{-------------------------------------------------------------------------------
Unit     : xlsxml

Implements a reader and writer for the SpreadsheetXML format.
This document was introduced by Microsoft for Excel XP and 2003.

REFERENCE: http://msdn.microsoft.com/en-us/library/aa140066%28v=office.15%29.aspx

AUTHOR   : Werner Pamler

LICENSE  : For details about the license, see the file
           COPYING.modifiedLGPL.txt included in the Lazarus distribution.
-------------------------------------------------------------------------------}

unit xlsxml;

{$ifdef fpc}
  {$mode objfpc}{$H+}
{$endif}

interface

uses
  Classes, SysUtils,
  laz2_xmlread, laz2_DOM,
  fpsTypes, fpsReaderWriter, fpsXMLCommon, xlsCommon;

type
  { TsSpreadExcelXMLReader }
  TsSpreadExcelXMLReader = class(TsSpreadXMLReader)
  private
    FPointSeparatorSettings: TFormatSettings;
    function ExtractDateTime(AText: String): TDateTime;

  protected
    FFirstNumFormatIndexInFile: Integer;
    procedure AddBuiltinNumFormats; override;

  protected
    procedure ReadAlignment(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadBorder(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadBorders(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadCell(ANode: TDOMNode; AWorksheet: TsBasicWorksheet; ARow, ACol: Integer);
    procedure ReadCellProtection(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadComment(ANode: TDOMNode; AWorksheet: TsBasicWorksheet; ACell: PCell);
    procedure ReadFont(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadInterior(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadNumberFormat(ANode: TDOMNode; var AFormat: TsCellFormat);
    procedure ReadRow(ANode: TDOMNode; AWorksheet: TsBasicWorksheet; ARow: Integer);
    procedure ReadStyle(ANode: TDOMNode);
    procedure ReadStyles(ANode: TDOMNode);
    procedure ReadTable(ANode: TDOMNode; AWorksheet: TsBasicWorksheet);
    procedure ReadWorksheet(ANode: TDOMNode; AWorksheet: TsBasicWorksheet);
    procedure ReadWorksheetOptions(ANode: TDOMNode; AWorksheet: TsBasicWorksheet);
    procedure ReadWorksheets(ANode: TDOMNode);

  public
    constructor Create(AWorkbook: TsBasicWorkbook); override;
    procedure ReadFromStream(AStream: TStream; APassword: String = '';
      AParams: TsStreamParams = []); override;
  end;


  { TsSpreadExcelXMLWriter }

  TsSpreadExcelXMLWriter = class(TsCustomSpreadWriter)
  private
    FDateMode: TDateMode;
    FPointSeparatorSettings: TFormatSettings;
    function GetCommentStr(ACell: PCell): String;
    function GetFormulaStr(ACell: PCell): String;
    function GetFrozenPanesStr(AWorksheet: TsBasicWorksheet; AIndent: String): String;
    function GetHyperlinkStr(ACell: PCell): String;
    function GetIndexStr(AIndex: Integer): String;
    function GetLayoutStr(AWorksheet: TsBasicWorksheet): String;
    function GetMergeStr(ACell: PCell): String;
    function GetPageFooterStr(AWorksheet: TsBasicWorksheet): String;
    function GetPageHeaderStr(AWorksheet: TsBasicWorksheet): String;
    function GetPageMarginStr(AWorksheet: TsBasicWorksheet): String;
    function GetStyleStr(AFormatIndex: Integer): String;
    procedure WriteExcelWorkbook(AStream: TStream);
    procedure WriteStyle(AStream: TStream; AIndex: Integer);
    procedure WriteStyles(AStream: TStream);
    procedure WriteTable(AStream: TStream; AWorksheet: TsBasicWorksheet);
    procedure WriteWorksheet(AStream: TStream; AWorksheet: TsBasicWorksheet);
    procedure WriteWorksheetOptions(AStream: TStream; AWorksheet: TsBasicWorksheet);
    procedure WriteWorksheets(AStream: TStream);

  protected
    procedure WriteBlank(AStream: TStream; const ARow, ACol: Cardinal;
      ACell: PCell); override;
    procedure WriteBool(AStream: TStream; const ARow, ACol: Cardinal;
      const AValue: boolean; ACell: PCell); override;
    procedure WriteCellToStream(AStream: TStream; ACell: PCell); override;
    procedure WriteDateTime(AStream: TStream; const ARow, ACol: Cardinal;
      const AValue: TDateTime; ACell: PCell); override;
    procedure WriteError(AStream: TStream; const ARow, ACol: Cardinal;
      const AValue: TsErrorValue; ACell: PCell); override;
    procedure WriteLabel(AStream: TStream; const ARow, ACol: Cardinal;
      const AValue: string; ACell: PCell); override;
    procedure WriteNumber(AStream: TStream; const ARow, ACol: Cardinal;
      const AValue: double; ACell: PCell); override;

  public
    constructor Create(AWorkbook: TsBasicWorkbook); override;
    procedure WriteToStream(AStream: TStream; AParams: TsStreamParams = []); override;

  end;

  TExcelXmlSettings = record
    DateMode: TDateMode;
  end;

var
  { Default parameters for reading/writing }
  ExcelXmlSettings: TExcelXmlSettings = (
    DateMode: dm1900;
  );

  sfidExcelXML: TsSpreadFormatID;


implementation

uses
  StrUtils, DateUtils, Math,
  fpsStrings, fpsClasses, fpspreadsheet, fpsUtils, fpsNumFormat, fpsHTMLUtils;

const
  FMT_OFFSET   = 61;

  INDENT1      = '  ';
  INDENT2      = '    ';
  INDENT3      = '      ';
  INDENT4      = '        ';
  INDENT5      = '          ';
  TABLE_INDENT = INDENT2;
  ROW_INDENT   = INDENT3;
  COL_INDENT   = INDENT3;
  CELL_INDENT  = INDENT4;
  VALUE_INDENT = INDENT5;

  LF           = LineEnding;

const
  {TsFillStyle = (
    fsNoFill, fsSolidFill,
    fsGray75, fsGray50, fsGray25, fsGray12, fsGray6,
    fsStripeHor, fsStripeVert, fsStripeDiagUp, fsStripeDiagDown,
    fsThinStripeHor, fsThinStripeVert, fsThinStripeDiagUp, fsThinStripeDiagDown,
    fsHatchDiag, fsThinHatchDiag, fsThickHatchDiag, fsThinHatchHor) }
  FILL_NAMES: array[TsFillStyle] of string = (
    '', 'Solid',
    'Gray75', 'Gray50', 'Gray25', 'Gray12', 'Gray0625',
    'HorzStripe', 'VertStripe', 'DiagStripe', 'ReverseDiagStripe',
    'ThinHorzStripe', 'ThinVertStripe', 'ThinDiagStripe', 'ThinReverseDiagStripe',
    'DiagCross', 'ThinDiagCross', 'ThickDiagCross', 'ThinHorzCross'
  );

  {TsCellBorder = (cbNorth, cbWest, cbEast, cbSouth, cbDiagUp, cbDiagDown); }
  BORDER_NAMES: array[TsCellBorder] of string = (
    'Top', 'Left', 'Right', 'Bottom', 'DiagonalRight', 'DiagonalLeft'
  );

  {TsLineStyle = (
    lsThin, lsMedium, lsDashed, lsDotted, lsThick, lsDouble, lsHair,
    lsMediumDash, lsDashDot, lsMediumDashDot, lsDashDotDot, lsMediumDashDotDot,
    lsSlantDashDot) }
  LINE_STYLES: array[TsLineStyle] of string = (
    'Continuous', 'Continuous', 'Dash', 'Dot', 'Continuous', 'Double', 'Continuous',
    'Dash', 'DashDot', 'DashDot', 'DashDotDot', 'DashDotDot',
    'SlantDashDot'
  );
  LINE_WIDTHS: array[TsLineStyle] of Integer = (
    1, 2, 1, 1, 3, 3, 0,
    2, 1, 2, 1, 2,
    2
  );

