From: balpha Date: Wed, 3 Aug 2011 16:29:58 +0000 (+0200) Subject: initial commit X-Git-Url: http://git.roojs.org/?p=pagedown;a=commitdiff_plain;h=340f85793552abe1775dc4457e50cd04c63ca590 initial commit --- 340f85793552abe1775dc4457e50cd04c63ca590 diff --git a/LICENSE.txt b/LICENSE.txt new file mode 100644 index 0000000..a0c9467 --- /dev/null +++ b/LICENSE.txt @@ -0,0 +1,32 @@ +A javascript port of Markdown, as used on Stack Overflow +and the rest of Stack Exchange network. + +Largely based on showdown.js by John Fraser (Attacklab). + +Original Markdown Copyright (c) 2004-2005 John Gruber + + + +Original Showdown code copyright (c) 2007 John Fraser + +Modifications and bugfixes (c) 2009 Dana Robinson +Modifications and bugfixes (c) 2009-2011 Stack Exchange Inc. + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. + diff --git a/Markdown.Converter.js b/Markdown.Converter.js new file mode 100644 index 0000000..4460c32 --- /dev/null +++ b/Markdown.Converter.js @@ -0,0 +1,1318 @@ +var Markdown; + +if (typeof exports === "object" && typeof require === "function") // we're in a CommonJS (e.g. Node.js) module + Markdown = exports; +else + Markdown = {}; + +// The following text is included for historical reasons, but should +// be taken with a pinch of salt; it's not all true anymore. + +// +// Wherever possible, Showdown is a straight, line-by-line port +// of the Perl version of Markdown. +// +// This is not a normal parser design; it's basically just a +// series of string substitutions. It's hard to read and +// maintain this way, but keeping Showdown close to the original +// design makes it easier to port new features. +// +// More importantly, Showdown behaves like markdown.pl in most +// edge cases. So web applications can do client-side preview +// in Javascript, and then build identical HTML on the server. +// +// This port needs the new RegExp functionality of ECMA 262, +// 3rd Edition (i.e. Javascript 1.5). Most modern web browsers +// should do fine. Even with the new regular expression features, +// We do a lot of work to emulate Perl's regex functionality. +// The tricky changes in this file mostly have the "attacklab:" +// label. Major or self-explanatory changes don't. +// +// Smart diff tools like Araxis Merge will be able to match up +// this file with markdown.pl in a useful way. A little tweaking +// helps: in a copy of markdown.pl, replace "#" with "//" and +// replace "$text" with "text". Be sure to ignore whitespace +// and line endings. +// + + +// +// Usage: +// +// var text = "Markdown *rocks*."; +// +// var converter = new Markdown.Converter(); +// var html = converter.makeHtml(text); +// +// alert(html); +// +// Note: move the sample code to the bottom of this +// file before uncommenting it. +// + +(function () { + + function identity(x) { return x; } + function returnFalse(x) { return false; } + + function HookCollection() { } + + HookCollection.prototype = { + + chain: function (hookname, func) { + var original = this[hookname]; + if (!original) + throw new Error("unknown hook " + hookname); + + if (original === identity) + this[hookname] = func; + else + this[hookname] = function (x) { return func(original(x)); } + }, + set: function (hookname, func) { + if (!this[hookname]) + throw new Error("unknown hook " + hookname); + this[hookname] = func; + }, + addNoop: function (hookname) { + this[hookname] = identity; + }, + addFalse: function (hookname) { + this[hookname] = returnFalse; + } + }; + + Markdown.HookCollection = HookCollection; + + // g_urls and g_titles allow arbitrary user-entered strings as keys. This + // caused an exception (and hence stopped the rendering) when the user entered + // e.g. [push] or [__proto__]. Adding a prefix to the actual key prevents