| /******************************************************************************* | 
 |  * You may amend and distribute as you like, but don't remove this header! | 
 |  * | 
 |  * EPPlus provides server-side generation of Excel 2007/2010 spreadsheets. | 
 |  * See http://www.codeplex.com/EPPlus for details. | 
 |  * | 
 |  * Copyright (C) 2011  Jan Källman | 
 |  * | 
 |  * This library is free software; you can redistribute it and/or | 
 |  * modify it under the terms of the GNU Lesser General Public | 
 |  * License as published by the Free Software Foundation; either | 
 |  * version 2.1 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 Lesser General Public License for more details. | 
 |  * | 
 |  * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php | 
 |  * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html | 
 |  * | 
 |  * All code and executables are provided "as is" with no warranty either express or implied. | 
 |  * The author accepts no liability for any damage or loss of business that this product may cause. | 
 |  * | 
 |  * Code change notes: | 
 |  * | 
 |  * Author							Change						Date | 
 |  * ****************************************************************************** | 
 |  * Jan Källman		    Added       		        2012-11-25 | 
 |  *******************************************************************************/ | 
 |  | 
 | using System; | 
 | using System.Collections; | 
 | using System.Collections.Generic; | 
 |  | 
 | namespace AppsheetEpplus; | 
 |  | 
 | internal class IndexBase : IComparable<IndexBase> { | 
 |   internal short Index; | 
 |  | 
 |   public int CompareTo(IndexBase other) { | 
 |     return Index < other.Index | 
 |         ? -1 | 
 |         : Index > other.Index | 
 |             ? 1 | 
 |             : 0; | 
 |   } | 
 | } | 
 |  | 
 | internal class IndexItem : IndexBase { | 
 |   internal int IndexPointer { get; set; } | 
 | } | 
 |  | 
 | internal class ColumnIndex : IndexBase { | 
 |   private readonly IndexBase _searchIx = new(); | 
 |  | 
 |   internal int GetPosition(int row) { | 
 |     var page = (short)(row >> CellStore<int>._pageBits); | 
 |     _searchIx.Index = page; | 
 |     var res = | 
 |         (_pages != null | 
 |                 && page >= 0 | 
 |                 && page < PageCount | 
 |                 && page < _pages.Length | 
 |                 && _pages[page] != null | 
 |                 && _pages[page].Index == page) | 
 |             ? page | 
 |             : Array.BinarySearch(_pages, 0, PageCount, _searchIx); | 
 |     if (res >= 0) { | 
 |       GetPage(row, ref res); | 
 |       return res; | 
 |     } | 
 |     var p = ~res; | 
 |  | 
 |     if (GetPage(row, ref p)) { | 
 |       return p; | 
 |     } | 
 |     return res; | 
 |   } | 
 |  | 
 |   private bool GetPage(int row, ref int res) { | 
 |     if (res < PageCount && _pages[res].MinIndex <= row && _pages[res].MaxIndex >= row) { | 
 |       return true; | 
 |     } | 
 |     if (res + 1 < PageCount && (_pages[res + 1].MinIndex <= row)) { | 
 |       do { | 
 |         res++; | 
 |       } while (res + 1 < PageCount && _pages[res + 1].MinIndex <= row); | 
 |       //if (res + 1 < PageCount && _pages[res + 1].MaxIndex >= Row) | 
 |       //{ | 
 |       return true; | 
 |       //} | 
 |       //else | 
 |       //{ | 
 |       //    return false; | 
 |       //} | 
 |     } | 
 |     if (res - 1 >= 0 && _pages[res - 1].MaxIndex >= row) { | 
 |       do { | 
 |         res--; | 
 |       } while (res - 1 > 0 && _pages[res - 1].MaxIndex >= row); | 
 |       //if (res > 0) | 
 |       //{ | 
 |       return true; | 
 |       //} | 
 |       //else | 
 |       //{ | 
 |       //    return false; | 
 |       //} | 
 |     } | 
 |     return false; | 
 |   } | 
 |  | 
 |   internal int GetNextRow(int row) { | 
 |     //var page = (int)((ulong)row >> CellStore<int>.pageBits); | 
 |     var p = GetPosition(row); | 
 |     if (p < 0) { | 
 |       p = ~p; | 
 |       if (p >= PageCount) { | 
 |         return -1; | 
 |       } | 
 |       if (_pages[p].IndexOffset + _pages[p].Rows[0].Index < row) { | 
 |         if (p + 1 >= PageCount) { | 
 |           return -1; | 
 |         } | 
 |         return _pages[p + 1].IndexOffset + _pages[p].Rows[0].Index; | 
 |       } | 
 |       return _pages[p].IndexOffset + _pages[p].Rows[0].Index; | 
 |     } | 
 |     if (p < PageCount) { | 
 |       var r = _pages[p].GetNextRow(row); | 
 |       if (r >= 0) { | 
 |         return _pages[p].IndexOffset + _pages[p].Rows[r].Index; | 
 |       } else { | 
 |         if (++p < PageCount) { | 
 |           return _pages[p].IndexOffset + _pages[p].Rows[0].Index; | 
 |         } else { | 
 |           return -1; | 
 |         } | 
 |       } | 
 |     } | 
 |     return -1; | 
 |   } | 
 |  | 
 |   internal PageIndex[] _pages = new PageIndex[CellStore<int>._pagesPerColumnMin]; | 
 |   internal int PageCount; | 
 | } | 
 |  | 
 | internal class PageIndex : IndexBase { | 
 |   private readonly IndexBase _searchIx = new(); | 
 |  | 
 |   public PageIndex() { | 
 |     Rows = new IndexItem[CellStore<int>._pageSizeMin]; | 
 |     RowCount = 0; | 
 |   } | 
 |  | 
 |   public PageIndex(IndexItem[] rows, int count) { | 
 |     Rows = rows; | 
 |     RowCount = count; | 
 |   } | 
 |  | 
 |   public PageIndex(PageIndex pageItem, int start, int size) | 
 |       : this(pageItem, start, size, pageItem.Index, pageItem.Offset) {} | 
 |  | 
 |   public PageIndex(PageIndex pageItem, int start, int size, short index, int offset) { | 
 |     Rows = new IndexItem[CellStore<int>.GetSize(size)]; | 
 |     Array.Copy(pageItem.Rows, start, Rows, 0, size); | 
 |     RowCount = size; | 
 |     Index = index; | 
 |     Offset = offset; | 
 |   } | 
 |  | 
 |   internal int Offset; | 
 |  | 
 |   internal int IndexOffset => IndexExpanded + Offset; | 
 |  | 
 |   internal int IndexExpanded => (Index << CellStore<int>._pageBits); | 
 |  | 
 |   internal IndexItem[] Rows { get; set; } | 
 |  | 
 |   internal int RowCount; | 
 |  | 
 |   internal int GetPosition(int offset) { | 
 |     _searchIx.Index = (short)offset; | 
 |     return (Rows != null | 
 |             && offset > 0 | 
 |             && offset - 1 < RowCount | 
 |             && offset - 1 < Rows.Length | 
 |             && Rows[offset - 1] != null | 
 |             && Rows[offset - 1].Index == offset) | 
 |         ? offset - 1 | 
 |         : Array.BinarySearch(Rows, 0, RowCount, _searchIx); | 
 |   } | 
 |  | 
 |   internal int GetNextRow(int row) { | 
 |     int offset = row - IndexOffset; | 
 |     var o = GetPosition(offset); | 