  FALSE_TRUE: array[boolean] of string = ('False', 'True');

function GetCellContentTypeStr(ACell: PCell): String;
begin
  case ACell^.ContentType of
    cctNumber     : Result := 'Number';
    cctUTF8String : Result := 'String';
    cctDateTime   : Result := 'DateTime';
    cctBool       : Result := 'Boolean';
    cctError      : Result := 'Error';
  else
    raise EFPSpreadsheet.Create('Content type error in cell ' + GetCellString(ACell^.Row, ACell^.Col));
  end;
end;

{@@ ----------------------------------------------------------------------------
  Constructor of the ExcelXML reader
-------------------------------------------------------------------------------}
constructor TsSpreadExcelXMLReader.Create(AWorkbook: TsBasicWorkbook);
begin
  inherited;

  // Cell formats (named "Styles" here).
  FCellFormatList := TsCellFormatList.Create(true);  // is destroyed by ancestor

  // Special version of FormatSettings using a point decimal separator for sure.
  FPointSeparatorSettings := DefaultFormatSettings;
  FPointSeparatorSettings.DecimalSeparator := '.';
end;

procedure TsSpreadExcelXMLReader.AddBuiltinNumFormats;
begin
  FFirstNumFormatIndexInFile := 164;
  AddBuiltInBiffFormats(
    FNumFormatList, FWorkbook.FormatSettings, FFirstNumFormatIndexInFile-1
  );
end;

{@@ ----------------------------------------------------------------------------
  Extracts the date/time value from the given string.
  The string is formatted as 'yyyy-mm-dd"T"hh:nn:ss.zzz'
-------------------------------------------------------------------------------}
function TsSpreadExcelXMLReader.ExtractDateTime(AText: String): TDateTime;
var
  dateStr, timeStr: String;
begin
  dateStr := Copy(AText, 1, 10);
  timeStr := Copy(AText, 12, MaxInt);
  Result := ScanDateTime('yyyy-mm-dd', dateStr) + ScanDateTime('hh:nn:ss.zzz', timeStr);
end;

{@@ ----------------------------------------------------------------------------
  Reads the cell alignment from the given node attributes
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadAlignment(ANode: TDOMNode;
  var AFormat: TsCellFormat);
var
  s: String;
begin
  // Vertical alignment
  s := GetAttrValue(ANode, 'ss:Vertical');
  if s <> '' then
    with AFormat do begin
      Include(UsedFormattingFields, uffVertAlign);
      case s of
        'Top':
          VertAlignment := vaTop;
        'Center':
          VertAlignment := vaCenter;
        'Bottom':
          VertAlignment := vaBottom;
        else
          Exclude(UsedFormattingFields, uffVertAlign);
      end;
    end;

  // Horizontal alignment
  s := GetAttrValue(ANode, 'ss:Horizontal');
  if s <> '' then
    with AFormat do begin
      Include(UsedFormattingFields, uffHorAlign);
      case s of
        'Left':
          HorAlignment := haLeft;
        'Center':
          HorAlignment := haCenter;
        'Right':
          HorAlignment := haRight;
        else
          Exclude(UsedFormattingFields, uffHorAlign);
      end;
    end;

  // Vertical text
  s := GetAttrValue(ANode, 'ss:Rotate');
  if s = '90' then
    with AFormat do begin
      TextRotation := rt90DegreeCounterClockwiseRotation;
      Include(UsedFormattingFields, uffTextRotation);
    end
  else if s = '-90' then
    with AFormat do begin
      TextRotation := rt90DegreeClockwiseRotation;
      Include(UsedFormattingFields, uffTextRotation);
    end;
  s := GetAttrValue(ANode, 'ss:VerticalText');
  if s <> '' then
    with AFormat do begin
      TextRotation := rtStacked;
      Include(UsedFormattingFields, uffTextRotation);
    end;

  // Word wrap
  s := GetAttrValue(ANode, 'ss:WrapText');
  if s = '1' then
    with AFormat do
      Include(UsedFormattingFields, uffWordWrap);

  // BiDi
  s := GetAttrValue(ANode, 'ss:ReadingOrder');
  if s <> '' then
    with AFormat do begin
      case s of
        'RightToLeft': BiDiMode := bdRTL;
        'LeftToRight': BiDiMode := bdLTR;
      end;
      Include(UsedFormattingFields, uffBiDi);
    end;
end;

{@@ ----------------------------------------------------------------------------
  Read a "Style/Borders/Border" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadBorder(ANode: TDOMNode;
  var AFormat: TsCellFormat);
// <Border ss:Position="Right" ss:LineStyle="Continuous" ss:Weight="3" ss:Color="#ED7D31"/>
var
  s, sw: String;
  b: TsCellBorder;
begin
  AFormat.UsedFormattingFields := AFormat.UsedFormattingFields + [uffBorder];

  // Border position
  s := GetAttrValue(ANode, 'ss:Position');
  case s of
    'Left':
      b := cbWest;
    'Right':
      b := cbEast;
    'Top':
      b := cbNorth;
    'Bottom':
      b := cbSouth;
    'DiagonalRight':
      b := cbDiagUp;
    'DiagonalLeft':
      b := cbDiagDown;
  end;
  Include(AFormat.Border, b);

  // Border color
  s := GetAttrValue(ANode, 'ss:Color');
  AFormat.BorderStyles[b].Color := HTMLColorStrToColor(s);

  // Line style
  s := GetAttrValue(ANode, 'ss:LineStyle');
  sw := GetAttrValue(ANode, 'ss:Weight');
  case s of
    'Continuous':
      if sw = '1' then
        AFormat.BorderStyles[b].LineStyle := lsThin
      else if sw = '2' then
        AFormat.BorderStyles[b].LineStyle := lsMedium
      else if sw = '3' then
        AFormat.BorderStyles[b].LineStyle := lsThick
      else if sw = '' then
        AFormat.BorderStyles[b].LineStyle := lsHair;
    'Double':
      AFormat.BorderStyles[b].LineStyle := lsDouble;
    'Dot':
      AFormat.BorderStyles[b].LineStyle := lsDotted;
    'Dash':
      if sw = '2' then
        AFormat.BorderStyles[b].LineStyle := lsMediumDash
      else
        AFormat.BorderStyles[b].LineStyle := lsDashed;
    'DashDot':
      if sw = '2' then
        AFormat.BorderStyles[b].LineStyle := lsMediumDashDot
      else
        AFormat.BorderStyles[b].LineStyle := lsDashDot;
    'DashDotDot':
      if sw = '2' then
        AFormat.BorderStyles[b].LineStyle := lsMediumDashDotDot
      else
        AFormat.BorderStyles[b].LineStyle := lsDashDotDot;
    'SlantDashDot':
        AFormat.BorderStyles[b].LineStyle := lsSlantDashDot;
  end;
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Styles/Style/Borders" nodes
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadBorders(ANode: TDOMNode;
  var AFormat: TsCellFormat);
var
  nodeName: String;
begin
  if ANode = nil then exit;
  ANode := ANode.FirstChild;
  while ANode <> nil do begin
    nodeName := ANode.NodeName;
    if nodeName = 'Border' then
      ReadBorder(ANode, AFormat);
    ANode := ANode.NextSibling;
  end;
end;

{@@ ----------------------------------------------------------------------------
  Reads a "Worksheet/Table/Row/Cell" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadCell(ANode: TDOMNode;
  AWorksheet: TsBasicWorksheet; ARow, ACol: Integer);
var
  sheet: TsWorksheet absolute AWorksheet;
  nodeName: string;
  s, st, sv: String;
  node: TDOMNode;
  err: TsErrorValue;
  cell: PCell;
  fmt: TsCellFormat;
  idx: Integer;
  mergedCols, mergedRows: Integer;
begin
  if ANode = nil then
    exit;
  nodeName := ANode.NodeName;
  if nodeName <> 'Cell' then
    raise Exception.Create('[ReadCell] Only "Cell" nodes expected.');

  cell := sheet.GetCell(ARow, ACol);

  s := GetAttrValue(ANode, 'ss:StyleID');
  if s <> '' then begin
    idx := FCellFormatList.FindIndexOfName(s);
    if idx <> -1 then begin
      fmt := FCellFormatList.Items[idx]^;
      cell^.FormatIndex := TsWorkbook(FWorkbook).AddCellFormat(fmt);
    end;
  end;

