runtime/autoload/tohtml.vim

" Vim autoload file for the tohtml plugin.
" Maintainer: Ben Fritz <fritzophrenic@gmail.com>
" Last Change: 2019 Aug 16
"
" Additional contributors:
"
"	      Original by Bram Moolenaar <Bram@vim.org>
"	      Diff2HTML() added by Christian Brabandt <cb@256bit.org>
"
"	      See Mercurial change logs for more!

" this file uses line continuations
let s:cpo_sav = &cpo
set cpo&vim

" Automatically find charsets from all encodings supported natively by Vim. With
" the 8bit- and 2byte- prefixes, Vim can actually support more encodings than
" this. Let the user specify these however since they won't be supported on
" every system.
"
" Note, not all of Vim's supported encodings have a charset to use.
"
" Names in this list are from:
"   http://www.iana.org/assignments/character-sets
" g:tohtml#encoding_to_charset: {{{
let g:tohtml#encoding_to_charset = {
      \ 'latin1' : 'ISO-8859-1',
      \ 'iso-8859-2' : 'ISO-8859-2',
      \ 'iso-8859-3' : 'ISO-8859-3',
      \ 'iso-8859-4' : 'ISO-8859-4',
      \ 'iso-8859-5' : 'ISO-8859-5',
      \ 'iso-8859-6' : 'ISO-8859-6',
      \ 'iso-8859-7' : 'ISO-8859-7',
      \ 'iso-8859-8' : 'ISO-8859-8',
      \ 'iso-8859-9' : 'ISO-8859-9',
      \ 'iso-8859-10' : '',
      \ 'iso-8859-13' : 'ISO-8859-13',
      \ 'iso-8859-14' : '',
      \ 'iso-8859-15' : 'ISO-8859-15',
      \ 'koi8-r' : 'KOI8-R',
      \ 'koi8-u' : 'KOI8-U',
      \ 'macroman' : 'macintosh',
      \ 'cp437' : '',
      \ 'cp775' : '',
      \ 'cp850' : '',
      \ 'cp852' : '',
      \ 'cp855' : '',
      \ 'cp857' : '',
      \ 'cp860' : '',
      \ 'cp861' : '',
      \ 'cp862' : '',
      \ 'cp863' : '',
      \ 'cp865' : '',
      \ 'cp866' : 'IBM866',
      \ 'cp869' : '',
      \ 'cp874' : '',
      \ 'cp1250' : 'windows-1250',
      \ 'cp1251' : 'windows-1251',
      \ 'cp1253' : 'windows-1253',
      \ 'cp1254' : 'windows-1254',
      \ 'cp1255' : 'windows-1255',
      \ 'cp1256' : 'windows-1256',
      \ 'cp1257' : 'windows-1257',
      \ 'cp1258' : 'windows-1258',
      \ 'euc-jp' : 'EUC-JP',
      \ 'sjis' : 'Shift_JIS',
      \ 'cp932' : 'Shift_JIS',
      \ 'cp949' : '',
      \ 'euc-kr' : 'EUC-KR',
      \ 'cp936' : 'GBK',
      \ 'euc-cn' : 'GB2312',
      \ 'big5' : 'Big5',
      \ 'cp950' : 'Big5',
      \ 'utf-8' : 'UTF-8',
      \ 'ucs-2' : 'UTF-8',
      \ 'ucs-2le' : 'UTF-8',
      \ 'utf-16' : 'UTF-8',
      \ 'utf-16le' : 'UTF-8',
      \ 'ucs-4' : 'UTF-8',
      \ 'ucs-4le' : 'UTF-8',
      \ }
lockvar g:tohtml#encoding_to_charset
" Notes:
"   1. All UCS/UTF are converted to UTF-8 because it is much better supported
"   2. Any blank spaces are there because Vim supports it but at least one major
"      web browser does not according to http://wiki.whatwg.org/wiki/Web_Encodings.
" }}}

