<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2012 PHPExcel
 *
 * 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.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_Writer_Excel5
 * @copyright  Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version    ##VERSION##, ##DATE##
 */

// Original file header of PEAR::Spreadsheet_Excel_Writer_Workbook (used as the base for this class):
// -----------------------------------------------------------------------------------------
// /*
// *  Module written/ported by Xavier Noguer <xnoguer@rezebra.com>
// *
// *  The majority of this is _NOT_ my code.  I simply ported it from the
// *  PERL Spreadsheet::WriteExcel module.
// *
// *  The author of the Spreadsheet::WriteExcel module is John McNamara
// *  <jmcnamara@cpan.org>
// *
// *  I _DO_ maintain this code, and John McNamara has nothing to do with the
// *  porting of this code to PHP.  Any questions directly related to this
// *  class library should be directed to me.
// *
// *  License Information:
// *
// *    Spreadsheet_Excel_Writer:  A library for generating Excel Spreadsheets
// *    Copyright (c) 2002-2003 Xavier Noguer xnoguer@rezebra.com
// *
// *    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.
// *
// *    You should have received a copy of the GNU Lesser General Public
// *    License along with this library; if not, write to the Free Software
// *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
// */


/**
 * PHPExcel_Writer_Excel5_Workbook
 *
 * @category   PHPExcel
 * @package    PHPExcel_Writer_Excel5
 * @copyright  Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Writer_Excel5_Workbook extends PHPExcel_Writer_Excel5_BIFFwriter
{
	/**
	 * Formula parser
	 *
	 * @var PHPExcel_Writer_Excel5_Parser
	 */
	private $_parser;

	/**
	 * The BIFF file size for the workbook.
	 * @var integer
	 * @see _calcSheetOffsets()
	 */
	public $_biffsize;

	/**
	 * XF Writers
	 * @var PHPExcel_Writer_Excel5_Xf[]
	 */
	private $_xfWriters = array();

	/**
	 * Array containing the colour palette
	 * @var array
	 */
	public $_palette;

	/**
	 * The codepage indicates the text encoding used for strings
	 * @var integer
	 */
	public $_codepage;

	/**
	 * The country code used for localization
	 * @var integer
	 */
	public $_country_code;

	/**
	 * Workbook
	 * @var PHPExcel
	 */
	private $_phpExcel;

	/**
	 * Fonts writers
	 *
	 * @var PHPExcel_Writer_Excel5_Font[]
	 */
	private $_fontWriters = array();

	/**
	 * Added fonts. Maps from font's hash => index in workbook
	 *
	 * @var array
	 */
	private $_addedFonts = array();

	/**
	 * Shared number formats
	 *
	 * @var array
	 */
	private $_numberFormats = array();

	/**
	 * Added number formats. Maps from numberFormat's hash => index in workbook
	 *
	 * @var array
	 */
	private $_addedNumberFormats = array();

	/**
	 * Sizes of the binary worksheet streams
	 *
	 * @var array
	 */
	private $_worksheetSizes = array();

	/**
	 * Offsets of the binary worksheet streams relative to the start of the global workbook stream
	 *
	 * @var array
	 */
	private $_worksheetOffsets = array();

	/**
	 * Total number of shared strings in workbook
	 *
	 * @var int
	 */
	private $_str_total;

	/**
	 * Number of unique shared strings in workbook
	 *
	 * @var int
	 */
	private $_str_unique;

	/**
	 * Array of unique shared strings in workbook
	 *
	 * @var array
	 */
	private $_str_table;

	/**
	 * Color cache
	 */
	private $_colors;

	/**
	 * Escher object corresponding to MSODRAWINGGROUP
	 *
	 * @var PHPExcel_Shared_Escher
	 */
	private $_escher;


	/**
	 * Class constructor
	 *
	 * @param PHPExcel	$phpExcel		The Workbook
	 * @param int		&$str_total		Total number of strings
	 * @param int		&$str_unique	Total number of unique strings
	 * @param array		&$str_table		String Table
	 * @param array		&$colors		Colour Table
	 * @param mixed		$parser			The formula parser created for the Workbook
	 */
	public function __construct(PHPExcel $phpExcel = null,
								&$str_total, &$str_unique, &$str_table, &$colors,
								$parser )
	{
		// It needs to call its parent's constructor explicitly
		parent::__construct();

		$this->_parser           = $parser;
		$this->_biffsize         = 0;
		$this->_palette          = array();
		$this->_country_code     = -1;

		$this->_str_total       = &$str_total;
		$this->_str_unique      = &$str_unique;
		$this->_str_table       = &$str_table;
		$this->_colors          = &$colors;
		$this->_setPaletteXl97();

		$this->_phpExcel = $phpExcel;

		// set BIFFwriter limit for CONTINUE records
		//		$this->_limit = 8224;
		$this->_codepage = 0x04B0;

		// Add empty sheets and Build color cache
		$countSheets = $phpExcel->getSheetCount();
		for ($i = 0; $i < $countSheets; ++$i) {
			$phpSheet = $phpExcel->getSheet($i);

			$this->_parser->setExtSheet($phpSheet->getTitle(), $i);  // Register worksheet name with parser

			$supbook_index = 0x00;
			$ref = pack('vvv', $supbook_index, $i, $i);
			$this->_parser->_references[] = $ref;  // Register reference with parser

			// Sheet tab colors?
			if ($phpSheet->isTabColorSet()) {
				$this->_addColor($phpSheet->getTabColor()->getRGB());
			}
		}

	}

	/**
	 * Add a new XF writer
	 *
	 * @param PHPExcel_Style
	 * @param boolean Is it a style XF?
	 * @return int Index to XF record
	 */
	public function addXfWriter($style, $isStyleXf = false)
	{
		$xfWriter = new PHPExcel_Writer_Excel5_Xf($style);
		$xfWriter->setIsStyleXf($isStyleXf);

		// Add the font if not already added
		$fontIndex = $this->_addFont($style->getFont());

		// Assign the font index to the xf record
		$xfWriter->setFontIndex($fontIndex);