  // Merged cells
  s := GetAttrValue(ANode, 'ss:MergeAcross');
  if not ((s <> '') and TryStrToInt(s, mergedCols)) then mergedCols := 0;
  s := GetAttrValue(ANode, 'ss:MergeDown');
  if not ((s <> '') and TryStrToint(s, mergedRows)) then mergedRows := 0;
  if (mergedCols > 0) or (mergedRows > 0) then
    sheet.MergeCells(ARow, ACol, ARow + mergedRows, ACol + mergedCols);

  // Hyperlink
  s := GetAttrValue(ANode, 'ss:HRef');
  if s <> '' then begin
    st := GetAttrValue(ANode, 'x:HRefScreenTip');
    sheet.WriteHyperlink(cell, s, st);
  end;

  // Cell data and comment
  node := ANode.FirstChild;
  if node = nil then
    sheet.WriteBlank(cell)
  else
    while node <> nil do begin
      nodeName := node.NodeName;
      if (nodeName = 'Data') or (nodeName = 'ss:Data') then begin
        sv := node.TextContent;
        st := GetAttrValue(node, 'ss:Type');
        case st of
          'String':
            sheet.WriteText(cell, sv);
          'Number':
            sheet.WriteNumber(cell, StrToFloat(sv, FPointSeparatorSettings));
          'DateTime':
            sheet.WriteDateTime(cell, ExtractDateTime(sv));
          'Boolean':
            if sv = '1' then
              sheet.WriteBoolValue(cell, true)
            else if sv = '0' then
              sheet.WriteBoolValue(cell, false);
          'Error':
            if TryStrToErrorValue(sv, err) then
              sheet.WriteErrorValue(cell, err);
        end;
      end
      else
      if (nodeName = 'Comment') then
        ReadComment(node, AWorksheet, cell);
      node := node.NextSibling;
    end;
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Styles/Style/Protection" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadCellProtection(ANode: TDOMNode;
  var AFormat: TsCellFormat);
var
  s: String;
begin
  if ANode = nil then
    exit;

  s := GetAttrValue(ANode, 'ss:Protected');
  if s = '0' then
    Exclude(AFormat.Protection, cpLockCell);

  s := GetAttrValue(ANode, 'x:HideFormula');
  if s = '1' then
    Include(AFormat.Protection, cpHideFormulas);

  if AFormat.Protection <> DEFAULT_CELL_PROTECTION then
    Include(AFormat.UsedFormattingFields, uffProtection);
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Worksheet/Table/Row/Cell/Comment" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadComment(ANode: TDOMNode;
  AWorksheet: TsBasicWorksheet; ACell: PCell);
var
  txt: String;
begin
  txt := ANode.TextContent;
  TsWorksheet(AWorksheet).WriteComment(ACell, txt);
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Styles/Style/Font" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLreader.ReadFont(ANode: TDOMNode;
  var AFormat: TsCellFormat);
var
  book: TsWorkbook;
  fname: String;
  fsize: Single;
  fcolor: TsColor;
  fstyle: TsFontStyles;
  s: String;
begin
  if ANode = nil then
    exit;

  book := TsWorkbook(FWorkbook);

  fname := GetAttrValue(ANode, 'ss:FontName');
  if fname = '' then
    fname := book.GetDefaultFont.FontName;

  s := GetAttrValue(ANode, 'ss:Size');
  if (s = '') or not TryStrToFloat(s, fsize, FPointSeparatorSettings) then
    fsize := book.GetDefaultFont.Size;

  s := GetAttrValue(ANode, 'ss:Color');
  if s <> '' then
    fcolor := HTMLColorStrToColor(s)
  else
    fcolor := book.GetDefaultFont.Color;

  fstyle := [];
  s := GetAttrValue(ANode, 'ss:Bold');
  if s = '1' then
    Include(fstyle, fssBold);
  s := GetAttrValue(ANode, 'ss:Italic');
  if s = '1' then
    Include(fstyle, fssItalic);
  s := GetAttrValue(ANode, 'ss:UnderLine');
  if s <> '' then
    Include(fstyle, fssUnderline);
  s := GetAttrValue(ANode, 'ss:StrikeThrough');
  if s = '1' then
    Include(fstyle, fssStrikeout);

  AFormat.FontIndex := book.AddFont(fname, fsize, fstyle, fcolor);
  Include(AFormat.UsedFormattingFields, uffFont);
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Styles/Style/Interior" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadInterior(ANode: TDOMNode;
  var AFormat: TsCellFormat);
var
  s: String;
  fs: TsFillStyle;
begin
  if ANode = nil then
    exit;

  s := GetAttrValue(ANode, 'ss:Pattern');
  if s = '' then
    exit;

  for fs in TsFillStyle do
    if FILL_NAMES[fs] = s then begin
      AFormat.Background.Style := fs;
      break;
    end;

  s := GetAttrValue(ANode, 'ss:PatternColor');
  if s = '' then
    AFormat.Background.FgColor := scBlack
  else
    AFormat.Background.FgColor := HTMLColorStrToColor(s);

  s := GetAttrValue(ANode, 'ss:Color');
  if s = '' then
    AFormat.Background.BgColor := scWhite
  else begin
    AFormat.Background.BgColor := HTMLColorStrToColor(s);
    if AFormat.Background.Style = fsSolidFill then
      AFormat.Background.FgColor := AFormat.Background.BgColor;
  end;

  Include(AFormat.UsedFormattingFields, uffBackground);
end;

{@@ ----------------------------------------------------------------------------
  Reads a "Styles/Style/NumberFormat" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadNumberFormat(ANode: TDOMNode;
  var AFormat: TsCellFormat);
var
  s: String;
  nf: TsNumberFormat = nfGeneral;
  nfs: String;
begin
  if ANode = nil then
    exit;

  s := GetAttrValue(ANode, 'ss:Format');
  case s of
    'General':
      exit;
    'Short Date':
      begin
        nf := nfShortDate;
        nfs := BuildDateTimeFormatString(nf, FWorkbook.FormatSettings);
      end;
    'Short Time':
      begin
        nf := nfShortTime;
        nfs := BuildDateTimeFormatString(nf, FWorkbook.FormatSettings);
      end;
    else
      nfs := s;
  end;
  if nfs = '' then
    exit;

  AFormat.NumberFormatIndex := TsWorkbook(FWorkbook).AddNumberFormat(nfs);
  AFormat.NumberFormatStr := nfs;
  AFormat.NumberFormat := nf;
  Include(AFormat.UsedFormattingFields, uffNumberFormat);
end;

{@@ ----------------------------------------------------------------------------
  Reads a "Worksheet/Table/Row" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadRow(ANode: TDOMNode;
  AWorksheet: TsBasicWorksheet; ARow: Integer);
var
  nodeName: String;
  s: String;
  c: Integer;
begin
  c := 0;
  while ANode <> nil do begin
    nodeName := ANode.NodeName;
    if nodeName = 'Cell' then begin
      s := GetAttrValue(ANode, 'ss:Index');
      if s <> '' then c := StrToInt(s) - 1;
      ReadCell(ANode, AWorksheet, ARow, c);
      inc(c);
    end;
    ANode := ANode.NextSibling;
  end;
end;

{@@ ----------------------------------------------------------------------------
  Reads a "Styles/Style" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadStyle(ANode: TDOMNode);
var
  nodeName: String;
  fmt: TsCellFormat;
  s: String;
  id: Integer;
  idx: Integer;
  childNode: TDOMNode;
begin
  // Respect ancestor of current style
  s := GetAttrValue(ANode, 'ss:Parent');
  if s <> '' then begin
    idx := FCellFormatList.FindIndexOfName(s);
    if idx > -1 then
      fmt := FCellFormatList.Items[idx]^;
  end else
    InitFormatRecord(fmt);

