<?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_Worksheet (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_Worksheet
 *
 * @category   PHPExcel
 * @package    PHPExcel_Writer_Excel5
 * @copyright  Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Writer_Excel5_Worksheet extends PHPExcel_Writer_Excel5_BIFFwriter
{
	/**
	 * Formula parser
	 *
	 * @var PHPExcel_Writer_Excel5_Parser
	 */
	private $_parser;

	/**
	 * Maximum number of characters for a string (LABEL record in BIFF5)
	 * @var integer
	 */
	public $_xls_strmax;

	/**
	 * Array containing format information for columns
	 * @var array
	 */
	public $_colinfo;

	/**
	 * Array containing the selected area for the worksheet
	 * @var array
	 */
	public $_selection;

	/**
	 * The active pane for the worksheet
	 * @var integer
	 */
	public $_active_pane;

	/**
	 * Whether to use outline.
	 * @var integer
	 */
	public $_outline_on;

	/**
	 * Auto outline styles.
	 * @var bool
	 */
	public $_outline_style;

	/**
	 * Whether to have outline summary below.
	 * @var bool
	 */
	public $_outline_below;

	/**
	 * Whether to have outline summary at the right.
	 * @var bool
	 */
	public $_outline_right;

	/**
	 * Reference to the total number of strings in the workbook
	 * @var integer
	 */
	public $_str_total;

	/**
	 * Reference to the number of unique strings in the workbook
	 * @var integer
	 */
	public $_str_unique;

	/**
	 * Reference to the array containing all the unique strings in the workbook
	 * @var array
	 */
	public $_str_table;

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

	/**
	 * Index of first used row (at least 0)
	 * @var int
	 */
	private $_firstRowIndex;

	/**
	 * Index of last used row. (no used rows means -1)
	 * @var int
	 */
	private $_lastRowIndex;

	/**
	 * Index of first used column (at least 0)
	 * @var int
	 */
	private $_firstColumnIndex;

	/**
	 * Index of last used column (no used columns means -1)
	 * @var int
	 */
	private $_lastColumnIndex;

	/**
	 * Sheet object
	 * @var PHPExcel_Worksheet
	 */
	public $_phpSheet;

	/**
	 * Count cell style Xfs
	 *
	 * @var int
	 */
	private $_countCellStyleXfs;

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

	/**
	 * Array of font hashes associated to FONT records index
	 *
	 * @var array
	 */
	public $_fntHashIndex;

	/**
	 * Constructor
	 *
	 * @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
	 * @param boolean	$preCalculateFormulas	Flag indicating whether formulas should be calculated or just written
	 * @param string	$phpSheet		The worksheet to write
	 * @param PHPExcel_Worksheet $phpSheet
	 */
	public function __construct(&$str_total, &$str_unique, &$str_table, &$colors,
								$parser, $preCalculateFormulas, $phpSheet)
	{
		// It needs to call its parent's constructor explicitly
		parent::__construct();

		// change BIFFwriter limit for CONTINUE records
//		$this->_limit = 8224;


		$this->_preCalculateFormulas = $preCalculateFormulas;
		$this->_str_total		= &$str_total;
		$this->_str_unique		= &$str_unique;
		$this->_str_table		= &$str_table;
		$this->_colors			= &$colors;
		$this->_parser			= $parser;

		$this->_phpSheet = $phpSheet;

		//$this->ext_sheets		= array();
		//$this->offset			= 0;
		$this->_xls_strmax		= 255;
		$this->_colinfo			= array();
		$this->_selection		= array(0,0,0,0);
		$this->_active_pane		= 3;

		$this->_print_headers		= 0;

		$this->_outline_style		= 0;
		$this->_outline_below		= 1;
		$this->_outline_right		= 1;
		$this->_outline_on			= 1;

		$this->_fntHashIndex	= array();

		// calculate values for DIMENSIONS record
		$minR = 1;
		$minC = 'A';

		$maxR  = $this->_phpSheet->getHighestRow();
		$maxC = $this->_phpSheet->getHighestColumn();

		// Determine lowest and highest column and row
//		$this->_firstRowIndex = ($minR > 65535) ? 65535 : $minR;
		$this->_lastRowIndex = ($maxR > 65535) ? 65535 : $maxR ;

		$this->_firstColumnIndex	= PHPExcel_Cell::columnIndexFromString($minC);
		$this->_lastColumnIndex		= PHPExcel_Cell::columnIndexFromString($maxC);

//		if ($this->_firstColumnIndex > 255) $this->_firstColumnIndex = 255;
		if ($this->_lastColumnIndex > 255) $this->_lastColumnIndex = 255;

		$this->_countCellStyleXfs = count($phpSheet->getParent()->getCellStyleXfCollection());
	}

	/**
	 * Add data to the beginning of the workbook (note the reverse order)
	 * and to the end of the workbook.
	 *
	 * @access public
	 * @see PHPExcel_Writer_Excel5_Workbook::storeWorkbook()
	 */
	function close()
	{
		$_phpSheet = $this->_phpSheet;

		$num_sheets = $_phpSheet->getParent()->getSheetCount();

		// Write BOF record
		$this->_storeBof(0x0010);

		// Write PRINTHEADERS
		$this->_writePrintHeaders();

		// Write PRINTGRIDLINES
		$this->_writePrintGridlines();

		// Write GRIDSET
		$this->_writeGridset();

		// Calculate column widths
		$_phpSheet->calculateColumnWidths();

		// Column dimensions
		if (($defaultWidth = $_phpSheet->getDefaultColumnDimension()->getWidth()) < 0) {
			$defaultWidth = PHPExcel_Shared_Font::getDefaultColumnWidthByFont($_phpSheet->getParent()->getDefaultStyle()->getFont());
		}

		$columnDimensions = $_phpSheet->getColumnDimensions();
		$maxCol = $this->_lastColumnIndex -1;
		for ($i = 0; $i <= $maxCol; ++$i) {
			$hidden = 0;
			$level = 0;
			$xfIndex = 15; // there are 15 cell style Xfs

			$width = $defaultWidth;

			$columnLetter = PHPExcel_Cell::stringFromColumnIndex($i);
			if (isset($columnDimensions[$columnLetter])) {
				$columnDimension = $columnDimensions[$columnLetter];
				if ($columnDimension->getWidth() >= 0) {
					$width = $columnDimension->getWidth();
				}
				$hidden = $columnDimension->getVisible() ? 0 : 1;
				$level = $columnDimension->getOutlineLevel();
				$xfIndex = $columnDimension->getXfIndex() + 15; // there are 15 cell style Xfs
			}

			// Components of _colinfo:
			// $firstcol first column on the range
			// $lastcol  last column on the range
			// $width	width to set
			// $xfIndex  The optional cell style Xf index to apply to the columns
			// $hidden   The optional hidden atribute
			// $level	The optional outline level
			$this->_colinfo[] = array($i, $i, $width, $xfIndex, $hidden, $level);
		}

		// Write GUTS
		$this->_writeGuts();

		// Write DEFAULTROWHEIGHT
		$this->_writeDefaultRowHeight();

		// Write WSBOOL
		$this->_writeWsbool();

		// Write horizontal and vertical page breaks
		$this->_writeBreaks();

		// Write page header
		$this->_writeHeader();

		// Write page footer
		$this->_writeFooter();

		// Write page horizontal centering
		$this->_writeHcenter();

		// Write page vertical centering
		$this->_writeVcenter();

		// Write left margin
		$this->_writeMarginLeft();

		// Write right margin
		$this->_writeMarginRight();

		// Write top margin
		$this->_writeMarginTop();

		// Write bottom margin
		$this->_writeMarginBottom();

		// Write page setup
		$this->_writeSetup();

		// Write sheet protection
		$this->_writeProtect();

		// Write SCENPROTECT
		$this->_writeScenProtect();

		// Write OBJECTPROTECT
		$this->_writeObjectProtect();

		// Write sheet password
		$this->_writePassword();

		// Write DEFCOLWIDTH record
		$this->_writeDefcol();

		// Write the COLINFO records if they exist
		if (!empty($this->_colinfo)) {
			$colcount = count($this->_colinfo);
			for ($i = 0; $i < $colcount; ++$i) {
				$this->_writeColinfo($this->_colinfo[$i]);
			}
		}
		$autoFilterRange = $_phpSheet->getAutoFilter()->getRange();
		if (!empty($autoFilterRange)) {
			// Write AUTOFILTERINFO
			$this->_writeAutoFilterInfo();
		}

		// Write sheet dimensions
		$this->_writeDimensions();

		// Row dimensions
		foreach ($_phpSheet->getRowDimensions() as $rowDimension) {
			$xfIndex = $rowDimension->getXfIndex() + 15; // there are 15 cellXfs
			$this->_writeRow( $rowDimension->getRowIndex() - 1, $rowDimension->getRowHeight(), $xfIndex, ($rowDimension->getVisible() ? '0' : '1'), $rowDimension->getOutlineLevel() );
		}

		// Write Cells
		foreach ($_phpSheet->getCellCollection() as $cellID) {
			$cell = $_phpSheet->getCell($cellID);
			$row = $cell->getRow() - 1;
			$column = PHPExcel_Cell::columnIndexFromString($cell->getColumn()) - 1;

			// Don't break Excel!
//			if ($row + 1 > 65536 or $column + 1 > 256) {
			if ($row > 65535 || $column > 255) {
				break;
			}

			// Write cell value
			$xfIndex = $cell->getXfIndex() + 15; // there are 15 cell style Xfs

			$cVal = $cell->getValue();
			if ($cVal instanceof PHPExcel_RichText) {
				// $this->_writeString($row, $column, $cVal->getPlainText(), $xfIndex);
				$arrcRun = array();
				$str_len = strlen($cVal->getPlainText());
				$str_pos = 0;
				$elements = $cVal->getRichTextElements();
				foreach ($elements as $element) {
					// FONT Index
					if ($element instanceof PHPExcel_RichText_Run) {
						$str_fontidx = $this->_fntHashIndex[$element->getFont()->getHashCode()];
					}
					else {
						$str_fontidx = 0;
					}
					$arrcRun[] = array('strlen' => $str_pos, 'fontidx' => $str_fontidx);
					// Position FROM
					$str_pos += strlen($element->getText());
				}
				$this->_writeRichTextString($row, $column, $cVal->getPlainText(), $xfIndex, $arrcRun);
			} else {
				switch ($cell->getDatatype()) {
					case PHPExcel_Cell_DataType::TYPE_STRING:
					case PHPExcel_Cell_DataType::TYPE_NULL:
						if ($cVal === '' || $cVal === null) {
							$this->_writeBlank($row, $column, $xfIndex);
						} else {
							$this->_writeString($row, $column, $cVal, $xfIndex);
						}
						break;

					case PHPExcel_Cell_DataType::TYPE_NUMERIC:
						$this->_writeNumber($row, $column, $cVal, $xfIndex);
						break;

					case PHPExcel_Cell_DataType::TYPE_FORMULA:
						$calculatedValue = $this->_preCalculateFormulas ?
							$cell->getCalculatedValue() : null;
						$this->_writeFormula($row, $column, $cVal, $xfIndex, $calculatedValue);
						break;

					case PHPExcel_Cell_DataType::TYPE_BOOL:
						$this->_writeBoolErr($row, $column, $cVal, 0, $xfIndex);
						break;

					case PHPExcel_Cell_DataType::TYPE_ERROR:
						$this->_writeBoolErr($row, $column, self::_mapErrorCode($cVal), 1, $xfIndex);
						break;

				}
			}
		}

		// Append
		$this->_writeMsoDrawing();

		$this->_writeWindow2();
		$this->_writePageLayoutView();
		$this->_writeZoom();
		if ($_phpSheet->getFreezePane()) {
			$this->_writePanes();
		}
		$this->_writeSelection();
		$this->_writeMergedCells();