" Only automatically find encodings supported natively by Vim, let the user
" specify the encoding if it's not natively supported. This function is only
" used when the user specifies the charset, they better know what they are
" doing!
"
" Names in this list are from:
"   http://www.iana.org/assignments/character-sets
" g:tohtml#charset_to_encoding: {{{
let g:tohtml#charset_to_encoding = {
      \ 'iso_8859-1:1987' : 'latin1',
      \ 'iso-ir-100' : 'latin1',
      \ 'iso_8859-1' : 'latin1',
      \ 'iso-8859-1' : 'latin1',
      \ 'latin1' : 'latin1',
      \ 'l1' : 'latin1',
      \ 'ibm819' : 'latin1',
      \ 'cp819' : 'latin1',
      \ 'csisolatin1' : 'latin1',
      \ 'iso_8859-2:1987' : 'iso-8859-2',
      \ 'iso-ir-101' : 'iso-8859-2',
      \ 'iso_8859-2' : 'iso-8859-2',
      \ 'iso-8859-2' : 'iso-8859-2',
      \ 'latin2' : 'iso-8859-2',
      \ 'l2' : 'iso-8859-2',
      \ 'csisolatin2' : 'iso-8859-2',
      \ 'iso_8859-3:1988' : 'iso-8859-3',
      \ 'iso-ir-109' : 'iso-8859-3',
      \ 'iso_8859-3' : 'iso-8859-3',
      \ 'iso-8859-3' : 'iso-8859-3',
      \ 'latin3' : 'iso-8859-3',
      \ 'l3' : 'iso-8859-3',
      \ 'csisolatin3' : 'iso-8859-3',
      \ 'iso_8859-4:1988' : 'iso-8859-4',
      \ 'iso-ir-110' : 'iso-8859-4',
      \ 'iso_8859-4' : 'iso-8859-4',
      \ 'iso-8859-4' : 'iso-8859-4',
      \ 'latin4' : 'iso-8859-4',
      \ 'l4' : 'iso-8859-4',
      \ 'csisolatin4' : 'iso-8859-4',
      \ 'iso_8859-5:1988' : 'iso-8859-5',
      \ 'iso-ir-144' : 'iso-8859-5',
      \ 'iso_8859-5' : 'iso-8859-5',
      \ 'iso-8859-5' : 'iso-8859-5',
      \ 'cyrillic' : 'iso-8859-5',
      \ 'csisolatincyrillic' : 'iso-8859-5',
      \ 'iso_8859-6:1987' : 'iso-8859-6',
      \ 'iso-ir-127' : 'iso-8859-6',
      \ 'iso_8859-6' : 'iso-8859-6',
      \ 'iso-8859-6' : 'iso-8859-6',
      \ 'ecma-114' : 'iso-8859-6',
      \ 'asmo-708' : 'iso-8859-6',
      \ 'arabic' : 'iso-8859-6',
      \ 'csisolatinarabic' : 'iso-8859-6',
      \ 'iso_8859-7:1987' : 'iso-8859-7',
      \ 'iso-ir-126' : 'iso-8859-7',
      \ 'iso_8859-7' : 'iso-8859-7',
      \ 'iso-8859-7' : 'iso-8859-7',
      \ 'elot_928' : 'iso-8859-7',
      \ 'ecma-118' : 'iso-8859-7',
      \ 'greek' : 'iso-8859-7',
      \ 'greek8' : 'iso-8859-7',
      \ 'csisolatingreek' : 'iso-8859-7',
      \ 'iso_8859-8:1988' : 'iso-8859-8',
      \ 'iso-ir-138' : 'iso-8859-8',
      \ 'iso_8859-8' : 'iso-8859-8',
      \ 'iso-8859-8' : 'iso-8859-8',
      \ 'hebrew' : 'iso-8859-8',
      \ 'csisolatinhebrew' : 'iso-8859-8',
      \ 'iso_8859-9:1989' : 'iso-8859-9',
      \ 'iso-ir-148' : 'iso-8859-9',
      \ 'iso_8859-9' : 'iso-8859-9',
      \ 'iso-8859-9' : 'iso-8859-9',
      \ 'latin5' : 'iso-8859-9',
      \ 'l5' : 'iso-8859-9',
      \ 'csisolatin5' : 'iso-8859-9',
      \ 'iso-8859-10' : 'iso-8859-10',
      \ 'iso-ir-157' : 'iso-8859-10',
      \ 'l6' : 'iso-8859-10',
      \ 'iso_8859-10:1992' : 'iso-8859-10',
      \ 'csisolatin6' : 'iso-8859-10',
      \ 'latin6' : 'iso-8859-10',
      \ 'iso-8859-13' : 'iso-8859-13',
      \ 'iso-8859-14' : 'iso-8859-14',
      \ 'iso-ir-199' : 'iso-8859-14',
      \ 'iso_8859-14:1998' : 'iso-8859-14',
      \ 'iso_8859-14' : 'iso-8859-14',
      \ 'latin8' : 'iso-8859-14',
      \ 'iso-celtic' : 'iso-8859-14',
      \ 'l8' : 'iso-8859-14',
