fpspreadsheet: Add reading/writing of boolean cell values for BIFF formats.

Add test case for boolean cell values for all formats (incl. CSV). 
Extend spready demo to be able to write sfExcel2 and sfExcel5 formats.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@3656 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/examples/spready/mainform.lfm

@@ -4,7 +4,7 @@ object MainFrm: TMainFrm
   Top = 258
   Width = 884
   Caption = 'spready'
-  ClientHeight = 614
+  ClientHeight = 619
   ClientWidth = 884
   Menu = MainMenu
   OnActivate = FormActivate
@@ -14,7 +14,7 @@ object MainFrm: TMainFrm
   object Panel1: TPanel
     Left = 0
     Height = 82
-    Top = 532
+    Top = 537
     Width = 884
     Align = alBottom
     BevelOuter = bvNone
@@ -23,7 +23,7 @@ object MainFrm: TMainFrm
     TabOrder = 6
     object EdFrozenCols: TSpinEdit
       Left = 429
-      Height = 28
+      Height = 23
       Top = 8
       Width = 52
       OnChange = EdFrozenColsChange
@@ -31,7 +31,7 @@ object MainFrm: TMainFrm
     end
     object EdFrozenRows: TSpinEdit
       Left = 429
-      Height = 28
+      Height = 23
       Top = 39
       Width = 52
       OnChange = EdFrozenRowsChange
@@ -39,37 +39,37 @@ object MainFrm: TMainFrm
     end
     object Label1: TLabel
       Left = 344
-      Height = 20
+      Height = 15
       Top = 13
-      Width = 77
+      Width = 62
       Caption = 'Frozen cols:'
       FocusControl = EdFrozenCols
       ParentColor = False
     end
     object Label2: TLabel
       Left = 344
-      Height = 20
+      Height = 15
       Top = 40
-      Width = 82
+      Width = 66
       Caption = 'Frozen rows:'
       FocusControl = EdFrozenRows
       ParentColor = False
     end
     object CbReadFormulas: TCheckBox
       Left = 8
-      Height = 24
+      Height = 19
       Top = 8
-      Width = 120
+      Width = 96
       Caption = 'Read formulas'
       OnChange = CbReadFormulasChange
       TabOrder = 0
     end
     object CbHeaderStyle: TComboBox
       Left = 200
-      Height = 28
+      Height = 23
       Top = 8
       Width = 116
-      ItemHeight = 20
+      ItemHeight = 15
       ItemIndex = 2
       Items.Strings = (
         'Lazarus'
@@ -83,18 +83,18 @@ object MainFrm: TMainFrm
     end
     object CbAutoCalcFormulas: TCheckBox
       Left = 8
-      Height = 24
+      Height = 19
       Top = 32
-      Width = 158
+      Width = 128
       Caption = 'Calculate on change'
       OnChange = CbAutoCalcFormulasChange
       TabOrder = 1
     end
     object CbTextOverflow: TCheckBox
       Left = 8
-      Height = 24
+      Height = 19
       Top = 56
-      Width = 114
+      Width = 91
       Caption = 'Text overflow'
       Checked = True
       OnChange = CbTextOverflowChange
@@ -206,19 +206,19 @@ object MainFrm: TMainFrm
     end
     object FontComboBox: TComboBox
       Left = 52
-      Height = 28
+      Height = 23
       Top = 2
       Width = 127
-      ItemHeight = 20
+      ItemHeight = 15
       OnSelect = FontComboBoxSelect
       TabOrder = 0
     end
     object FontSizeComboBox: TComboBox
       Left = 179
-      Height = 28
+      Height = 23
       Top = 2
       Width = 48
-      ItemHeight = 20
+      ItemHeight = 15
       Items.Strings = (
         '8'
         '9'
@@ -394,7 +394,7 @@ object MainFrm: TMainFrm
       TabOrder = 2
       object EdCellAddress: TEdit
         Left = 0
-        Height = 28
+        Height = 23
         Top = 0
         Width = 170
         Align = alTop
@@ -406,7 +406,7 @@ object MainFrm: TMainFrm
   end
   object InspectorSplitter: TSplitter
     Left = 648
-    Height = 446
+    Height = 451
     Top = 86
     Width = 5
     Align = alRight
@@ -414,7 +414,7 @@ object MainFrm: TMainFrm
   end
   object InspectorPageControl: TPageControl
     Left = 653
-    Height = 446
+    Height = 451
     Top = 86
     Width = 231
     ActivePage = PgCellValue
@@ -424,11 +424,11 @@ object MainFrm: TMainFrm
     OnChange = InspectorPageControlChange
     object PgCellValue: TTabSheet
       Caption = 'Cell value'
-      ClientHeight = 413
+      ClientHeight = 423
       ClientWidth = 223
       object CellInspector: TValueListEditor
         Left = 0
-        Height = 413
+        Height = 423
         Top = 0
         Width = 223
         Align = alClient
@@ -472,7 +472,7 @@ object MainFrm: TMainFrm
   end
   object TabControl: TTabControl
     Left = 0
-    Height = 446
+    Height = 451
     Top = 86
     Width = 648
     OnChange = TabControlChange
@@ -480,7 +480,7 @@ object MainFrm: TMainFrm
     TabOrder = 3
     object WorksheetGrid: TsWorksheetGrid
       Left = 2
-      Height = 441
+      Height = 446
       Top = 3
       Width = 644
       FrozenCols = 0
@@ -498,7 +498,7 @@ object MainFrm: TMainFrm
       OnHeaderClick = WorksheetGridHeaderClick
       OnSelection = WorksheetGridSelection
       ColWidths = (
-        56
+        42
         64
         64
         64
@@ -546,7 +546,7 @@ object MainFrm: TMainFrm
   end
   object SaveDialog: TSaveDialog
     DefaultExt = '.xls'
-    Filter = 'Excel spreadsheet (*.xls)|*.xls|Excel XML spreadsheet (*.xlsx)|*.xlsx|LibreOffice/OpenOffice spreadsheet (*.ods)|*.ods|Comma-delimited file (*.csv)|*.csv|Wikitable (wikimedia) (.wikitable_wikimedia)|*.wikitable_wikimedia'
+    Filter = 'Excel 97-2003 spreadsheet (*.xls)|*.xls|Excel 5.0/95 spreadsheet (*.xls)|*.xls|Excel 2 spreadsheet (*.xls)|*.xls|Excel 2007+  XML spreadsheet (*.xlsx)|*.xlsx|LibreOffice/OpenOffice spreadsheet (*.ods)|*.ods|Comma-delimited file (*.csv)|*.csv|Wikitable (wikimedia) (*.wikitable_wikimedia)|*.wikitable_wikimedia'
     Options = [ofOverwritePrompt, ofExtensionDifferent, ofEnableSizing, ofViewDetail]
     left = 184
     top = 264