 |     if (o < 0) { | 
 |       o = ~o; | 
 |       if (o < RowCount) { | 
 |         return o; | 
 |       } | 
 |       return -1; | 
 |     } | 
 |     return o; | 
 |   } | 
 |  | 
 |   public int MinIndex { | 
 |     get { | 
 |       if (Rows.Length > 0) { | 
 |         return IndexOffset + Rows[0].Index; | 
 |       } | 
 |       return -1; | 
 |     } | 
 |   } | 
 |  | 
 |   public int MaxIndex { | 
 |     get { | 
 |       if (RowCount > 0) { | 
 |         return IndexOffset + Rows[RowCount - 1].Index; | 
 |       } | 
 |       return -1; | 
 |     } | 
 |   } | 
 |  | 
 |   public int GetIndex(int pos) { | 
 |     return IndexOffset + Rows[pos].Index; | 
 |   } | 
 | } | 
 |  | 
 | /// <summary> | 
 | /// This is the store for all Rows, Columns and Cells. | 
 | /// It is a Dictionary implementation that allows you to change the Key (the RowID, ColumnID or CellID ) | 
 | /// </summary> | 
 | internal class CellStore<T> { | 
 |   /**** Size constants ****/ | 
 |   internal const int _pageBits = 10; //13bits=8192  Note: Maximum is 13 bits since short is used (PageMax=16K) | 
 |   internal const int _pageSize = 1 << _pageBits; | 
 |   internal const int _pageSizeMin = 1 << 10; | 
 |   internal const int _pageSizeMax = _pageSize << 1; //Double page size | 
 |   internal const int _colSizeMin = 32; | 
 |   internal const int _pagesPerColumnMin = 32; | 
 |  | 
 |   private List<T> _values = new(); | 
 |   internal ColumnIndex[] _columnIndex = new ColumnIndex[_colSizeMin]; | 
 |   internal IndexBase _searchIx = new(); | 
 |   internal int ColumnCount; | 
 |  | 
 |   ~CellStore() { | 
 |     if (_values != null) { | 
 |       _values.Clear(); | 
 |       _values = null; | 
 |     } | 
 |     _columnIndex = null; | 
 |   } | 
 |  | 
 |   internal int GetPosition(int column) { | 
 |     _searchIx.Index = (short)column; | 
 |     return (_columnIndex != null | 
 |             && column > 0 | 
 |             && column - 1 < ColumnCount | 
 |             && column - 1 < _columnIndex.Length | 
 |             && _columnIndex[column - 1] != null | 
 |             && _columnIndex[column - 1].Index == column) | 
 |         ? column - 1 | 
 |         : Array.BinarySearch(_columnIndex, 0, ColumnCount, _searchIx); | 
 |   } | 
 |  | 
 |   internal bool GetDimension(out int fromRow, out int fromCol, out int toRow, out int toCol) { | 
 |     if (ColumnCount == 0) { | 
 |       fromRow = fromCol = toRow = toCol = 0; | 
 |       return false; | 
 |     } | 
 |     fromCol = _columnIndex[0].Index; | 
 |     var fromIndex = 0; | 
 |     if (fromCol <= 0 && ColumnCount > 1) { | 
 |       fromCol = _columnIndex[1].Index; | 
 |       fromIndex = 1; | 
 |     } else if (ColumnCount == 1 && fromCol <= 0) { | 
 |       fromRow = fromCol = toRow = toCol = 0; | 
 |       return false; | 
 |     } | 
 |     var col = ColumnCount - 1; | 
 |     while (col > 0) { | 
 |       if (_columnIndex[col].PageCount == 0 | 
 |           || _columnIndex[col]._pages[0].RowCount > 1 | 
 |           || _columnIndex[col]._pages[0].Rows[0].Index > 0) { | 
 |         break; | 
 |       } | 
 |       col--; | 
 |     } | 
 |     toCol = _columnIndex[col].Index; | 
 |     if (toCol == 0) { | 
 |       fromRow = fromCol = toRow = toCol = 0; | 
 |       return false; | 
 |     } | 
 |     fromRow = toRow = 0; | 
 |  | 
 |     for (int c = fromIndex; c < ColumnCount; c++) { | 
 |       int first, | 
 |           last; | 
 |       if (_columnIndex[c].PageCount == 0) { | 
 |         continue; | 
 |       } | 
 |       if (_columnIndex[c]._pages[0].RowCount > 0 && _columnIndex[c]._pages[0].Rows[0].Index > 0) { | 
 |         first = _columnIndex[c]._pages[0].IndexOffset + _columnIndex[c]._pages[0].Rows[0].Index; | 
 |       } else { | 
 |         if (_columnIndex[c]._pages[0].RowCount > 1) { | 
 |           first = _columnIndex[c]._pages[0].IndexOffset + _columnIndex[c]._pages[0].Rows[1].Index; | 
 |         } else if (_columnIndex[c].PageCount > 1) { | 
 |           first = _columnIndex[c]._pages[0].IndexOffset + _columnIndex[c]._pages[1].Rows[0].Index; | 
 |         } else { | 
 |           first = 0; | 
 |         } | 
 |       } | 
 |       var lp = _columnIndex[c].PageCount - 1; | 
 |       while (_columnIndex[c]._pages[lp].RowCount == 0 && lp != 0) { | 
 |         lp--; | 
 |       } | 
 |       var p = _columnIndex[c]._pages[lp]; | 
 |       if (p.RowCount > 0) { | 
 |         last = p.IndexOffset + p.Rows[p.RowCount - 1].Index; | 
 |       } else { | 
 |         last = first; | 
 |       } | 
 |       if (first > 0 && (first < fromRow || fromRow == 0)) { | 
 |         fromRow = first; | 
 |       } | 
 |       if (first > 0 && (last > toRow || toRow == 0)) { | 
 |         toRow = last; | 
 |       } | 
 |     } | 
 |     if (fromRow <= 0 || toRow <= 0) { | 
 |       fromRow = fromCol = toRow = toCol = 0; | 
 |       return false; | 
 |     } | 
 |     return true; | 
 |   } | 
 |  | 
 |   internal int FindNext(int column) { | 
 |     var c = GetPosition(column); | 
 |     if (c < 0) { | 
 |       return ~c; | 
 |     } | 
 |     return c; | 
 |   } | 
 |  | 
 |   internal T GetValue(int row, int column) { | 
 |     int i = GetPointer(row, column); | 
 |     if (i >= 0) { | 
 |       return _values[i]; | 
 |     } | 
 |     return default(T); | 
 |   } | 
 |  | 
 |   private int GetPointer(int row, int column) { | 
 |     var col = GetPosition(column); | 
 |     if (col >= 0) { | 
 |       var pos = _columnIndex[col].GetPosition(row); | 
 |       if (pos >= 0 && pos < _columnIndex[col].PageCount) { | 
 |         var pageItem = _columnIndex[col]._pages[pos]; | 
 |         if (pageItem.MinIndex > row) { | 
 |           pos--; | 
 |           if (pos < 0) { | 
 |             return -1; | 
 |           } | 
 |           pageItem = _columnIndex[col]._pages[pos]; | 
 |         } | 
 |         short ix = (short)(row - pageItem.IndexOffset); | 
 |         _searchIx.Index = ix; | 
 |         var cellPos = | 
 |             (pageItem.Rows != null | 
 |                     && ix > 0 | 
 |                     && ix - 1 < pageItem.RowCount | 
 |                     && ix - 1 < pageItem.Rows.Length | 
 |                     && pageItem.Rows[ix - 1] != null | 
 |                     && pageItem.Rows[ix - 1].Index == ix) | 
 |                 ? ix - 1 | 
 |                 : Array.BinarySearch(pageItem.Rows, 0, pageItem.RowCount, _searchIx); | 
 |         if (cellPos >= 0) { | 
 |           return pageItem.Rows[cellPos].IndexPointer; | 
 |         } //Cell does not exist | 
 |         return -1; | 
 |       } //Page does not exist | 
 |       return -1; | 