      \ 'iso-8859-15' : 'iso-8859-15',
      \ 'iso_8859-15' : 'iso-8859-15',
      \ 'latin-9' : 'iso-8859-15',
      \ 'koi8-r' : 'koi8-r',
      \ 'cskoi8r' : 'koi8-r',
      \ 'koi8-u' : 'koi8-u',
      \ 'macintosh' : 'macroman',
      \ 'mac' : 'macroman',
      \ 'csmacintosh' : 'macroman',
      \ 'ibm437' : 'cp437',
      \ 'cp437' : 'cp437',
      \ '437' : 'cp437',
      \ 'cspc8codepage437' : 'cp437',
      \ 'ibm775' : 'cp775',
      \ 'cp775' : 'cp775',
      \ 'cspc775baltic' : 'cp775',
      \ 'ibm850' : 'cp850',
      \ 'cp850' : 'cp850',
      \ '850' : 'cp850',
      \ 'cspc850multilingual' : 'cp850',
      \ 'ibm852' : 'cp852',
      \ 'cp852' : 'cp852',
      \ '852' : 'cp852',
      \ 'cspcp852' : 'cp852',
      \ 'ibm855' : 'cp855',
      \ 'cp855' : 'cp855',
      \ '855' : 'cp855',
      \ 'csibm855' : 'cp855',
      \ 'ibm857' : 'cp857',
      \ 'cp857' : 'cp857',
      \ '857' : 'cp857',
      \ 'csibm857' : 'cp857',
      \ 'ibm860' : 'cp860',
      \ 'cp860' : 'cp860',
      \ '860' : 'cp860',
      \ 'csibm860' : 'cp860',
      \ 'ibm861' : 'cp861',
      \ 'cp861' : 'cp861',
      \ '861' : 'cp861',
      \ 'cp-is' : 'cp861',
      \ 'csibm861' : 'cp861',
      \ 'ibm862' : 'cp862',
      \ 'cp862' : 'cp862',
      \ '862' : 'cp862',
      \ 'cspc862latinhebrew' : 'cp862',
      \ 'ibm863' : 'cp863',
      \ 'cp863' : 'cp863',
      \ '863' : 'cp863',
      \ 'csibm863' : 'cp863',
      \ 'ibm865' : 'cp865',
      \ 'cp865' : 'cp865',
      \ '865' : 'cp865',
      \ 'csibm865' : 'cp865',
      \ 'ibm866' : 'cp866',
      \ 'cp866' : 'cp866',
      \ '866' : 'cp866',
      \ 'csibm866' : 'cp866',
      \ 'ibm869' : 'cp869',
      \ 'cp869' : 'cp869',
      \ '869' : 'cp869',
      \ 'cp-gr' : 'cp869',
      \ 'csibm869' : 'cp869',
      \ 'windows-1250' : 'cp1250',
      \ 'windows-1251' : 'cp1251',
      \ 'windows-1253' : 'cp1253',
      \ 'windows-1254' : 'cp1254',
      \ 'windows-1255' : 'cp1255',
      \ 'windows-1256' : 'cp1256',
      \ 'windows-1257' : 'cp1257',
      \ 'windows-1258' : 'cp1258',
      \ 'extended_unix_code_packed_format_for_japanese' : 'euc-jp',
      \ 'cseucpkdfmtjapanese' : 'euc-jp',
      \ 'euc-jp' : 'euc-jp',
      \ 'shift_jis' : 'sjis',
      \ 'ms_kanji' : 'sjis',
      \ 'sjis' : 'sjis',
      \ 'csshiftjis' : 'sjis',
      \ 'ibm-thai' : 'cp874',
      \ 'csibmthai' : 'cp874',
      \ 'ks_c_5601-1987' : 'cp949',
      \ 'iso-ir-149' : 'cp949',
      \ 'ks_c_5601-1989' : 'cp949',
      \ 'ksc_5601' : 'cp949',
      \ 'korean' : 'cp949',
      \ 'csksc56011987' : 'cp949',
      \ 'euc-kr' : 'euc-kr',
      \ 'cseuckr' : 'euc-kr',
      \ 'gbk' : 'cp936',
      \ 'cp936' : 'cp936',
      \ 'ms936' : 'cp936',
      \ 'windows-936' : 'cp936',
      \ 'gb_2312-80' : 'euc-cn',
      \ 'iso-ir-58' : 'euc-cn',
      \ 'chinese' : 'euc-cn',
      \ 'csiso58gb231280' : 'euc-cn',
      \ 'big5' : 'big5',
      \ 'csbig5' : 'big5',
      \ 'utf-8' : 'utf-8',
      \ 'iso-10646-ucs-2' : 'ucs-2',
      \ 'csunicode' : 'ucs-2',
      \ 'utf-16' : 'utf-16',
      \ 'utf-16be' : 'utf-16',
      \ 'utf-16le' : 'utf-16le',
      \ 'utf-32' : 'ucs-4',
      \ 'utf-32be' : 'ucs-4',
      \ 'utf-32le' : 'ucs-4le',
      \ 'iso-10646-ucs-4' : 'ucs-4',
      \ 'csucs4' : 'ucs-4'
      \ }
lockvar g:tohtml#charset_to_encoding
"}}}