components/fpspreadsheet/examples/spready/mainform.pas

@@ -326,6 +326,7 @@ type
 
   end;
 
+//  Excel 97-2003 spreadsheet (*.xls)|*.xls|Excel 5.0 spreadsheet (*.xls)|*.xls|Excel 2.1 spreadsheet (*.xls)|*.xls|Excel XML spreadsheet (*.xlsx)|*.xlsx|LibreOffice/OpenOffice spreadsheet (*.ods)|*.ods|Comma-delimited file (*.csv)|*.csv|Wikitable (wikimedia) (.wikitable_wikimedia)|*.wikitable_wikimedia
 var
   MainFrm: TMainFrm;
 
@@ -669,6 +670,7 @@ procedure TMainFrm.acSaveAsExecute(Sender: TObject);
 // Saves sheet in grid to file, overwriting existing file
 var
   err: String = '';
+  fmt: TsSpreadsheetFormat;
 begin
   if WorksheetGrid.Workbook = nil then
     exit;
@@ -676,8 +678,17 @@ begin
   if SaveDialog.Execute then
   begin
     Screen.Cursor := crHourglass;
+    case SaveDialog.FilterIndex of
+      1: fmt := sfExcel8;
+      2: fmt := sfExcel5;
+      3: fmt := sfExcel2;
+      4: fmt := sfOOXML;
+      5: fmt := sfOpenDocument;
+      6: fmt := sfCSV;
+      7: fmt := sfWikiTable_wikimedia;
+    end;
     try
-      WorksheetGrid.SaveToSpreadsheetFile(SaveDialog.FileName);
+      WorksheetGrid.SaveToSpreadsheetFile(SaveDialog.FileName, fmt);
     finally
       Screen.Cursor := crDefault;
       err := WorksheetGrid.Workbook.ErrorMsg;