		// Background colors, best to treat these after the font so black will come after white in custom palette
		$xfWriter->setFgColor($this->_addColor($style->getFill()->getStartColor()->getRGB()));
		$xfWriter->setBgColor($this->_addColor($style->getFill()->getEndColor()->getRGB()));
		$xfWriter->setBottomColor($this->_addColor($style->getBorders()->getBottom()->getColor()->getRGB()));
		$xfWriter->setTopColor($this->_addColor($style->getBorders()->getTop()->getColor()->getRGB()));
		$xfWriter->setRightColor($this->_addColor($style->getBorders()->getRight()->getColor()->getRGB()));
		$xfWriter->setLeftColor($this->_addColor($style->getBorders()->getLeft()->getColor()->getRGB()));
		$xfWriter->setDiagColor($this->_addColor($style->getBorders()->getDiagonal()->getColor()->getRGB()));

		// Add the number format if it is not a built-in one and not already added
		if ($style->getNumberFormat()->getBuiltInFormatCode() === false) {
			$numberFormatHashCode = $style->getNumberFormat()->getHashCode();

			if (isset($this->_addedNumberFormats[$numberFormatHashCode])) {
				$numberFormatIndex = $this->_addedNumberFormats[$numberFormatHashCode];
			} else {
				$numberFormatIndex = 164 + count($this->_numberFormats);
				$this->_numberFormats[$numberFormatIndex] = $style->getNumberFormat();
				$this->_addedNumberFormats[$numberFormatHashCode] = $numberFormatIndex;
			}
		} else {
			$numberFormatIndex = (int) $style->getNumberFormat()->getBuiltInFormatCode();
		}

		// Assign the number format index to xf record
		$xfWriter->setNumberFormatIndex($numberFormatIndex);

		$this->_xfWriters[] = $xfWriter;

		$xfIndex = count($this->_xfWriters) - 1;
		return $xfIndex;
	}

	/**
	 * Add a font to added fonts
	 *
	 * @param PHPExcel_Style_Font $font
	 * @return int Index to FONT record
	 */
	public function _addFont(PHPExcel_Style_Font $font)
	{
		$fontHashCode = $font->getHashCode();
		if(isset($this->_addedFonts[$fontHashCode])){
			$fontIndex = $this->_addedFonts[$fontHashCode];
		} else {
			$countFonts = count($this->_fontWriters);
			$fontIndex = ($countFonts < 4) ? $countFonts : $countFonts + 1;

			$fontWriter = new PHPExcel_Writer_Excel5_Font($font);
			$fontWriter->setColorIndex($this->_addColor($font->getColor()->getRGB()));
			$this->_fontWriters[] = $fontWriter;

			$this->_addedFonts[$fontHashCode] = $fontIndex;
		}
		return $fontIndex;
	}

	/**
	 * Alter color palette adding a custom color
	 *
	 * @param string $rgb E.g. 'FF00AA'
	 * @return int Color index
	 */
	private function _addColor($rgb) {
		if (!isset($this->_colors[$rgb])) {
			if (count($this->_colors) < 57) {
				// then we add a custom color altering the palette
				$colorIndex = 8 + count($this->_colors);
				$this->_palette[$colorIndex] =
					array(
						hexdec(substr($rgb, 0, 2)),
						hexdec(substr($rgb, 2, 2)),
						hexdec(substr($rgb, 4)),
						0
					);
				$this->_colors[$rgb] = $colorIndex;
			} else {
				// no room for more custom colors, just map to black
				$colorIndex = 0;
			}
		} else {
			// fetch already added custom color
			$colorIndex = $this->_colors[$rgb];
		}

		return $colorIndex;
	}

	/**
	 * Sets the colour palette to the Excel 97+ default.
	 *
	 * @access private
	 */
	function _setPaletteXl97()
	{
		$this->_palette = array(
			0x08 => array(0x00, 0x00, 0x00, 0x00),
			0x09 => array(0xff, 0xff, 0xff, 0x00),
			0x0A => array(0xff, 0x00, 0x00, 0x00),
			0x0B => array(0x00, 0xff, 0x00, 0x00),
			0x0C => array(0x00, 0x00, 0xff, 0x00),
			0x0D => array(0xff, 0xff, 0x00, 0x00),
			0x0E => array(0xff, 0x00, 0xff, 0x00),
			0x0F => array(0x00, 0xff, 0xff, 0x00),
			0x10 => array(0x80, 0x00, 0x00, 0x00),
			0x11 => array(0x00, 0x80, 0x00, 0x00),
			0x12 => array(0x00, 0x00, 0x80, 0x00),
			0x13 => array(0x80, 0x80, 0x00, 0x00),
			0x14 => array(0x80, 0x00, 0x80, 0x00),
			0x15 => array(0x00, 0x80, 0x80, 0x00),
			0x16 => array(0xc0, 0xc0, 0xc0, 0x00),
			0x17 => array(0x80, 0x80, 0x80, 0x00),
			0x18 => array(0x99, 0x99, 0xff, 0x00),
			0x19 => array(0x99, 0x33, 0x66, 0x00),
			0x1A => array(0xff, 0xff, 0xcc, 0x00),
			0x1B => array(0xcc, 0xff, 0xff, 0x00),
			0x1C => array(0x66, 0x00, 0x66, 0x00),
			0x1D => array(0xff, 0x80, 0x80, 0x00),
			0x1E => array(0x00, 0x66, 0xcc, 0x00),
			0x1F => array(0xcc, 0xcc, 0xff, 0x00),
			0x20 => array(0x00, 0x00, 0x80, 0x00),
			0x21 => array(0xff, 0x00, 0xff, 0x00),
			0x22 => array(0xff, 0xff, 0x00, 0x00),
			0x23 => array(0x00, 0xff, 0xff, 0x00),
			0x24 => array(0x80, 0x00, 0x80, 0x00),
			0x25 => array(0x80, 0x00, 0x00, 0x00),
			0x26 => array(0x00, 0x80, 0x80, 0x00),
			0x27 => array(0x00, 0x00, 0xff, 0x00),
			0x28 => array(0x00, 0xcc, 0xff, 0x00),
			0x29 => array(0xcc, 0xff, 0xff, 0x00),
			0x2A => array(0xcc, 0xff, 0xcc, 0x00),
			0x2B => array(0xff, 0xff, 0x99, 0x00),
			0x2C => array(0x99, 0xcc, 0xff, 0x00),
			0x2D => array(0xff, 0x99, 0xcc, 0x00),
			0x2E => array(0xcc, 0x99, 0xff, 0x00),
			0x2F => array(0xff, 0xcc, 0x99, 0x00),
			0x30 => array(0x33, 0x66, 0xff, 0x00),
			0x31 => array(0x33, 0xcc, 0xcc, 0x00),
			0x32 => array(0x99, 0xcc, 0x00, 0x00),
			0x33 => array(0xff, 0xcc, 0x00, 0x00),
			0x34 => array(0xff, 0x99, 0x00, 0x00),
			0x35 => array(0xff, 0x66, 0x00, 0x00),
			0x36 => array(0x66, 0x66, 0x99, 0x00),
			0x37 => array(0x96, 0x96, 0x96, 0x00),
			0x38 => array(0x00, 0x33, 0x66, 0x00),
			0x39 => array(0x33, 0x99, 0x66, 0x00),
			0x3A => array(0x00, 0x33, 0x00, 0x00),
			0x3B => array(0x33, 0x33, 0x00, 0x00),
			0x3C => array(0x99, 0x33, 0x00, 0x00),
			0x3D => array(0x99, 0x33, 0x66, 0x00),
			0x3E => array(0x33, 0x33, 0x99, 0x00),
			0x3F => array(0x33, 0x33, 0x33, 0x00),
		);
	}