func! tohtml#Convert2HTML(line1, line2) "{{{
  let s:settings = tohtml#GetUserSettings()

  if !&diff || s:settings.diff_one_file "{{{
    if a:line2 >= a:line1
      let g:html_start_line = a:line1
      let g:html_end_line = a:line2
    else
      let g:html_start_line = a:line2
      let g:html_end_line = a:line1
    endif
    runtime syntax/2html.vim "}}}
  else "{{{
    let win_list = []
    let buf_list = []
    windo if &diff | call add(win_list, winbufnr(0)) | endif
    let s:settings.whole_filler = 1
    let g:html_diff_win_num = 0
    for window in win_list
      " switch to the next buffer to convert
      exe ":" . bufwinnr(window) . "wincmd w"

      " figure out whether current charset and encoding will work, if not
      " default to UTF-8
      if !exists('g:html_use_encoding') &&
	    \ (((&l:fileencoding=='' || (&l:buftype!='' && &l:buftype!=?'help'))
	    \      && &encoding!=?s:settings.vim_encoding)
	    \ || &l:fileencoding!='' && &l:fileencoding!=?s:settings.vim_encoding)
	echohl WarningMsg
	echomsg "TOhtml: mismatched file encodings in Diff buffers, using UTF-8"
	echohl None
	let s:settings.vim_encoding = 'utf-8'
	let s:settings.encoding = 'UTF-8'
      endif

      " set up for diff-mode conversion
      let g:html_start_line = 1
      let g:html_end_line = line('$')
      let g:html_diff_win_num += 1

      " convert this file
      runtime syntax/2html.vim

      " remember the HTML buffer for later combination
      call add(buf_list, bufnr('%'))
    endfor
    unlet g:html_diff_win_num
    call tohtml#Diff2HTML(win_list, buf_list)
  endif "}}}

  unlet g:html_start_line
  unlet g:html_end_line
  unlet s:settings
endfunc "}}}

func! tohtml#Diff2HTML(win_list, buf_list) "{{{
  let xml_line = ""
  let tag_close = '>'

  let s:old_paste = &paste
  set paste
  let s:old_magic = &magic
  set magic

  if s:settings.use_xhtml
    if s:settings.encoding != ""
      let xml_line = "<?xml version=\"1.0\" encoding=\"" . s:settings.encoding . "\"?>"
    else
      let xml_line = "<?xml version=\"1.0\"?>"
    endif
    let tag_close = ' />'
  endif

  let style = [s:settings.use_xhtml ? "" : '-->']
  let body_line = ''

  let html = []
  let s:html5 = 0
  if s:settings.use_xhtml
    call add(html, xml_line)
  endif
  if s:settings.use_xhtml
    call add(html, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">")
    call add(html, '<html xmlns="http://www.w3.org/1999/xhtml">')
  elseif s:settings.use_css && !s:settings.no_pre
    call add(html, "<!DOCTYPE html>")
    call add(html, '<html>')
    let s:html5 = 1
  else
    call add(html, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"')
    call add(html, '  "http://www.w3.org/TR/html4/loose.dtd">')
    call add(html, '<html>')
  endif
  call add(html, '<head>')

  " include encoding as close to the top as possible, but only if not already
  " contained in XML information
  if s:settings.encoding != "" && !s:settings.use_xhtml
    if s:html5
      call add(html, '<meta charset="' . s:settings.encoding . '"' . tag_close)
    else
      call add(html, "<meta http-equiv=\"content-type\" content=\"text/html; charset=" . s:settings.encoding . '"' . tag_close)
    endif
  endif

  call add(html, '<title>diff</title>')
  call add(html, '<meta name="Generator" content="Vim/'.v:version/100.'.'.v:version%100.'"'.tag_close)
  call add(html, '<meta name="plugin-version" content="'.g:loaded_2html_plugin.'"'.tag_close)
  call add(html, '<meta name="settings" content="'.
	\ join(filter(keys(s:settings),'s:settings[v:val]'),',').
	\ ',prevent_copy='.s:settings.prevent_copy.
	\ ',use_input_for_pc='.s:settings.use_input_for_pc.
	\ '"'.tag_close)
  call add(html, '<meta name="colorscheme" content="'.
	\ (exists('g:colors_name')
	\ ? g:colors_name
	\ : 'none'). '"'.tag_close)

  call add(html, '</head>')
  let body_line_num = len(html)
  call add(html, '<body'.(s:settings.line_ids ? ' onload="JumpToLine();"' : '').'>')
  call add(html, "<table ".(s:settings.use_css? "" : "border='1' width='100%' ")."id='vimCodeElement".s:settings.id_suffix."'>")

  call add(html, '<tr>')
  for buf in a:win_list
    call add(html, '<th>'.bufname(buf).'</th>')
  endfor
  call add(html, '</tr><tr>')

  let diff_style_start = 0
  let insert_index = 0

  for buf in a:buf_list
    let temp = []
    exe bufwinnr(buf) . 'wincmd w'