components/fpspreadsheet/fpsopendocument.pas

@@ -178,6 +178,8 @@ type
       ACell: PCell); override;
     procedure WriteBool(AStream: TStream; const ARow, ACol: Cardinal;
       const AValue: Boolean; ACell: PCell); override;
+    procedure WriteError(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: TsErrorValue; ACell: PCell); override;
     procedure WriteFormula(AStream: TStream; const ARow, ACol: Cardinal;
       ACell: PCell); override;
     procedure WriteLabel(AStream: TStream; const ARow, ACol: Cardinal;
@@ -3406,6 +3408,12 @@ begin
   );
 end;
 
+procedure TsSpreadOpenDocWriter.WriteError(AStream: TStream;
+  const ARow, ACol: Cardinal; const AValue: TsErrorValue; ACell: PCell);
+begin
+  // ??
+end;
+
 function TsSpreadOpenDocWriter.WriteFontStyleXMLAsString(const AFormat: TCell): String;
 var
   fnt: TsFont;

components/fpspreadsheet/fpspreadsheet.pas

@@ -1063,6 +1063,8 @@ type
     { Record reading methods }
     {@@ Abstract method for reading a blank cell. Must be overridden by descendent classes. }
     procedure ReadBlank(AStream: TStream); virtual; abstract;
+    {@@ Abstract method for reading a BOOLEAN cell. Must be overridden by descendent classes. }
+    procedure ReadBool(AStream: TSTream); virtual; abstract;
     {@@ Abstract method for reading a formula cell. Must be overridden by descendent classes. }
     procedure ReadFormula(AStream: TStream); virtual; abstract;
     {@@ Abstract method for reading a text cell. Must be overridden by descendent classes. }
@@ -1110,19 +1112,26 @@ type
     procedure WriteCellsToStream(AStream: TStream; ACells: TAVLTree);
     { Record writing methods }
     {@@ Abstract method for writing a blank cell. Must be overridden by descendent classes. }
-    procedure WriteBlank(AStream: TStream; const ARow, ACol: Cardinal; ACell: PCell); virtual; abstract;
+    procedure WriteBlank(AStream: TStream; const ARow, ACol: Cardinal;
+      ACell: PCell); virtual; abstract;
     {@@ Abstract method for writing a boolean cell. Must be overridden by descendent classes. }
-    procedure WriteBool(AStream: TStream; const ARow, ACol: Cardinal; const AValue: Boolean; ACell: PCell); virtual; abstract;
+    procedure WriteBool(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: Boolean; ACell: PCell); virtual; abstract;
     {@@ Abstract method for writing a date/time value to a cell. Must be overridden by descendent classes. }
-    procedure WriteDateTime(AStream: TStream; const ARow, ACol: Cardinal; const AValue: TDateTime; ACell: PCell); virtual; abstract;
+    procedure WriteDateTime(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: TDateTime; ACell: PCell); virtual; abstract;
     {@@ Abstract method for writing an Excel error value to a cell. Must be overridden by descendent classes. }
-    procedure WriteError(AStream: TStream; const ARow, ACol: Cardinal; const AValue: TsErrorValue; ACell: PCell); virtual; abstract;
+    procedure WriteError(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: TsErrorValue; ACell: PCell); virtual; abstract;
     {@@ Abstract method for writing a formula to a cell. Must be overridden by descendent classes. }
-    procedure WriteFormula(AStream: TStream; const ARow, ACol: Cardinal; ACell: PCell); virtual;
+    procedure WriteFormula(AStream: TStream; const ARow, ACol: Cardinal;
+      ACell: PCell); virtual;
     {@@ Abstract method for writing a string to a cell. Must be overridden by descendent classes. }
-    procedure WriteLabel(AStream: TStream; const ARow, ACol: Cardinal; const AValue: string; ACell: PCell); virtual; abstract;
+    procedure WriteLabel(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: string; ACell: PCell); virtual; abstract;
     {@@ Abstract method for writing a number value to a cell. Must be overridden by descendent classes. }
-    procedure WriteNumber(AStream: TStream; const ARow, ACol: Cardinal; const AValue: double; ACell: PCell); virtual; abstract;
+    procedure WriteNumber(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: double; ACell: PCell); virtual; abstract;
 
   public
     {@@ An array with cells which are models for the used styles

components/fpspreadsheet/reference/BIFFExplorer/bebiffgrid.pas

@@ -687,7 +687,10 @@ var
   w: Word;
   b: Byte;
 begin
-  RowCount := FixedRows + 5;
+  if FFormat = sfExcel2 then
+    RowCount := FixedRows + 7
+  else
+    RowCount := FixedRows + 5;
 