 |     } //Column does not exist | 
 |     return -1; | 
 |   } | 
 |  | 
 |   internal bool Exists(int row, int column) { | 
 |     return GetPointer(row, column) >= 0; | 
 |   } | 
 |  | 
 |   internal bool Exists(int row, int column, ref T value) { | 
 |     var p = GetPointer(row, column); | 
 |     if (p >= 0) { | 
 |       value = _values[p]; | 
 |       return true; | 
 |     } | 
 |     return false; | 
 |   } | 
 |  | 
 |   internal void SetValue(int row, int column, T value) { | 
 |     var col = | 
 |         (_columnIndex != null | 
 |                 && column > 0 | 
 |                 && column - 1 < ColumnCount | 
 |                 && column - 1 < _columnIndex.Length | 
 |                 && _columnIndex[column - 1] != null | 
 |                 && _columnIndex[column - 1].Index == column) | 
 |             ? column - 1 | 
 |             : Array.BinarySearch( | 
 |                 _columnIndex, | 
 |                 0, | 
 |                 ColumnCount, | 
 |                 new IndexBase { | 
 |                   Index = (short)(column), | 
 |                 }); | 
 |     var page = (short)(row >> _pageBits); | 
 |     if (col >= 0) { | 
 |       //var pos = Array.BinarySearch(_columnIndex[col].Pages, 0, _columnIndex[col].Count, new IndexBase() { Index = page }); | 
 |       var pos = _columnIndex[col].GetPosition(row); | 
 |       if (pos < 0) { | 
 |         pos = ~pos; | 
 |         if (pos - 1 < 0 || _columnIndex[col]._pages[pos - 1].IndexOffset + _pageSize - 1 < row) { | 
 |           AddPage(_columnIndex[col], pos, page); | 
 |         } else { | 
 |           pos--; | 
 |         } | 
 |       } | 
 |       if (pos >= _columnIndex[col].PageCount) { | 
 |         AddPage(_columnIndex[col], pos, page); | 
 |       } | 
 |       var pageItem = _columnIndex[col]._pages[pos]; | 
 |       if (pageItem.IndexOffset > row) { | 
 |         pos--; | 
 |         page--; | 
 |         if (pos < 0) { | 
 |           throw (new("Unexpected error when setting value")); | 
 |         } | 
 |         pageItem = _columnIndex[col]._pages[pos]; | 
 |       } | 
 |  | 
 |       short ix = (short)(row - ((pageItem.Index << _pageBits) + pageItem.Offset)); | 
 |       _searchIx.Index = ix; | 
 |       var cellPos = | 
 |           (pageItem.Rows != null | 
 |                   && ix >= 0 | 
 |                   && ix < pageItem.RowCount | 
 |                   && ix < pageItem.Rows.Length | 
 |                   && pageItem.Rows[ix] != null | 
 |                   && pageItem.Rows[ix].Index == ix) | 
 |               ? ix | 
 |               : Array.BinarySearch(pageItem.Rows, 0, pageItem.RowCount, _searchIx); | 
 |       if (cellPos < 0) { | 
 |         cellPos = ~cellPos; | 
 |         AddCell(_columnIndex[col], pos, cellPos, ix, value); | 
 |       } else { | 
 |         _values[pageItem.Rows[cellPos].IndexPointer] = value; | 
 |       } | 
 |     } else //Column does not exist | 
 |     { | 
 |       col = ~col; | 
 |       AddColumn(col, column); | 
 |       AddPage(_columnIndex[col], 0, page); | 
 |       short ix = (short)(row - (page << _pageBits)); | 
 |       AddCell(_columnIndex[col], 0, 0, ix, value); | 
 |     } | 
 |   } | 
 |  | 
 |   internal void Insert(int fromRow, int fromCol, int rows, int columns) { | 
 |     if (columns > 0) { | 
 |       var col = GetPosition(fromCol); | 
 |       if (col < 0) { | 
 |         col = ~col; | 
 |       } | 
 |       for (var c = col; c < ColumnCount; c++) { | 
 |         _columnIndex[c].Index += (short)columns; | 
 |       } | 
 |     } else { | 
 |       var page = fromRow >> _pageBits; | 
 |       for (int c = 0; c < ColumnCount; c++) { | 
 |         var column = _columnIndex[c]; | 
 |         var pagePos = column.GetPosition(fromRow); | 
 |         if (pagePos >= 0) { | 
 |           if (fromRow >= column._pages[pagePos].MinIndex | 
 |               && fromRow | 
 |                   <= column._pages[pagePos].MaxIndex) //The row is inside the page | 
 |           { | 
 |             int offset = fromRow - column._pages[pagePos].IndexOffset; | 
 |             var rowPos = column._pages[pagePos].GetPosition(offset); | 
 |             if (rowPos < 0) { | 
 |               rowPos = ~rowPos; | 
 |             } | 
 |             UpdateIndexOffset(column, pagePos, rowPos, fromRow, rows); | 
 |           } else if (column._pages[pagePos].MinIndex > fromRow - 1 | 
 |               && pagePos | 
 |                   > 0) //The row is on the page before. | 
 |           { | 
 |             int offset = fromRow - ((page - 1) << _pageBits); | 
 |             var rowPos = column._pages[pagePos - 1].GetPosition(offset); | 
 |             if (rowPos > 0 && pagePos > 0) { | 
 |               UpdateIndexOffset(column, pagePos - 1, rowPos, fromRow, rows); | 
 |             } | 
 |           } else if (column.PageCount >= pagePos + 1) { | 
 |             int offset = fromRow - column._pages[pagePos].IndexOffset; | 
 |             var rowPos = column._pages[pagePos].GetPosition(offset); | 
 |             if (rowPos < 0) { | 
 |               rowPos = ~rowPos; | 
 |             } | 
 |             if (column._pages[pagePos].RowCount > rowPos) { | 
 |               UpdateIndexOffset(column, pagePos, rowPos, fromRow, rows); | 
 |             } else { | 
 |               UpdateIndexOffset(column, pagePos + 1, 0, fromRow, rows); | 
 |             } | 
 |           } | 
 |         } else { | 
 |           UpdateIndexOffset(column, ~pagePos, 0, fromRow, rows); | 
 |         } | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   internal void Clear(int fromRow, int fromCol, int rows, int columns) { | 
 |     Delete(fromRow, fromCol, rows, columns, false); | 
 |   } | 
 |  | 
 |   internal void Delete(int fromRow, int fromCol, int rows, int columns) { | 
 |     Delete(fromRow, fromCol, rows, columns, true); | 
 |   } | 
 |  | 
 |   internal void Delete(int fromRow, int fromCol, int rows, int columns, bool shift) { | 
 |     if (columns > 0 && fromRow == 1 && rows >= ExcelPackage.MaxRows) { | 
 |       DeleteColumns(fromCol, columns, shift); | 
 |     } else { | 
 |       var toCol = fromCol + columns - 1; | 
 |       var pageFromRow = fromRow >> _pageBits; | 
 |       for (int c = 0; c < ColumnCount; c++) { | 
 |         var column = _columnIndex[c]; | 
 |         if (column.Index >= fromCol) { | 
 |           if (column.Index > toCol) { | 
 |             break; | 
 |           } | 
 |           var pagePos = column.GetPosition(fromRow); | 
 |           if (pagePos < 0) { | 
 |             pagePos = ~pagePos; | 
 |           } | 