    " If text is folded because of user foldmethod settings, etc. we don't want
    " to act on everything in a fold by mistake.
    setlocal nofoldenable

    " When not using CSS or when using xhtml, the <body> line can be important.
    " Assume it will be the same for all buffers and grab it from the first
    " buffer. Similarly, need to grab the body end line as well.
    if body_line == ''
      1
      call search('<body')
      let body_line = getline('.')
      $
      call search('</body>', 'b')
      let s:body_end_line = getline('.')
    endif

    " Grab the style information. Some of this will be duplicated so only insert
    " it if it's not already there. {{{
    1
    let style_start = search('^<style\( type="text/css"\)\?>')
    1
    let style_end = search('^</style>')
    if style_start > 0 && style_end > 0
      let buf_styles = getline(style_start + 1, style_end - 1)
      for a_style in buf_styles
	if index(style, a_style) == -1
	  if diff_style_start == 0
	    if a_style =~ '\<Diff\(Change\|Text\|Add\|Delete\)'
	      let diff_style_start = len(style)-1
	    endif
	  endif
	  call insert(style, a_style, insert_index)
	  let insert_index += 1
	endif
      endfor
    endif " }}}

    " everything new will get added before the diff styles so diff highlight
    " properly overrides normal highlight
    if diff_style_start != 0
      let insert_index = diff_style_start
    endif

    " Delete those parts that are not needed so we can include the rest into the
    " resulting table.
    1,/^<body.*\%(\n<!--.*-->\_s\+.*id='oneCharWidth'.*\_s\+.*id='oneInputWidth'.*\_s\+.*id='oneEmWidth'\)\?\zs/d_
    $
    ?</body>?,$d_
    let temp = getline(1,'$')
    " clean out id on the main content container because we already set it on
    " the table
    let temp[0] = substitute(temp[0], " id='vimCodeElement[^']*'", "", "")
    " undo deletion of start and end part
    " so we can later save the file as valid html
    " TODO: restore using grabbed lines if undolevel is 1?
    normal! 2u
    if s:settings.use_css
      call add(html, '<td><div>')
    elseif s:settings.use_xhtml
      call add(html, '<td nowrap="nowrap" valign="top"><div>')
    else
      call add(html, '<td nowrap valign="top"><div>')
    endif
    let html += temp
    call add(html, '</div></td>')

    " Close this buffer
    " TODO: the comment above says we're going to allow saving the file
    " later...but here we discard it?
    quit!
  endfor

  let html[body_line_num] = body_line

  call add(html, '</tr>')
  call add(html, '</table>')
  call add(html, s:body_end_line)
  call add(html, '</html>')

  " The generated HTML is admittedly ugly and takes a LONG time to fold.
  " Make sure the user doesn't do syntax folding when loading a generated file,
  " using a modeline.
  call add(html, '<!-- vim: set foldmethod=manual : -->')

  let i = 1
  let name = "Diff" . (s:settings.use_xhtml ? ".xhtml" : ".html")
  " Find an unused file name if current file name is already in use
  while filereadable(name)
    let name = substitute(name, '\d*\.x\?html$', '', '') . i . '.' . fnamemodify(copy(name), ":t:e")
    let i += 1
  endwhile

  let s:ei_sav = &eventignore
  set eventignore+=FileType
  exe "topleft new " . name
  let &eventignore=s:ei_sav
  unlet s:ei_sav

  setlocal modifiable

  " just in case some user autocmd creates content in the new buffer, make sure
  " it is empty before proceeding
  %d

  " set the fileencoding to match the charset we'll be using
  let &l:fileencoding=s:settings.vim_encoding

  " According to http://www.w3.org/TR/html4/charset.html#doc-char-set, the byte
  " order mark is highly recommend on the web when using multibyte encodings. But,
  " it is not a good idea to include it on UTF-8 files. Otherwise, let Vim
  " determine when it is actually inserted.
  if s:settings.vim_encoding == 'utf-8'
    setlocal nobomb
  else
    setlocal bomb
  endif

  call append(0, html)

  if len(style) > 0
    1
    let style_start = search('^</head>')-1

    " add required javascript in reverse order so we can just call append again
    " and again without adjusting {{{

    let s:uses_script = s:settings.dynamic_folds || s:settings.line_ids

    " insert script closing tag if needed
    if s:uses_script
      call append(style_start, [
	    \ '',
	    \ s:settings.use_xhtml ? '//]]>' : '-->',
	    \ "</script>"
	    \ ])
    endif