	/**
	 * Assemble worksheets into a workbook and send the BIFF data to an OLE
	 * storage.
	 *
	 * @param	array	$pWorksheetSizes	The sizes in bytes of the binary worksheet streams
	 * @return	string	Binary data for workbook stream
	 */
	public function writeWorkbook($pWorksheetSizes = null)
	{
		$this->_worksheetSizes = $pWorksheetSizes;

		// Calculate the number of selected worksheet tabs and call the finalization
		// methods for each worksheet
		$total_worksheets = $this->_phpExcel->getSheetCount();

		// Add part 1 of the Workbook globals, what goes before the SHEET records
		$this->_storeBof(0x0005);
		$this->_writeCodepage();
		$this->_writeWindow1();

		$this->_writeDatemode();
		$this->_writeAllFonts();
		$this->_writeAllNumFormats();
		$this->_writeAllXfs();
		$this->_writeAllStyles();
		$this->_writePalette();

		// Prepare part 3 of the workbook global stream, what goes after the SHEET records
		$part3 = '';
		if ($this->_country_code != -1) {
			$part3 .= $this->_writeCountry();
		}
		$part3 .= $this->_writeRecalcId();

		$part3 .= $this->_writeSupbookInternal();
		/* TODO: store external SUPBOOK records and XCT and CRN records
		in case of external references for BIFF8 */
		$part3 .= $this->_writeExternsheetBiff8();
		$part3 .= $this->_writeAllDefinedNamesBiff8();
		$part3 .= $this->_writeMsoDrawingGroup();
		$part3 .= $this->_writeSharedStringsTable();

		$part3 .= $this->writeEof();

		// Add part 2 of the Workbook globals, the SHEET records
		$this->_calcSheetOffsets();
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$this->_writeBoundsheet($this->_phpExcel->getSheet($i), $this->_worksheetOffsets[$i]);
		}

		// Add part 3 of the Workbook globals
		$this->_data .= $part3;

		return $this->_data;
	}

	/**
	 * Calculate offsets for Worksheet BOF records.
	 *
	 * @access private
	 */
	function _calcSheetOffsets()
	{
		$boundsheet_length = 10;  // fixed length for a BOUNDSHEET record

		// size of Workbook globals part 1 + 3
		$offset            = $this->_datasize;

		// add size of Workbook globals part 2, the length of the SHEET records
		$total_worksheets = count($this->_phpExcel->getAllSheets());
		foreach ($this->_phpExcel->getWorksheetIterator() as $sheet) {
			$offset += $boundsheet_length + strlen(PHPExcel_Shared_String::UTF8toBIFF8UnicodeShort($sheet->getTitle()));
		}

		// add the sizes of each of the Sheet substreams, respectively
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$this->_worksheetOffsets[$i] = $offset;
			$offset += $this->_worksheetSizes[$i];
		}
		$this->_biffsize = $offset;
	}

	/**
	 * Store the Excel FONT records.
	 */
	private function _writeAllFonts()
	{
		foreach ($this->_fontWriters as $fontWriter) {
			$this->_append($fontWriter->writeFont());
		}
	}

	/**
	 * Store user defined numerical formats i.e. FORMAT records
	 */
	private function _writeAllNumFormats()
	{
		foreach ($this->_numberFormats as $numberFormatIndex => $numberFormat) {
			$this->_writeNumFormat($numberFormat->getFormatCode(), $numberFormatIndex);
		}
	}

	/**
	 * Write all XF records.
	 */
	private function _writeAllXfs()
	{
		foreach ($this->_xfWriters as $xfWriter) {
			$this->_append($xfWriter->writeXf());
		}
	}

	/**
	 * Write all STYLE records.
	 */
	private function _writeAllStyles()
	{
		$this->_writeStyle();
	}

	/**
	 * Write the EXTERNCOUNT and EXTERNSHEET records. These are used as indexes for
	 * the NAME records.
	 */
	private function _writeExterns()
	{
		$countSheets = $this->_phpExcel->getSheetCount();
		// Create EXTERNCOUNT with number of worksheets
		$this->_writeExterncount($countSheets);

		// Create EXTERNSHEET for each worksheet
		for ($i = 0; $i < $countSheets; ++$i) {
			$this->_writeExternsheet($this->_phpExcel->getSheet($i)->getTitle());
		}
	}

	/**
	 * Write the NAME record to define the print area and the repeat rows and cols.
	 */
	private function _writeNames()
	{
		// total number of sheets
		$total_worksheets = $this->_phpExcel->getSheetCount();

		// Create the print area NAME records
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$sheetSetup = $this->_phpExcel->getSheet($i)->getPageSetup();
			// Write a Name record if the print area has been defined
			if ($sheetSetup->isPrintAreaSet()) {
				// Print area
				$printArea = PHPExcel_Cell::splitRange($sheetSetup->getPrintArea());
				$printArea = $printArea[0];
				$printArea[0] = PHPExcel_Cell::coordinateFromString($printArea[0]);
				$printArea[1] = PHPExcel_Cell::coordinateFromString($printArea[1]);