  // ID of current style. We store it in the "Name" field of the TsCellFormat
  // because it is a string while ID is an Integer (mostly "s<number>", but also
  // "Default").
  fmt.Name := GetAttrValue(ANode, 'ss:ID');

  if fmt.Name = 's125' then
    idx := 0;

  // Style elements
  childNode := ANode.FirstChild;
  while childNode <> nil do begin
    nodeName := childNode.NodeName;
    if nodeName = 'Alignment' then
      ReadAlignment(childNode, fmt)
    else if nodeName = 'Borders' then
      ReadBorders(childNode, fmt)
    else if nodeName = 'Interior' then
      ReadInterior(childNode, fmt)
    else if nodeName = 'Font' then
      ReadFont(childNode, fmt)
    else if nodeName = 'NumberFormat' then
      ReadNumberFormat(childnode, fmt)
    else if nodeName = 'Protection' then
      ReadCellProtection(childNode, fmt);
    childNode := childNode.NextSibling;
  end;

  FCellFormatList.Add(fmt);
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Styles" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadStyles(ANode: TDOMNode);
var
  nodeName: String;
  styleNode: TDOMNode;
begin
  if ANode = nil then
    exit;
  styleNode := ANode.FirstChild;
  while styleNode <> nil do begin
    nodeName := styleNode.NodeName;
    if nodeName = 'Style' then
      ReadStyle(styleNode);
    styleNode := styleNode.NextSibling;
  end;
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Worksheet/Table" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadTable(ANode: TDOMNode;
  AWorksheet: TsBasicWorksheet);
var
  sheet: TsWorksheet absolute AWorksheet;
  nodeName: String;
  s: String;
  r, c: Integer;
  x: Double;
  idx: Integer;
  fmt: TsCellFormat;
begin
  r := 0;
  c := 0;
  while ANode <> nil do begin
    nodeName := ANode.NodeName;
    if nodeName = 'Column' then begin
      // Column index
      s := GetAttrValue(ANode, 'ss:Index');
      if (s <> '') and TryStrToInt(s, c) then
        dec(c);

      // Column width, in Points
      s := GetAttrValue(ANode, 'ss:Width');
      if (s <> '') and TryStrToFloat(s, x, FPointSeparatorSettings) then
        sheet.WriteColWidth(c, x, suPoints);

      // Column format
      s := GetAttrValue(ANode, 'ss:StyleID');
      if s <> '' then begin
        idx := FCellFormatList.FindIndexOfName(s);
        if idx <> -1 then begin
          fmt := FCellFormatList.Items[idx]^;
          idx := TsWorkbook(FWorkbook).AddCellFormat(fmt);
          sheet.WriteColFormatIndex(c, idx);
        end;
      end;

      inc(c);
    end
    else
    if nodeName = 'Row' then begin
      // Default column width
      s := GetAttrValue(ANode, 'ss:DefaultColumnWidth');
      if (s <> '') and TryStrToFloat(s, x, FPointSeparatorSettings) then
        sheet.WriteDefaultColWidth(x, suPoints);

      // Default row height
      s := GetAttrValue(ANode, 'ss:DefaultRowHeight');
      if (s <> '') and TryStrToFloat(s, x, FPointSeparatorSettings) then
        sheet.WriteDefaultRowHeight(x, suPoints);

      // Index
      s := GetAttrValue(ANode, 'ss:Index');
      if s <> '' then r := StrToInt(s) - 1;

      // Height
      s := GetAttrValue(ANode, 'ss:Height');
      if (s <> '') and TryStrToFloat(s, x, FPointSeparatorSettings) then
        sheet.WriteRowHeight(r, x, suPoints);

      // Row format
      s := GetAttrValue(ANode, 'ss:StyleID');
      if s <> '' then begin
        idx := FCellFormatList.FindIndexOfName(s);
        if idx <> -1 then begin
          fmt := FCellFormatList.Items[idx]^;
          idx := TsWorkbook(FWorkbook).AddCellFormat(fmt);
          sheet.WriteRowFormatIndex(r, idx);
        end;
      end;

      // Cells in row
      ReadRow(ANode.FirstChild, AWorksheet, r);

      inc(r);
    end;
    ANode := ANode.NextSibling;
  end;
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Worksheet" node
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadWorksheet(ANode: TDOMNode;
  AWorksheet: TsBasicWorksheet);
var
  nodeName: String;
  s: String;
begin
  while ANode <> nil do begin
    nodeName := ANode.NodeName;
    if nodeName = 'Table' then
      ReadTable(ANode.FirstChild, AWorksheet)
    else if nodeName = 'WorksheetOptions' then
      ReadWorksheetOptions(ANode, AWorksheet);
    ANode := ANode.NextSibling;
  end;
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Worksheet/WorksheetOptions" nodes
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadWorksheetOptions(ANode: TDOMNode;
  AWorksheet: TsBasicWorksheet);
begin
  // to do
end;

{@@ ----------------------------------------------------------------------------
  Reads the "Worksheet" nodes
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadWorksheets(ANode: TDOMNode);
var
  nodeName: String;
  s: String;
begin
  while ANode <> nil do begin
    nodeName := ANode.NodeName;
    if nodeName = 'Worksheet' then begin
      s := GetAttrValue(ANode, 'ss:Name');
      if s <> '' then begin   // the case of '' should not happen
        FWorksheet := TsWorkbook(FWorkbook).AddWorksheet(s);
        ReadWorksheet(ANode.FirstChild, FWorksheet);
      end;
    end;
    ANode := ANode.NextSibling;
  end;
end;


{@@ ----------------------------------------------------------------------------
  Reads the workbook from the specified stream
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLReader.ReadFromStream(AStream: TStream;
  APassword: String = ''; AParams: TsStreamParams = []);
var
  doc: TXMLDocument;
begin
  try
    ReadXMLStream(doc, AStream);
    ReadStyles(doc.DocumentElement.FindNode('Styles'));
    ReadWorksheets(doc.DocumentElement.FindNode('Worksheet'));
  finally
    doc.Free;
  end;
end;



{@@ ----------------------------------------------------------------------------
  Constructor of the ExcelXML writer

  Defines the date mode and the limitations of the file format.
  Initializes the format settings to be used when writing to xml.
-------------------------------------------------------------------------------}
constructor TsSpreadExcelXMLWriter.Create(AWorkbook: TsBasicWorkbook);
begin
  inherited Create(AWorkbook);

  // Initial base date in case it won't be set otherwise.
  // Use 1900 to get a bit more range between 1900..1904.
  FDateMode := ExcelXMLSettings.DateMode;

  // Special version of FormatSettings using a point decimal separator for sure.
  FPointSeparatorSettings := DefaultFormatSettings;
  FPointSeparatorSettings.DecimalSeparator := '.';

  // http://en.wikipedia.org/wiki/List_of_spreadsheet_software#Specifications
  FLimitations.MaxColCount := 256;
  FLimitations.MaxRowCount := 65536;
end;

function TsSpreadExcelXMLWriter.GetCommentStr(ACell: PCell): String;
var
  comment: PsComment;
begin
  Result := '';
  comment := (FWorksheet as TsWorksheet).FindComment(ACell);
  if Assigned(comment) then
    Result := INDENT1 + '<Comment><Data>' + comment^.Text + '</Data></Comment>' + LF + CELL_INDENT;
  // If there will be some rich-text-like formatting in the future, use
  //  Result := '<Comment><ss:Data xmlns="http://www.w3.org/TR/REC-html40">'+comment^.Text+'</ss:Data></Comment>':
end;

function TsSpreadExcelXMLWriter.GetFormulaStr(ACell: PCell): String;
begin
  if HasFormula(ACell) then
  begin
    Result := UTF8TextToXMLText((FWorksheet as TsWorksheet).ConvertFormulaDialect(ACell, fdExcelR1C1));
    Result := ' ss:Formula="=' + Result + '"';
  end else
    Result := '';
end;