		// Hyperlinks
		foreach ($_phpSheet->getHyperLinkCollection() as $coordinate => $hyperlink) {
			list($column, $row) = PHPExcel_Cell::coordinateFromString($coordinate);

			$url = $hyperlink->getUrl();

			if ( strpos($url, 'sheet://') !== false ) {
				// internal to current workbook
				$url = str_replace('sheet://', 'internal:', $url);

			} else if ( preg_match('/^(http:|https:|ftp:|mailto:)/', $url) ) {
				// URL
				// $url = $url;

			} else {
				// external (local file)
				$url = 'external:' . $url;
			}

			$this->_writeUrl($row - 1, PHPExcel_Cell::columnIndexFromString($column) - 1, $url);
		}

		$this->_writeDataValidity();
		$this->_writeSheetLayout();
		$this->_writeSheetProtection();
		$this->_writeRangeProtection();

		$this->_storeEof();
	}

	/**
	 * Write a cell range address in BIFF8
	 * always fixed range
	 * See section 2.5.14 in OpenOffice.org's Documentation of the Microsoft Excel File Format
	 *
	 * @param string $range E.g. 'A1' or 'A1:B6'
	 * @return string Binary data
	 */
	private function _writeBIFF8CellRangeAddressFixed($range = 'A1')
	{
		$explodes = explode(':', $range);

		// extract first cell, e.g. 'A1'
		$firstCell = $explodes[0];

		// extract last cell, e.g. 'B6'
		if (count($explodes) == 1) {
			$lastCell = $firstCell;
		} else {
			$lastCell = $explodes[1];
		}

		$firstCellCoordinates = PHPExcel_Cell::coordinateFromString($firstCell); // e.g. array(0, 1)
		$lastCellCoordinates  = PHPExcel_Cell::coordinateFromString($lastCell);  // e.g. array(1, 6)

		return(pack('vvvv',
			$firstCellCoordinates[1] - 1,
			$lastCellCoordinates[1] - 1,
			PHPExcel_Cell::columnIndexFromString($firstCellCoordinates[0]) - 1,
			PHPExcel_Cell::columnIndexFromString($lastCellCoordinates[0]) - 1
		));
	}

	/**
	 * Retrieves data from memory in one chunk, or from disk in $buffer
	 * sized chunks.
	 *
	 * @return string The data
	 */
	function getData()
	{
		$buffer = 4096;

		// Return data stored in memory
		if (isset($this->_data)) {
			$tmp   = $this->_data;
			unset($this->_data);
			return $tmp;
		}
		// No data to return
		return false;
	}

	/**
	 * Set the option to print the row and column headers on the printed page.
	 *
	 * @access public
	 * @param integer $print Whether to print the headers or not. Defaults to 1 (print).
	 */
	function printRowColHeaders($print = 1)
	{
		$this->_print_headers = $print;
	}

	/**
	 * This method sets the properties for outlining and grouping. The defaults
	 * correspond to Excel's defaults.
	 *
	 * @param bool $visible
	 * @param bool $symbols_below
	 * @param bool $symbols_right
	 * @param bool $auto_style
	 */
	function setOutline($visible = true, $symbols_below = true, $symbols_right = true, $auto_style = false)
	{
		$this->_outline_on	= $visible;
		$this->_outline_below = $symbols_below;
		$this->_outline_right = $symbols_right;
		$this->_outline_style = $auto_style;

		// Ensure this is a boolean vale for Window2
		if ($this->_outline_on) {
			$this->_outline_on = 1;
		}
	 }

	/**
	 * Write a double to the specified row and column (zero indexed).
	 * An integer can be written as a double. Excel will display an
	 * integer. $format is optional.
	 *
	 * Returns  0 : normal termination
	 *		 -2 : row or column out of range
	 *
	 * @param integer $row	Zero indexed row
	 * @param integer $col	Zero indexed column
	 * @param float   $num	The number to write
	 * @param mixed   $xfIndex The optional XF format
	 * @return integer
	 */
	private function _writeNumber($row, $col, $num, $xfIndex)
	{
		$record	= 0x0203;				 // Record identifier
		$length	= 0x000E;				 // Number of bytes to follow

		$header		= pack("vv",  $record, $length);
		$data		= pack("vvv", $row, $col, $xfIndex);
		$xl_double	= pack("d",   $num);
		if (self::getByteOrder()) { // if it's Big Endian
			$xl_double = strrev($xl_double);
		}

		$this->_append($header.$data.$xl_double);
		return(0);
	}

	/**
	 * Write a LABELSST record or a LABEL record. Which one depends on BIFF version
	 *
	 * @param int $row Row index (0-based)
	 * @param int $col Column index (0-based)
	 * @param string $str The string
	 * @param int $xfIndex Index to XF record
	 */
	private function _writeString($row, $col, $str, $xfIndex)
	{
		$this->_writeLabelSst($row, $col, $str, $xfIndex);
	}

	/**
	 * Write a LABELSST record or a LABEL record. Which one depends on BIFF version
	 * It differs from _writeString by the writing of rich text strings.
	 * @param int $row Row index (0-based)
	 * @param int $col Column index (0-based)
	 * @param string $str The string
	 * @param mixed   $xfIndex The XF format index for the cell
	 * @param array $arrcRun Index to Font record and characters beginning
	 */
	private function _writeRichTextString($row, $col, $str, $xfIndex, $arrcRun){
		$record	= 0x00FD;				   // Record identifier
		$length	= 0x000A;				   // Bytes to follow

		$str = PHPExcel_Shared_String::UTF8toBIFF8UnicodeShort($str, $arrcRun);

		/* check if string is already present */
		if (!isset($this->_str_table[$str])) {
			$this->_str_table[$str] = $this->_str_unique++;
		}
		$this->_str_total++;

		$header	= pack('vv',   $record, $length);
		$data	= pack('vvvV', $row, $col, $xfIndex, $this->_str_table[$str]);
		$this->_append($header.$data);
	}

	/**
	 * Write a string to the specified row and column (zero indexed).
	 * NOTE: there is an Excel 5 defined limit of 255 characters.
	 * $format is optional.
	 * Returns  0 : normal termination
	 *		 -2 : row or column out of range
	 *		 -3 : long string truncated to 255 chars
	 *
	 * @access public
	 * @param integer $row	Zero indexed row
	 * @param integer $col	Zero indexed column
	 * @param string  $str	The string to write
	 * @param mixed   $xfIndex The XF format index for the cell
	 * @return integer
	 */
	private function _writeLabel($row, $col, $str, $xfIndex)
	{
		$strlen	= strlen($str);
		$record	= 0x0204;				   // Record identifier
		$length	= 0x0008 + $strlen;		 // Bytes to follow

		$str_error = 0;

		if ($strlen > $this->_xls_strmax) { // LABEL must be < 255 chars
			$str	= substr($str, 0, $this->_xls_strmax);
			$length	= 0x0008 + $this->_xls_strmax;
			$strlen	= $this->_xls_strmax;
			$str_error = -3;
		}

		$header	= pack("vv",   $record, $length);
		$data	= pack("vvvv", $row, $col, $xfIndex, $strlen);
		$this->_append($header . $data . $str);
		return($str_error);
	}

	/**
	 * Write a string to the specified row and column (zero indexed).
	 * This is the BIFF8 version (no 255 chars limit).
	 * $format is optional.
	 * Returns  0 : normal termination
	 *		 -2 : row or column out of range
	 *		 -3 : long string truncated to 255 chars
	 *
	 * @access public
	 * @param integer $row	Zero indexed row
	 * @param integer $col	Zero indexed column
	 * @param string  $str	The string to write
	 * @param mixed   $xfIndex The XF format index for the cell
	 * @return integer
	 */
	private function _writeLabelSst($row, $col, $str, $xfIndex)
	{
		$record	= 0x00FD;				   // Record identifier
		$length	= 0x000A;				   // Bytes to follow

		$str = PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($str);

		/* check if string is already present */
		if (!isset($this->_str_table[$str])) {
			$this->_str_table[$str] = $this->_str_unique++;
		}
		$this->_str_total++;

		$header	= pack('vv',   $record, $length);
		$data	= pack('vvvV', $row, $col, $xfIndex, $this->_str_table[$str]);
		$this->_append($header.$data);
	}

	/**
	 * Writes a note associated with the cell given by the row and column.
	 * NOTE records don't have a length limit.
	 *
	 * @param integer $row	Zero indexed row
	 * @param integer $col	Zero indexed column
	 * @param string  $note   The note to write
	 */
	private function _writeNote($row, $col, $note)
	{
		$note_length	= strlen($note);
		$record			= 0x001C;			// Record identifier
		$max_length		= 2048;				// Maximun length for a NOTE record

		// Length for this record is no more than 2048 + 6
		$length	= 0x0006 + min($note_length, 2048);
		$header	= pack("vv",   $record, $length);
		$data	= pack("vvv", $row, $col, $note_length);
		$this->_append($header . $data . substr($note, 0, 2048));

		for ($i = $max_length; $i < $note_length; $i += $max_length) {
			$chunk  = substr($note, $i, $max_length);
			$length = 0x0006 + strlen($chunk);
			$header = pack("vv",   $record, $length);
			$data   = pack("vvv", -1, 0, strlen($chunk));
			$this->_append($header.$data.$chunk);
		}
		return(0);
	}

	/**
	 * Write a blank cell to the specified row and column (zero indexed).
	 * A blank cell is used to specify formatting without adding a string
	 * or a number.
	 *
	 * A blank cell without a format serves no purpose. Therefore, we don't write
	 * a BLANK record unless a format is specified.
	 *
	 * Returns  0 : normal termination (including no format)
	 *		 -1 : insufficient number of arguments
	 *		 -2 : row or column out of range
	 *
	 * @param integer $row	Zero indexed row
	 * @param integer $col	Zero indexed column
	 * @param mixed   $xfIndex The XF format index
	 */
	function _writeBlank($row, $col, $xfIndex)
	{
		$record	= 0x0201;				 // Record identifier
		$length	= 0x0006;				 // Number of bytes to follow

		$header	= pack("vv",  $record, $length);
		$data	  = pack("vvv", $row, $col, $xfIndex);
		$this->_append($header . $data);
		return 0;
	}

	/**
	 * Write a boolean or an error type to the specified row and column (zero indexed)
	 *
	 * @param int $row Row index (0-based)
	 * @param int $col Column index (0-based)
	 * @param int $value
	 * @param boolean $isError Error or Boolean?
	 * @param int $xfIndex
	 */
	private function _writeBoolErr($row, $col, $value, $isError, $xfIndex)
	{
		$record = 0x0205;
		$length = 8;

		$header	= pack("vv",  $record, $length);
		$data	  = pack("vvvCC", $row, $col, $xfIndex, $value, $isError);
		$this->_append($header . $data);
		return 0;
	}

	/**
	 * Write a formula to the specified row and column (zero indexed).
	 * The textual representation of the formula is passed to the parser in
	 * Parser.php which returns a packed binary string.
	 *
	 * Returns  0 : normal termination
	 *		 -1 : formula errors (bad formula)
	 *		 -2 : row or column out of range
	 *
	 * @param integer $row	 Zero indexed row
	 * @param integer $col	 Zero indexed column
	 * @param string  $formula The formula text string
	 * @param mixed   $xfIndex  The XF format index
	 * @param mixed   $calculatedValue  Calculated value
	 * @return integer
	 */
	private function _writeFormula($row, $col, $formula, $xfIndex, $calculatedValue)
	{
		$record	= 0x0006;	 // Record identifier

		// Initialize possible additional value for STRING record that should be written after the FORMULA record?
		$stringValue = null;