				$print_rowmin = $printArea[0][1] - 1;
				$print_rowmax = $printArea[1][1] - 1;
				$print_colmin = PHPExcel_Cell::columnIndexFromString($printArea[0][0]) - 1;
				$print_colmax = PHPExcel_Cell::columnIndexFromString($printArea[1][0]) - 1;

				$this->_writeNameShort(
					$i, // sheet index
					0x06, // NAME type
					$print_rowmin,
					$print_rowmax,
					$print_colmin,
					$print_colmax
					);
			}
		}

		// Create the print title NAME records
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$sheetSetup = $this->_phpExcel->getSheet($i)->getPageSetup();

			// simultaneous repeatColumns repeatRows
			if ($sheetSetup->isColumnsToRepeatAtLeftSet() && $sheetSetup->isRowsToRepeatAtTopSet()) {
				$repeat = $sheetSetup->getColumnsToRepeatAtLeft();
				$colmin = PHPExcel_Cell::columnIndexFromString($repeat[0]) - 1;
				$colmax = PHPExcel_Cell::columnIndexFromString($repeat[1]) - 1;

				$repeat = $sheetSetup->getRowsToRepeatAtTop();
				$rowmin = $repeat[0] - 1;
				$rowmax = $repeat[1] - 1;

				$this->_writeNameLong(
					$i, // sheet index
					0x07, // NAME type
					$rowmin,
					$rowmax,
					$colmin,
					$colmax
					);

			// (exclusive) either repeatColumns or repeatRows
			} else if ($sheetSetup->isColumnsToRepeatAtLeftSet() || $sheetSetup->isRowsToRepeatAtTopSet()) {

				// Columns to repeat
				if ($sheetSetup->isColumnsToRepeatAtLeftSet()) {
					$repeat = $sheetSetup->getColumnsToRepeatAtLeft();
					$colmin = PHPExcel_Cell::columnIndexFromString($repeat[0]) - 1;
					$colmax = PHPExcel_Cell::columnIndexFromString($repeat[1]) - 1;
				} else {
					$colmin = 0;
					$colmax = 255;
				}

				// Rows to repeat
				if ($sheetSetup->isRowsToRepeatAtTopSet()) {
					$repeat = $sheetSetup->getRowsToRepeatAtTop();
					$rowmin = $repeat[0] - 1;
					$rowmax = $repeat[1] - 1;
				} else {
					$rowmin = 0;
					$rowmax = 65535;
				}

				$this->_writeNameShort(
					$i, // sheet index
					0x07, // NAME type
					$rowmin,
					$rowmax,
					$colmin,
					$colmax
					);
			}
		}
	}

	/**
	 * Writes all the DEFINEDNAME records (BIFF8).
	 * So far this is only used for repeating rows/columns (print titles) and print areas
	 */
	private function _writeAllDefinedNamesBiff8()
	{
		$chunk = '';

		// Named ranges
		if (count($this->_phpExcel->getNamedRanges()) > 0) {
			// Loop named ranges
			$namedRanges = $this->_phpExcel->getNamedRanges();
			foreach ($namedRanges as $namedRange) {

				// Create absolute coordinate
				$range = PHPExcel_Cell::splitRange($namedRange->getRange());
				for ($i = 0; $i < count($range); $i++) {
					$range[$i][0] = '\'' . str_replace("'", "''", $namedRange->getWorksheet()->getTitle()) . '\'!' . PHPExcel_Cell::absoluteCoordinate($range[$i][0]);
					if (isset($range[$i][1])) {
						$range[$i][1] = PHPExcel_Cell::absoluteCoordinate($range[$i][1]);
					}
				}
				$range = PHPExcel_Cell::buildRange($range); // e.g. Sheet1!$A$1:$B$2

				// parse formula
				try {
					$error = $this->_parser->parse($range);
					$formulaData = $this->_parser->toReversePolish();

					// make sure tRef3d is of type tRef3dR (0x3A)
					if (isset($formulaData{0}) and ($formulaData{0} == "\x7A" or $formulaData{0} == "\x5A")) {
						$formulaData = "\x3A" . substr($formulaData, 1);
					}

					if ($namedRange->getLocalOnly()) {
						// local scope
						$scope = $this->_phpExcel->getIndex($namedRange->getScope()) + 1;
					} else {
						// global scope
						$scope = 0;
					}
					$chunk .= $this->writeData($this->_writeDefinedNameBiff8($namedRange->getName(), $formulaData, $scope, false));

				} catch(PHPExcel_Exception $e) {
					// do nothing
				}
			}
		}

		// total number of sheets
		$total_worksheets = $this->_phpExcel->getSheetCount();

		// write the print titles (repeating rows, columns), if any
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$sheetSetup = $this->_phpExcel->getSheet($i)->getPageSetup();
			// simultaneous repeatColumns repeatRows
			if ($sheetSetup->isColumnsToRepeatAtLeftSet() && $sheetSetup->isRowsToRepeatAtTopSet()) {
				$repeat = $sheetSetup->getColumnsToRepeatAtLeft();
				$colmin = PHPExcel_Cell::columnIndexFromString($repeat[0]) - 1;
				$colmax = PHPExcel_Cell::columnIndexFromString($repeat[1]) - 1;

				$repeat = $sheetSetup->getRowsToRepeatAtTop();
				$rowmin = $repeat[0] - 1;
				$rowmax = $repeat[1] - 1;

				// construct formula data manually
				$formulaData = pack('Cv', 0x29, 0x17); // tMemFunc
				$formulaData .= pack('Cvvvvv', 0x3B, $i, 0, 65535, $colmin, $colmax); // tArea3d
				$formulaData .= pack('Cvvvvv', 0x3B, $i, $rowmin, $rowmax, 0, 255); // tArea3d
				$formulaData .= pack('C', 0x10); // tList

				// store the DEFINEDNAME record
				$chunk .= $this->writeData($this->_writeDefinedNameBiff8(pack('C', 0x07), $formulaData, $i + 1, true));

			// (exclusive) either repeatColumns or repeatRows
			} else if ($sheetSetup->isColumnsToRepeatAtLeftSet() || $sheetSetup->isRowsToRepeatAtTopSet()) {