 |           if (pagePos < column.PageCount) { | 
 |             var page = column._pages[pagePos]; | 
 |             if (shift | 
 |                 && page.RowCount > 0 | 
 |                 && page.MinIndex > fromRow | 
 |                 && page.MaxIndex >= fromRow + rows) { | 
 |               var o = page.MinIndex - fromRow; | 
 |               if (o < rows) { | 
 |                 rows -= o; | 
 |                 page.Offset -= o; | 
 |                 UpdatePageOffset(column, pagePos, o); | 
 |               } else { | 
 |                 page.Offset -= rows; | 
 |                 UpdatePageOffset(column, pagePos, rows); | 
 |                 continue; | 
 |               } | 
 |             } | 
 |             if (page.RowCount > 0 | 
 |                 && page.MinIndex <= fromRow + rows - 1 | 
 |                 && page.MaxIndex | 
 |                     >= fromRow) //The row is inside the page | 
 |             { | 
 |               var endRow = fromRow + rows; | 
 |               var delEndRow = DeleteCells(column._pages[pagePos], fromRow, endRow, shift); | 
 |               if (shift && delEndRow != fromRow) { | 
 |                 UpdatePageOffset(column, pagePos, delEndRow - fromRow); | 
 |               } | 
 |               if (endRow > delEndRow | 
 |                   && pagePos < column.PageCount | 
 |                   && column._pages[pagePos].MinIndex < endRow) { | 
 |                 pagePos = (delEndRow == fromRow ? pagePos : pagePos + 1); | 
 |                 var rowsLeft = DeletePage( | 
 |                     shift ? fromRow : delEndRow, | 
 |                     endRow - delEndRow, | 
 |                     column, | 
 |                     pagePos, | 
 |                     shift); | 
 |                 //if (shift) UpdatePageOffset(column, pagePos, endRow - fromRow - rowsLeft); | 
 |                 if (rowsLeft > 0) { | 
 |                   var fr = shift ? fromRow : endRow - rowsLeft; | 
 |                   pagePos = column.GetPosition(fr); | 
 |                   DeleteCells(column._pages[pagePos], fr, shift ? fr + rowsLeft : endRow, shift); | 
 |                   if (shift) { | 
 |                     UpdatePageOffset(column, pagePos, rowsLeft); | 
 |                   } | 
 |                 } | 
 |               } | 
 |             } else if (pagePos > 0 | 
 |                 && column._pages[pagePos].IndexOffset | 
 |                     > fromRow) //The row is on the page before. | 
 |             { | 
 |               int offset = fromRow + rows - 1 - ((pageFromRow - 1) << _pageBits); | 
 |               var rowPos = column._pages[pagePos - 1].GetPosition(offset); | 
 |               if (rowPos > 0 && pagePos > 0) { | 
 |                 if (shift) { | 
 |                   UpdateIndexOffset(column, pagePos - 1, rowPos, fromRow + rows - 1, -rows); | 
 |                 } | 
 |               } | 
 |             } else { | 
 |               if (shift && pagePos + 1 < column.PageCount) { | 
 |                 UpdateIndexOffset( | 
 |                     column, | 
 |                     pagePos + 1, | 
 |                     0, | 
 |                     column._pages[pagePos + 1].MinIndex, | 
 |                     -rows); | 
 |               } | 
 |             } | 
 |           } | 
 |         } | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private void UpdatePageOffset(ColumnIndex column, int pagePos, int rows) { | 
 |     //Update Pageoffset | 
 |  | 
 |     if (++pagePos < column.PageCount) { | 
 |       for (int p = pagePos; p < column.PageCount; p++) { | 
 |         if (column._pages[p].Offset - rows <= -_pageSize) { | 
 |           column._pages[p].Index--; | 
 |           column._pages[p].Offset -= rows - _pageSize; | 
 |         } else { | 
 |           column._pages[p].Offset -= rows; | 
 |         } | 
 |       } | 
 |  | 
 |       if (Math.Abs(column._pages[pagePos].Offset) > _pageSize | 
 |           || Math.Abs(column._pages[pagePos].Rows[column._pages[pagePos].RowCount - 1].Index) | 
 |               > _pageSizeMax) //Split or Merge??? | 
 |       { | 
 |         ResetPageOffset(column, pagePos, rows); | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private void ResetPageOffset(ColumnIndex column, int pagePos, int rows) { | 
 |     PageIndex fromPage = column._pages[pagePos]; | 
 |     PageIndex toPage; | 
 |     short pageAdd = 0; | 
 |     if (fromPage.Offset < -_pageSize) { | 
 |       toPage = column._pages[pagePos - 1]; | 
 |       pageAdd = -1; | 
 |       if (fromPage.Index - 1 == toPage.Index) { | 
 |         if (fromPage.IndexOffset | 
 |                 + fromPage.Rows[fromPage.RowCount - 1].Index | 
 |                 - toPage.IndexOffset | 
 |                 + toPage.Rows[0].Index | 
 |             <= _pageSizeMax) { | 
 |           MergePage(column, pagePos - 1); | 
 |         } | 
 |       } else //No page after | 
 |       { | 
 |         fromPage.Index -= pageAdd; | 
 |         fromPage.Offset += _pageSize; | 
 |       } | 
 |     } else if (fromPage.Offset > _pageSize) { | 
 |       toPage = column._pages[pagePos + 1]; | 
 |       pageAdd = 1; | 
 |       if (fromPage.Index + 1 == toPage.Index) {} else { | 
 |         fromPage.Index += pageAdd; | 
 |         fromPage.Offset += _pageSize; | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private int DeletePage(int fromRow, int rows, ColumnIndex column, int pagePos, bool shift) { | 
 |     PageIndex page = column._pages[pagePos]; | 
 |     var startRows = rows; | 
 |     while (page != null | 
 |             && page.MinIndex >= fromRow | 
 |             && ((shift && page.MaxIndex < fromRow + rows) | 
 |                     || (!shift && page.MaxIndex < fromRow + startRows))) { | 
 |       //Delete entire page. | 
 |       var delSize = page.MaxIndex - page.MinIndex + 1; | 
 |       rows -= delSize; | 
 |       var prevOffset = page.Offset; | 
 |       Array.Copy( | 
 |           column._pages, | 
 |           pagePos + 1, | 
 |           column._pages, | 
 |           pagePos, | 
 |           column.PageCount - pagePos + 1); | 
 |       column.PageCount--; | 
 |       if (column.PageCount == 0) { | 
 |         return 0; | 
 |       } | 
 |       if (shift) { | 
 |         for (int i = pagePos; i < column.PageCount; i++) { | 
 |           column._pages[i].Offset -= delSize; | 
 |           if (column._pages[i].Offset <= -_pageSize) { | 
 |             column._pages[i].Index--; | 
 |             column._pages[i].Offset += _pageSize; | 
 |           } | 
 |         } | 
 |       } | 
 |       if (column.PageCount > pagePos) { | 
 |         page = column._pages[pagePos]; | 