this + // (since no builtin property starts with "s_"). See + // http://meta.stackoverflow.com/questions/64655/strange-wmd-bug + // (granted, switching from Array() to Object() alone would have left only __proto__ + // to be a problem) + function SaveHash() { } + SaveHash.prototype = { + set: function (key, value) { + this["s_" + key] = value; + }, + get: function (key) { + return this["s_" + key]; + } + }; + + Markdown.Converter = function () { + var pluginHooks = this.hooks = new HookCollection(); + pluginHooks.addNoop("plainLinkText"); // given a URL that was encountered by itself (without markup), should return the link text that's to be given to this link + pluginHooks.addNoop("preConversion"); // called with the orignal text as given to makeHtml. The result of this plugin hook is the actual markdown source that will be cooked + pluginHooks.addNoop("postConversion"); // called with the final cooked HTML code. The result of this plugin hook is the actual output of makeHtml + + // + // Private state of the converter instance: + // + + // Global hashes, used by various utility routines + var g_urls; + var g_titles; + var g_html_blocks; + + // Used to track when we're inside an ordered or unordered list + // (see _ProcessListItems() for details): + var g_list_level; + + this.makeHtml = function (text) { + + // + // Main function. The order in which other subs are called here is + // essential. Link and image substitutions need to happen before + // _EscapeSpecialCharsWithinTagAttributes(), so that any *'s or _'s in the + // and tags get encoded. + // + + // This will only happen if makeHtml on the same converter instance is called from a plugin hook. + // Don't do that. + if (g_urls) + throw new Error("Recursive call to converter.makeHtml"); + + // Create the private state objects. + g_urls = new SaveHash(); + g_titles = new SaveHash(); + g_html_blocks = []; + g_list_level = 0; + + text = pluginHooks.preConversion(text); + + // attacklab: Replace ~ with ~T + // This lets us use tilde as an escape char to avoid md5 hashes + // The choice of character is arbitray; anything that isn't + // magic in Markdown will work. + text = text.replace(/~/g, "~T"); + + // attacklab: Replace $ with ~D + // RegExp interprets $ as a special character + // when it's in a replacement string + text = text.replace(/\$/g, "~D"); + + // Standardize line endings + text = text.replace(/\r\n/g, "\n"); // DOS to Unix + text = text.replace(/\r/g, "\n"); // Mac to Unix + + // Make sure text begins and ends with a couple of newlines: + text = "\n\n" + text + "\n\n"; + + // Convert all tabs to spaces. + text = _Detab(text); + + // Strip any lines consisting only of spaces and tabs. + // This makes subsequent regexen easier to write, because we can + // match consecutive blank lines with /\n+/ instead of something + // contorted like /[ \t]*\n+/ . + text = text.replace(/^[ \t]+$/mg, ""); + + // Turn block-level HTML blocks into hash entries + text = _HashHTMLBlocks(text); + + // Strip link definitions, store in hashes. + text = _StripLinkDefinitions(text); + + text = _RunBlockGamut(text); + + text = _UnescapeSpecialChars(text); + + // attacklab: Restore dollar signs + text = text.replace(/~D/g, "$$"); + + // attacklab: Restore tildes + text = text.replace(/~T/g, "~"); + + text = pluginHooks.postConversion(text); + + g_html_blocks = g_titles = g_urls = null; + + return text; + }; + + function _StripLinkDefinitions(text) { + // + // Strips link definitions from text, stores the URLs and titles in + // hash references. + // + + // Link defs are in the form: ^[id]: url "optional title" + + /* + text = text.replace(/ + ^[ ]{0,3}\[(.+)\]: // id = $1 attacklab: g_tab_width - 1 + [ \t]* + \n? // maybe *one* newline + [ \t]* + ? // url = $2 + (?