				// Columns to repeat
				if ($sheetSetup->isColumnsToRepeatAtLeftSet()) {
					$repeat = $sheetSetup->getColumnsToRepeatAtLeft();
					$colmin = PHPExcel_Cell::columnIndexFromString($repeat[0]) - 1;
					$colmax = PHPExcel_Cell::columnIndexFromString($repeat[1]) - 1;
				} else {
					$colmin = 0;
					$colmax = 255;
				}
				// Rows to repeat
				if ($sheetSetup->isRowsToRepeatAtTopSet()) {
					$repeat = $sheetSetup->getRowsToRepeatAtTop();
					$rowmin = $repeat[0] - 1;
					$rowmax = $repeat[1] - 1;
				} else {
					$rowmin = 0;
					$rowmax = 65535;
				}

				// construct formula data manually because parser does not recognize absolute 3d cell references
				$formulaData = pack('Cvvvvv', 0x3B, $i, $rowmin, $rowmax, $colmin, $colmax);

				// store the DEFINEDNAME record
				$chunk .= $this->writeData($this->_writeDefinedNameBiff8(pack('C', 0x07), $formulaData, $i + 1, true));
			}
		}

		// write the print areas, if any
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$sheetSetup = $this->_phpExcel->getSheet($i)->getPageSetup();
			if ($sheetSetup->isPrintAreaSet()) {
				// Print area, e.g. A3:J6,H1:X20
				$printArea = PHPExcel_Cell::splitRange($sheetSetup->getPrintArea());
				$countPrintArea = count($printArea);

				$formulaData = '';
				for ($j = 0; $j < $countPrintArea; ++$j) {
					$printAreaRect = $printArea[$j]; // e.g. A3:J6
					$printAreaRect[0] = PHPExcel_Cell::coordinateFromString($printAreaRect[0]);
					$printAreaRect[1] = PHPExcel_Cell::coordinateFromString($printAreaRect[1]);

					$print_rowmin = $printAreaRect[0][1] - 1;
					$print_rowmax = $printAreaRect[1][1] - 1;
					$print_colmin = PHPExcel_Cell::columnIndexFromString($printAreaRect[0][0]) - 1;
					$print_colmax = PHPExcel_Cell::columnIndexFromString($printAreaRect[1][0]) - 1;

					// construct formula data manually because parser does not recognize absolute 3d cell references
					$formulaData .= pack('Cvvvvv', 0x3B, $i, $print_rowmin, $print_rowmax, $print_colmin, $print_colmax);

					if ($j > 0) {
						$formulaData .= pack('C', 0x10); // list operator token ','
					}
				}

				// store the DEFINEDNAME record
				$chunk .= $this->writeData($this->_writeDefinedNameBiff8(pack('C', 0x06), $formulaData, $i + 1, true));
			}
		}

		// write autofilters, if any
		for ($i = 0; $i < $total_worksheets; ++$i) {
			$sheetAutoFilter = $this->_phpExcel->getSheet($i)->getAutoFilter();
			$autoFilterRange = $sheetAutoFilter->getRange();
			if(!empty($autoFilterRange)) {
				$rangeBounds = PHPExcel_Cell::rangeBoundaries($autoFilterRange);

				//Autofilter built in name
				$name = pack('C', 0x0D);

				$chunk .= $this->writeData($this->_writeShortNameBiff8($name, $i + 1, $rangeBounds, true));
			}
		}

		return $chunk;
	}

	/**
	 * Write a DEFINEDNAME record for BIFF8 using explicit binary formula data
	 *
	 * @param	string		$name			The name in UTF-8
	 * @param	string		$formulaData	The binary formula data
	 * @param	string		$sheetIndex		1-based sheet index the defined name applies to. 0 = global
	 * @param	boolean		$isBuiltIn		Built-in name?
	 * @return	string	Complete binary record data
	 */
	private function _writeDefinedNameBiff8($name, $formulaData, $sheetIndex = 0, $isBuiltIn = false)
	{
		$record = 0x0018;

		// option flags
		$options = $isBuiltIn ? 0x20 : 0x00;

		// length of the name, character count
		$nlen = PHPExcel_Shared_String::CountCharacters($name);

		// name with stripped length field
		$name = substr(PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($name), 2);

		// size of the formula (in bytes)
		$sz = strlen($formulaData);

		// combine the parts
		$data = pack('vCCvvvCCCC', $options, 0, $nlen, $sz, 0, $sheetIndex, 0, 0, 0, 0)
			. $name . $formulaData;
		$length = strlen($data);

		$header = pack('vv', $record, $length);

		return $header . $data;
	}

	/**
	 * Write a short NAME record
	 *
	 * @param	string		 $name
	 * @param	string		 $sheetIndex		1-based sheet index the defined name applies to. 0 = global
	 * @param	integer[][]  $rangeBounds    range boundaries
	 * @param	boolean      $isHidden
	 * @return	string	Complete binary record data
	 * */
	private function _writeShortNameBiff8($name, $sheetIndex = 0, $rangeBounds, $isHidden = false){
		$record = 0x0018;

		// option flags
		$options = ($isHidden  ? 0x21 : 0x00);

		$extra  = pack('Cvvvvv',
				0x3B,
				$sheetIndex - 1,
				$rangeBounds[0][1] - 1,
				$rangeBounds[1][1] - 1,
				$rangeBounds[0][0] - 1,
				$rangeBounds[1][0] - 1);

		// size of the formula (in bytes)
		$sz = strlen($extra);

		// combine the parts
		$data = pack('vCCvvvCCCCC', $options, 0, 1, $sz, 0, $sheetIndex, 0, 0, 0, 0, 0)
			. $name . $extra;
		$length = strlen($data);

		$header = pack('vv', $record, $length);

		return $header . $data;
	}

	/**
	 * Stores the CODEPAGE biff record.
	 */
	private function _writeCodepage()
	{
		$record          = 0x0042;             // Record identifier
		$length          = 0x0002;             // Number of bytes to follow
		$cv              = $this->_codepage;   // The code page

		$header          = pack('vv', $record, $length);
		$data            = pack('v',  $cv);

		$this->_append($header . $data);
	}

	/**
	 * Write Excel BIFF WINDOW1 record.
	 */
	private function _writeWindow1()
	{
		$record    = 0x003D;                 // Record identifier
		$length    = 0x0012;                 // Number of bytes to follow