 |         //page.Offset = pagePos == 0 ? 1 : prevOffset;  //First page can only reference to rows starting from Index == 1 | 
 |       } else { | 
 |         //No more pages, return 0 | 
 |         return 0; | 
 |       } | 
 |     } | 
 |     return rows; | 
 |   } | 
 |  | 
 |   private int DeleteCells(PageIndex page, int fromRow, int toRow, bool shift) { | 
 |     var fromPos = page.GetPosition(fromRow - (page.IndexOffset)); | 
 |     if (fromPos < 0) { | 
 |       fromPos = ~fromPos; | 
 |     } | 
 |     var maxRow = page.MaxIndex; | 
 |     var offset = toRow - page.IndexOffset; | 
 |     if (offset > _pageSizeMax) { | 
 |       offset = _pageSizeMax; | 
 |     } | 
 |     var toPos = page.GetPosition(offset); | 
 |     if (toPos < 0) { | 
 |       toPos = ~toPos; | 
 |     } | 
 |  | 
 |     if (fromPos <= toPos && fromPos < page.RowCount && page.GetIndex(fromPos) < toRow) { | 
 |       if (toRow > page.MaxIndex) { | 
 |         if (fromRow | 
 |             == page.MinIndex) //Delete entire page, late in the page delete method | 
 |         { | 
 |           return fromRow; | 
 |         } | 
 |         var r = page.MaxIndex; | 
 |         var deletedRow = page.RowCount - fromPos; | 
 |         page.RowCount -= deletedRow; | 
 |         return r + 1; | 
 |       } | 
 |       var rows = toRow - fromRow; | 
 |       if (shift) { | 
 |         UpdateRowIndex(page, toPos, rows); | 
 |       } | 
 |       Array.Copy(page.Rows, toPos, page.Rows, fromPos, page.RowCount - toPos); | 
 |       page.RowCount -= toPos - fromPos; | 
 |  | 
 |       return toRow; | 
 |     } | 
 |     if (shift) { | 
 |       UpdateRowIndex(page, toPos, toRow - fromRow); | 
 |     } | 
 |     return toRow < maxRow ? toRow : maxRow; | 
 |   } | 
 |  | 
 |   private static void UpdateRowIndex(PageIndex page, int toPos, int rows) { | 
 |     for (int r = toPos; r < page.RowCount; r++) { | 
 |       page.Rows[r].Index -= (short)rows; | 
 |     } | 
 |   } | 
 |  | 
 |   private void DeleteColumns(int fromCol, int columns, bool shift) { | 
 |     var fPos = GetPosition(fromCol); | 
 |     if (fPos < 0) { | 
 |       fPos = ~fPos; | 
 |     } | 
 |     int tPos = fPos; | 
 |     for (var c = fPos; c <= ColumnCount; c++) { | 
 |       tPos = c; | 
 |       if (tPos == ColumnCount || _columnIndex[c].Index >= fromCol + columns) { | 
 |         break; | 
 |       } | 
 |     } | 
 |  | 
 |     if (ColumnCount <= fPos) { | 
 |       return; | 
 |     } | 
 |  | 
 |     if (_columnIndex[fPos].Index >= fromCol && _columnIndex[fPos].Index <= fromCol + columns) { | 
 |       if (tPos < ColumnCount) { | 
 |         Array.Copy(_columnIndex, tPos, _columnIndex, fPos, ColumnCount - tPos); | 
 |       } | 
 |       ColumnCount -= (tPos - fPos); | 
 |     } | 
 |     if (shift) { | 
 |       for (var c = fPos; c < ColumnCount; c++) { | 
 |         _columnIndex[c].Index -= (short)columns; | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private void UpdateIndexOffset(ColumnIndex column, int pagePos, int rowPos, int row, int rows) { | 
 |     if (pagePos >= column.PageCount) { | 
 |       return; //A page after last cell. | 
 |     } | 
 |     var page = column._pages[pagePos]; | 
 |     if (rows > _pageSize) { | 
 |       short addPages = (short)(rows >> _pageBits); | 
 |       int offset = +(rows - (_pageSize * addPages)); | 
 |       for (int p = pagePos + 1; p < column.PageCount; p++) { | 
 |         if (column._pages[p].Offset + offset > _pageSize) { | 
 |           column._pages[p].Index += (short)(addPages + 1); | 
 |           column._pages[p].Offset += offset - _pageSize; | 
 |         } else { | 
 |           column._pages[p].Index += addPages; | 
 |           column._pages[p].Offset += offset; | 
 |         } | 
 |       } | 
 |  | 
 |       var size = page.RowCount - rowPos; | 
 |       if (page.RowCount > rowPos) { | 
 |         if (column.PageCount - 1 | 
 |             == pagePos) //No page after, create a new one. | 
 |         { | 
 |           //Copy rows to next page. | 
 |           var newPage = CopyNew(page, rowPos, size); | 
 |           newPage.Index = (short)((row + rows) >> _pageBits); | 
 |           newPage.Offset = row + rows - (newPage.Index * _pageSize) - newPage.Rows[0].Index; | 
 |           if (newPage.Offset > _pageSize) { | 
 |             newPage.Index++; | 
 |             newPage.Offset -= _pageSize; | 
 |           } | 
 |           AddPage(column, pagePos + 1, newPage); | 
 |           page.RowCount = rowPos; | 
 |         } else { | 
 |           if (column._pages[pagePos + 1].RowCount + size | 
 |               > _pageSizeMax) //Split Page | 
 |           { | 
 |             SplitPageInsert(column, pagePos, rowPos, rows, size, addPages); | 
 |           } else //Copy Page. | 
 |           { | 
 |             CopyMergePage(page, rowPos, rows, size, column._pages[pagePos + 1]); | 
 |           } | 
 |         } | 
 |       } | 
 |     } else { | 
 |       //Add to Pages. | 
 |       for (int r = rowPos; r < page.RowCount; r++) { | 
 |         page.Rows[r].Index += (short)rows; | 
 |       } | 
 |       if (page.Offset + page.Rows[page.RowCount - 1].Index | 
 |           >= _pageSizeMax) //Can not be larger than the max size of the page. | 
 |       { | 
 |         AdjustIndex(column, pagePos); | 
 |         if (page.Offset + page.Rows[page.RowCount - 1].Index >= _pageSizeMax) { | 
 |           pagePos = SplitPage(column, pagePos); | 
 |         } | 
 |         //IndexItem[] newRows = new IndexItem[GetSize(page.RowCount - page.Rows[r].Index)]; | 
 |         //var newPage = new PageIndex(newRows, r); | 
 |         //newPage.Index = (short)(pagePos + 1); | 
 |         //TODO: MoveRows to next page. | 
 |       } | 
 |  | 
 |       for (int p = pagePos + 1; p < column.PageCount; p++) { | 
 |         if (column._pages[p].Offset + rows < _pageSize) { | 
 |           column._pages[p].Offset += rows; | 
 |         } else { | 
 |           column._pages[p].Index++; | 
 |           column._pages[p].Offset = (column._pages[p].Offset + rows) % _pageSize; | 
 |         } | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private void SplitPageInsert( | 
 |       ColumnIndex column, | 
 |       int pagePos, | 
 |       int rowPos, | 
 |       int rows, | 
 |       int size, | 
 |       int addPages) { | 
 |     var newRows = new IndexItem[GetSize(size)]; | 
 |     var page = column._pages[pagePos]; | 
 |  | 
 |     var rStart = -1; | 
 |     for (int r = rowPos; r < page.RowCount; r++) { | 
 |       if (page.IndexExpanded - (page.Rows[r].Index + rows) > _pageSize) { | 
 |         rStart = r; | 