=\s|$) // lookahead for whitespace instead of the lookbehind removed below + [ \t]* + \n? // maybe one newline + [ \t]* + ( // (potential) title = $3 + (\n*) // any lines skipped = $4 attacklab: lookbehind removed + [ \t]+ + ["(] + (.+?) // title = $5 + [")] + [ \t]* + )? // title is optional + (?:\n+|$) + /gm, function(){...}); + */ + + text = text.replace(/^[ ]{0,3}\[(.+)\]:[ \t]*\n?[ \t]*?(?=\s|$)[ \t]*\n?[ \t]*((\n*)["(](.+?)[")][ \t]*)?(?:\n+)/gm, + function (wholeMatch, m1, m2, m3, m4, m5) { + m1 = m1.toLowerCase(); + g_urls.set(m1, _EncodeAmpsAndAngles(m2)); // Link IDs are case-insensitive + if (m4) { + // Oops, found blank lines, so it's not a title. + // Put back the parenthetical statement we stole. + return m3; + } else if (m5) { + g_titles.set(m1, m5.replace(/"/g, """)); + } + + // Completely remove the definition from the text + return ""; + } + ); + + return text; + } + + function _HashHTMLBlocks(text) { + + // Hashify HTML blocks: + // We only want to do this for block-level HTML tags, such as headers, + // lists, and tables. That's because we still want to wrap

s around + // "paragraphs" that are wrapped in non-block-level tags, such as anchors, + // phrase emphasis, and spans. The list of tags we're looking for is + // hard-coded: + var block_tags_a = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del" + var block_tags_b = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math" + + // First, look for nested blocks, e.g.: + //

+ //
+ // tags for inner block must be indented. + //
+ //
+ // + // The outermost tags must start at the left margin for this to match, and + // the inner nested divs must be indented. + // We need to do this before the next, more liberal match, because the next + // match will start at the first `
` and stop at the first `
`. + + // attacklab: This regex can be expensive when it fails. + + /* + text = text.replace(/ + ( // save in $1 + ^ // start of line (with /m) + <($block_tags_a) // start tag = $2 + \b // word break + // attacklab: hack around khtml/pcre bug... + [^\r]*?\n // any number of lines, minimally matching + // the matching end tag + [ \t]* // trailing spaces/tabs + (?=\n+) // followed by a newline + ) // attacklab: there are sentinel newlines at end of document + /gm,function(){...}}; + */ + text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del)\b[^\r]*?\n<\/\2>[ \t]*(?=\n+))/gm, hashElement); + + // + // Now match more liberally, simply from `\n` to `\n` + // + + /* + text = text.replace(/ + ( // save in $1 + ^ // start of line (with /m) + <($block_tags_b) // start tag = $2 + \b // word break + // attacklab: hack around khtml/pcre bug... + [^\r]*? // any number of lines, minimally matching + .* // the matching end tag + [ \t]* // trailing spaces/tabs + (?=\n+) // followed by a newline + ) // attacklab: there are sentinel newlines at end of document + /gm,function(){...}}; + */ + text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math)\b[^\r]*?.*<\/\2>[ \t]*(?=\n+)\n)/gm, hashElement); + + // Special case just for
. It was easier to make a special case than + // to make the other regex more complicated. + + /* + text = text.replace(/ + \n // Starting after a blank line + [ ]{0,3} + ( // save in $1 + (<(hr) // start tag = $2 + \b // word break + ([^<>])*? + \/?>) // the matching end tag + [ \t]* + (?=\n{2,}) // followed by a blank line + ) + /g,hashElement); + */ + text = text.replace(/\n[ ]{0,3}((<(hr)\b([^<>])*?\/?>)[ \t]*(?=\n{2,}))/g, hashElement); + + // Special case for standalone HTML comments: + + /* + text = text.replace(/ + \n\n // Starting after a blank line + [ ]{0,3} // attacklab: g_tab_width - 1 + ( // save in $1 + -]|-[^>])(?:[^-]|-[^-])*)--) // see http://www.w3.org/TR/html-markup/syntax.html#comments and http://meta.stackoverflow.com/q/95256 + > + [ \t]* + (?