		$xWn       = 0x0000;                 // Horizontal position of window
		$yWn       = 0x0000;                 // Vertical position of window
		$dxWn      = 0x25BC;                 // Width of window
		$dyWn      = 0x1572;                 // Height of window

		$grbit     = 0x0038;                 // Option flags

		// not supported by PHPExcel, so there is only one selected sheet, the active
		$ctabsel   = 1;       // Number of workbook tabs selected

		$wTabRatio = 0x0258;                 // Tab to scrollbar ratio

		// not supported by PHPExcel, set to 0
		$itabFirst = 0;     // 1st displayed worksheet
		$itabCur   = $this->_phpExcel->getActiveSheetIndex();    // Active worksheet

		$header    = pack("vv",        $record, $length);
		$data      = pack("vvvvvvvvv", $xWn, $yWn, $dxWn, $dyWn,
									   $grbit,
									   $itabCur, $itabFirst,
									   $ctabsel, $wTabRatio);
		$this->_append($header . $data);
	}

	/**
	 * Writes Excel BIFF BOUNDSHEET record.
	 *
	 * @param PHPExcel_Worksheet  $sheet Worksheet name
	 * @param integer $offset    Location of worksheet BOF
	 */
	private function _writeBoundsheet($sheet, $offset)
	{
		$sheetname = $sheet->getTitle();
		$record    = 0x0085;                    // Record identifier

		// sheet state
		switch ($sheet->getSheetState()) {
			case PHPExcel_Worksheet::SHEETSTATE_VISIBLE:	$ss = 0x00; break;
			case PHPExcel_Worksheet::SHEETSTATE_HIDDEN:		$ss = 0x01; break;
			case PHPExcel_Worksheet::SHEETSTATE_VERYHIDDEN:	$ss = 0x02; break;
			default: $ss = 0x00; break;
		}

		// sheet type
		$st = 0x00;

		$grbit     = 0x0000;                    // Visibility and sheet type

		$data      = pack("VCC", $offset, $ss, $st);
		$data .= PHPExcel_Shared_String::UTF8toBIFF8UnicodeShort($sheetname);

		$length = strlen($data);
		$header = pack("vv",  $record, $length);
		$this->_append($header . $data);
	}

	/**
	 * Write Internal SUPBOOK record
	 */
	private function _writeSupbookInternal()
	{
		$record    = 0x01AE;   // Record identifier
		$length    = 0x0004;   // Bytes to follow

		$header    = pack("vv", $record, $length);
		$data      = pack("vv", $this->_phpExcel->getSheetCount(), 0x0401);
		return $this->writeData($header . $data);
	}

	/**
	 * Writes the Excel BIFF EXTERNSHEET record. These references are used by
	 * formulas.
	 *
	 */
	private function _writeExternsheetBiff8()
	{
		$total_references = count($this->_parser->_references);
		$record   = 0x0017;                     // Record identifier
		$length   = 2 + 6 * $total_references;  // Number of bytes to follow

		$supbook_index = 0;           // FIXME: only using internal SUPBOOK record
		$header           = pack("vv",  $record, $length);
		$data             = pack('v', $total_references);
		for ($i = 0; $i < $total_references; ++$i) {
			$data .= $this->_parser->_references[$i];
		}
		return $this->writeData($header . $data);
	}

	/**
	 * Write Excel BIFF STYLE records.
	 */
	private function _writeStyle()
	{
		$record    = 0x0293;   // Record identifier
		$length    = 0x0004;   // Bytes to follow

		$ixfe      = 0x8000;  // Index to cell style XF
		$BuiltIn   = 0x00;     // Built-in style
		$iLevel    = 0xff;     // Outline style level

		$header    = pack("vv",  $record, $length);
		$data      = pack("vCC", $ixfe, $BuiltIn, $iLevel);
		$this->_append($header . $data);
	}

	/**
	 * Writes Excel FORMAT record for non "built-in" numerical formats.
	 *
	 * @param string  $format Custom format string
	 * @param integer $ifmt   Format index code
	 */
	private function _writeNumFormat($format, $ifmt)
	{
		$record    = 0x041E;                      // Record identifier

		$numberFormatString = PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($format);
		$length    = 2 + strlen($numberFormatString);      // Number of bytes to follow


		$header    = pack("vv", $record, $length);
		$data      = pack("v", $ifmt) .  $numberFormatString;
		$this->_append($header . $data);
	}

	/**
	 * Write DATEMODE record to indicate the date system in use (1904 or 1900).
	 */
	private function _writeDatemode()
	{
		$record    = 0x0022;         // Record identifier
		$length    = 0x0002;         // Bytes to follow

		$f1904     = (PHPExcel_Shared_Date::getExcelCalendar() == PHPExcel_Shared_Date::CALENDAR_MAC_1904) ?
			1 : 0;   // Flag for 1904 date system

		$header    = pack("vv", $record, $length);
		$data      = pack("v", $f1904);
		$this->_append($header . $data);
	}

	/**
	 * Write BIFF record EXTERNCOUNT to indicate the number of external sheet
	 * references in the workbook.
	 *
	 * Excel only stores references to external sheets that are used in NAME.
	 * The workbook NAME record is required to define the print area and the repeat
	 * rows and columns.
	 *
	 * A similar method is used in Worksheet.php for a slightly different purpose.
	 *
	 * @param integer $cxals Number of external references
	 */
	private function _writeExterncount($cxals)
	{
		$record   = 0x0016;          // Record identifier
		$length   = 0x0002;          // Number of bytes to follow

		$header   = pack("vv", $record, $length);
		$data     = pack("v",  $cxals);
		$this->_append($header . $data);
	}

	/**
	 * Writes the Excel BIFF EXTERNSHEET record. These references are used by
	 * formulas. NAME record is required to define the print area and the repeat
	 * rows and columns.
	 *
	 * A similar method is used in Worksheet.php for a slightly different purpose.
	 *
	 * @param string $sheetname Worksheet name
	 */
	private function _writeExternsheet($sheetname)
	{
		$record      = 0x0017;                     // Record identifier
		$length      = 0x02 + strlen($sheetname);  // Number of bytes to follow

		$cch         = strlen($sheetname);         // Length of sheet name
		$rgch        = 0x03;                       // Filename encoding

		$header      = pack("vv",  $record, $length);
		$data        = pack("CC", $cch, $rgch);
		$this->_append($header . $data . $sheetname);
	}