   ShowRowColData(FBufferIndex);
 

components/fpspreadsheet/tests/spreadtestgui.lpi

@@ -40,7 +40,7 @@
         <PackageName Value="FCL"/>
       </Item4>
     </RequiredPackages>
-    <Units Count="18">
+    <Units Count="19">
       <Unit0>
         <Filename Value="spreadtestgui.lpr"/>
         <IsPartOfProject Value="True"/>
@@ -48,7 +48,6 @@
       <Unit1>
         <Filename Value="datetests.pas"/>
         <IsPartOfProject Value="True"/>
-        <UnitName Value="datetests"/>
       </Unit1>
       <Unit2>
         <Filename Value="stringtests.pas"/>
@@ -57,6 +56,7 @@
       <Unit3>
         <Filename Value="numberstests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="numberstests"/>
       </Unit3>
       <Unit4>
         <Filename Value="manualtests.pas"/>
@@ -76,14 +76,17 @@
       <Unit7>
         <Filename Value="formattests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="formattests"/>
       </Unit7>
       <Unit8>
         <Filename Value="colortests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="colortests"/>
       </Unit8>
       <Unit9>
         <Filename Value="fonttests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="fonttests"/>
       </Unit9>
       <Unit10>
         <Filename Value="optiontests.pas"/>
@@ -96,6 +99,7 @@
       <Unit12>
         <Filename Value="rpnformulaunit.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="rpnFormulaUnit"/>
       </Unit12>
       <Unit13>
         <Filename Value="formulatests.pas"/>
@@ -105,6 +109,7 @@
       <Unit14>
         <Filename Value="emptycelltests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="emptycelltests"/>
       </Unit14>
       <Unit15>
         <Filename Value="errortests.pas"/>
@@ -120,6 +125,11 @@
         <IsPartOfProject Value="True"/>
         <UnitName Value="insertdeletetests"/>
       </Unit17>
+      <Unit18>
+        <Filename Value="celltypetests.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="celltypetests"/>
+      </Unit18>
     </Units>
   </ProjectOptions>
   <CompilerOptions>

components/fpspreadsheet/tests/spreadtestgui.lpr

@@ -11,7 +11,8 @@ uses
   Interfaces, Forms, GuiTestRunner, datetests, stringtests, numberstests,
   manualtests, testsutility, internaltests, formattests, colortests, fonttests,
   optiontests, numformatparsertests, formulatests, rpnFormulaUnit,
-  emptycelltests, errortests, virtualmodetests, insertdeletetests;
+  emptycelltests, errortests, virtualmodetests, insertdeletetests,
+  celltypetests;
 
 begin
  {$IFDEF HEAPTRC}

components/fpspreadsheet/xlsbiff2.pas

@@ -65,6 +65,7 @@ type
     procedure ExtractNumberFormat(AXFIndex: WORD;
       out ANumberFormat: TsNumberFormat; out ANumberFormatStr: String); override;
     procedure ReadBlank(AStream: TStream); override;
+    procedure ReadBool(AStream: TStream); override;
     procedure ReadColWidth(AStream: TStream);
     procedure ReadDefRowHeight(AStream: TStream);
     procedure ReadFont(AStream: TStream);
@@ -438,6 +439,42 @@ begin
     Workbook.OnReadCellData(Workbook, ARow, ACol, cell);
 end;
 