=\n{2,}) // followed by a blank line + ) + /g,hashElement); + */ + text = text.replace(/\n\n[ ]{0,3}(-]|-[^>])(?:[^-]|-[^-])*)--)>[ \t]*(?=\n{2,}))/g, hashElement); + + // PHP and ASP-style processor instructions ( and <%...%>) + + /* + text = text.replace(/ + (?: + \n\n // Starting after a blank line + ) + ( // save in $1 + [ ]{0,3} // attacklab: g_tab_width - 1 + (?: + <([?%]) // $2 + [^\r]*? + \2> + ) + [ \t]* + (?=\n{2,}) // followed by a blank line + ) + /g,hashElement); + */ + text = text.replace(/(?:\n\n)([ ]{0,3}(?:<([?%])[^\r]*?\2>)[ \t]*(?=\n{2,}))/g, hashElement); + + return text; + } + + function hashElement(wholeMatch, m1) { + var blockText = m1; + + // Undo double lines + blockText = blockText.replace(/^\n+/, ""); + + // strip trailing blank lines + blockText = blockText.replace(/\n+$/g, ""); + + // Replace the element text with a marker ("~KxK" where x is its key) + blockText = "\n\n~K" + (g_html_blocks.push(blockText) - 1) + "K\n\n"; + + return blockText; + } + + function _RunBlockGamut(text, doNotUnhash) { + // + // These are all the transformations that form block-level + // tags like paragraphs, headers, and list items. + // + text = _DoHeaders(text); + + // Do Horizontal Rules: + var replacement = "
\n"; + text = text.replace(/^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$/gm, replacement); + text = text.replace(/^[ ]{0,2}([ ]?-[ ]?){3,}[ \t]*$/gm, replacement); + text = text.replace(/^[ ]{0,2}([ ]?_[ ]?){3,}[ \t]*$/gm, replacement); + + text = _DoLists(text); + text = _DoCodeBlocks(text); + text = _DoBlockQuotes(text); + + // We already ran _HashHTMLBlocks() before, in Markdown(), but that + // was to escape raw HTML in the original Markdown source. This time, + // we're escaping the markup we've just created, so that we don't wrap + //

tags around block-level tags. + text = _HashHTMLBlocks(text); + text = _FormParagraphs(text, doNotUnhash); + + return text; + } + + function _RunSpanGamut(text) { + // + // These are all the transformations that occur *within* block-level + // tags like paragraphs, headers, and list items. + // + + text = _DoCodeSpans(text); + text = _EscapeSpecialCharsWithinTagAttributes(text); + text = _EncodeBackslashEscapes(text); + + // Process anchor and image tags. Images must come first, + // because ![foo][f] looks like an anchor. + text = _DoImages(text); + text = _DoAnchors(text); + + // Make links out of things like `` + // Must come after _DoAnchors(), because you can use < and > + // delimiters in inline links like [this](). + text = _DoAutoLinks(text); + text = _EncodeAmpsAndAngles(text); + text = _DoItalicsAndBold(text); + + // Do hard breaks: + text = text.replace(/ +\n/g, "
\n"); + + return text; + } + + function _EscapeSpecialCharsWithinTagAttributes(text) { + // + // Within tags -- meaning between < and > -- encode [\ ` * _] so they + // don't conflict with their use in Markdown for code, italics and strong. + // + + // Build a regex to find HTML tags and comments. See Friedl's + // "Mastering Regular Expressions", 2nd Ed., pp. 200-201. + + // SE: changed the comment part of the regex + + var regex = /(<[a-z\/!$]("[^"]*"|'[^']*'|[^'">])*>|-]|-[^>])(?:[^-]|-[^-])*)--)>)/gi; + + text = text.replace(regex, function (wholeMatch) { + var tag = wholeMatch.replace(/(.)<\/?code>(?=.)/g, "$1`"); + tag = escapeCharacters(tag, wholeMatch.charAt(1) == "!" ? "\\`*_/" : "\\`*_"); // also escape slashes in comments to prevent autolinking there -- http://meta.stackoverflow.com/questions/95987 + return tag; + }); + + return text; + } + + function _DoAnchors(text) { + // + // Turn Markdown link shortcuts into XHTML tags. + // + // + // First, handle reference-style links: [link text] [id] + // + + /* + text = text.replace(/ + ( // wrap whole match in $1 + \[ + ( + (?: + \[[^\]]*\] // allow brackets nested one level + | + [^\[] // or anything else + )* + ) + \] + + [ ]? // one optional space + (?:\n[ ]*)? // one optional newline followed by spaces + + \[ + (.