		// calculated value
		if (isset($calculatedValue)) {
			// Since we can't yet get the data type of the calculated value,
			// we use best effort to determine data type
			if (is_bool($calculatedValue)) {
				// Boolean value
				$num = pack('CCCvCv', 0x01, 0x00, (int)$calculatedValue, 0x00, 0x00, 0xFFFF);
			} elseif (is_int($calculatedValue) || is_float($calculatedValue)) {
				// Numeric value
				$num = pack('d', $calculatedValue);
			} elseif (is_string($calculatedValue)) {
				if (array_key_exists($calculatedValue, PHPExcel_Cell_DataType::getErrorCodes())) {
					// Error value
					$num = pack('CCCvCv', 0x02, 0x00, self::_mapErrorCode($calculatedValue), 0x00, 0x00, 0xFFFF);
				} elseif ($calculatedValue === '') {
					// Empty string (and BIFF8)
					$num = pack('CCCvCv', 0x03, 0x00, 0x00, 0x00, 0x00, 0xFFFF);
				} else {
					// Non-empty string value (or empty string BIFF5)
					$stringValue = $calculatedValue;
					$num = pack('CCCvCv', 0x00, 0x00, 0x00, 0x00, 0x00, 0xFFFF);
				}
			} else {
				// We are really not supposed to reach here
				$num = pack('d', 0x00);
			}
		} else {
			$num = pack('d', 0x00);
		}

		$grbit		= 0x03;				// Option flags
		$unknown	= 0x0000;			// Must be zero

		// Strip the '=' or '@' sign at the beginning of the formula string
		if ($formula{0} == '=') {
			$formula = substr($formula,1);
		} else {
			// Error handling
			$this->_writeString($row, $col, 'Unrecognised character for formula');
			return -1;
		}

		// Parse the formula using the parser in Parser.php
		try {
			$error = $this->_parser->parse($formula);
			$formula = $this->_parser->toReversePolish();

			$formlen	= strlen($formula);	// Length of the binary string
			$length	 = 0x16 + $formlen;	 // Length of the record data

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

			$data	  = pack("vvv", $row, $col, $xfIndex)
						. $num
						. pack("vVv", $grbit, $unknown, $formlen);
			$this->_append($header . $data . $formula);

			// Append also a STRING record if necessary
			if ($stringValue !== null) {
				$this->_writeStringRecord($stringValue);
			}

			return 0;

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

	}

	/**
	 * Write a STRING record. This
	 *
	 * @param string $stringValue
	 */
	private function _writeStringRecord($stringValue)
	{
		$record = 0x0207;	 // Record identifier
		$data = PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($stringValue);

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

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

	/**
	 * Write a hyperlink.
	 * This is comprised of two elements: the visible label and
	 * the invisible link. The visible label is the same as the link unless an
	 * alternative string is specified. The label is written using the
	 * _writeString() method. Therefore the 255 characters string limit applies.
	 * $string and $format are optional.
	 *
	 * The hyperlink can be to a http, ftp, mail, internal sheet (not yet), or external
	 * directory url.
	 *
	 * Returns  0 : normal termination
	 *		 -2 : row or column out of range
	 *		 -3 : long string truncated to 255 chars
	 *
	 * @param integer $row	Row
	 * @param integer $col	Column
	 * @param string  $url	URL string
	 * @return integer
	 */
	private function _writeUrl($row, $col, $url)
	{
		// Add start row and col to arg list
		return($this->_writeUrlRange($row, $col, $row, $col, $url));
	}

	/**
	 * This is the more general form of _writeUrl(). It allows a hyperlink to be
	 * written to a range of cells. This function also decides the type of hyperlink
	 * to be written. These are either, Web (http, ftp, mailto), Internal
	 * (Sheet1!A1) or external ('c:\temp\foo.xls#Sheet1!A1').
	 *
	 * @access private
	 * @see _writeUrl()
	 * @param integer $row1   Start row
	 * @param integer $col1   Start column
	 * @param integer $row2   End row
	 * @param integer $col2   End column
	 * @param string  $url	URL string
	 * @return integer
	 */
	function _writeUrlRange($row1, $col1, $row2, $col2, $url)
	{
		// Check for internal/external sheet links or default to web link
		if (preg_match('[^internal:]', $url)) {
			return($this->_writeUrlInternal($row1, $col1, $row2, $col2, $url));
		}
		if (preg_match('[^external:]', $url)) {
			return($this->_writeUrlExternal($row1, $col1, $row2, $col2, $url));
		}
		return($this->_writeUrlWeb($row1, $col1, $row2, $col2, $url));
	}

	/**
	 * Used to write http, ftp and mailto hyperlinks.
	 * The link type ($options) is 0x03 is the same as absolute dir ref without
	 * sheet. However it is differentiated by the $unknown2 data stream.
	 *
	 * @access private
	 * @see _writeUrl()
	 * @param integer $row1   Start row
	 * @param integer $col1   Start column
	 * @param integer $row2   End row
	 * @param integer $col2   End column
	 * @param string  $url	URL string
	 * @return integer
	 */
	function _writeUrlWeb($row1, $col1, $row2, $col2, $url)
	{
		$record	  = 0x01B8;					   // Record identifier
		$length	  = 0x00000;					  // Bytes to follow

		// Pack the undocumented parts of the hyperlink stream
		$unknown1	= pack("H*", "D0C9EA79F9BACE118C8200AA004BA90B02000000");
		$unknown2	= pack("H*", "E0C9EA79F9BACE118C8200AA004BA90B");

		// Pack the option flags
		$options	 = pack("V", 0x03);

		// Convert URL to a null terminated wchar string
		$url		 = join("\0", preg_split("''", $url, -1, PREG_SPLIT_NO_EMPTY));
		$url		 = $url . "\0\0\0";

		// Pack the length of the URL
		$url_len	 = pack("V", strlen($url));

		// Calculate the data length
		$length	  = 0x34 + strlen($url);

		// Pack the header data
		$header	  = pack("vv",   $record, $length);
		$data		= pack("vvvv", $row1, $row2, $col1, $col2);

		// Write the packed data
		$this->_append($header . $data .
					   $unknown1 . $options .
					   $unknown2 . $url_len . $url);
		return 0;
	}

	/**
	 * Used to write internal reference hyperlinks such as "Sheet1!A1".
	 *
	 * @access private
	 * @see _writeUrl()
	 * @param integer $row1   Start row
	 * @param integer $col1   Start column
	 * @param integer $row2   End row
	 * @param integer $col2   End column
	 * @param string  $url	URL string
	 * @return integer
	 */
	function _writeUrlInternal($row1, $col1, $row2, $col2, $url)
	{
		$record	  = 0x01B8;					   // Record identifier
		$length	  = 0x00000;					  // Bytes to follow

		// Strip URL type
		$url = preg_replace('/^internal:/', '', $url);

		// Pack the undocumented parts of the hyperlink stream
		$unknown1	= pack("H*", "D0C9EA79F9BACE118C8200AA004BA90B02000000");

		// Pack the option flags
		$options	 = pack("V", 0x08);

		// Convert the URL type and to a null terminated wchar string
		$url .= "\0";

		// character count
		$url_len = PHPExcel_Shared_String::CountCharacters($url);
		$url_len = pack('V', $url_len);

		$url = PHPExcel_Shared_String::ConvertEncoding($url, 'UTF-16LE', 'UTF-8');

		// Calculate the data length
		$length	  = 0x24 + strlen($url);

		// Pack the header data
		$header	  = pack("vv",   $record, $length);
		$data		= pack("vvvv", $row1, $row2, $col1, $col2);

		// Write the packed data
		$this->_append($header . $data .
					   $unknown1 . $options .
					   $url_len . $url);
		return 0;
	}

	/**
	 * Write links to external directory names such as 'c:\foo.xls',
	 * c:\foo.xls#Sheet1!A1', '../../foo.xls'. and '../../foo.xls#Sheet1!A1'.
	 *
	 * Note: Excel writes some relative links with the $dir_long string. We ignore
	 * these cases for the sake of simpler code.
	 *
	 * @access private
	 * @see _writeUrl()
	 * @param integer $row1   Start row
	 * @param integer $col1   Start column
	 * @param integer $row2   End row
	 * @param integer $col2   End column
	 * @param string  $url	URL string
	 * @return integer
	 */
	function _writeUrlExternal($row1, $col1, $row2, $col2, $url)
	{
		// Network drives are different. We will handle them separately
		// MS/Novell network drives and shares start with \\
		if (preg_match('[^external:\\\\]', $url)) {
			return; //($this->_writeUrlExternal_net($row1, $col1, $row2, $col2, $url, $str, $format));
		}

		$record	  = 0x01B8;					   // Record identifier
		$length	  = 0x00000;					  // Bytes to follow

		// Strip URL type and change Unix dir separator to Dos style (if needed)
		//
		$url = preg_replace('/^external:/', '', $url);
		$url = preg_replace('/\//', "\\", $url);

		// Determine if the link is relative or absolute:
		//   relative if link contains no dir separator, "somefile.xls"
		//   relative if link starts with up-dir, "..\..\somefile.xls"
		//   otherwise, absolute

		$absolute = 0x00; // relative path
		if ( preg_match('/^[A-Z]:/', $url) ) {
			$absolute = 0x02; // absolute path on Windows, e.g. C:\...
		}
		$link_type			   = 0x01 | $absolute;

		// Determine if the link contains a sheet reference and change some of the
		// parameters accordingly.
		// Split the dir name and sheet name (if it exists)
		$dir_long = $url;
		if (preg_match("/\#/", $url)) {
			$link_type |= 0x08;
		}


		// Pack the link type
		$link_type   = pack("V", $link_type);

		// Calculate the up-level dir count e.g.. (..\..\..\ == 3)
		$up_count	= preg_match_all("/\.\.\\\/", $dir_long, $useless);
		$up_count	= pack("v", $up_count);

		// Store the short dos dir name (null terminated)
		$dir_short   = preg_replace("/\.\.\\\/", '', $dir_long) . "\0";

		// Store the long dir name as a wchar string (non-null terminated)
		$dir_long	   = $dir_long . "\0";

		// Pack the lengths of the dir strings
		$dir_short_len = pack("V", strlen($dir_short)	  );
		$dir_long_len  = pack("V", strlen($dir_long)	   );
		$stream_len	= pack("V", 0);//strlen($dir_long) + 0x06);

		// Pack the undocumented parts of the hyperlink stream
		$unknown1 = pack("H*",'D0C9EA79F9BACE118C8200AA004BA90B02000000'	   );
		$unknown2 = pack("H*",'0303000000000000C000000000000046'			   );
		$unknown3 = pack("H*",'FFFFADDE000000000000000000000000000000000000000');
		$unknown4 = pack("v",  0x03											);

		// Pack the main data stream
		$data		= pack("vvvv", $row1, $row2, $col1, $col2) .
						  $unknown1	 .
						  $link_type	.
						  $unknown2	 .
						  $up_count	 .
						  $dir_short_len.
						  $dir_short	.
						  $unknown3	 .
						  $stream_len   ;/*.
						  $dir_long_len .
						  $unknown4	 .
						  $dir_long	 .
						  $sheet_len	.
						  $sheet		;*/

		// Pack the header data
		$length   = strlen($data);
		$header   = pack("vv", $record, $length);

		// Write the packed data
		$this->_append($header. $data);
		return 0;
	}

	/**
	 * This method is used to set the height and format for a row.
	 *
	 * @param integer $row	The row to set
	 * @param integer $height Height we are giving to the row.
	 *						Use null to set XF without setting height
	 * @param integer $xfIndex  The optional cell style Xf index to apply to the columns
	 * @param bool	$hidden The optional hidden attribute
	 * @param integer $level  The optional outline level for row, in range [0,7]
	 */
	private function _writeRow($row, $height, $xfIndex, $hidden = false, $level = 0)
	{
		$record	  = 0x0208;			   // Record identifier
		$length	  = 0x0010;			   // Number of bytes to follow

		$colMic	  = 0x0000;			   // First defined column
		$colMac	  = 0x0000;			   // Last defined column
		$irwMac	  = 0x0000;			   // Used by Excel to optimise loading
		$reserved	= 0x0000;			   // Reserved
		$grbit	   = 0x0000;			   // Option flags
		$ixfe		= $xfIndex;

		if ( $height < 0 ){
			$height = null;
		}

		// Use _writeRow($row, null, $XF) to set XF format without setting height
		if ($height != null) {
			$miyRw = $height * 20;  // row height
		} else {
			$miyRw = 0xff;		  // default row height is 256
		}

		// Set the options flags. fUnsynced is used to show that the font and row
		// heights are not compatible. This is usually the case for WriteExcel.
		// The collapsed flag 0x10 doesn't seem to be used to indicate that a row
		// is collapsed. Instead it is used to indicate that the previous row is
		// collapsed. The zero height flag, 0x20, is used to collapse a row.