function TsSpreadExcelXMLWriter.GetFrozenPanesStr(AWorksheet: TsBasicWorksheet;
  AIndent: String): String;
var
  activePane: Integer;
  sheet: TsWorksheet absolute AWorksheet;
begin
  if (soHasFrozenPanes in sheet.Options) then
  begin
    Result := AIndent +
        '<FreezePanes/>' + LF + AIndent +
        '<FrozenNoSplit/>' + LF;

    if sheet.LeftPaneWidth > 0 then
      Result := Result + AIndent +
        '<SplitVertical>1</SplitVertical>' + LF + AIndent +
        '<LeftColumnRightPane>' + IntToStr(sheet.LeftPaneWidth) + '</LeftColumnRightPane>' + LF;

    if sheet.TopPaneHeight > 0 then
      Result := Result + AIndent +
        '<SplitHorizontal>1</SplitHorizontal>' + LF + AIndent +
        '<TopRowBottomPane>' + IntToStr(sheet.TopPaneHeight) + '</TopRowBottomPane>' + LF;

    if (sheet.LeftPaneWidth = 0) and (sheet.TopPaneHeight = 0) then
      activePane := 3
    else
    if (sheet.LeftPaneWidth = 0) then
      activePane := 2
    else
    if (sheet.TopPaneHeight = 0) then
      activePane := 1
    else
      activePane := 0;
    Result := Result + AIndent +
      '<ActivePane>' + IntToStr(activePane) + '</ActivePane>' + LF;
  end else
    Result := '';
end;

function TsSpreadExcelXMLWriter.GetHyperlinkStr(ACell: PCell): String;
var
  hyperlink: PsHyperlink;
begin
  Result := '';
  hyperlink := (FWorksheet as TsWorksheet).FindHyperlink(ACell);
  if Assigned(hyperlink) then
    Result := ' ss:HRef="' + hyperlink^.Target + '"';
end;

function TsSpreadExcelXMLWriter.GetIndexStr(AIndex: Integer): String;
begin
  Result := Format(' ss:Index="%d"', [AIndex]);
end;

function TsSpreadExcelXMLWriter.GetLayoutStr(AWorksheet: TsBasicWorksheet): String;
var
  sheet: TsWorksheet absolute AWorksheet;
begin
  Result := '';
  if sheet.PageLayout.Orientation = spoLandscape then
    Result := Result + ' x:Orientation="Landscape"';
  if (poHorCentered in sheet.PageLayout.Options) then
    Result := Result + ' x:CenterHorizontal="1"';
  if (poVertCentered in sheet.PageLayout.Options) then
    Result := Result + ' x:CenterVertical="1"';
  if (poUseStartPageNumber in sheet.PageLayout.Options) then
    Result := Result + ' x:StartPageNumber="' + IntToStr(sheet.PageLayout.StartPageNumber) + '"';
  Result := '<Layout' + Result + '/>';
end;

function TsSpreadExcelXMLWriter.GetMergeStr(ACell: PCell): String;
var
  r1, c1, r2, c2: Cardinal;
begin
  Result := '';
  if (FWorksheet as TsWorksheet).IsMerged(ACell) then begin
    (FWorksheet as TsWorksheet).FindMergedRange(ACell, r1, c1, r2, c2);
    if c2 > c1 then
      Result := Result + Format(' ss:MergeAcross="%d"', [c2-c1]);
    if r2 > r1 then
      Result := Result + Format(' ss:MergeDown="%d"', [r2-r1]);
  end;
end;

function TsSpreadExcelXMLWriter.GetPageFooterStr(
  AWorksheet: TsBasicWorksheet): String;
var
  sheet: TsWorksheet absolute AWorksheet;
begin
  Result := Format('x:Margin="%g"', [mmToIn(sheet.PageLayout.FooterMargin)], FPointSeparatorSettings);
  if (sheet.PageLayout.Footers[HEADER_FOOTER_INDEX_ALL] <> '') then
    Result := Result + ' x:Data="' + UTF8TextToXMLText(sheet.PageLayout.Footers[HEADER_FOOTER_INDEX_ALL], true) + '"';
  Result := '<Footer ' + result + '/>';
end;

function TsSpreadExcelXMLWriter.GetPageHeaderStr(
  AWorksheet: TsBasicWorksheet): String;
var
  sheet: TsWorksheet absolute AWorksheet;
begin
  Result := Format('x:Margin="%g"', [mmToIn(sheet.PageLayout.HeaderMargin)], FPointSeparatorSettings);
  if (sheet.PageLayout.Headers[HEADER_FOOTER_INDEX_ALL] <> '') then
    Result := Result + ' x:Data="' + UTF8TextToXMLText(sheet.PageLayout.Headers[HEADER_FOOTER_INDEX_ALL], true) + '"';
  Result := '<Header ' + Result + '/>';
end;

function TsSpreadExcelXMLWriter.GetPageMarginStr(
  AWorksheet: TsBasicWorksheet): String;
var
  sheet: TsWorksheet absolute AWorksheet;
begin
  Result := Format('x:Bottom="%g" x:Left="%g" x:Right="%g" x:Top="%g"', [
    mmToIn(sheet.PageLayout.BottomMargin),
    mmToIn(sheet.PageLayout.LeftMargin),
    mmToIn(sheet.PageLayout.RightMargin),
    mmToIn(sheet.PageLayout.TopMargin)
    ], FPointSeparatorSettings);
  Result := '<PageMargins ' + Result + '/>';
end;

function TsSpreadExcelXMLWriter.GetStyleStr(AFormatIndex: Integer): String;
begin
  Result := '';
  if AFormatIndex > 0 then
    Result := Format(' ss:StyleID="s%d"', [AFormatIndex + FMT_OFFSET]);
end;

procedure TsSpreadExcelXMLWriter.WriteBlank(AStream: TStream;
  const ARow, ACol: Cardinal; ACell: PCell);
begin
  Unused(ARow, ACol);
  AppendToStream(AStream, Format(CELL_INDENT +
    '<Cell%s%s%s%s>' +              // colIndex, style, hyperlink, merge
      '%s' +                        // Comment <Comment>...</Comment>
    '</Cell>' + LF, [
    GetIndexStr(ACol+1), GetStyleStr(ACell^.FormatIndex), GetHyperlinkStr(ACell), GetMergeStr(ACell),
    GetCommentStr(ACell)
  ]));
end;

procedure TsSpreadExcelXMLWriter.WriteBool(AStream: TStream;
  const ARow, ACol: Cardinal; const AValue: boolean; ACell: PCell);
begin
  Unused(ARow, ACol);
  AppendToStream(AStream, Format(CELL_INDENT +
    '<Cell%s%s%s%s%s>' +         // colIndex, style, formula, hyperlink, merge
      '<Data ss:Type="%s">' +    // data type
        '%s' +                   // value string
      '</Data>' +
      '%s' +                     // Comment <Comment>...</Comment>
    '</Cell>' + LF, [
    GetIndexStr(ACol+1), GetStyleStr(ACell^.FormatIndex), GetFormulaStr(ACell),
      GetHyperlinkStr(ACell), GetMergeStr(ACell),
    StrUtils.IfThen(HasFormula(ACell), GetCellContentTypeStr(ACell), 'Boolean'),
    StrUtils.IfThen(AValue, '1', '0'),
    GetCommentStr(ACell)
  ]));
end;

procedure TsSpreadExcelXMLWriter.WriteCellToStream(AStream: TStream; ACell: PCell);
begin
  case ACell^.ContentType of
    cctBool:
      WriteBool(AStream, ACell^.Row, ACell^.Col, ACell^.BoolValue, ACell);
    cctDateTime:
      WriteDateTime(AStream, ACell^.Row, ACell^.Col, ACell^.DateTimeValue, ACell);
    cctEmpty:
      WriteBlank(AStream, ACell^.Row, ACell^.Col, ACell);
    cctError:
      WriteError(AStream, ACell^.Row, ACell^.Col, ACell^.ErrorValue, ACell);
    cctNumber:
      WriteNumber(AStream, ACell^.Row, ACell^.Col, ACell^.NumberValue, ACell);
    cctUTF8String:
      WriteLabel(AStream, ACell^.Row, ACell^.Col, ACell^.UTF8StringValue, ACell);
  end;