 |         break; | 
 |       } | 
 |       page.Rows[r].Index += (short)rows; | 
 |     } | 
 |     var rc = page.RowCount - rStart; | 
 |     page.RowCount = rStart; | 
 |     if (rc > 0) { | 
 |       //Copy to a new page | 
 |       var row = page.IndexOffset; | 
 |       var newPage = CopyNew(page, rStart, rc); | 
 |       var ix = (short)(page.Index + addPages); | 
 |       var offset = page.IndexOffset + rows - (ix * _pageSize); | 
 |       if (offset > _pageSize) { | 
 |         ix += (short)(offset / _pageSize); | 
 |         offset %= _pageSize; | 
 |       } | 
 |       newPage.Index = ix; | 
 |       newPage.Offset = offset; | 
 |       AddPage(column, pagePos + 1, newPage); | 
 |     } | 
 |  | 
 |     //Copy from next Row | 
 |   } | 
 |  | 
 |   private void CopyMergePage(PageIndex page, int rowPos, int rows, int size, PageIndex toPage) { | 
 |     var startRow = page.IndexOffset + page.Rows[rowPos].Index + rows; | 
 |     var newRows = new IndexItem[GetSize(toPage.RowCount + size)]; | 
 |     page.RowCount -= size; | 
 |     Array.Copy(page.Rows, rowPos, newRows, 0, size); | 
 |     for (int r = 0; r < size; r++) { | 
 |       newRows[r].Index += (short)(page.IndexOffset + rows - toPage.IndexOffset); | 
 |     } | 
 |  | 
 |     Array.Copy(toPage.Rows, 0, newRows, size, toPage.RowCount); | 
 |     toPage.Rows = newRows; | 
 |     toPage.RowCount += size; | 
 |   } | 
 |  | 
 |   private void MergePage(ColumnIndex column, int pagePos) { | 
 |     PageIndex page1 = column._pages[pagePos]; | 
 |     PageIndex page2 = column._pages[pagePos + 1]; | 
 |  | 
 |     var newPage = new PageIndex(page1, 0, page1.RowCount + page2.RowCount); | 
 |     newPage.RowCount = page1.RowCount + page2.RowCount; | 
 |     Array.Copy(page1.Rows, 0, newPage.Rows, 0, page1.RowCount); | 
 |     Array.Copy(page2.Rows, 0, newPage.Rows, page1.RowCount, page2.RowCount); | 
 |     for (int r = page1.RowCount; r < newPage.RowCount; r++) { | 
 |       newPage.Rows[r].Index += (short)(page2.IndexOffset - page1.IndexOffset); | 
 |     } | 
 |  | 
 |     column._pages[pagePos] = newPage; | 
 |     column.PageCount--; | 
 |  | 
 |     if (column.PageCount > (pagePos + 1)) { | 
 |       Array.Copy( | 
 |           column._pages, | 
 |           pagePos + 2, | 
 |           column._pages, | 
 |           pagePos + 1, | 
 |           column.PageCount - (pagePos + 1)); | 
 |       for (int p = pagePos + 1; p < column.PageCount; p++) { | 
 |         column._pages[p].Index--; | 
 |         column._pages[p].Offset += _pageSize; | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   private PageIndex CopyNew(PageIndex pageFrom, int rowPos, int size) { | 
 |     IndexItem[] newRows = new IndexItem[GetSize(size)]; | 
 |     Array.Copy(pageFrom.Rows, rowPos, newRows, 0, size); | 
 |     return new(newRows, size); | 
 |   } | 
 |  | 
 |   internal static int GetSize(int size) { | 
 |     var newSize = 256; | 
 |     while (newSize < size) { | 
 |       newSize <<= 1; | 
 |     } | 
 |     return newSize; | 
 |   } | 
 |  | 
 |   private void AddCell(ColumnIndex columnIndex, int pagePos, int pos, short ix, T value) { | 
 |     PageIndex pageItem = columnIndex._pages[pagePos]; | 
 |     if (pageItem.RowCount == pageItem.Rows.Length) { | 
 |       if (pageItem.RowCount | 
 |           == _pageSizeMax) //Max size-->Split | 
 |       { | 
 |         pagePos = SplitPage(columnIndex, pagePos); | 
 |         if (columnIndex._pages[pagePos - 1].RowCount > pos) { | 
 |           pagePos--; | 
 |         } else { | 
 |           pos -= columnIndex._pages[pagePos - 1].RowCount; | 
 |         } | 
 |         pageItem = columnIndex._pages[pagePos]; | 
 |       } else //Expand to double size. | 
 |       { | 
 |         var rowsTmp = new IndexItem[pageItem.Rows.Length << 1]; | 
 |         Array.Copy(pageItem.Rows, 0, rowsTmp, 0, pageItem.RowCount); | 
 |         pageItem.Rows = rowsTmp; | 
 |       } | 
 |     } | 
 |     if (pos < pageItem.RowCount) { | 
 |       Array.Copy(pageItem.Rows, pos, pageItem.Rows, pos + 1, pageItem.RowCount - pos); | 
 |     } | 
 |     pageItem.Rows[pos] = new() { | 
 |       Index = ix, | 
 |       IndexPointer = _values.Count, | 
 |     }; | 
 |     _values.Add(value); | 
 |     pageItem.RowCount++; | 
 |   } | 
 |  | 
 |   private int SplitPage(ColumnIndex columnIndex, int pagePos) { | 
 |     var page = columnIndex._pages[pagePos]; | 
 |     if (page.Offset != 0) { | 
 |       var offset = page.Offset; | 
 |       page.Offset = 0; | 
 |       for (int r = 0; r < page.RowCount; r++) { | 
 |         page.Rows[r].Index -= (short)offset; | 
 |       } | 
 |     } | 
 |     //Find Split pos | 
 |     int splitPos = 0; | 
 |     for (int r = 0; r < page.RowCount; r++) { | 
 |       if (page.Rows[r].Index > _pageSize) { | 
 |         splitPos = r; | 
 |         break; | 
 |       } | 
 |     } | 
 |     var newPage = new PageIndex(page, 0, splitPos); | 
 |     var nextPage = new PageIndex( | 
 |         page, | 
 |         splitPos, | 
 |         page.RowCount - splitPos, | 
 |         (short)(page.Index + 1), | 
 |         page.Offset); | 
 |  | 
 |     for (int r = 0; r < nextPage.RowCount; r++) { | 
 |       nextPage.Rows[r].Index = (short)(nextPage.Rows[r].Index - _pageSize); | 
 |     } | 
 |  | 
 |     columnIndex._pages[pagePos] = newPage; | 
 |     if (columnIndex.PageCount + 1 > columnIndex._pages.Length) { | 
 |       var pageTmp = new PageIndex[columnIndex._pages.Length << 1]; | 
 |       Array.Copy(columnIndex._pages, 0, pageTmp, 0, columnIndex.PageCount); | 
 |       columnIndex._pages = pageTmp; | 
 |     } | 
 |     Array.Copy( | 
 |         columnIndex._pages, | 
 |         pagePos + 1, | 
 |         columnIndex._pages, | 
 |         pagePos + 2, | 
 |         columnIndex.PageCount - pagePos - 1); | 
 |     columnIndex._pages[pagePos + 1] = nextPage; | 
 |     page = nextPage; | 
 |     //pos -= PageSize; | 
 |     columnIndex.PageCount++; | 
 |     return pagePos + 1; | 
 |   } | 
 |  | 
 |   private PageIndex AdjustIndex(ColumnIndex columnIndex, int pagePos) { | 
 |     PageIndex page = columnIndex._pages[pagePos]; | 
 |     //First Adjust indexes | 
 |     if (page.Offset + page.Rows[0].Index >= _pageSize | 
 |         || page.Offset >= _pageSize | 
 |         || page.Rows[0].Index >= _pageSize) { | 
 |       page.Index++; | 
 |       page.Offset -= _pageSize; | 
 |     } else if (page.Offset + page.Rows[0].Index <= -_pageSize | 
 |         || page.Offset <= -_pageSize | 
 |         || page.Rows[0].Index <= -_pageSize) { | 
 |       page.Index--; | 
 |       page.Offset += _pageSize; | 