		$grbit |= $level;
		if ($hidden) {
			$grbit |= 0x0020;
		}
		if ($height !== null) {
			$grbit |= 0x0040; // fUnsynced
		}
		if ($xfIndex !== 0xF) {
			$grbit |= 0x0080;
		}
		$grbit |= 0x0100;

		$header   = pack("vv",	   $record, $length);
		$data	 = pack("vvvvvvvv", $row, $colMic, $colMac, $miyRw,
									 $irwMac,$reserved, $grbit, $ixfe);
		$this->_append($header.$data);
	}

	/**
	 * Writes Excel DIMENSIONS to define the area in which there is data.
	 */
	private function _writeDimensions()
	{
		$record = 0x0200; // Record identifier

		$length = 0x000E;
		$data = pack('VVvvv'
				, $this->_firstRowIndex
				, $this->_lastRowIndex + 1
				, $this->_firstColumnIndex
				, $this->_lastColumnIndex + 1
				, 0x0000 // reserved
			);

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

	/**
	 * Write BIFF record Window2.
	 */
	private function _writeWindow2()
	{
		$record		 = 0x023E;	 // Record identifier
		$length		 = 0x0012;

		$grbit		  = 0x00B6;	 // Option flags
		$rwTop		  = 0x0000;	 // Top row visible in window
		$colLeft		= 0x0000;	 // Leftmost column visible in window


		// The options flags that comprise $grbit
		$fDspFmla	   = 0;					 // 0 - bit
		$fDspGrid	   = $this->_phpSheet->getShowGridlines() ? 1 : 0; // 1
		$fDspRwCol	  = $this->_phpSheet->getShowRowColHeaders() ? 1 : 0; // 2
		$fFrozen		= $this->_phpSheet->getFreezePane() ? 1 : 0;		// 3
		$fDspZeros	  = 1;					 // 4
		$fDefaultHdr	= 1;					 // 5
		$fArabic		= $this->_phpSheet->getRightToLeft() ? 1 : 0; // 6
		$fDspGuts	   = $this->_outline_on;	// 7
		$fFrozenNoSplit = 0;					 // 0 - bit
		// no support in PHPExcel for selected sheet, therefore sheet is only selected if it is the active sheet
		$fSelected	  = ($this->_phpSheet === $this->_phpSheet->getParent()->getActiveSheet()) ? 1 : 0;
		$fPaged		 = 1;					 // 2

		$grbit			 = $fDspFmla;
		$grbit			|= $fDspGrid	   << 1;
		$grbit			|= $fDspRwCol	   << 2;
		$grbit			|= $fFrozen		   << 3;
		$grbit			|= $fDspZeros	   << 4;
		$grbit			|= $fDefaultHdr	   << 5;
		$grbit			|= $fArabic		   << 6;
		$grbit			|= $fDspGuts	   << 7;
		$grbit			|= $fFrozenNoSplit << 8;
		$grbit			|= $fSelected	   << 9;
		$grbit			|= $fPaged		   << 10;

		$header  = pack("vv",   $record, $length);
		$data	= pack("vvv", $grbit, $rwTop, $colLeft);

		// FIXME !!!
		$rgbHdr	   = 0x0040; // Row/column heading and gridline color index
		$zoom_factor_page_break = 0x0000;
		$zoom_factor_normal	 = 0x0000;
		$data .= pack("vvvvV", $rgbHdr, 0x0000, $zoom_factor_page_break, $zoom_factor_normal, 0x00000000);

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

	/**
	 * Write BIFF record DEFAULTROWHEIGHT.
	 */
	private function _writeDefaultRowHeight()
	{
		$defaultRowHeight = $this->_phpSheet->getDefaultRowDimension()->getRowHeight();

		if ($defaultRowHeight < 0) {
			return;
		}

		// convert to twips
		$defaultRowHeight = (int) 20 * $defaultRowHeight;

		$record   = 0x0225;	  // Record identifier
		$length   = 0x0004;	  // Number of bytes to follow

		$header   = pack("vv", $record, $length);
		$data	 = pack("vv",  1, $defaultRowHeight);
		$this->_append($header . $data);
	}

	/**
	 * Write BIFF record DEFCOLWIDTH if COLINFO records are in use.
	 */
	private function _writeDefcol()
	{
		$defaultColWidth = 8;

		$record   = 0x0055;	  // Record identifier
		$length   = 0x0002;	  // Number of bytes to follow

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

	/**
	 * Write BIFF record COLINFO to define column widths
	 *
	 * Note: The SDK says the record length is 0x0B but Excel writes a 0x0C
	 * length record.
	 *
	 * @param array $col_array This is the only parameter received and is composed of the following:
	 *				0 => First formatted column,
	 *				1 => Last formatted column,
	 *				2 => Col width (8.43 is Excel default),
	 *				3 => The optional XF format of the column,
	 *				4 => Option flags.
	 *				5 => Optional outline level
	 */
	private function _writeColinfo($col_array)
	{
		if (isset($col_array[0])) {
			$colFirst = $col_array[0];
		}
		if (isset($col_array[1])) {
			$colLast = $col_array[1];
		}
		if (isset($col_array[2])) {
			$coldx = $col_array[2];
		} else {
			$coldx = 8.43;
		}
		if (isset($col_array[3])) {
			$xfIndex = $col_array[3];
		} else {
			$xfIndex = 15;
		}
		if (isset($col_array[4])) {
			$grbit = $col_array[4];
		} else {
			$grbit = 0;
		}
		if (isset($col_array[5])) {
			$level = $col_array[5];
		} else {
			$level = 0;
		}
		$record   = 0x007D;		  // Record identifier
		$length   = 0x000C;		  // Number of bytes to follow

		$coldx   *= 256;			 // Convert to units of 1/256 of a char

		$ixfe	 = $xfIndex;
		$reserved = 0x0000;			// Reserved

		$level = max(0, min($level, 7));
		$grbit |= $level << 8;

		$header   = pack("vv",	 $record, $length);
		$data	 = pack("vvvvvv", $colFirst, $colLast, $coldx,
								   $ixfe, $grbit, $reserved);
		$this->_append($header.$data);
	}

	/**
	 * Write BIFF record SELECTION.
	 */
	private function _writeSelection()
	{
		// look up the selected cell range
		$selectedCells = $this->_phpSheet->getSelectedCells();
		$selectedCells = PHPExcel_Cell::splitRange($this->_phpSheet->getSelectedCells());
		$selectedCells = $selectedCells[0];
		if (count($selectedCells) == 2) {
			list($first, $last) = $selectedCells;
		} else {
			$first = $selectedCells[0];
			$last  = $selectedCells[0];
		}

		list($colFirst, $rwFirst) = PHPExcel_Cell::coordinateFromString($first);
		$colFirst = PHPExcel_Cell::columnIndexFromString($colFirst) - 1; // base 0 column index
		--$rwFirst; // base 0 row index

		list($colLast, $rwLast) = PHPExcel_Cell::coordinateFromString($last);
		$colLast = PHPExcel_Cell::columnIndexFromString($colLast) - 1; // base 0 column index
		--$rwLast; // base 0 row index

		// make sure we are not out of bounds
		$colFirst = min($colFirst, 255);
		$colLast  = min($colLast,  255);

		$rwFirst = min($rwFirst, 65535);
		$rwLast  = min($rwLast,  65535);

		$record   = 0x001D;				  // Record identifier
		$length   = 0x000F;				  // Number of bytes to follow

		$pnn	  = $this->_active_pane;	 // Pane position
		$rwAct	= $rwFirst;				// Active row
		$colAct   = $colFirst;			   // Active column
		$irefAct  = 0;					   // Active cell ref
		$cref	 = 1;					   // Number of refs

		if (!isset($rwLast)) {
			$rwLast   = $rwFirst;	   // Last  row in reference
		}
		if (!isset($colLast)) {
			$colLast  = $colFirst;	  // Last  col in reference
		}

		// Swap last row/col for first row/col as necessary
		if ($rwFirst > $rwLast) {
			list($rwFirst, $rwLast) = array($rwLast, $rwFirst);
		}

		if ($colFirst > $colLast) {
			list($colFirst, $colLast) = array($colLast, $colFirst);
		}

		$header   = pack("vv",		 $record, $length);
		$data	 = pack("CvvvvvvCC",  $pnn, $rwAct, $colAct,
									   $irefAct, $cref,
									   $rwFirst, $rwLast,
									   $colFirst, $colLast);
		$this->_append($header . $data);
	}

	/**
	 * Store the MERGEDCELLS records for all ranges of merged cells
	 */
	private function _writeMergedCells()
	{
		$mergeCells = $this->_phpSheet->getMergeCells();
		$countMergeCells = count($mergeCells);

		if ($countMergeCells == 0) {
			return;
		}

		// maximum allowed number of merged cells per record
		$maxCountMergeCellsPerRecord = 1027;

		// record identifier
		$record = 0x00E5;

		// counter for total number of merged cells treated so far by the writer
		$i = 0;

		// counter for number of merged cells written in record currently being written
		$j = 0;

		// initialize record data
		$recordData = '';

		// loop through the merged cells
		foreach ($mergeCells as $mergeCell) {
			++$i;
			++$j;

			// extract the row and column indexes
			$range = PHPExcel_Cell::splitRange($mergeCell);
			list($first, $last) = $range[0];
			list($firstColumn, $firstRow) = PHPExcel_Cell::coordinateFromString($first);
			list($lastColumn, $lastRow) = PHPExcel_Cell::coordinateFromString($last);

			$recordData .= pack('vvvv', $firstRow - 1, $lastRow - 1, PHPExcel_Cell::columnIndexFromString($firstColumn) - 1, PHPExcel_Cell::columnIndexFromString($lastColumn) - 1);

			// flush record if we have reached limit for number of merged cells, or reached final merged cell
			if ($j == $maxCountMergeCellsPerRecord or $i == $countMergeCells) {
				$recordData = pack('v', $j) . $recordData;
				$length = strlen($recordData);
				$header = pack('vv', $record, $length);
				$this->_append($header . $recordData);

				// initialize for next record, if any
				$recordData = '';
				$j = 0;
			}
		}
	}

	/**
	 * Write SHEETLAYOUT record
	 */
	private function _writeSheetLayout()
	{
		if (!$this->_phpSheet->isTabColorSet()) {
			return;
		}

		$recordData = pack(
			'vvVVVvv'
			, 0x0862
			, 0x0000		// unused
			, 0x00000000	// unused
			, 0x00000000	// unused
			, 0x00000014	// size of record data
			, $this->_colors[$this->_phpSheet->getTabColor()->getRGB()]	// color index
			, 0x0000		// unused
		);

		$length = strlen($recordData);

		$record = 0x0862; // Record identifier
		$header = pack('vv', $record, $length);
		$this->_append($header . $recordData);
	}

	/**
	 * Write SHEETPROTECTION
	 */
	private function _writeSheetProtection()
	{
		// record identifier
		$record = 0x0867;