  if (FWorksheet as TsWorksheet).ReadComment(ACell) <> '' then
    WriteComment(AStream, ACell);
end;

procedure TsSpreadExcelXMLWriter.WriteDateTime(AStream: TStream;
  const ARow, ACol: Cardinal; const AValue: TDateTime; ACell: PCell);
var
  valueStr: String;
  ExcelDate: TDateTime;
  nfp: TsNumFormatParams;
  fmt: PsCellFormat;
begin
  Unused(ARow, ACol);
  ExcelDate := AValue;
  fmt := (FWorkbook as TsWorkbook).GetPointerToCellFormat(ACell^.FormatIndex);
  // Times have an offset of 1 day!
  if (fmt <> nil) and (uffNumberFormat in fmt^.UsedFormattingFields) then
  begin
    nfp := (FWorkbook as TsWorkbook).GetNumberFormat(fmt^.NumberFormatIndex);
    if IsTimeIntervalFormat(nfp) or IsTimeFormat(nfp) then
      case FDateMode of
        dm1900: ExcelDate := AValue + DATEMODE_1900_BASE;
        dm1904: ExcelDate := AValue + DATEMODE_1904_BASE;
      end;
  end;
  valueStr := FormatDateTime('yyyy-mm-dd"T"hh:nn:ss.zzz', ExcelDate);

  AppendToStream(AStream, Format(CELL_INDENT +
    '<Cell%s%s%s%s%s>' + LF + VALUE_INDENT + // colIndex, style, formula, hyperlink, merge
      '<Data ss:Type="%s">' +                // data type
        '%s' +                               // value string
      '</Data>' + LF + CELL_INDENT +
      '%s' +                                 // Comment <Comment>...</Comment>
    '</Cell>' + LF, [
    GetIndexStr(ACol+1), GetStyleStr(ACell^.FormatIndex), GetFormulaStr(ACell),
      GetHyperlinkStr(ACell), GetMergeStr(ACell),
    StrUtils.IfThen(HasFormula(ACell), GetCellContentTypeStr(ACell), 'DateTime'),
    valueStr,
    GetCommentStr(ACell)
  ]));
end;

procedure TsSpreadExcelXMLWriter.WriteError(AStream: TStream;
  const ARow, ACol: Cardinal; const AValue: TsErrorValue; ACell: PCell);
begin
  Unused(ARow, ACol);
  AppendToStream(AStream, Format(CELL_INDENT +
    '<Cell%s%s%s%s%s>' + LF + VALUE_INDENT + // colIndex, style, formula, hyperlink, merge
      '<Data ss:Type="%s">' +                // data type
        '%s' +                               // value string
      '</Data>' + LF + CELL_INDENT +
      '%s' +                                 // Comment <Comment>...</Comment>
    '</Cell>' + LF, [
    GetIndexStr(ACol+1), GetStyleStr(ACell^.FormatIndex), GetFormulaStr(ACell),
      GetHyperlinkStr(ACell), GetMergeStr(ACell),
    StrUtils.IfThen(HasFormula(ACell), GetCellContentTypeStr(ACell), 'Error'),
    GetErrorValueStr(AValue),
    GetCommentStr(ACell)
  ]));
end;

procedure TsSpreadExcelXMLWriter.WriteExcelWorkbook(AStream: TStream);
var
  datemodeStr: String;
  protectStr: String;
begin
  if FDateMode = dm1904 then
    datemodeStr := INDENT2 + '<Date1904/>' + LF else
    datemodeStr := '';

  protectStr := Format(
    '<ProtectStructure>%s</ProtectStructure>' + LF + INDENT2 +
    '<ProtectWindows>%s</ProtectWindows>' + LF, [
    FALSE_TRUE[bpLockStructure in Workbook.Protection],
    FALSE_TRUE[bpLockWindows in Workbook.Protection]
  ]);

  AppendToStream(AStream, INDENT1 +
    '<ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">' + LF +
      datemodeStr + INDENT2 +
      protectStr + INDENT1 +
    '</ExcelWorkbook>' + LF);
end;

procedure TsSpreadExcelXMLWriter.WriteLabel(AStream: TStream; const ARow,
  ACol: Cardinal; const AValue: string; ACell: PCell);
var
  valueStr: String;
  cctStr: String;
  xmlnsStr: String;
  dataTagStr: String;
  p: Integer;
  tmp: String;
  ch:char;
begin
  if Length(ACell^.RichTextParams) > 0 then
  begin
    RichTextToHTML(
      FWorkbook as TsWorkbook,
      (FWorksheet as TsWorksheet).ReadCellFont(ACell),
      AValue,
      ACell^.RichTextParams,
      valueStr,             // html-formatted rich text
      'html:', tcProperCase
    );
    xmlnsStr := ' xmlns="http://www.w3.org/TR/REC-html40"';
    dataTagStr := 'ss:';

    // Excel does not like units in font size specification...
    tmp := valueStr;
    p := pos('<Font html:Size="', valueStr);
    if p > 0 then begin
      valueStr := '';
      while p > 0 do begin
        inc(p, Length('<Font html:Size="'));
        valueStr := valueStr + copy(tmp, 1, p-1);
        while (tmp[p] <> '"') do begin
          if (tmp[p] in ['0'..'9', '.']) then valueStr := valueStr + tmp[p];
          inc(p);
        end;
        tmp := copy(tmp, p, MaxInt);
        p := pos('<Font html:Size="', tmp);
      end;
      valueStr := valuestr + tmp;
    end;
  end else
  begin
    valueStr := AValue;
    if not ValidXMLText(valueStr, true, true) then
      Workbook.AddErrorMsg(
        rsInvalidCharacterInCell, [
        GetCellString(ARow, ACol)
      ]);
    xmlnsStr := '';
    dataTagStr := '';
  end;

  cctStr := 'String';
  if HasFormula(ACell) then
    cctStr := GetCellContentTypeStr(ACell) else
    cctStr := 'String';

  AppendToStream(AStream, Format(CELL_INDENT +
    '<Cell%s%s%s%s%s>' + LF + VALUE_INDENT + // colIndex, style, formula, hyperlink, merge
      '<%sData ss:Type="%s"%s>'+             // "ss:", data type, "xmlns=.."
        '%s' +                               // value string
      '</%sData>' + LF + CELL_INDENT +       // "ss:"
      '%s' +                                 // Comment
    '</Cell>' + LF, [
    GetIndexStr(ACol+1), GetStyleStr(ACell^.FormatIndex), GetFormulaStr(ACell),
      GetHyperlinkStr(ACell), GetMergeStr(ACell),
    dataTagStr, cctStr, xmlnsStr,
    valueStr,
    dataTagStr,
    GetCommentStr(ACell)
  ]));
end;

procedure TsSpreadExcelXMLWriter.WriteNumber(AStream: TStream; const ARow, ACol: Cardinal;
  const AValue: double; ACell: PCell);
begin
  Unused(ARow, ACol);
  AppendToStream(AStream, Format(CELL_INDENT +
    '<Cell%s%s%s%s%s>' + LF + VALUE_INDENT +  // colIndex, style, formula, hyperlink, merge
      '<Data ss:Type="%s">' +                 // data type
        '%g' +                                // value
      '</Data>' + LF + CELL_INDENT +
      '%s' +                                  // Comment <Comment>...</Comment>
    '</Cell>' + LF, [
    GetIndexStr(ACol+1), GetStyleStr(ACell^.FormatIndex), GetFormulaStr(ACell),
      GetHyperlinkStr(ACell), GetMergeStr(ACell),
    StrUtils.IfThen(HasFormula(ACell), GetCellContentTypeStr(ACell), 'Number'),
    AValue,
    GetCommentStr(ACell)], FPointSeparatorSettings)
  );
end;