 |     } | 
 |     return page; | 
 |   } | 
 |  | 
 |   private void AddPage(ColumnIndex column, int pos, short index) { | 
 |     AddPage(column, pos); | 
 |     column._pages[pos] = new() { | 
 |       Index = index, | 
 |     }; | 
 |     if (pos > 0) { | 
 |       var pp = column._pages[pos - 1]; | 
 |       if (pp.RowCount > 0 && pp.Rows[pp.RowCount - 1].Index > _pageSize) { | 
 |         column._pages[pos].Offset = pp.Rows[pp.RowCount - 1].Index - _pageSize; | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   /// <summary> | 
 |   /// Add a new page to the collection | 
 |   /// </summary> | 
 |   /// <param name="column">The column</param> | 
 |   /// <param name="pos">Position</param> | 
 |   /// <param name="page">The new page object to add</param> | 
 |   private void AddPage(ColumnIndex column, int pos, PageIndex page) { | 
 |     AddPage(column, pos); | 
 |     column._pages[pos] = page; | 
 |   } | 
 |  | 
 |   /// <summary> | 
 |   /// Add a new page to the collection | 
 |   /// </summary> | 
 |   /// <param name="column">The column</param> | 
 |   /// <param name="pos">Position</param> | 
 |   private void AddPage(ColumnIndex column, int pos) { | 
 |     if (column.PageCount == column._pages.Length) { | 
 |       var pageTmp = new PageIndex[column._pages.Length * 2]; | 
 |       Array.Copy(column._pages, 0, pageTmp, 0, column.PageCount); | 
 |       column._pages = pageTmp; | 
 |     } | 
 |     if (pos < column.PageCount) { | 
 |       Array.Copy(column._pages, pos, column._pages, pos + 1, column.PageCount - pos); | 
 |     } | 
 |     column.PageCount++; | 
 |   } | 
 |  | 
 |   private void AddColumn(int pos, int column) { | 
 |     if (ColumnCount == _columnIndex.Length) { | 
 |       var colTmp = new ColumnIndex[_columnIndex.Length * 2]; | 
 |       Array.Copy(_columnIndex, 0, colTmp, 0, ColumnCount); | 
 |       _columnIndex = colTmp; | 
 |     } | 
 |     if (pos < ColumnCount) { | 
 |       Array.Copy(_columnIndex, pos, _columnIndex, pos + 1, ColumnCount - pos); | 
 |     } | 
 |     _columnIndex[pos] = new() { | 
 |       Index = (short)(column), | 
 |     }; | 
 |     ColumnCount++; | 
 |   } | 
 |  | 
 |   internal bool NextCell(ref int row, ref int col) { | 
 |     return NextCell(ref row, ref col, 0, 0, ExcelPackage.MaxRows, ExcelPackage.MaxColumns); | 
 |   } | 
 |  | 
 |   internal bool NextCell( | 
 |       ref int row, | 
 |       ref int col, | 
 |       int minRow, | 
 |       int minColPos, | 
 |       int maxRow, | 
 |       int maxColPos) { | 
 |     if (minColPos >= ColumnCount) { | 
 |       return false; | 
 |     } | 
 |     if (maxColPos >= ColumnCount) { | 
 |       maxColPos = ColumnCount - 1; | 
 |     } | 
 |     var c = GetPosition(col); | 
 |     if (c >= 0) { | 
 |       if (c > maxColPos) { | 
 |         if (col <= minColPos) { | 
 |           return false; | 
 |         } | 
 |         col = minColPos; | 
 |         return NextCell(ref row, ref col); | 
 |       } | 
 |       var r = GetNextCell(ref row, ref c, minColPos, maxRow, maxColPos); | 
 |       col = _columnIndex[c].Index; | 
 |       return r; | 
 |     } | 
 |     c = ~c; | 
 |     if (c > _columnIndex[c].Index) { | 
 |       if (col <= minColPos) { | 
 |         return false; | 
 |       } | 
 |       col = minColPos; | 
 |       return NextCell(ref row, ref col, minRow, minColPos, maxRow, maxColPos); | 
 |     } | 
 |     { | 
 |       var r = GetNextCell(ref c, ref row, minColPos, maxRow, maxColPos); | 
 |       col = _columnIndex[c].Index; | 
 |       return r; | 
 |     } | 
 |   } | 
 |  | 
 |   internal bool GetNextCell( | 
 |       ref int row, | 
 |       ref int colPos, | 
 |       int startColPos, | 
 |       int endRow, | 
 |       int endColPos) { | 
 |     if (ColumnCount == 0) { | 
 |       return false; | 
 |     } | 
 |     if (++colPos < ColumnCount && colPos <= endColPos) { | 
 |       var r = _columnIndex[colPos].GetNextRow(row); | 
 |       if (r | 
 |           == row) //Exists next Row | 
 |       { | 
 |         return true; | 
 |       } | 
 |       int minRow, | 
 |           minCol; | 
 |       if (r > row) { | 
 |         minRow = r; | 
 |         minCol = colPos; | 
 |       } else { | 
 |         minRow = int.MaxValue; | 
 |         minCol = 0; | 
 |       } | 
 |  | 
 |       var c = colPos + 1; | 
 |       while (c < ColumnCount && c <= endColPos) { | 
 |         r = _columnIndex[c].GetNextRow(row); | 
 |         if (r | 
 |             == row) //Exists next Row | 
 |         { | 
 |           colPos = c; | 
 |           return true; | 
 |         } | 
 |         if (r > row && r < minRow) { | 
 |           minRow = r; | 
 |           minCol = c; | 
 |         } | 
 |         c++; | 
 |       } | 
 |       c = startColPos; | 
 |       if (row < endRow) { | 
 |         row++; | 
 |         while (c < colPos) { | 
 |           r = _columnIndex[c].GetNextRow(row); | 
 |           if (r | 
 |               == row) //Exists next Row | 
 |           { | 
 |             colPos = c; | 
 |             return true; | 
 |           } | 
 |           if (r > row && (r < minRow || (r == minRow && c < minCol)) && r <= endRow) { | 
 |             minRow = r; | 
 |             minCol = c; | 
 |           } | 
 |           c++; | 
 |         } | 
 |       } | 
 |  | 
 |       if (minRow == int.MaxValue || minRow > endRow) { | 
 |         return false; | 
 |       } | 
 |       row = minRow; | 
 |       colPos = minCol; | 
 |       return true; | 
 |     } | 
 |     if (colPos <= startColPos || row >= endRow) { | 
 |       return false; | 
 |     } | 
 |     colPos = startColPos - 1; | 
 |     row++; | 
 |     return GetNextCell(ref row, ref colPos, startColPos, endRow, endColPos); | 
 |   } | 
 |  | 
 |   internal bool PrevCell(ref int row, ref int col) { | 
 |     return PrevCell(ref row, ref col, 0, 0, ExcelPackage.MaxRows, ExcelPackage.MaxColumns); | 
 |   } | 
 |  | 
 |   private bool PrevCell( | 
 |       ref int row, | 
 |       ref int col, | 
 |       int minRow, | 
 |       int minColPos, | 
 |       int maxRow, | 
 |       int maxColPos) { | 
 |     if (minColPos >= ColumnCount) { | 
 |       return false; | 
 |     } | 
 |     if (maxColPos >= ColumnCount) { | 
 |       maxColPos = ColumnCount - 1; | 
 |     } | 
 |     var c = GetPosition(col); | 
 |     if (c >= 0) { | 
 |       if (c == 0) { | 
 |         if (col >= maxColPos) { | 
 |           return false; | 
 |         } | 
 |         if (row == minRow) { | 
 |           return false; | 
 |         } | 
 |         row--; | 
 |         col = maxColPos; | 