		// prepare options
		$options  =   (int) !$this->_phpSheet->getProtection()->getObjects()
					| (int) !$this->_phpSheet->getProtection()->getScenarios()           << 1
					| (int) !$this->_phpSheet->getProtection()->getFormatCells()         << 2
					| (int) !$this->_phpSheet->getProtection()->getFormatColumns()       << 3
					| (int) !$this->_phpSheet->getProtection()->getFormatRows()          << 4
					| (int) !$this->_phpSheet->getProtection()->getInsertColumns()       << 5
					| (int) !$this->_phpSheet->getProtection()->getInsertRows()          << 6
					| (int) !$this->_phpSheet->getProtection()->getInsertHyperlinks()    << 7
					| (int) !$this->_phpSheet->getProtection()->getDeleteColumns()       << 8
					| (int) !$this->_phpSheet->getProtection()->getDeleteRows()          << 9
					| (int) !$this->_phpSheet->getProtection()->getSelectLockedCells()   << 10
					| (int) !$this->_phpSheet->getProtection()->getSort()                << 11
					| (int) !$this->_phpSheet->getProtection()->getAutoFilter()          << 12
					| (int) !$this->_phpSheet->getProtection()->getPivotTables()         << 13
					| (int) !$this->_phpSheet->getProtection()->getSelectUnlockedCells() << 14 ;

		// record data
		$recordData = pack(
			'vVVCVVvv'
			, 0x0867		// repeated record identifier
			, 0x0000		// not used
			, 0x0000		// not used
			, 0x00			// not used
			, 0x01000200	// unknown data
			, 0xFFFFFFFF	// unknown data
			, $options		// options
			, 0x0000		// not used
		);

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

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

	/**
	 * Write BIFF record RANGEPROTECTION
	 *
	 * Openoffice.org's Documentaion of the Microsoft Excel File Format uses term RANGEPROTECTION for these records
	 * Microsoft Office Excel 97-2007 Binary File Format Specification uses term FEAT for these records
	 */
	private function _writeRangeProtection()
	{
		foreach ($this->_phpSheet->getProtectedCells() as $range => $password) {
			// number of ranges, e.g. 'A1:B3 C20:D25'
			$cellRanges = explode(' ', $range);
			$cref = count($cellRanges);

			$recordData = pack(
				'vvVVvCVvVv',
				0x0868,
				0x00,
				0x0000,
				0x0000,
				0x02,
				0x0,
				0x0000,
				$cref,
				0x0000,
				0x00
			);

			foreach ($cellRanges as $cellRange) {
				$recordData .= $this->_writeBIFF8CellRangeAddressFixed($cellRange);
			}

			// the rgbFeat structure
			$recordData .= pack(
				'VV',
				0x0000,
				hexdec($password)
			);

			$recordData .= PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong('p' . md5($recordData));

			$length = strlen($recordData);

			$record = 0x0868;		// Record identifier
			$header = pack("vv", $record, $length);
			$this->_append($header . $recordData);
		}
	}

	/**
	 * Write BIFF record EXTERNCOUNT to indicate the number of external sheet
	 * references in a worksheet.
	 *
	 * Excel only stores references to external sheets that are used in formulas.
	 * For simplicity we store references to all the sheets in the workbook
	 * regardless of whether they are used or not. This reduces the overall
	 * complexity and eliminates the need for a two way dialogue between the formula
	 * parser the worksheet objects.
	 *
	 * @param integer $count The number of external sheet references in this worksheet
	 */
	private function _writeExterncount($count)
	{
		$record = 0x0016;		  // Record identifier
		$length = 0x0002;		  // Number of bytes to follow

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

	/**
	 * Writes the Excel BIFF EXTERNSHEET record. These references are used by
	 * formulas. A formula references a sheet name via an index. Since we store a
	 * reference to all of the external worksheets the EXTERNSHEET index is the same
	 * as the worksheet index.
	 *
	 * @param string $sheetname The name of a external worksheet
	 */
	private function _writeExternsheet($sheetname)
	{
		$record	= 0x0017;		 // Record identifier

		// References to the current sheet are encoded differently to references to
		// external sheets.
		//
		if ($this->_phpSheet->getTitle() == $sheetname) {
			$sheetname = '';
			$length	= 0x02;  // The following 2 bytes
			$cch	   = 1;	 // The following byte
			$rgch	  = 0x02;  // Self reference
		} else {
			$length	= 0x02 + strlen($sheetname);
			$cch	   = strlen($sheetname);
			$rgch	  = 0x03;  // Reference to a sheet in the current workbook
		}

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

	/**
	 * Writes the Excel BIFF PANE record.
	 * The panes can either be frozen or thawed (unfrozen).
	 * Frozen panes are specified in terms of an integer number of rows and columns.
	 * Thawed panes are specified in terms of Excel's units for rows and columns.
	 */
	private function _writePanes()
	{
		$panes = array();
		if ($freezePane = $this->_phpSheet->getFreezePane()) {
			list($column, $row) = PHPExcel_Cell::coordinateFromString($freezePane);
			$panes[0] = $row - 1;
			$panes[1] = PHPExcel_Cell::columnIndexFromString($column) - 1;
		} else {
			// thaw panes
			return;
		}

		$y	   = isset($panes[0]) ? $panes[0] : null;
		$x	   = isset($panes[1]) ? $panes[1] : null;
		$rwTop   = isset($panes[2]) ? $panes[2] : null;
		$colLeft = isset($panes[3]) ? $panes[3] : null;
		if (count($panes) > 4) { // if Active pane was received
			$pnnAct = $panes[4];
		} else {
			$pnnAct = null;
		}
		$record  = 0x0041;	   // Record identifier
		$length  = 0x000A;	   // Number of bytes to follow

		// Code specific to frozen or thawed panes.
		if ($this->_phpSheet->getFreezePane()) {
			// Set default values for $rwTop and $colLeft
			if (!isset($rwTop)) {
				$rwTop   = $y;
			}
			if (!isset($colLeft)) {
				$colLeft = $x;
			}
		} else {
			// Set default values for $rwTop and $colLeft
			if (!isset($rwTop)) {
				$rwTop   = 0;
			}
			if (!isset($colLeft)) {
				$colLeft = 0;
			}

			// Convert Excel's row and column units to the internal units.
			// The default row height is 12.75
			// The default column width is 8.43
			// The following slope and intersection values were interpolated.
			//
			$y = 20*$y + 255;
			$x = 113.879*$x + 390;
		}


		// Determine which pane should be active. There is also the undocumented
		// option to override this should it be necessary: may be removed later.
		//
		if (!isset($pnnAct)) {
			if ($x != 0 && $y != 0) {
				$pnnAct = 0; // Bottom right
			}
			if ($x != 0 && $y == 0) {
				$pnnAct = 1; // Top right
			}
			if ($x == 0 && $y != 0) {
				$pnnAct = 2; // Bottom left
			}
			if ($x == 0 && $y == 0) {
				$pnnAct = 3; // Top left
			}
		}

		$this->_active_pane = $pnnAct; // Used in _writeSelection

		$header	 = pack("vv",	$record, $length);
		$data	   = pack("vvvvv", $x, $y, $rwTop, $colLeft, $pnnAct);
		$this->_append($header . $data);
	}

	/**
	 * Store the page setup SETUP BIFF record.
	 */
	private function _writeSetup()
	{
		$record	   = 0x00A1;				  // Record identifier
		$length	   = 0x0022;				  // Number of bytes to follow

		$iPaperSize   = $this->_phpSheet->getPageSetup()->getPaperSize();	// Paper size

		$iScale = $this->_phpSheet->getPageSetup()->getScale() ?
			$this->_phpSheet->getPageSetup()->getScale() : 100;   // Print scaling factor

		$iPageStart   = 0x01;				 // Starting page number
		$iFitWidth	= (int) $this->_phpSheet->getPageSetup()->getFitToWidth();	// Fit to number of pages wide
		$iFitHeight	= (int) $this->_phpSheet->getPageSetup()->getFitToHeight();	// Fit to number of pages high
		$grbit		= 0x00;				 // Option flags
		$iRes		 = 0x0258;			   // Print resolution
		$iVRes		= 0x0258;			   // Vertical print resolution

		$numHdr	   = $this->_phpSheet->getPageMargins()->getHeader();  // Header Margin

		$numFtr	   = $this->_phpSheet->getPageMargins()->getFooter();   // Footer Margin
		$iCopies	  = 0x01;				 // Number of copies

		$fLeftToRight = 0x0;					 // Print over then down

		// Page orientation
		$fLandscape = ($this->_phpSheet->getPageSetup()->getOrientation() == PHPExcel_Worksheet_PageSetup::ORIENTATION_LANDSCAPE) ?
			0x0 : 0x1;

		$fNoPls	   = 0x0;					 // Setup not read from printer
		$fNoColor	 = 0x0;					 // Print black and white
		$fDraft	   = 0x0;					 // Print draft quality
		$fNotes	   = 0x0;					 // Print notes
		$fNoOrient	= 0x0;					 // Orientation not set
		$fUsePage	 = 0x0;					 // Use custom starting page

		$grbit		   = $fLeftToRight;
		$grbit		  |= $fLandscape	<< 1;
		$grbit		  |= $fNoPls		<< 2;
		$grbit		  |= $fNoColor	  << 3;
		$grbit		  |= $fDraft		<< 4;
		$grbit		  |= $fNotes		<< 5;
		$grbit		  |= $fNoOrient	 << 6;
		$grbit		  |= $fUsePage	  << 7;

		$numHdr = pack("d", $numHdr);
		$numFtr = pack("d", $numFtr);
		if (self::getByteOrder()) { // if it's Big Endian
			$numHdr = strrev($numHdr);
			$numFtr = strrev($numFtr);
		}

		$header = pack("vv", $record, $length);
		$data1  = pack("vvvvvvvv", $iPaperSize,
								   $iScale,
								   $iPageStart,
								   $iFitWidth,
								   $iFitHeight,
								   $grbit,
								   $iRes,
								   $iVRes);
		$data2  = $numHdr.$numFtr;
		$data3  = pack("v", $iCopies);
		$this->_append($header . $data1 . $data2 . $data3);
	}

	/**
	 * Store the header caption BIFF record.
	 */
	private function _writeHeader()
	{
		$record  = 0x0014;			   // Record identifier

		/* removing for now
		// need to fix character count (multibyte!)
		if (strlen($this->_phpSheet->getHeaderFooter()->getOddHeader()) <= 255) {
			$str	  = $this->_phpSheet->getHeaderFooter()->getOddHeader();	   // header string
		} else {
			$str = '';
		}
		*/

		$recordData = PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($this->_phpSheet->getHeaderFooter()->getOddHeader());
		$length = strlen($recordData);

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

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

	/**
	 * Store the footer caption BIFF record.
	 */
	private function _writeFooter()
	{
		$record  = 0x0015;			   // Record identifier

		/* removing for now
		// need to fix character count (multibyte!)
		if (strlen($this->_phpSheet->getHeaderFooter()->getOddFooter()) <= 255) {
			$str = $this->_phpSheet->getHeaderFooter()->getOddFooter();
		} else {
			$str = '';
		}
		*/

		$recordData = PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($this->_phpSheet->getHeaderFooter()->getOddFooter());
		$length = strlen($recordData);

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

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

	/**
	 * Store the horizontal centering HCENTER BIFF record.
	 *
	 * @access private
	 */
	private function _writeHcenter()
	{
		$record   = 0x0083;			  // Record identifier
		$length   = 0x0002;			  // Bytes to follow

		$fHCenter = $this->_phpSheet->getPageSetup()->getHorizontalCentered() ? 1 : 0;	 // Horizontal centering

		$header	= pack("vv", $record, $length);
		$data	  = pack("v",  $fHCenter);