procedure TsSpreadExcelXMLWriter.WriteStyle(AStream: TStream; AIndex: Integer);
var
  fmt: PsCellFormat;
  deffnt, fnt: TsFont;
  s, fmtVert, fmtHor, fmtWrap, fmtRot: String;
  nfp: TsNumFormatParams;
  fill: TsFillPattern;
  cb: TsCellBorder;
  cbs: TsCellBorderStyle;
  book: TsWorkbook;
begin
  book := FWorkbook as TsWorkbook;
  deffnt := book.GetDefaultFont;
  if AIndex = 0 then
  begin
    AppendToStream(AStream, Format(INDENT2 +
      '<Style ss:ID="Default" ss:Name="Normal">' + LF + INDENT3 +
        '<Aligment ss:Vertical="Bottom" />' + LF + INDENT3 +
        '<Borders />' + LF + INDENT3 +
        '<Font ss:FontName="%s" x:Family="Swiss" ss:Size="%d" ss:Color="%s" />' + LF + INDENT3 +
        '<Interior />' + LF + INDENT3 +
        '<NumberFormat />' + LF + INDENT3 +
        '<Protection />' + LF + INDENT2 +
      '</Style>' + LF,
      [deffnt.FontName, round(deffnt.Size), ColorToHTMLColorStr(deffnt.Color)] )
    )
  end else
  begin
    AppendToStream(AStream, Format(INDENT2 +
      '<Style ss:ID="s%d">' + LF, [AIndex + FMT_OFFSET]));

    fmt := book.GetPointerToCellFormat(AIndex);

    // Horizontal alignment
    fmtHor := '';
    if uffHorAlign in fmt^.UsedFormattingFields then
      case fmt^.HorAlignment of
        haDefault: ;
        haLeft   : fmtHor := 'ss:Horizontal="Left" ';
        haCenter : fmtHor := 'ss:Horizontal="Center" ';
        haRight  : fmtHor := 'ss:Horizontal="Right" ';
        else
          raise EFPSpreadsheetWriter.Create('[TsSpreadXMLWriter.WriteStyle] Horizontal alignment cannot be handled.');
      end;

    // Vertical alignment
    fmtVert := 'ss:Vertical="Bottom" ';
    if uffVertAlign in fmt^.UsedFormattingFields then
      case fmt^.VertAlignment of
        vaDefault: ;
        vaTop    : fmtVert := 'ss:Vertical="Top" ';
        vaCenter : fmtVert := 'ss:Vertical="Center" ';
        vaBottom : ;
        else
          raise EFPSpreadsheetWriter.Create('[TsSpreadXMLWriter.WriteStyle] Vertical alignment cannot be handled.');
      end;

    // Wrap text
    if uffWordwrap in fmt^.UsedFormattingFields then
      fmtWrap := 'ss:WrapText="1" ' else
      fmtWrap := '';

    // Text rotation
    fmtRot := '';
    if uffTextRotation in fmt^.UsedFormattingFields then
      case fmt^.TextRotation of
        rt90DegreeClockwiseRotation        : fmtRot := 'ss:Rotate="-90" ';
        rt90DegreeCounterClockwiseRotation : fmtRot := 'ss:Rotate="90" ';
        rtStacked                          : fmtRot := 'ss:VerticalText="1" ';
      end;

    // Write all the alignment, text rotation and wordwrap attributes to stream
    AppendToStream(AStream, Format(INDENT3 +
      '<Alignment %s%s%s%s />' + LF,
      [fmtHor, fmtVert, fmtWrap, fmtRot])
    );

    // Font
    if (uffFont in fmt^.UsedFormattingFields) then
    begin
      fnt := book.GetFont(fmt^.FontIndex);
      s := '';
      if fnt.FontName <> deffnt.FontName then
        s := s + Format('ss:FontName="%s" ', [fnt.FontName]);
      if not SameValue(fnt.Size, deffnt.Size, 1E-3) then
        s := s + Format('ss:Size="%g" ', [fnt.Size], FPointSeparatorSettings);
      if fnt.Color <> deffnt.Color then
        s := s + Format('ss:Color="%s" ', [ColorToHTMLColorStr(fnt.Color)]);
      if fssBold in fnt.Style then
        s := s + 'ss:Bold="1" ';
      if fssItalic in fnt.Style then
        s := s + 'ss:Italic="1" ';
      if fssUnderline in fnt.Style then
        s := s + 'ss:Underline="Single" ';    // or "Double", not supported by fps
      if fssStrikeout in fnt.Style then
        s := s + 'ss:StrikeThrough="1" ';
      if s <> '' then
        AppendToStream(AStream, INDENT3 +
          '<Font ' + s + '/>' + LF);
    end;

    // Number Format
    if (uffNumberFormat in fmt^.UsedFormattingFields) then
    begin
      nfp := book.GetNumberFormat(fmt^.NumberFormatIndex);
      AppendToStream(AStream, Format(INDENT3 +
        '<NumberFormat ss:Format="%s"/>' + LF, [UTF8TextToXMLText(nfp.NumFormatStr)]));
    end;

    // Background
    if (uffBackground in fmt^.UsedFormattingFields) then
    begin
      fill := fmt^.Background;
      s := 'ss:Color="' + ColorToHTMLColorStr(fill.BgColor) + '" ';
      if not (fill.Style in [fsNoFill, fsSolidFill]) then
        s := s + 'ss:PatternColor="' + ColorToHTMLColorStr(fill.FgColor) + '" ';
      s := s + 'ss:Pattern="' + FILL_NAMES[fill.Style] + '"';
      AppendToStream(AStream, INDENT3 +
        '<Interior ' + s + '/>' + LF)
    end;

    // Borders
    if (uffBorder in fmt^.UsedFormattingFields) then
    begin
      s := '';
      for cb in TsCellBorder do
        if cb in fmt^.Border then begin
          cbs := fmt^.BorderStyles[cb];
          s := s + INDENT4 + Format('<Border ss:Position="%s" ss:LineStyle="%s"', [
            BORDER_NAMES[cb], LINE_STYLES[cbs.LineStyle]]);
          if fmt^.BorderStyles[cb].LineStyle <> lsHair then
            s := Format('%s ss:Weight="%d"', [s, LINE_WIDTHS[cbs.LineStyle]]);
          if fmt^.BorderStyles[cb].Color <> scBlack then
            s := Format('%s ss:Color="%s"', [s, ColorToHTMLColorStr(cbs.Color)]);
          s := s + '/>' + LF;
        end;
      if s <> '' then
        AppendToStream(AStream, INDENT3 +
          '<Borders>' + LF + s + INDENT3 +
          '</Borders>' + LF);
    end;

    // Protection
    s := '';
    if FWorkbook.IsProtected then begin
      if not (cpLockCell in fmt^.Protection) then
        s := s + 'ss:Protected="0" ';
      if cpHideFormulas in fmt^.Protection then
        s := s + 'x:HideFormula="1" ';
    end;
    if s <> '' then
      AppendToStream(AStream, INDENT3 +
        '<Protection ' + s + '/>' + LF);

