/*
   xls2xml: Converts from Microsoft Excel files to XML.
   Copyright 1999  Roberto Arturo Tena Sanchez

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published  by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 */
/*
   Roberto Arturo Tena Sanchez <arturo@directmail.org>
 */
/*
   This file is highly speculative.
 */

for content in cell tag:
sss      means a string
=sss     means a formula
="sss"   means a formula with that uses a string


---

XML output is coded using UTF8:
(I got this from gnome-xml/encoding.c)
From rfc2044: encoding of the Unicode values on UTF-8:
UCS-2 range    UTF-8 octet sequence
(hex)          (binary)
0000 to 007F   0xxxxxxx
0080 to 07FF   110xxxxx 10xxxxxx
0800 to FFFF   1110xxxx 10xxxxxx 10xxxxxx

---

Symbols:
dddieee = float point number, converted from IEEE double precision number
fffieee = float point number, converted from IEEE single precision number
nnn = number
nnnlist = numbers separated by comma: nnn,nnn,nnn,... (vg. 0,1,2,3)
ppp = number in 1/20th of a point  (to get points, divide by 20)
ttt = number in 1/1000             (to get ratio [percent], divide by 1000)
sss = UTF8 string
xxxx ? = xxxx has zero or one instance
xxxx * = xxxx has zero, one or many instances
xxxx + = xxxx has one or many instances
xxxx ?(1) has one instance if specified EXTRACT_ALL, otherwise it has zero
xxxx ?(1) ? has zero or one instance if specified EXTRACT_ALL,
            otherwise it has zero

<?xml version="1.0"?>
fil_spreadsheet
  children =
  defaults
    children =
    tabsstate
      children =
      order ?
        content                  (it's zero-based)
          nnnlist                 they are sheets refnum list)
      top
        content =                (tab nnnth of sheetnumber is displayed at top)
        nnn
      first
        content =  (tab nnnth of sheetnumber is displayed first in bottom list)
        nnn
      howmanyselected
        content =
        nnn
      widthratiovshorizscrollbar
        content =
        ttt               (Ratio of the width of the workbook tabs list vs the
                           width of the horizontal scroll bar)
    build ?(1)
      children =
      appid ?(1)
        content =
        nnn
      appyear ?(1)
        content =
        nnn
      lasteditedWin ?(1) ?
      lasteditedRISC ?(1) ?
      lasteditedBeta ?(1) ?
      evereditedWin ?(1) ?
      evereditedMac ?(1) ?
      vereditedBeta ?(1) ?
      evereditedRISC ?(1) ?
    windowstate =
      children =
      metrics
        children =
        xpos
          content =
          ppp
        ypos
          content =
          ppp
        width =
          content =
          ppp
        height
          content =
          ppp
      display
        hidden
          content =
          yes|no                (if main window is hidden or not)
        iconic
          content =
          yes|no                (if main window is iconified or not)
        horizscrollbar
          content =
          yes|no                (if horizontal scrollbar is displayed or not)
        vertscrollbar
          content =
          yes|no                (if vertical scrollbar is displayed or not)
        tabs
          content =
          yes|no                (if sheets' tabs are displayed or not)
    ui
      children =                (reserved)
    codepage ?       (USELESS BECAUSE ALL WILL BE UNICODE UTF8 ENCODED)
      content =
      nnn
    username
      content =
      sss
    backup
      content =
      yes|no
    showobjects
      content =
      yes|placeholders|no
    precisionasdisplayed
      content =
      yes|no
    fonts ?
      children =
      font +
        attrib =
        refnum
          content =
          nnn
        children =
        height
          content =
          nnn
        italic
          content =
          yes|no
        strikeout
          content =
          yes|no
        outline
          content =
          yes|no
        shadow
          content =
          yes|no
        bold
          attrib =
          type
            content =
            numeric|yesno
          content =
            nnn |  (if type=numeric)
            yes|no (if type=yesno)
        pos
          content =
          normal|superscript|subscript
        underline
          content =
          yes|no
        family
          attrib =
          type
            content =
            numeric|word
          content =
            nnn |   (if type=numeric)
            sss     (if type=word)
        name
          content =
          sss
  sheets
    children =
    sheet
      attrib =
      refnum
        content =
        nnn
      children =
      cells
        children =
        cell *
          attrib =
          volatile ?        (if cell contains formula)
            content =
            yes|no
          coord
            content =
            Annn|RnnnCnnn
          content ? =
            dddieee|fffieee|=sss|sss
          children =
            formatting *
              attrib =
                fontrefnum
                  content =
                  nnn
              content =
                sss
      name
        content =
        sss
      hidden
        content =
        no|yes|very
      calculationmode
        content =
        auto|manual|autoexcepttables
      maxiterations
        content =
        nnn
      referencemode
        content =
        a1|r1c1
      takeiterationoptions
        content =
        no
      iterationdelta
        content =
        dddieee