+{ The name of this method is misleading - it reads a BOOLEAN cell value,
+  but also an ERROR value; BIFF stores them in the same record. }
+procedure TsSpreadBIFF2Reader.ReadBool(AStream: TStream);
+var
+  rec: TBIFF2BoolErrRecord;
+  r, c: Cardinal;
+  xf: Word;
+  cell: PCell;
+begin
+  { Read entire record, starting at Row }
+  rec.Row := 0;  // to silence the compiler...
+  AStream.ReadBuffer(rec.Row, SizeOf(TBIFF2BoolErrRecord) - 2*SizeOf(Word));
+  r := WordLEToN(rec.Row);
+  c := WordLEToN(rec.Col);
+  xf := rec.Attrib1 and $3F;
+
+  { Create cell }
+  if FIsVirtualMode then begin
+    InitCell(r, c, FVirtualCell);
+    cell := @FVirtualCell;
+  end else
+    cell := FWorksheet.GetCell(r, c);
+
+  { Retrieve boolean or error value depending on the "ValueType" }
+  case rec.ValueType of
+    0: FWorksheet.WriteBoolValue(cell, boolean(rec.BoolErrValue));
+    1: FWorksheet.WriteErrorValue(cell, ConvertFromExcelError(rec.BoolErrValue));
+  end;
+
+  { Apply formatting }
+  ApplyCellFormatting(cell, xf);
+
+  if FIsVirtualMode then
+    Workbook.OnReadCellData(Workbook, r, c, cell);
+end;
+
 procedure TsSpreadBIFF2Reader.ReadColWidth(AStream: TStream);
 var
   c, c1, c2: Cardinal;
@@ -540,6 +577,7 @@ begin
 
     case RecordType of
       INT_EXCEL_ID_BLANK       : ReadBlank(AStream);
+      INT_EXCEL_ID_BOOLERROR   : ReadBool(AStream);
       INT_EXCEL_ID_FONT        : ReadFont(AStream);
       INT_EXCEL_ID_FONTCOLOR   : ReadFontColor(AStream);
       INT_EXCEL_ID_FORMAT      : ReadFormat(AStream);
@@ -1733,7 +1771,7 @@ begin
 
   { Cell value }
   rec.BoolErrValue := ord(AValue);
-  rec.ValueType := 1;  // 0 = boolean value, 1 = error value
+  rec.ValueType := 0;  // 0 = boolean value, 1 = error value
 
   { Write out }
   AStream.WriteBuffer(rec, SizeOf(rec));
@@ -1765,16 +1803,7 @@ begin
   GetCellAttributes(ACell, xf, rec.Attrib1, rec.Attrib2, rec.Attrib3);
 
   { Cell value }
-  case AValue of
+  rec.BoolErrValue := ConvertToExcelError(AValue);
-    errEmptyIntersection : rec.BoolErrValue := $00;  // #NULL!
-    errDivideByZero      : rec.BoolErrValue := $07;  // #DIV/0!
-    errWrongType         : rec.BoolErrValue := $0F;  // #VALUE!
-    errIllegalRef        : rec.BoolErrValue := $17;  // #REF!
-    errWrongName         : rec.BoolErrValue := $1D;  // #NAME?
-    errOverflow          : rec.BoolErrValue := $24;  // #NUM!
-    errArgError          : rec.BoolErrValue := $2A;  // #N/A
-    else                   exit;
-  end;
   rec.ValueType := 1;  // 0 = boolean value, 1 = error value
 
   { Write out }

components/fpspreadsheet/xlsbiff5.pas

@@ -1142,6 +1142,7 @@ begin
     case RecordType of
 
     INT_EXCEL_ID_BLANK         : ReadBlank(AStream);
+    INT_EXCEL_ID_BOOLERROR     : ReadBool(AStream);
     INT_EXCEL_ID_MULBLANK      : ReadMulBlank(AStream);
     INT_EXCEL_ID_NUMBER        : ReadNumber(AStream);
     INT_EXCEL_ID_LABEL         : ReadLabel(AStream);

components/fpspreadsheet/xlsbiff8.pas

@@ -1440,6 +1440,7 @@ begin
     case RecordType of
 
     INT_EXCEL_ID_BLANK       : ReadBlank(AStream);
+    INT_EXCEL_ID_BOOLERROR   : ReadBool(AStream);
     INT_EXCEL_ID_MULBLANK    : ReadMulBlank(AStream);
     INT_EXCEL_ID_NUMBER      : ReadNumber(AStream);
     INT_EXCEL_ID_LABEL       : ReadLabel(AStream);

components/fpspreadsheet/xlscommon.pas

@@ -248,6 +248,7 @@ type
     // Here we can add reading of records which didn't change across BIFF5-8 versions
     // Read a blank cell
     procedure ReadBlank(AStream: TStream); override;
+    procedure ReadBool(AStream: TStream); override;
     procedure ReadCodePage(AStream: TStream);
     // Read column info
     procedure ReadColInfo(const AStream: TStream);
@@ -848,6 +849,43 @@ begin
     Workbook.OnReadCellData(Workbook, ARow, ACol, cell);
 end;
 