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

	/**
	 * Store the vertical centering VCENTER BIFF record.
	 */
	private function _writeVcenter()
	{
		$record   = 0x0084;			  // Record identifier
		$length   = 0x0002;			  // Bytes to follow

		$fVCenter = $this->_phpSheet->getPageSetup()->getVerticalCentered() ? 1 : 0;	 // Horizontal centering

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

	/**
	 * Store the LEFTMARGIN BIFF record.
	 */
	private function _writeMarginLeft()
	{
		$record  = 0x0026;				   // Record identifier
		$length  = 0x0008;				   // Bytes to follow

		$margin  = $this->_phpSheet->getPageMargins()->getLeft();	 // Margin in inches

		$header	= pack("vv",  $record, $length);
		$data	  = pack("d",   $margin);
		if (self::getByteOrder()) { // if it's Big Endian
			$data = strrev($data);
		}

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

	/**
	 * Store the RIGHTMARGIN BIFF record.
	 */
	private function _writeMarginRight()
	{
		$record  = 0x0027;				   // Record identifier
		$length  = 0x0008;				   // Bytes to follow

		$margin  = $this->_phpSheet->getPageMargins()->getRight();	 // Margin in inches

		$header	= pack("vv",  $record, $length);
		$data	  = pack("d",   $margin);
		if (self::getByteOrder()) { // if it's Big Endian
			$data = strrev($data);
		}

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

	/**
	 * Store the TOPMARGIN BIFF record.
	 */
	private function _writeMarginTop()
	{
		$record  = 0x0028;				   // Record identifier
		$length  = 0x0008;				   // Bytes to follow

		$margin  = $this->_phpSheet->getPageMargins()->getTop();	 // Margin in inches

		$header	= pack("vv",  $record, $length);
		$data	  = pack("d",   $margin);
		if (self::getByteOrder()) { // if it's Big Endian
			$data = strrev($data);
		}

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

	/**
	 * Store the BOTTOMMARGIN BIFF record.
	 */
	private function _writeMarginBottom()
	{
		$record  = 0x0029;				   // Record identifier
		$length  = 0x0008;				   // Bytes to follow

		$margin  = $this->_phpSheet->getPageMargins()->getBottom();	 // Margin in inches

		$header	= pack("vv",  $record, $length);
		$data	  = pack("d",   $margin);
		if (self::getByteOrder()) { // if it's Big Endian
			$data = strrev($data);
		}

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

	/**
	 * Write the PRINTHEADERS BIFF record.
	 */
	private function _writePrintHeaders()
	{
		$record	  = 0x002a;				   // Record identifier
		$length	  = 0x0002;				   // Bytes to follow

		$fPrintRwCol = $this->_print_headers;	 // Boolean flag

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

	/**
	 * Write the PRINTGRIDLINES BIFF record. Must be used in conjunction with the
	 * GRIDSET record.
	 */
	private function _writePrintGridlines()
	{
		$record	  = 0x002b;					// Record identifier
		$length	  = 0x0002;					// Bytes to follow

		$fPrintGrid  = $this->_phpSheet->getPrintGridlines() ? 1 : 0;	// Boolean flag

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

	/**
	 * Write the GRIDSET BIFF record. Must be used in conjunction with the
	 * PRINTGRIDLINES record.
	 */
	private function _writeGridset()
	{
		$record	  = 0x0082;						// Record identifier
		$length	  = 0x0002;						// Bytes to follow

		$fGridSet	= !$this->_phpSheet->getPrintGridlines();	 // Boolean flag

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

	/**
	 * Write the AUTOFILTERINFO BIFF record. This is used to configure the number of autofilter select used in the sheet.
	 */
	private function _writeAutoFilterInfo(){
		$record	  = 0x009D;						// Record identifier
		$length	  = 0x0002;						// Bytes to follow

		$rangeBounds = PHPExcel_Cell::rangeBoundaries($this->_phpSheet->getAutoFilter()->getRange());
		$iNumFilters = 1 + $rangeBounds[1][0] - $rangeBounds[0][0];

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

	/**
	 * Write the GUTS BIFF record. This is used to configure the gutter margins
	 * where Excel outline symbols are displayed. The visibility of the gutters is
	 * controlled by a flag in WSBOOL.
	 *
	 * @see _writeWsbool()
	 */
	private  function _writeGuts()
	{
		$record	  = 0x0080;   // Record identifier
		$length	  = 0x0008;   // Bytes to follow

		$dxRwGut	 = 0x0000;   // Size of row gutter
		$dxColGut	= 0x0000;   // Size of col gutter

		// determine maximum row outline level
		$maxRowOutlineLevel = 0;
		foreach ($this->_phpSheet->getRowDimensions() as $rowDimension) {
			$maxRowOutlineLevel = max($maxRowOutlineLevel, $rowDimension->getOutlineLevel());
		}

		$col_level   = 0;

		// Calculate the maximum column outline level. The equivalent calculation
		// for the row outline level is carried out in _writeRow().
		$colcount = count($this->_colinfo);
		for ($i = 0; $i < $colcount; ++$i) {
			$col_level = max($this->_colinfo[$i][5], $col_level);
		}

		// Set the limits for the outline levels (0 <= x <= 7).
		$col_level = max(0, min($col_level, 7));

		// The displayed level is one greater than the max outline levels
		if ($maxRowOutlineLevel) {
			++$maxRowOutlineLevel;
		}
		if ($col_level) {
			++$col_level;
		}

		$header	  = pack("vv",   $record, $length);
		$data		= pack("vvvv", $dxRwGut, $dxColGut, $maxRowOutlineLevel, $col_level);

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

	/**
	 * Write the WSBOOL BIFF record, mainly for fit-to-page. Used in conjunction
	 * with the SETUP record.
	 */
	private function _writeWsbool()
	{
		$record	  = 0x0081;   // Record identifier
		$length	  = 0x0002;   // Bytes to follow
		$grbit	   = 0x0000;

		// The only option that is of interest is the flag for fit to page. So we
		// set all the options in one go.
		//
		// Set the option flags
		$grbit |= 0x0001;						   // Auto page breaks visible
		if ($this->_outline_style) {
			$grbit |= 0x0020; // Auto outline styles
		}
		if ($this->_phpSheet->getShowSummaryBelow()) {
			$grbit |= 0x0040; // Outline summary below
		}
		if ($this->_phpSheet->getShowSummaryRight()) {
			$grbit |= 0x0080; // Outline summary right
		}
		if ($this->_phpSheet->getPageSetup()->getFitToPage()) {
			$grbit |= 0x0100; // Page setup fit to page
		}
		if ($this->_outline_on) {
			$grbit |= 0x0400; // Outline symbols displayed
		}

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

	/**
	 * Write the HORIZONTALPAGEBREAKS and VERTICALPAGEBREAKS BIFF records.
	 */
	private function _writeBreaks()
	{
		// initialize
		$vbreaks = array();
		$hbreaks = array();

		foreach ($this->_phpSheet->getBreaks() as $cell => $breakType) {
			// Fetch coordinates
			$coordinates = PHPExcel_Cell::coordinateFromString($cell);

			// Decide what to do by the type of break
			switch ($breakType) {
				case PHPExcel_Worksheet::BREAK_COLUMN:
					// Add to list of vertical breaks
					$vbreaks[] = PHPExcel_Cell::columnIndexFromString($coordinates[0]) - 1;
					break;

				case PHPExcel_Worksheet::BREAK_ROW:
					// Add to list of horizontal breaks
					$hbreaks[] = $coordinates[1];
					break;

				case PHPExcel_Worksheet::BREAK_NONE:
				default:
					// Nothing to do
					break;
			}
		}

		//horizontal page breaks
		if (!empty($hbreaks)) {

			// Sort and filter array of page breaks
			sort($hbreaks, SORT_NUMERIC);
			if ($hbreaks[0] == 0) { // don't use first break if it's 0
				array_shift($hbreaks);
			}

			$record  = 0x001b;			   // Record identifier
			$cbrk	= count($hbreaks);	   // Number of page breaks
			$length  = 2 + 6 * $cbrk;	  // Bytes to follow

			$header  = pack("vv", $record, $length);
			$data	= pack("v",  $cbrk);

			// Append each page break
			foreach ($hbreaks as $hbreak) {
				$data .= pack("vvv", $hbreak, 0x0000, 0x00ff);
			}

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

		// vertical page breaks
		if (!empty($vbreaks)) {

			// 1000 vertical pagebreaks appears to be an internal Excel 5 limit.
			// It is slightly higher in Excel 97/200, approx. 1026
			$vbreaks = array_slice($vbreaks, 0, 1000);

			// Sort and filter array of page breaks
			sort($vbreaks, SORT_NUMERIC);
			if ($vbreaks[0] == 0) { // don't use first break if it's 0
				array_shift($vbreaks);
			}

			$record  = 0x001a;			   // Record identifier
			$cbrk	= count($vbreaks);	   // Number of page breaks
			$length  = 2 + 6 * $cbrk;	  // Bytes to follow

			$header  = pack("vv",  $record, $length);
			$data	= pack("v",   $cbrk);

			// Append each page break
			foreach ($vbreaks as $vbreak) {
				$data .= pack("vvv", $vbreak, 0x0000, 0xffff);
			}

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

	/**
	 * Set the Biff PROTECT record to indicate that the worksheet is protected.
	 */
	private function _writeProtect()
	{
		// Exit unless sheet protection has been specified
		if (!$this->_phpSheet->getProtection()->getSheet()) {
			return;
		}

		$record	  = 0x0012;			 // Record identifier
		$length	  = 0x0002;			 // Bytes to follow

		$fLock	  = 1;	// Worksheet is protected

		$header	  = pack("vv", $record, $length);
		$data	  = pack("v",  $fLock);

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

	/**
	 * Write SCENPROTECT
	 */
	private function _writeScenProtect()
	{
		// Exit if sheet protection is not active
		if (!$this->_phpSheet->getProtection()->getSheet()) {
			return;
		}

		// Exit if scenarios are not protected
		if (!$this->_phpSheet->getProtection()->getScenarios()) {
			return;
		}

		$record = 0x00DD; // Record identifier
		$length = 0x0002; // Bytes to follow

		$header = pack('vv', $record, $length);
		$data = pack('v', 1);

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

	/**
	 * Write OBJECTPROTECT
	 */
	private function _writeObjectProtect()
	{
		// Exit if sheet protection is not active
		if (!$this->_phpSheet->getProtection()->getSheet()) {
			return;
		}

		// Exit if objects are not protected
		if (!$this->_phpSheet->getProtection()->getObjects()) {
			return;
		}

		$record = 0x0063; // Record identifier
		$length = 0x0002; // Bytes to follow

		$header = pack('vv', $record, $length);
		$data = pack('v', 1);

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

	/**
	 * Write the worksheet PASSWORD record.
	 */
	private function _writePassword()
	{
		// Exit unless sheet protection and password have been specified
		if (!$this->_phpSheet->getProtection()->getSheet() || !$this->_phpSheet->getProtection()->getPassword()) {
			return;
		}

		$record	  = 0x0013;			   // Record identifier
		$length	  = 0x0002;			   // Bytes to follow

		$wPassword   = hexdec($this->_phpSheet->getProtection()->getPassword());	 // Encoded password

		$header	  = pack("vv", $record, $length);
		$data		= pack("v",  $wPassword);

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

	/**
	 * Insert a 24bit bitmap image in a worksheet.
	 *
	 * @access public
	 * @param integer $row	 The row we are going to insert the bitmap into
	 * @param integer $col	 The column we are going to insert the bitmap into
	 * @param mixed   $bitmap  The bitmap filename or GD-image resource
	 * @param integer $x	   The horizontal position (offset) of the image inside the cell.
	 * @param integer $y	   The vertical position (offset) of the image inside the cell.
	 * @param float   $scale_x The horizontal scale
	 * @param float   $scale_y The vertical scale
	 */
	function insertBitmap($row, $col, $bitmap, $x = 0, $y = 0, $scale_x = 1, $scale_y = 1)
	{
		$bitmap_array = (is_resource($bitmap) ? $this->_processBitmapGd($bitmap) : $this->_processBitmap($bitmap));
		list($width, $height, $size, $data) = $bitmap_array; //$this->_processBitmap($bitmap);