 |         return PrevCell(ref row, ref col, minRow, minColPos, maxRow, maxColPos); | 
 |       } | 
 |       var ret = GetPrevCell(ref row, ref c, minRow, minColPos, maxColPos); | 
 |       if (ret) { | 
 |         col = _columnIndex[c].Index; | 
 |       } | 
 |       return ret; | 
 |     } | 
 |     c = ~c; | 
 |     if (c == 0) { | 
 |       if (col >= maxColPos || row <= 0) { | 
 |         return false; | 
 |       } | 
 |       col = maxColPos; | 
 |       row--; | 
 |       return PrevCell(ref row, ref col, minRow, minColPos, maxRow, maxColPos); | 
 |     } | 
 |     { | 
 |       var ret = GetPrevCell(ref row, ref c, minRow, minColPos, maxColPos); | 
 |       if (ret) { | 
 |         col = _columnIndex[c].Index; | 
 |       } | 
 |       return ret; | 
 |     } | 
 |   } | 
 |  | 
 |   internal bool GetPrevCell( | 
 |       ref int row, | 
 |       ref int colPos, | 
 |       int startRow, | 
 |       int startColPos, | 
 |       int endColPos) { | 
 |     if (ColumnCount == 0) { | 
 |       return false; | 
 |     } | 
 |     if (--colPos >= startColPos) | 
 |     //                if (++colPos < ColumnCount && colPos <= endColPos) | 
 |     { | 
 |       var r = _columnIndex[colPos].GetNextRow(row); | 
 |       if (r | 
 |           == row) //Exists next Row | 
 |       { | 
 |         return true; | 
 |       } | 
 |       int minRow, | 
 |           minCol; | 
 |       if (r > row && r >= startRow) { | 
 |         minRow = r; | 
 |         minCol = colPos; | 
 |       } else { | 
 |         minRow = int.MaxValue; | 
 |         minCol = 0; | 
 |       } | 
 |  | 
 |       var c = colPos - 1; | 
 |       if (c >= startColPos) { | 
 |         while (c >= startColPos) { | 
 |           r = _columnIndex[c].GetNextRow(row); | 
 |           if (r | 
 |               == row) //Exists next Row | 
 |           { | 
 |             colPos = c; | 
 |             return true; | 
 |           } | 
 |           if (r > row && r < minRow && r >= startRow) { | 
 |             minRow = r; | 
 |             minCol = c; | 
 |           } | 
 |           c--; | 
 |         } | 
 |       } | 
 |       if (row > startRow) { | 
 |         c = endColPos; | 
 |         row--; | 
 |         while (c > colPos) { | 
 |           r = _columnIndex[c].GetNextRow(row); | 
 |           if (r | 
 |               == row) //Exists next Row | 
 |           { | 
 |             colPos = c; | 
 |             return true; | 
 |           } | 
 |           if (r > row && r < minRow && r >= startRow) { | 
 |             minRow = r; | 
 |             minCol = c; | 
 |           } | 
 |           c--; | 
 |         } | 
 |       } | 
 |       if (minRow == int.MaxValue || startRow < minRow) { | 
 |         return false; | 
 |       } | 
 |       row = minRow; | 
 |       colPos = minCol; | 
 |       return true; | 
 |     } | 
 |     colPos = ColumnCount; | 
 |     row--; | 
 |     if (row < startRow) { | 
 |       return false; | 
 |     } | 
 |     return GetPrevCell(ref colPos, ref row, startRow, startColPos, endColPos); | 
 |   } | 
 | } | 
 |  | 
 | internal class CellsStoreEnumerator<T> : IEnumerable<T>, IEnumerator<T> { | 
 |   private readonly CellStore<T> _cellStore; | 
 |   private int row, | 
 |       colPos; | 
 |   private int[] pagePos, | 
 |       cellPos; | 
 |   private readonly int _startRow; | 
 |   private readonly int _startCol; | 
 |   private readonly int _endRow; | 
 |   private readonly int _endCol; | 
 |   private int minRow, | 
 |       minColPos, | 
 |       maxRow, | 
 |       maxColPos; | 
 |  | 
 |   public CellsStoreEnumerator(CellStore<T> cellStore) | 
 |       : this(cellStore, 0, 0, ExcelPackage.MaxRows, ExcelPackage.MaxColumns) {} | 
 |  | 
 |   public CellsStoreEnumerator( | 
 |       CellStore<T> cellStore, | 
 |       int startRow, | 
 |       int startCol, | 
 |       int endRow, | 
 |       int endCol) { | 
 |     _cellStore = cellStore; | 
 |  | 
 |     _startRow = startRow; | 
 |     _startCol = startCol; | 
 |     _endRow = endRow; | 
 |     _endCol = endCol; | 
 |  | 
 |     Init(); | 
 |   } | 
 |  | 
 |   internal void Init() { | 
 |     minRow = _startRow; | 
 |     maxRow = _endRow; | 
 |  | 
 |     minColPos = _cellStore.GetPosition(_startCol); | 
 |     if (minColPos < 0) { | 
 |       minColPos = ~minColPos; | 
 |     } | 
 |     maxColPos = _cellStore.GetPosition(_endCol); | 
 |     if (maxColPos < 0) { | 
 |       maxColPos = ~maxColPos - 1; | 
 |     } | 
 |     row = minRow; | 
 |     colPos = minColPos - 1; | 
 |  | 
 |     var cols = maxColPos - minColPos + 1; | 
 |     pagePos = new int[cols]; | 
 |     cellPos = new int[cols]; | 
 |     for (int i = 0; i < cols; i++) { | 
 |       pagePos[i] = -1; | 
 |       cellPos[i] = -1; | 
 |     } | 
 |   } | 
 |  | 
 |   internal int Row => row; | 
 |  | 
 |   internal int Column { | 
 |     get { | 
 |       if (colPos == -1) { | 
 |         MoveNext(); | 
 |       } | 
 |       if (colPos == -1) { | 
 |         return 0; | 
 |       } | 
 |       return _cellStore._columnIndex[colPos].Index; | 
 |     } | 
 |   } | 
 |  | 
 |   internal T Value { | 
 |     get => _cellStore.GetValue(row, Column); | 
 |     set => _cellStore.SetValue(row, Column, value); | 
 |   } | 
 |  | 
 |   internal bool Next() { | 
 |     return _cellStore.GetNextCell(ref row, ref colPos, minColPos, maxRow, maxColPos); | 
 |   } | 
 |  | 
 |   public string CellAddress => ExcelCellBase.GetAddress(Row, Column); | 
 |  | 
 |   public IEnumerator<T> GetEnumerator() { | 
 |     Reset(); | 
 |     return this; | 
 |   } | 
 |  | 
 |   IEnumerator IEnumerable.GetEnumerator() { | 
 |     Reset(); | 
 |     return this; | 
 |   } | 
 |  | 
 |   public T Current => Value; | 
 |  | 
 |   public void Dispose() {} | 
 |  | 
 |   object IEnumerator.Current { | 
 |     get { | 
 |       Reset(); | 
 |       return this; | 
 |     } | 
 |   } | 
 |  | 
 |   public bool MoveNext() { | 
 |     return Next(); | 
 |   } | 
 |  | 
 |   public void Reset() { | 
 |     Init(); | 
 |   } | 
 | } | 
 |  | 
 | internal class FlagCellStore : CellStore<byte> { | 
 |   internal void SetFlagValue(int row, int col, bool value, CellFlags cellFlags) { | 
 |     CellFlags currentValue = (CellFlags)GetValue(row, col); | 
 |     if (value) { | 
 |       SetValue(row, col, (byte)(currentValue | cellFlags)); // add the CellFlag bit | 
 |     } else { | 
 |       SetValue(row, col, (byte)(currentValue & ~cellFlags)); // remove the CellFlag bit | 
 |     } | 
 |   } | 
 |  | 
 |   internal bool GetFlagValue(int row, int col, CellFlags cellFlags) { | 
 |     return !(((byte)cellFlags & GetValue(row, col)) == 0); | 
 |   } | 
 | } |