worksheetName, int row, int column);
    }
}