	/**
	 * Store the NAME record in the short format that is used for storing the print
	 * area, repeat rows only and repeat columns only.
	 *
	 * @param integer $index  Sheet index
	 * @param integer $type   Built-in name type
	 * @param integer $rowmin Start row
	 * @param integer $rowmax End row
	 * @param integer $colmin Start colum
	 * @param integer $colmax End column
	 */
	private function _writeNameShort($index, $type, $rowmin, $rowmax, $colmin, $colmax)
	{
		$record          = 0x0018;       // Record identifier
		$length          = 0x0024;       // Number of bytes to follow

		$grbit           = 0x0020;       // Option flags
		$chKey           = 0x00;         // Keyboard shortcut
		$cch             = 0x01;         // Length of text name
		$cce             = 0x0015;       // Length of text definition
		$ixals           = $index + 1;   // Sheet index
		$itab            = $ixals;       // Equal to ixals
		$cchCustMenu     = 0x00;         // Length of cust menu text
		$cchDescription  = 0x00;         // Length of description text
		$cchHelptopic    = 0x00;         // Length of help topic text
		$cchStatustext   = 0x00;         // Length of status bar text
		$rgch            = $type;        // Built-in name type

		$unknown03       = 0x3b;
		$unknown04       = 0xffff-$index;
		$unknown05       = 0x0000;
		$unknown06       = 0x0000;
		$unknown07       = 0x1087;
		$unknown08       = 0x8005;

		$header             = pack("vv", $record, $length);
		$data               = pack("v", $grbit);
		$data              .= pack("C", $chKey);
		$data              .= pack("C", $cch);
		$data              .= pack("v", $cce);
		$data              .= pack("v", $ixals);
		$data              .= pack("v", $itab);
		$data              .= pack("C", $cchCustMenu);
		$data              .= pack("C", $cchDescription);
		$data              .= pack("C", $cchHelptopic);
		$data              .= pack("C", $cchStatustext);
		$data              .= pack("C", $rgch);
		$data              .= pack("C", $unknown03);
		$data              .= pack("v", $unknown04);
		$data              .= pack("v", $unknown05);
		$data              .= pack("v", $unknown06);
		$data              .= pack("v", $unknown07);
		$data              .= pack("v", $unknown08);
		$data              .= pack("v", $index);
		$data              .= pack("v", $index);
		$data              .= pack("v", $rowmin);
		$data              .= pack("v", $rowmax);
		$data              .= pack("C", $colmin);
		$data              .= pack("C", $colmax);
		$this->_append($header . $data);
	}

	/**
	 * Store the NAME record in the long format that is used for storing the repeat
	 * rows and columns when both are specified. This shares a lot of code with
	 * _writeNameShort() but we use a separate method to keep the code clean.
	 * Code abstraction for reuse can be carried too far, and I should know. ;-)
	 *
	 * @param integer $index Sheet index
	 * @param integer $type  Built-in name type
	 * @param integer $rowmin Start row
	 * @param integer $rowmax End row
	 * @param integer $colmin Start colum
	 * @param integer $colmax End column
	 */
	private function _writeNameLong($index, $type, $rowmin, $rowmax, $colmin, $colmax)
	{
		$record          = 0x0018;       // Record identifier
		$length          = 0x003d;       // Number of bytes to follow
		$grbit           = 0x0020;       // Option flags
		$chKey           = 0x00;         // Keyboard shortcut
		$cch             = 0x01;         // Length of text name
		$cce             = 0x002e;       // Length of text definition
		$ixals           = $index + 1;   // Sheet index
		$itab            = $ixals;       // Equal to ixals
		$cchCustMenu     = 0x00;         // Length of cust menu text
		$cchDescription  = 0x00;         // Length of description text
		$cchHelptopic    = 0x00;         // Length of help topic text
		$cchStatustext   = 0x00;         // Length of status bar text
		$rgch            = $type;        // Built-in name type

		$unknown01       = 0x29;
		$unknown02       = 0x002b;
		$unknown03       = 0x3b;
		$unknown04       = 0xffff-$index;
		$unknown05       = 0x0000;
		$unknown06       = 0x0000;
		$unknown07       = 0x1087;
		$unknown08       = 0x8008;

		$header             = pack("vv",  $record, $length);
		$data               = pack("v", $grbit);
		$data              .= pack("C", $chKey);
		$data              .= pack("C", $cch);
		$data              .= pack("v", $cce);
		$data              .= pack("v", $ixals);
		$data              .= pack("v", $itab);
		$data              .= pack("C", $cchCustMenu);
		$data              .= pack("C", $cchDescription);
		$data              .= pack("C", $cchHelptopic);
		$data              .= pack("C", $cchStatustext);
		$data              .= pack("C", $rgch);
		$data              .= pack("C", $unknown01);
		$data              .= pack("v", $unknown02);
		// Column definition
		$data              .= pack("C", $unknown03);
		$data              .= pack("v", $unknown04);
		$data              .= pack("v", $unknown05);
		$data              .= pack("v", $unknown06);
		$data              .= pack("v", $unknown07);
		$data              .= pack("v", $unknown08);
		$data              .= pack("v", $index);
		$data              .= pack("v", $index);
		$data              .= pack("v", 0x0000);
		$data              .= pack("v", 0x3fff);
		$data              .= pack("C", $colmin);
		$data              .= pack("C", $colmax);
		// Row definition
		$data              .= pack("C", $unknown03);
		$data              .= pack("v", $unknown04);
		$data              .= pack("v", $unknown05);
		$data              .= pack("v", $unknown06);
		$data              .= pack("v", $unknown07);
		$data              .= pack("v", $unknown08);
		$data              .= pack("v", $index);
		$data              .= pack("v", $index);
		$data              .= pack("v", $rowmin);
		$data              .= pack("v", $rowmax);
		$data              .= pack("C", 0x00);
		$data              .= pack("C", 0xff);
		// End of data
		$data              .= pack("C", 0x10);
		$this->_append($header . $data);
	}

	/**
	 * Stores the COUNTRY record for localization
	 *
	 * @return string
	 */
	private function _writeCountry()
	{
		$record          = 0x008C;    // Record identifier
		$length          = 4;         // Number of bytes to follow