    " insert javascript to get IDs from line numbers, and to open a fold before
    " jumping to any lines contained therein
    if s:settings.line_ids
      call append(style_start, [
	    \ "  /* Always jump to new location even if the line was hidden inside a fold, or",
	    \ "   * we corrected the raw number to a line ID.",
	    \ "   */",
	    \ "  if (lineElem) {",
	    \ "    lineElem.scrollIntoView(true);",
	    \ "  }",
	    \ "  return true;",
	    \ "}",
	    \ "if ('onhashchange' in window) {",
	    \ "  window.onhashchange = JumpToLine;",
	    \ "}"
	    \ ])

      if s:settings.dynamic_folds
	call append(style_start, [
	      \ "",
	      \ "  /* navigate upwards in the DOM tree to open all folds containing the line */",
	      \ "  var node = lineElem;",
	      \ "  while (node && node.id != 'vimCodeElement".s:settings.id_suffix."')",
	      \ "  {",
	      \ "    if (node.className == 'closed-fold')",
	      \ "    {",
	      \ "      /* toggle open the fold ID (remove window ID) */",
	      \ "      toggleFold(node.id.substr(4));",
	      \ "    }",
	      \ "    node = node.parentNode;",
	      \ "  }",
	      \ ])
      endif
    endif

    if s:settings.line_ids
      call append(style_start, [
	    \ "",
	    \ "/* function to open any folds containing a jumped-to line before jumping to it */",
	    \ "function JumpToLine()",
	    \ "{",
	    \ "  var lineNum;",
	    \ "  lineNum = window.location.hash;",
	    \ "  lineNum = lineNum.substr(1); /* strip off '#' */",
	    \ "",
	    \ "  if (lineNum.indexOf('L') == -1) {",
	    \ "    lineNum = 'L'+lineNum;",
	    \ "  }",
	    \ "  if (lineNum.indexOf('W') == -1) {",
	    \ "    lineNum = 'W1'+lineNum;",
	    \ "  }",
	    \ "  var lineElem = document.getElementById(lineNum);"
	    \ ])
    endif

    " Insert javascript to toggle matching folds open and closed in all windows,
    " if dynamic folding is active.
    if s:settings.dynamic_folds
      call append(style_start, [
	    \  "  function toggleFold(objID)",
	    \  "  {",
	    \  "    for (win_num = 1; win_num <= ".len(a:buf_list)."; win_num++)",
	    \  "    {",
	    \  "      var fold;",
	    \  '      fold = document.getElementById("win"+win_num+objID);',
	    \  "      if(fold.className == 'closed-fold')",
	    \  "      {",
	    \  "        fold.className = 'open-fold';",
	    \  "      }",
	    \  "      else if (fold.className == 'open-fold')",
	    \  "      {",
	    \  "        fold.className = 'closed-fold';",
	    \  "      }",
	    \  "    }",
	    \  "  }",
	    \ ])
    endif

    if s:uses_script
      " insert script tag if needed
      call append(style_start, [
	    \ "<script" . (s:html5 ? "" : " type='text/javascript'") . ">",
	    \ s:settings.use_xhtml ? '//<![CDATA[' : "<!--"])
    endif

    " Insert styles from all the generated html documents and additional styles
    " for the table-based layout of the side-by-side diff. The diff should take
    " up the full browser window (but not more), and be static in size,
    " horizontally scrollable when the lines are too long. Otherwise, the diff
    " is pretty useless for really long lines. {{{
    if s:settings.use_css
      call append(style_start,
	    \ ['<style' . (s:html5 ? '' : 'type="text/css"') . '>']+
	    \ style+
	    \ [ s:settings.use_xhtml ? '' : '<!--',
	    \   'table { table-layout: fixed; }',
	    \   'html, body, table, tbody { width: 100%; margin: 0; padding: 0; }',
	    \   'table, td, th { border: 1px solid; }',
	    \   'td { vertical-align: top; }',
	    \   'th, td { width: '.printf("%.1f",100.0/len(a:win_list)).'%; }',
	    \   'td div { overflow: auto; }',
	    \   s:settings.use_xhtml ? '' : '-->',
	    \   '</style>'
	    \])
    endif "}}}
  endif

  let &paste = s:old_paste
  let &magic = s:old_magic
endfunc "}}}

" Gets a single user option and sets it in the passed-in Dict, or gives it the
" default value if the option doesn't actually exist.
func! tohtml#GetOption(settings, option, default) "{{{
  if exists('g:html_'.a:option)
    let a:settings[a:option] = g:html_{a:option}
  else
    let a:settings[a:option] = a:default
  endif
endfunc "}}}

" returns a Dict containing the values of all user options for 2html, including
" default values for those not given an explicit value by the user. Discards the
" html_ prefix of the option for nicer looking code.
func! tohtml#GetUserSettings() "{{{
  if exists('s:settings')
    " just restore the known options if we've already retrieved them
    return s:settings
  else
    " otherwise figure out which options are set
    let user_settings = {}