		// Scale the frame of the image.
		$width  *= $scale_x;
		$height *= $scale_y;

		// Calculate the vertices of the image and write the OBJ record
		$this->_positionImage($col, $row, $x, $y, $width, $height);

		// Write the IMDATA record to store the bitmap data
		$record	  = 0x007f;
		$length	  = 8 + $size;
		$cf		  = 0x09;
		$env		 = 0x01;
		$lcb		 = $size;

		$header	  = pack("vvvvV", $record, $length, $cf, $env, $lcb);
		$this->_append($header.$data);
	}

	/**
	 * Calculate the vertices that define the position of the image as required by
	 * the OBJ record.
	 *
	 *		 +------------+------------+
	 *		 |	 A	  |	  B	 |
	 *   +-----+------------+------------+
	 *   |	 |(x1,y1)	 |			|
	 *   |  1  |(A1)._______|______	  |
	 *   |	 |	|			  |	 |
	 *   |	 |	|			  |	 |
	 *   +-----+----|	BITMAP	|-----+
	 *   |	 |	|			  |	 |
	 *   |  2  |	|______________.	 |
	 *   |	 |			|		(B2)|
	 *   |	 |			|	 (x2,y2)|
	 *   +---- +------------+------------+
	 *
	 * Example of a bitmap that covers some of the area from cell A1 to cell B2.
	 *
	 * Based on the width and height of the bitmap we need to calculate 8 vars:
	 *	 $col_start, $row_start, $col_end, $row_end, $x1, $y1, $x2, $y2.
	 * The width and height of the cells are also variable and have to be taken into
	 * account.
	 * The values of $col_start and $row_start are passed in from the calling
	 * function. The values of $col_end and $row_end are calculated by subtracting
	 * the width and height of the bitmap from the width and height of the
	 * underlying cells.
	 * The vertices are expressed as a percentage of the underlying cell width as
	 * follows (rhs values are in pixels):
	 *
	 *	   x1 = X / W *1024
	 *	   y1 = Y / H *256
	 *	   x2 = (X-1) / W *1024
	 *	   y2 = (Y-1) / H *256
	 *
	 *	   Where:  X is distance from the left side of the underlying cell
	 *			   Y is distance from the top of the underlying cell
	 *			   W is the width of the cell
	 *			   H is the height of the cell
	 * The SDK incorrectly states that the height should be expressed as a
	 *		percentage of 1024.
	 *
	 * @access private
	 * @param integer $col_start Col containing upper left corner of object
	 * @param integer $row_start Row containing top left corner of object
	 * @param integer $x1		Distance to left side of object
	 * @param integer $y1		Distance to top of object
	 * @param integer $width	 Width of image frame
	 * @param integer $height	Height of image frame
	 */
	function _positionImage($col_start, $row_start, $x1, $y1, $width, $height)
	{
		// Initialise end cell to the same as the start cell
		$col_end	= $col_start;  // Col containing lower right corner of object
		$row_end	= $row_start;  // Row containing bottom right corner of object

		// Zero the specified offset if greater than the cell dimensions
		if ($x1 >= PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_start))) {
			$x1 = 0;
		}
		if ($y1 >= PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_start + 1)) {
			$y1 = 0;
		}

		$width	  = $width  + $x1 -1;
		$height	 = $height + $y1 -1;

		// Subtract the underlying cell widths to find the end cell of the image
		while ($width >= PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_end))) {
			$width -= PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_end));
			++$col_end;
		}

		// Subtract the underlying cell heights to find the end cell of the image
		while ($height >= PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_end + 1)) {
			$height -= PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_end + 1);
			++$row_end;
		}

		// Bitmap isn't allowed to start or finish in a hidden cell, i.e. a cell
		// with zero eight or width.
		//
		if (PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_start)) == 0) {
			return;
		}
		if (PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_end))   == 0) {
			return;
		}
		if (PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_start + 1) == 0) {
			return;
		}
		if (PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_end + 1)   == 0) {
			return;
		}

		// Convert the pixel values to the percentage value expected by Excel
		$x1 = $x1	 / PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_start))   * 1024;
		$y1 = $y1	 / PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_start + 1)   *  256;
		$x2 = $width  / PHPExcel_Shared_Excel5::sizeCol($this->_phpSheet, PHPExcel_Cell::stringFromColumnIndex($col_end))	 * 1024; // Distance to right side of object
		$y2 = $height / PHPExcel_Shared_Excel5::sizeRow($this->_phpSheet, $row_end + 1)	 *  256; // Distance to bottom of object

		$this->_writeObjPicture($col_start, $x1,
								 $row_start, $y1,
								 $col_end, $x2,
								 $row_end, $y2);
	}

	/**
	 * Store the OBJ record that precedes an IMDATA record. This could be generalise
	 * to support other Excel objects.
	 *
	 * @param integer $colL Column containing upper left corner of object
	 * @param integer $dxL  Distance from left side of cell
	 * @param integer $rwT  Row containing top left corner of object
	 * @param integer $dyT  Distance from top of cell
	 * @param integer $colR Column containing lower right corner of object
	 * @param integer $dxR  Distance from right of cell
	 * @param integer $rwB  Row containing bottom right corner of object
	 * @param integer $dyB  Distance from bottom of cell
	 */
	private function _writeObjPicture($colL,$dxL,$rwT,$dyT,$colR,$dxR,$rwB,$dyB)
	{
		$record	  = 0x005d;   // Record identifier
		$length	  = 0x003c;   // Bytes to follow

		$cObj		= 0x0001;   // Count of objects in file (set to 1)
		$OT		  = 0x0008;   // Object type. 8 = Picture
		$id		  = 0x0001;   // Object ID
		$grbit	   = 0x0614;   // Option flags

		$cbMacro	 = 0x0000;   // Length of FMLA structure
		$Reserved1   = 0x0000;   // Reserved
		$Reserved2   = 0x0000;   // Reserved

		$icvBack	 = 0x09;	 // Background colour
		$icvFore	 = 0x09;	 // Foreground colour
		$fls		 = 0x00;	 // Fill pattern
		$fAuto	   = 0x00;	 // Automatic fill
		$icv		 = 0x08;	 // Line colour
		$lns		 = 0xff;	 // Line style
		$lnw		 = 0x01;	 // Line weight
		$fAutoB	  = 0x00;	 // Automatic border
		$frs		 = 0x0000;   // Frame style
		$cf		  = 0x0009;   // Image format, 9 = bitmap
		$Reserved3   = 0x0000;   // Reserved
		$cbPictFmla  = 0x0000;   // Length of FMLA structure
		$Reserved4   = 0x0000;   // Reserved
		$grbit2	  = 0x0001;   // Option flags
		$Reserved5   = 0x0000;   // Reserved


		$header	  = pack("vv", $record, $length);
		$data		= pack("V", $cObj);
		$data	   .= pack("v", $OT);
		$data	   .= pack("v", $id);
		$data	   .= pack("v", $grbit);
		$data	   .= pack("v", $colL);
		$data	   .= pack("v", $dxL);
		$data	   .= pack("v", $rwT);
		$data	   .= pack("v", $dyT);
		$data	   .= pack("v", $colR);
		$data	   .= pack("v", $dxR);
		$data	   .= pack("v", $rwB);
		$data	   .= pack("v", $dyB);
		$data	   .= pack("v", $cbMacro);
		$data	   .= pack("V", $Reserved1);
		$data	   .= pack("v", $Reserved2);
		$data	   .= pack("C", $icvBack);
		$data	   .= pack("C", $icvFore);
		$data	   .= pack("C", $fls);
		$data	   .= pack("C", $fAuto);
		$data	   .= pack("C", $icv);
		$data	   .= pack("C", $lns);
		$data	   .= pack("C", $lnw);
		$data	   .= pack("C", $fAutoB);
		$data	   .= pack("v", $frs);
		$data	   .= pack("V", $cf);
		$data	   .= pack("v", $Reserved3);
		$data	   .= pack("v", $cbPictFmla);
		$data	   .= pack("v", $Reserved4);
		$data	   .= pack("v", $grbit2);
		$data	   .= pack("V", $Reserved5);

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

	/**
	 * Convert a GD-image into the internal format.
	 *
	 * @access private
	 * @param resource $image The image to process
	 * @return array Array with data and properties of the bitmap
	 */
	function _processBitmapGd($image) {
		$width = imagesx($image);
		$height = imagesy($image);

		$data = pack("Vvvvv", 0x000c, $width, $height, 0x01, 0x18);
		for ($j=$height; $j--; ) {
			for ($i=0; $i < $width; ++$i) {
				$color = imagecolorsforindex($image, imagecolorat($image, $i, $j));
				foreach (array("red", "green", "blue") as $key) {
					$color[$key] = $color[$key] + round((255 - $color[$key]) * $color["alpha"] / 127);
				}
				$data .= chr($color["blue"]) . chr($color["green"]) . chr($color["red"]);
			}
			if (3*$width % 4) {
				$data .= str_repeat("\x00", 4 - 3*$width % 4);
			}
		}

		return array($width, $height, strlen($data), $data);
	}

	/**
	 * Convert a 24 bit bitmap into the modified internal format used by Windows.
	 * This is described in BITMAPCOREHEADER and BITMAPCOREINFO structures in the
	 * MSDN library.
	 *
	 * @access private
	 * @param string $bitmap The bitmap to process
	 * @return array Array with data and properties of the bitmap
	 */
	function _processBitmap($bitmap)
	{
		// Open file.
		$bmp_fd = @fopen($bitmap,"rb");
		if (!$bmp_fd) {
			throw new PHPExcel_Writer_Exception("Couldn't import $bitmap");
		}

		// Slurp the file into a string.
		$data = fread($bmp_fd, filesize($bitmap));

		// Check that the file is big enough to be a bitmap.
		if (strlen($data) <= 0x36) {
			throw new PHPExcel_Writer_Exception("$bitmap doesn't contain enough data.\n");
		}

		// The first 2 bytes are used to identify the bitmap.
		$identity = unpack("A2ident", $data);
		if ($identity['ident'] != "BM") {
			throw new PHPExcel_Writer_Exception("$bitmap doesn't appear to be a valid bitmap image.\n");
		}

		// Remove bitmap data: ID.
		$data = substr($data, 2);

		// Read and remove the bitmap size. This is more reliable than reading
		// the data size at offset 0x22.
		//
		$size_array   = unpack("Vsa", substr($data, 0, 4));
		$size   = $size_array['sa'];
		$data   = substr($data, 4);
		$size  -= 0x36; // Subtract size of bitmap header.
		$size  += 0x0C; // Add size of BIFF header.