    AppendToStream(AStream, INDENT2 +
      '</Style>' + LF);
  end;
end;

procedure TsSpreadExcelXMLWriter.WriteStyles(AStream: TStream);
var
  i: Integer;
begin
  AppendToStream(AStream, INDENT1 +
    '<Styles>' + LF);
  for i:=0 to (FWorkbook as TsWorkbook).GetNumCellFormats-1 do
    WriteStyle(AStream, i);
  AppendToStream(AStream, INDENT1 +
    '</Styles>' + LF);
end;

procedure TsSpreadExcelXMLWriter.WriteTable(AStream: TStream;
  AWorksheet: TsBasicWorksheet);
var
  c, c1, c2: Cardinal;
  r, r1, r2: Cardinal;
  cell: PCell;
  rowheightStr: String;
  colwidthStr: String;
  styleStr: String;
  col: PCol;
  row: PRow;
  sheet: TsWorksheet absolute AWorksheet;
begin
  r1 := 0;
  c1 := 0;
  r2 := sheet.GetLastRowIndex;
  c2 := sheet.GetLastColIndex;
  AppendToStream(AStream, TABLE_INDENT + Format(
    '<Table ss:ExpandedColumnCount="%d" ss:ExpandedRowCount="%d" ' +
      'x:FullColumns="1" x:FullRows="1" ' +
      'ss:DefaultColumnWidth="%.2f" ' +
      'ss:DefaultRowHeight="%.2f">' + LF,
      [
      sheet.GetLastColIndex + 1, sheet.GetLastRowIndex + 1,
      sheet.ReadDefaultColWidth(suPoints),
      sheet.ReadDefaultRowHeight(suPoints)
      ],
      FPointSeparatorSettings
    ));

  for c := c1 to c2 do
  begin
    col := sheet.FindCol(c);
    styleStr := '';
    colWidthStr := '';
    if Assigned(col) then
    begin
      // column width is needed in pts.
      if col^.ColWidthType = cwtCustom then
        colwidthStr := Format(' ss:Width="%0.2f" ss:AutoFitWidth="0"',
          [(FWorkbook as TsWorkbook).ConvertUnits(col^.Width, FWorkbook.Units, suPoints)],
          FPointSeparatorSettings);
      // column style
      if col^.FormatIndex > 0 then
        styleStr := GetStyleStr(col^.FormatIndex);
    end;
    AppendToStream(AStream, COL_INDENT + Format(
      '<Column ss:Index="%d" %s%s />' + LF, [c+1, colWidthStr, styleStr]));
  end;

  for r := r1 to r2 do
  begin
    row := sheet.FindRow(r);
    styleStr := '';
    // Row height is needed in pts.
    if Assigned(row) then
    begin
      rowheightStr := Format(' ss:Height="%.2f"',
        [(FWorkbook as TsWorkbook).ConvertUnits(row^.Height, FWorkbook.Units, suPoints)],
        FPointSeparatorSettings
      );
      if row^.RowHeightType = rhtCustom then
        rowHeightStr := 'ss:AutoFitHeight="0"' + rowHeightStr else
        rowHeightStr := 'ss:AutoFitHeight="1"' + rowHeightStr;
      if row^.FormatIndex > 0 then
        styleStr := GetStyleStr(row^.FormatIndex);
    end else
      rowheightStr := 'ss:AutoFitHeight="1"';
    AppendToStream(AStream, ROW_INDENT + Format(
      '<Row %s%s>' + LF, [rowheightStr, styleStr]));
    for c := c1 to c2 do
    begin
      cell := sheet.FindCell(r, c);
      if cell <> nil then
      begin
        if sheet.IsMerged(cell) and not sheet.IsMergeBase(cell) then
          Continue;
        WriteCellToStream(AStream, cell);
      end;
    end;
    AppendToStream(AStream, ROW_INDENT +
      '</Row>' + LF);
  end;

  AppendToStream(AStream, TABLE_INDENT +
    '</Table>' + LF);
end;

{@@ ----------------------------------------------------------------------------
  Writes an ExcelXML document to a stream
-------------------------------------------------------------------------------}
procedure TsSpreadExcelXMLWriter.WriteToStream(AStream: TStream;
  AParams: TsStreamParams = []);
begin
  Unused(AParams);

  AppendToStream(AStream,
    '<?xml version="1.0"?>' + LF +
    '<?mso-application progid="Excel.Sheet"?>' + LF
  );
  AppendToStream(AStream,
    '<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"' + LF +
    '          xmlns:o="urn:schemas-microsoft-com:office:office"' + LF +
    '          xmlns:x="urn:schemas-microsoft-com:office:excel"' + LF +
    '          xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"' + LF +
    '          xmlns:html="http://www.w3.org/TR/REC-html40">' + LF);

  WriteExcelWorkbook(AStream);
  WriteStyles(AStream);
  WriteWorksheets(AStream);

  AppendToStream(AStream,
    '</Workbook>');
end;

procedure TsSpreadExcelXMLWriter.WriteWorksheet(AStream: TStream;
  AWorksheet: TsBasicWorksheet);
var
  protectedStr: String;
begin
  FWorksheet := AWorksheet;

  if FWorksheet.IsProtected then
    protectedStr := ' ss:Protected="1"' else
    protectedStr := '';

  AppendToStream(AStream, Format(
    '  <Worksheet ss:Name="%s"%s>' + LF, [
    UTF8TextToXMLText(AWorksheet.Name),
    protectedStr
  ]) );
  WriteTable(AStream, AWorksheet);
  WriteWorksheetOptions(AStream, AWorksheet);
  AppendToStream(AStream,
    '  </Worksheet>' + LF
  );
end;

procedure TsSpreadExcelXMLWriter.WriteWorksheetOptions(AStream: TStream;
  AWorksheet: TsBasicWorksheet);
var
  footerStr, headerStr: String;
  hideGridStr: String;
  hideHeadersStr: String;
  frozenStr: String;
  layoutStr: String;
  marginStr: String;
  selectedStr: String;
  protectStr: String;
  sheet: TsWorksheet absolute AWorksheet;
begin
  // Orientation, some PageLayout.Options
  layoutStr := GetLayoutStr(AWorksheet);
  if layoutStr <> '' then layoutStr := INDENT4 + layoutStr + LF;

  // Header
  headerStr := GetPageHeaderStr(AWorksheet);
  if headerStr <> '' then headerStr := INDENT4 + headerStr + LF;

  // Footer
  footerStr := GetPageFooterStr(AWorksheet);
  if footerStr <> '' then footerStr := INDENT4 + footerStr + LF;

  // Page margins
  marginStr := GetPageMarginStr(AWorksheet);
  if marginStr <> '' then marginStr := INDENT4 + marginStr + LF;

  // Show/hide grid lines
  if not (soShowGridLines in AWorksheet.Options) then
    hideGridStr := INDENT3 + '<DoNotDisplayGridlines/>' + LF else
    hideGridStr := '';

  // Show/hide column/row headers
  if not (soShowHeaders in AWorksheet.Options) then
    hideHeadersStr := INDENT3 + '<DoNotDisplayHeadings/>' + LF else
    hideHeadersStr := '';

  if (FWorkbook as TsWorkbook).ActiveWorksheet = AWorksheet then
    selectedStr := INDENT3 + '<Selected/>' + LF else
    selectedStr := '';

  // Frozen panes
  frozenStr := GetFrozenPanesStr(AWorksheet, INDENT3);

  // Protection
  protectStr := Format(INDENT3 + '<ProtectObjects>%s</ProtectObjects>' + LF +
                       INDENT3 + '<ProtectScenarios>%s</ProtectScenarios>' + LF, [
    StrUtils.IfThen(AWorksheet.IsProtected and (spObjects in AWorksheet.Protection), 'True', 'False'),
    StrUtils.IfThen(AWorksheet.IsProtected {and [spScenarios in AWorksheet.Protection])}, 'True', 'False')
  ]);

  // Put it all together...
  AppendToStream(AStream, INDENT2 +
    '<WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">' + LF + INDENT3 +
      '<PageSetup>' + LF +
        layoutStr +
        headerStr +
        footerStr +
        marginStr + INDENT3 +
      '</PageSetup>' + LF +
      selectedStr +
      protectStr +
      frozenStr +
      hideGridStr +
      hideHeadersStr + INDENT2 +
    '</WorksheetOptions>' + LF
  );
end;

procedure TsSpreadExcelXMLWriter.WriteWorksheets(AStream: TStream);
var
  i: Integer;
  book: TsWorkbook;
begin
  book := FWorkbook as TsWorkbook;
  for i:=0 to book.GetWorksheetCount-1 do
    WriteWorksheet(AStream, book.GetWorksheetByIndex(i));
end;


initialization

  // Registers this reader / writer in fpSpreadsheet
  sfidExcelXML := RegisterSpreadFormat(sfExcelXML,
    TsSpreadExcelXMLReader, TsSpreadExcelXMLWriter,
    STR_FILEFORMAT_EXCEL_XML, 'ExcelXML', [STR_XML_EXCEL_EXTENSION]
  );

end.