    " Define the correct option if the old option name exists and we haven't
    " already defined the correct one. Maybe I'll put out a warning message about
    " this sometime and remove the old option entirely at some even later time,
    " but for now just silently accept the old option.
    if exists('g:use_xhtml') && !exists("g:html_use_xhtml")
      let g:html_use_xhtml = g:use_xhtml
    endif

    " get current option settings with appropriate defaults {{{
    call tohtml#GetOption(user_settings,       'no_progress', !has("statusline") )
    call tohtml#GetOption(user_settings,     'diff_one_file', 0 )
    call tohtml#GetOption(user_settings,      'number_lines', &number )
    call tohtml#GetOption(user_settings,          'pre_wrap', &wrap )
    call tohtml#GetOption(user_settings,           'use_css', 1 )
    call tohtml#GetOption(user_settings,    'ignore_conceal', 0 )
    call tohtml#GetOption(user_settings,    'ignore_folding', 0 )
    call tohtml#GetOption(user_settings,     'dynamic_folds', 0 )
    call tohtml#GetOption(user_settings,     'no_foldcolumn', user_settings.ignore_folding)
    call tohtml#GetOption(user_settings,      'hover_unfold', 0 )
    call tohtml#GetOption(user_settings,            'no_pre', 0 )
    call tohtml#GetOption(user_settings,        'no_invalid', 0 )
    call tohtml#GetOption(user_settings,      'whole_filler', 0 )
    call tohtml#GetOption(user_settings,         'use_xhtml', 0 )
    call tohtml#GetOption(user_settings,          'line_ids', user_settings.number_lines )
    call tohtml#GetOption(user_settings, 'use_input_for_pc', 'fallback')
    " }}}
    
    " override those settings that need it {{{

    " hover opening implies dynamic folding
    if user_settings.hover_unfold
      let user_settings.dynamic_folds = 1
    endif

    " ignore folding overrides dynamic folding
    if user_settings.ignore_folding && user_settings.dynamic_folds
      let user_settings.dynamic_folds = 0
      let user_settings.hover_unfold = 0
    endif

    " dynamic folding with no foldcolumn implies hover opens
    if user_settings.dynamic_folds && user_settings.no_foldcolumn
      let user_settings.hover_unfold = 1
    endif

    " dynamic folding implies css
    if user_settings.dynamic_folds
      let user_settings.use_css = 1
    else
      let user_settings.no_foldcolumn = 1 " won't do anything but for consistency and for the test suite
    endif

    " if we're not using CSS we cannot use a pre section because <font> tags
    " aren't allowed inside a <pre> block
    if !user_settings.use_css
      let user_settings.no_pre = 1
    endif

    " pre_wrap doesn't do anything if not using pre or not using CSS
    if user_settings.no_pre || !user_settings.use_css
      let user_settings.pre_wrap=0
    endif
    "}}}

    " set up expand_tabs option after all the overrides so we know the
    " appropriate defaults {{{
    if user_settings.no_pre == 0
      call tohtml#GetOption(user_settings,
	    \ 'expand_tabs',
	    \ &expandtab || &ts != 8 || &vts != '' || user_settings.number_lines ||
	    \   (user_settings.dynamic_folds && !user_settings.no_foldcolumn))
    else
      let user_settings.expand_tabs = 1
    endif
    " }}}

    " textual options
    if exists("g:html_use_encoding") "{{{
      " user specified the desired MIME charset, figure out proper
      " 'fileencoding' from it or warn the user if we cannot
      let user_settings.encoding = g:html_use_encoding
      let user_settings.vim_encoding = tohtml#EncodingFromCharset(g:html_use_encoding)
      if user_settings.vim_encoding == ''
	echohl WarningMsg
	echomsg "TOhtml: file encoding for"
	      \ g:html_use_encoding
	      \ "unknown, please set 'fileencoding'"
	echohl None
      endif
    else
      " Figure out proper MIME charset from 'fileencoding' if possible
      if &l:fileencoding != '' 
	" If the buffer is not a "normal" type, the 'fileencoding' value may not
	" be trusted; since the buffer should not be written the fileencoding is
	" not intended to be used.
	if &l:buftype=='' || &l:buftype==?'help'
	  let user_settings.vim_encoding = &l:fileencoding
	  call tohtml#CharsetFromEncoding(user_settings)
	else
	  let user_settings.encoding = '' " trigger detection using &encoding
	endif
      endif

      " else from 'encoding' if possible
      if &l:fileencoding == '' || user_settings.encoding == ''
	let user_settings.vim_encoding = &encoding
	call tohtml#CharsetFromEncoding(user_settings)
      endif