		// Remove bitmap data: reserved, offset, header length.
		$data = substr($data, 12);

		// Read and remove the bitmap width and height. Verify the sizes.
		$width_and_height = unpack("V2", substr($data, 0, 8));
		$width  = $width_and_height[1];
		$height = $width_and_height[2];
		$data   = substr($data, 8);
		if ($width > 0xFFFF) {
			throw new PHPExcel_Writer_Exception("$bitmap: largest image width supported is 65k.\n");
		}
		if ($height > 0xFFFF) {
			throw new PHPExcel_Writer_Exception("$bitmap: largest image height supported is 65k.\n");
		}

		// Read and remove the bitmap planes and bpp data. Verify them.
		$planes_and_bitcount = unpack("v2", substr($data, 0, 4));
		$data = substr($data, 4);
		if ($planes_and_bitcount[2] != 24) { // Bitcount
			throw new PHPExcel_Writer_Exception("$bitmap isn't a 24bit true color bitmap.\n");
		}
		if ($planes_and_bitcount[1] != 1) {
			throw new PHPExcel_Writer_Exception("$bitmap: only 1 plane supported in bitmap image.\n");
		}

		// Read and remove the bitmap compression. Verify compression.
		$compression = unpack("Vcomp", substr($data, 0, 4));
		$data = substr($data, 4);

		//$compression = 0;
		if ($compression['comp'] != 0) {
			throw new PHPExcel_Writer_Exception("$bitmap: compression not supported in bitmap image.\n");
		}

		// Remove bitmap data: data size, hres, vres, colours, imp. colours.
		$data = substr($data, 20);

		// Add the BITMAPCOREHEADER data
		$header  = pack("Vvvvv", 0x000c, $width, $height, 0x01, 0x18);
		$data	= $header . $data;

		return (array($width, $height, $size, $data));
	}

	/**
	 * Store the window zoom factor. This should be a reduced fraction but for
	 * simplicity we will store all fractions with a numerator of 100.
	 */
	private function _writeZoom()
	{
		// If scale is 100 we don't need to write a record
		if ($this->_phpSheet->getSheetView()->getZoomScale() == 100) {
			return;
		}

		$record	  = 0x00A0;			   // Record identifier
		$length	  = 0x0004;			   // Bytes to follow

		$header	  = pack("vv", $record, $length);
		$data		= pack("vv", $this->_phpSheet->getSheetView()->getZoomScale(), 100);
		$this->_append($header . $data);
	}

	/**
	 * 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;
	}

	/**
	 * Write MSODRAWING record
	 */
	private function _writeMsoDrawing()
	{
		// write the Escher stream if necessary
		if (isset($this->_escher)) {
			$writer = new PHPExcel_Writer_Excel5_Escher($this->_escher);
			$data = $writer->close();
			$spOffsets = $writer->getSpOffsets();
			$spTypes = $writer->getSpTypes();
			// write the neccesary MSODRAWING, OBJ records

			// split the Escher stream
			$spOffsets[0] = 0;
			$nm = count($spOffsets) - 1; // number of shapes excluding first shape
			for ($i = 1; $i <= $nm; ++$i) {
				// MSODRAWING record
				$record = 0x00EC;			// Record identifier

				// chunk of Escher stream for one shape
				$dataChunk = substr($data, $spOffsets[$i -1], $spOffsets[$i] - $spOffsets[$i - 1]);

				$length = strlen($dataChunk);
				$header = pack("vv", $record, $length);

				$this->_append($header . $dataChunk);

				// OBJ record
				$record = 0x005D; // record identifier
				$objData = '';

				// ftCmo
				if($spTypes[$i] == 0x00C9){
					// Add ftCmo (common object data) subobject
					$objData .=
						pack('vvvvvVVV'
								, 0x0015	// 0x0015 = ftCmo
								, 0x0012	// length of ftCmo data
								, 0x0014	// object type, 0x0014 = filter
								, $i		// object id number, Excel seems to use 1-based index, local for the sheet
								, 0x2101	// option flags, 0x2001 is what OpenOffice.org uses
								, 0			// reserved
								, 0			// reserved
								, 0			// reserved
						);

					// Add ftSbs Scroll bar subobject
					$objData .= pack('vv', 0x00C, 0x0014);
					$objData .= pack('H*', '0000000000000000640001000A00000010000100');
					// Add ftLbsData (List box data) subobject
					$objData .= pack('vv', 0x0013, 0x1FEE);
					$objData .= pack('H*', '00000000010001030000020008005700');
				}
				else {
					// Add ftCmo (common object data) subobject
					$objData .=
						pack('vvvvvVVV'
							, 0x0015	// 0x0015 = ftCmo
							, 0x0012	// length of ftCmo data
							, 0x0008	// object type, 0x0008 = picture
							, $i		// object id number, Excel seems to use 1-based index, local for the sheet
							, 0x6011	// option flags, 0x6011 is what OpenOffice.org uses
							, 0			// reserved
							, 0			// reserved
							, 0			// reserved
						);
				}

				// ftEnd
				$objData .=
					pack('vv'
						, 0x0000	// 0x0000 = ftEnd
						, 0x0000	// length of ftEnd data
					);

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

	/**
	 * Store the DATAVALIDATIONS and DATAVALIDATION records.
	 */
	private function _writeDataValidity()
	{
		// Datavalidation collection
		$dataValidationCollection = $this->_phpSheet->getDataValidationCollection();

		// Write data validations?
		if (!empty($dataValidationCollection)) {

			// DATAVALIDATIONS record
			$record = 0x01B2;	  // Record identifier
			$length	  = 0x0012;	  // Bytes to follow

			$grbit  = 0x0000;	   // Prompt box at cell, no cached validity data at DV records
			$horPos	  = 0x00000000;  // Horizontal position of prompt box, if fixed position
			$verPos	  = 0x00000000;  // Vertical position of prompt box, if fixed position
			$objId  = 0xFFFFFFFF;  // Object identifier of drop down arrow object, or -1 if not visible

			$header	  = pack('vv', $record, $length);
			$data		= pack('vVVVV', $grbit, $horPos, $verPos, $objId,
										 count($dataValidationCollection));
			$this->_append($header.$data);

			// DATAVALIDATION records
			$record = 0x01BE;			  // Record identifier

			foreach ($dataValidationCollection as $cellCoordinate => $dataValidation) {
				// initialize record data
				$data = '';

				// options
				$options = 0x00000000;

				// data type
				$type = $dataValidation->getType();
				switch ($type) {
					case PHPExcel_Cell_DataValidation::TYPE_NONE:		$type = 0x00;	break;
					case PHPExcel_Cell_DataValidation::TYPE_WHOLE:		$type = 0x01;	break;
					case PHPExcel_Cell_DataValidation::TYPE_DECIMAL:	$type = 0x02;	break;
					case PHPExcel_Cell_DataValidation::TYPE_LIST:		$type = 0x03;	break;
					case PHPExcel_Cell_DataValidation::TYPE_DATE:		$type = 0x04;	break;
					case PHPExcel_Cell_DataValidation::TYPE_TIME:		$type = 0x05;	break;
					case PHPExcel_Cell_DataValidation::TYPE_TEXTLENGTH:	$type = 0x06;	break;
					case PHPExcel_Cell_DataValidation::TYPE_CUSTOM:		$type = 0x07;	break;
				}
				$options |= $type << 0;

				// error style
				$errorStyle = $dataValidation->getType();
				switch ($errorStyle) {
					case PHPExcel_Cell_DataValidation::STYLE_STOP:			$errorStyle = 0x00;		break;
					case PHPExcel_Cell_DataValidation::STYLE_WARNING:		$errorStyle = 0x01;		break;
					case PHPExcel_Cell_DataValidation::STYLE_INFORMATION:	$errorStyle = 0x02;		break;
				}
				$options |= $errorStyle << 4;

				// explicit formula?
				if ($type == 0x03 && preg_match('/^\".*\"$/', $dataValidation->getFormula1())) {
					$options |= 0x01				<< 7;
				}

				// empty cells allowed
				$options |= $dataValidation->getAllowBlank() << 8;

				// show drop down
				$options |= (!$dataValidation->getShowDropDown()) << 9;

				// show input message
				$options |= $dataValidation->getShowInputMessage() << 18;

				// show error message
				$options |= $dataValidation->getShowErrorMessage() << 19;

				// condition operator
				$operator = $dataValidation->getOperator();
				switch ($operator) {
					case PHPExcel_Cell_DataValidation::OPERATOR_BETWEEN: $operator = 0x00			;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_NOTBETWEEN: $operator = 0x01		;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_EQUAL: $operator = 0x02				;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_NOTEQUAL: $operator = 0x03			;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_GREATERTHAN: $operator = 0x04		;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_LESSTHAN: $operator = 0x05			;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_GREATERTHANOREQUAL: $operator = 0x06;	break;
					case PHPExcel_Cell_DataValidation::OPERATOR_LESSTHANOREQUAL: $operator = 0x07	;	break;
				}
				$options |= $operator << 20;

				$data		= pack('V', $options);

				// prompt title
				$promptTitle = $dataValidation->getPromptTitle() !== '' ?
					$dataValidation->getPromptTitle() : chr(0);
				$data .= PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($promptTitle);

				// error title
				$errorTitle = $dataValidation->getErrorTitle() !== '' ?
					$dataValidation->getErrorTitle() : chr(0);
				$data .= PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($errorTitle);

				// prompt text
				$prompt = $dataValidation->getPrompt() !== '' ?
					$dataValidation->getPrompt() : chr(0);
				$data .= PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($prompt);

				// error text
				$error = $dataValidation->getError() !== '' ?
					$dataValidation->getError() : chr(0);
				$data .= PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($error);

				// formula 1
				try {
					$formula1 = $dataValidation->getFormula1();
					if ($type == 0x03) { // list type
						$formula1 = str_replace(',', chr(0), $formula1);
					}
					$this->_parser->parse($formula1);
					$formula1 = $this->_parser->toReversePolish();
					$sz1 = strlen($formula1);

				} catch(PHPExcel_Writer_Exception $e) {
					$sz1 = 0;
					$formula1 = '';
				}
				$data .= pack('vv', $sz1, 0x0000);
				$data .= $formula1;

				// formula 2
				try {
					$formula2 = $dataValidation->getFormula2();
					if ($formula2 === '') {
						throw new PHPExcel_Writer_Exception('No formula2');
					}
					$this->_parser->parse($formula2);
					$formula2 = $this->_parser->toReversePolish();
					$sz2 = strlen($formula2);

				} catch(PHPExcel_Writer_Exception $e) {
					$sz2 = 0;
					$formula2 = '';
				}
				$data .= pack('vv', $sz2, 0x0000);
				$data .= $formula2;

				// cell range address list
				$data .= pack('v', 0x0001);
				$data .= $this->_writeBIFF8CellRangeAddressFixed($cellCoordinate);

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

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

	/**
	 * Map Error code
	 *
	 * @param string $errorCode
	 * @return int
	 */
	private static function _mapErrorCode($errorCode) {
		switch ($errorCode) {
			case '#NULL!':	return 0x00;
			case '#DIV/0!':	return 0x07;
			case '#VALUE!':	return 0x0F;
			case '#REF!':	return 0x17;
			case '#NAME?':	return 0x1D;
			case '#NUM!':	return 0x24;
			case '#N/A':	return 0x2A;
		}

		return 0;
	}

	/**
	 * Write PLV Record
	 */
	private function _writePageLayoutView(){
		$record	  = 0x088B;			   // Record identifier
		$length	  = 0x0010;			   // Bytes to follow
		
		$rt         = 0x088B; // 2
		$grbitFrt   = 0x0000; // 2
		$reserved   = 0x0000000000000000; // 8
		$wScalvePLV = $this->_phpSheet->getSheetView()->getZoomScale(); // 2
		
		// The options flags that comprise $grbit
		if($this->_phpSheet->getSheetView()->getView() == PHPExcel_Worksheet_SheetView::SHEETVIEW_PAGE_LAYOUT){
			$fPageLayoutView   = 1;
		} else {
			$fPageLayoutView   = 0;
		}
		$fRulerVisible     = 0;
		$fWhitespaceHidden = 0;		
		
		$grbit      = $fPageLayoutView; // 2
		$grbit		|= $fRulerVisible	   << 1;
		$grbit		|= $fWhitespaceHidden  << 3;
		
		$header	  = pack("vv", $record, $length);
		$data	  = pack("vvVVvv", $rt, $grbitFrt, 0x00000000, 0x00000000, $wScalvePLV, $grbit);
		$this->_append($header . $data);
	}
}