		$header = pack('vv',  $record, $length);
		/* using the same country code always for simplicity */
		$data = pack('vv', $this->_country_code, $this->_country_code);
		//$this->_append($header . $data);
		return $this->writeData($header . $data);
	}

	/**
	 * Write the RECALCID record
	 *
	 * @return string
	 */
	private function _writeRecalcId()
	{
		$record = 0x01C1;    // Record identifier
		$length = 8;         // Number of bytes to follow

		$header = pack('vv',  $record, $length);

		// by inspection of real Excel files, MS Office Excel 2007 writes this
		$data = pack('VV', 0x000001C1, 0x00001E667);

		return $this->writeData($header . $data);
	}

	/**
	 * Stores the PALETTE biff record.
	 */
	private function _writePalette()
	{
		$aref            = $this->_palette;

		$record          = 0x0092;                 // Record identifier
		$length          = 2 + 4 * count($aref);   // Number of bytes to follow
		$ccv             =         count($aref);   // Number of RGB values to follow
		$data = '';                                // The RGB data

		// Pack the RGB data
		foreach ($aref as $color) {
			foreach ($color as $byte) {
				$data .= pack("C",$byte);
			}
		}

		$header = pack("vvv",  $record, $length, $ccv);
		$this->_append($header . $data);
	}

	/**
	 * Handling of the SST continue blocks is complicated by the need to include an
	 * additional continuation byte depending on whether the string is split between
	 * blocks or whether it starts at the beginning of the block. (There are also
	 * additional complications that will arise later when/if Rich Strings are
	 * supported).
	 *
	 * The Excel documentation says that the SST record should be followed by an
	 * EXTSST record. The EXTSST record is a hash table that is used to optimise
	 * access to SST. However, despite the documentation it doesn't seem to be
	 * required so we will ignore it.
	 *
	 * @return string Binary data
	 */
	private function _writeSharedStringsTable()
	{
		// maximum size of record data (excluding record header)
		$continue_limit = 8224;

		// initialize array of record data blocks
		$recordDatas = array();

		// start SST record data block with total number of strings, total number of unique strings
		$recordData = pack("VV", $this->_str_total, $this->_str_unique);

		// loop through all (unique) strings in shared strings table
		foreach (array_keys($this->_str_table) as $string) {

			// here $string is a BIFF8 encoded string

			// length = character count
			$headerinfo = unpack("vlength/Cencoding", $string);

			// currently, this is always 1 = uncompressed
			$encoding = $headerinfo["encoding"];

			// initialize finished writing current $string
			$finished = false;

			while ($finished === false) {

				// normally, there will be only one cycle, but if string cannot immediately be written as is
				// there will be need for more than one cylcle, if string longer than one record data block, there
				// may be need for even more cycles

				if (strlen($recordData) + strlen($string) <= $continue_limit) {
					// then we can write the string (or remainder of string) without any problems
					$recordData .= $string;

					if (strlen($recordData) + strlen($string) == $continue_limit) {
						// we close the record data block, and initialize a new one
						$recordDatas[] = $recordData;
						$recordData = '';
					}

					// we are finished writing this string
					$finished = true;
				} else {
					// special treatment writing the string (or remainder of the string)
					// If the string is very long it may need to be written in more than one CONTINUE record.

					// check how many bytes more there is room for in the current record
					$space_remaining = $continue_limit - strlen($recordData);

					// minimum space needed
					// uncompressed: 2 byte string length length field + 1 byte option flags + 2 byte character
					// compressed:   2 byte string length length field + 1 byte option flags + 1 byte character
					$min_space_needed = ($encoding == 1) ? 5 : 4;

					// We have two cases
					// 1. space remaining is less than minimum space needed
					//		here we must waste the space remaining and move to next record data block
					// 2. space remaining is greater than or equal to minimum space needed
					//		here we write as much as we can in the current block, then move to next record data block

					// 1. space remaining is less than minimum space needed
					if ($space_remaining < $min_space_needed) {
						// we close the block, store the block data
						$recordDatas[] = $recordData;

						// and start new record data block where we start writing the string
						$recordData = '';

					// 2. space remaining is greater than or equal to minimum space needed
					} else {
						// initialize effective remaining space, for Unicode strings this may need to be reduced by 1, see below
						$effective_space_remaining = $space_remaining;

						// for uncompressed strings, sometimes effective space remaining is reduced by 1
						if ( $encoding == 1 && (strlen($string) - $space_remaining) % 2 == 1 ) {
							--$effective_space_remaining;
						}

						// one block fininshed, store the block data
						$recordData .= substr($string, 0, $effective_space_remaining);

						$string = substr($string, $effective_space_remaining); // for next cycle in while loop
						$recordDatas[] = $recordData;

						// start new record data block with the repeated option flags
						$recordData = pack('C', $encoding);
					}
				}
			}
		}

		// Store the last record data block unless it is empty
		// if there was no need for any continue records, this will be the for SST record data block itself
		if (strlen($recordData) > 0) {
			$recordDatas[] = $recordData;
		}

		// combine into one chunk with all the blocks SST, CONTINUE,...
		$chunk = '';
		foreach ($recordDatas as $i => $recordData) {
			// first block should have the SST record header, remaing should have CONTINUE header
			$record = ($i == 0) ? 0x00FC : 0x003C;

			$header = pack("vv", $record, strlen($recordData));
			$data = $header . $recordData;

			$chunk .= $this->writeData($data);
		}

		return $chunk;
	}

	/**
	 * Writes the MSODRAWINGGROUP record if needed. Possibly split using CONTINUE records.
	 */
	private function _writeMsoDrawingGroup()
	{
		// write the Escher stream if necessary
		if (isset($this->_escher)) {
			$writer = new PHPExcel_Writer_Excel5_Escher($this->_escher);
			$data = $writer->close();

			$record = 0x00EB;
			$length = strlen($data);
			$header = pack("vv",  $record, $length);

			return $this->writeData($header . $data);

		} else {
			return '';
		}
	}

	/**
	 * Get Escher object
	 *
	 * @return PHPExcel_Shared_Escher
	 */
	public function getEscher()
	{
		return $this->_escher;
	}

	/**
	 * Set Escher object
	 *
	 * @param PHPExcel_Shared_Escher $pValue
	 */
	public function setEscher(PHPExcel_Shared_Escher $pValue = null)
	{
		$this->_escher = $pValue;
	}
}