      " else default to UTF-8 and warn user
      if user_settings.encoding == ''
	let user_settings.vim_encoding = 'utf-8'
	let user_settings.encoding = 'UTF-8'
	echohl WarningMsg
	echomsg "TOhtml: couldn't determine MIME charset, using UTF-8"
	echohl None
      endif
    endif "}}}

    " Default to making nothing uncopyable, because we default to
    " not-standards way of doing things, and also because Microsoft Word and
    " others paste the <input> elements anyway.
    "
    " html_prevent_copy only has an effect when using CSS.
    "
    " All options:
    "	  f - fold column
    "	  n - line numbers (also within fold text)
    "	  t - fold text
    "	  d - diff filler
    "	  c - concealed text (reserved future)
    "	  l - listchars (reserved possible future)
    "	  s - signs (reserved possible future)
    "
    " Normal text is always selectable.
    let user_settings.prevent_copy = ""
    if user_settings.use_css
      if exists("g:html_prevent_copy")
	if user_settings.dynamic_folds && !user_settings.no_foldcolumn && g:html_prevent_copy =~# 'f'
	  let user_settings.prevent_copy .= 'f'
	endif
	if user_settings.number_lines && g:html_prevent_copy =~# 'n'
	  let user_settings.prevent_copy .= 'n'
	endif
	if &diff && g:html_prevent_copy =~# 'd'
	  let user_settings.prevent_copy .= 'd'
	endif
	if !user_settings.ignore_folding && g:html_prevent_copy =~# 't'
	  let user_settings.prevent_copy .= 't'
	endif
      else
	let user_settings.prevent_copy = ""
      endif
    endif
    if empty(user_settings.prevent_copy)
      let user_settings.no_invalid = 0
    endif

    " enforce valid values for use_input_for_pc
    if user_settings.use_input_for_pc !~# 'fallback\|none\|all'
      let user_settings.use_input_for_pc = 'fallback'
      echohl WarningMsg
      echomsg '2html: "' . g:html_use_input_for_pc . '" is not valid for g:html_use_input_for_pc'
      echomsg '2html: defaulting to "' . user_settings.use_input_for_pc . '"'
      echohl None
      sleep 3
    endif

    if exists('g:html_id_expr')
      let user_settings.id_suffix = eval(g:html_id_expr)
      if user_settings.id_suffix !~ '^[-_:.A-Za-z0-9]*$'
	echohl WarningMsg
	echomsg '2html: g:html_id_expr evaluated to invalid string for HTML id attributes'
	echomsg '2html: Omitting user-specified suffix'
	echohl None
	sleep 3
	let user_settings.id_suffix=""
      endif
    else
      let user_settings.id_suffix=""
    endif

    " TODO: font

    return user_settings
  endif
endfunc "}}}

" get the proper HTML charset name from a Vim encoding option.
function! tohtml#CharsetFromEncoding(settings) "{{{
  let l:vim_encoding = a:settings.vim_encoding
  if exists('g:html_charset_override') && has_key(g:html_charset_override, l:vim_encoding)
    let a:settings.encoding = g:html_charset_override[l:vim_encoding]
  else
    if l:vim_encoding =~ '^8bit\|^2byte'
      " 8bit- and 2byte- prefixes are to indicate encodings available on the
      " system that Vim will convert with iconv(), look up just the encoding name,
      " not Vim's prefix.
      let l:vim_encoding = substitute(l:vim_encoding, '^8bit-\|^2byte-', '', '')
    endif
    if has_key(g:tohtml#encoding_to_charset, l:vim_encoding)
      let a:settings.encoding = g:tohtml#encoding_to_charset[l:vim_encoding]
    else
      let a:settings.encoding = ""
    endif
  endif
  if a:settings.encoding != ""
    let l:vim_encoding = tohtml#EncodingFromCharset(a:settings.encoding)
    if l:vim_encoding != ""
      " if the Vim encoding to HTML encoding conversion is set up (by default or
      " by the user) to convert to a different encoding, we need to also change
      " the Vim encoding of the new buffer
      let a:settings.vim_encoding = l:vim_encoding
    endif
  endif
endfun "}}}

" Get the proper Vim encoding option setting from an HTML charset name.
function! tohtml#EncodingFromCharset(encoding) "{{{
  if exists('g:html_encoding_override') && has_key(g:html_encoding_override, a:encoding)
    return g:html_encoding_override[a:encoding]
  elseif has_key(g:tohtml#charset_to_encoding, tolower(a:encoding))
    return g:tohtml#charset_to_encoding[tolower(a:encoding)]
  else
    return ""
  endif
endfun "}}}

let &cpo = s:cpo_sav
unlet s:cpo_sav

" Make sure any patches will probably use consistent indent
"   vim: ts=8 sw=2 sts=2 noet fdm=marker