+{ The name of this method is misleading - it reads a BOOLEAN cell value,
+  but also an ERROR value; BIFF stores them in the same record. }
+procedure TsSpreadBIFFReader.ReadBool(AStream: TStream);
+var
+  rec: TBIFF38BoolErrRecord;
+  r, c: Cardinal;
+  XF: Word;
+  cell: PCell;
+begin
+  rec.Row := 0;  // to silence the compiler
+
+  { Read entire record into a buffer }
+  AStream.ReadBuffer(rec.Row, SizeOf(TBIFF38BoolErrRecord) - 2*SizeOf(Word));
+
+  r := WordLEToN(rec.Row);
+  c := WordLEToN(rec.Col);
+  XF := WordLEToN(rec.XFIndex);
+
+  if FIsVirtualMode then begin
+    InitCell(r, c, FVirtualCell);
+    cell := @FVirtualCell;
+  end else
+    cell := FWorksheet.GetCell(r, c);
+
+  { Retrieve boolean or error value depending on the "ValueType" }
+  case rec.ValueType of
+    0: FWorksheet.WriteBoolValue(cell, boolean(rec.BoolErrValue));
+    1: FWorksheet.WriteErrorValue(cell, ConvertFromExcelError(rec.BoolErrValue));
+  end;
+
+  { Add attributes to cell}
+  ApplyCellFormatting(cell, XF);
+
+  if FIsVirtualMode then
+    Workbook.OnReadCellData(Workbook, r, c, cell);
+end;
+
 // In BIFF8 it seams to always use the UTF-16 codepage
 procedure TsSpreadBIFFReader.ReadCodePage(AStream: TStream);
 var
@@ -2016,16 +2054,7 @@ begin
   rec.XFIndex := WordToLE(FindXFIndex(ACell));
 
   { Cell value }
-  case AValue of
+  rec.BoolErrValue := ConvertToExcelError(AValue);
-    errEmptyIntersection : rec.BoolErrValue := $00;  // #NULL!
-    errDivideByZero      : rec.BoolErrValue := $07;  // #DIV/0!
-    errWrongType         : rec.BoolErrValue := $0F;  // #VALUE!
-    errIllegalRef        : rec.BoolErrValue := $17;  // #REF!
-    errWrongName         : rec.BoolErrValue := $1D;  // #NAME?
-    errOverflow          : rec.BoolErrValue := $24;  // #NUM!
-    errArgError          : rec.BoolErrValue := $2A;  // #N/A
-    else                   exit;
-  end;
   rec.ValueType := 1;  // 0 = boolean value, 1 = error value
 
   { Write out }

components/fpspreadsheet/xlsxooxml.pas

@@ -153,6 +153,8 @@ type
       ACell: PCell); override;
     procedure WriteBool(AStream: TStream; const ARow, ACol: Cardinal;
       const AValue: Boolean; ACell: PCell); override;
+    procedure WriteError(AStream: TStream; const ARow, ACol: Cardinal;
+      const AValue: TsErrorValue; ACell: PCell); override;
     procedure WriteFormula(AStream: TStream; const ARow, ACol: Cardinal;
       ACell: PCell); override;
     procedure WriteLabel(AStream: TStream; const ARow, ACol: Cardinal;
@@ -2563,6 +2565,13 @@ begin
     '<c r="%s" s="%d" t="b"><v>%s</v></c>', [CellPosText, lStyleIndex, CellValueText]));
 end;
 
+{ Writes an error value to the specified cell. }
+procedure TsSpreadOOXMLWriter.WriteError(AStream: TStream;
+  const ARow, ACol: Cardinal; const AValue: TsErrorValue; ACell: PCell);
+begin
+  // ???
+end;
+
 { Writes a string formula to the given cell. }
 procedure TsSpreadOOXMLWriter.WriteFormula(AStream: TStream;
   const ARow, ACol: Cardinal; ACell: PCell);