*?) // id = $3 + \] + ) + ()()()() // pad remaining backreferences + /g, writeAnchorTag); + */ + text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeAnchorTag); + + // + // Next, inline-style links: [link text](url "optional title") + // + + /* + text = text.replace(/ + ( // wrap whole match in $1 + \[ + ( + (?: + \[[^\]]*\] // allow brackets nested one level + | + [^\[\]] // or anything else + )* + ) + \] + \( // literal paren + [ \t]* + () // no id, so leave $3 empty + ? + [ \t]* + ( // $5 + (['"]) // quote char = $6 + (.*?) // Title = $7 + \6 // matching quote + [ \t]* // ignore any spaces/tabs between closing quote and ) + )? // title is optional + \) + ) + /g, writeAnchorTag); + */ + + text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\]\([ \t]*()?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeAnchorTag); + + // + // Last, handle reference-style shortcuts: [link text] + // These must come last in case you've also got [link test][1] + // or [link test](/foo) + // + + /* + text = text.replace(/ + ( // wrap whole match in $1 + \[ + ([^\[\]]+) // link text = $2; can't contain '[' or ']' + \] + ) + ()()()()() // pad rest of backreferences + /g, writeAnchorTag); + */ + text = text.replace(/(\[([^\[\]]+)\])()()()()()/g, writeAnchorTag); + + return text; + } + + function writeAnchorTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) { + if (m7 == undefined) m7 = ""; + var whole_match = m1; + var link_text = m2; + var link_id = m3.toLowerCase(); + var url = m4; + var title = m7; + + if (url == "") { + if (link_id == "") { + // lower-case and turn embedded newlines into spaces + link_id = link_text.toLowerCase().replace(/ ?\n/g, " "); + } + url = "#" + link_id; + + if (g_urls.get(link_id) != undefined) { + url = g_urls.get(link_id); + if (g_titles.get(link_id) != undefined) { + title = g_titles.get(link_id); + } + } + else { + if (whole_match.search(/\(\s*\)$/m) > -1) { + // Special case for explicit empty url + url = ""; + } else { + return whole_match; + } + } + } + url = encodeProblemUrlChars(url); + url = escapeCharacters(url, "*_"); + var result = ""; + + return result; + } + + function _DoImages(text) { + // + // Turn Markdown image shortcuts into tags. + // + + // + // First, handle reference-style labeled images: ![alt text][id] + // + + /* + text = text.replace(/ + ( // wrap whole match in $1 + !\[ + (.*?) // alt text = $2 + \] + + [ ]? // one optional space + (?:\n[ ]*)? // one optional newline followed by spaces + + \[ + (.*?) // id = $3 + \] + ) + ()()()() // pad rest of backreferences + /g, writeImageTag); + */ + text = text.replace(/(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeImageTag); + + // + // Next, handle inline images: ![alt text](url "optional title") + // Don't forget: encode * and _ + + /* + text = text.replace(/ + ( // wrap whole match in $1 + !\[ + (.*?) // alt text = $2 + \] + \s? // One optional whitespace character + \( // literal paren + [ \t]* + () // no id, so leave $3 empty + ? // src url = $4 + [ \t]* + ( // $5 + (['"]) // quote char = $6 + (.*?) // title = $7 + \6 // matching quote + [ \t]* + )? // title is optional + \) + ) + /g, writeImageTag); + */ + text = text.replace(/(!\[(.*?)\]\s?\([ \t]*()?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeImageTag); + + return text; + } + + function writeImageTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) { + var whole_match = m1; + var alt_text = m2; + var link_id = m3.toLowerCase(); + var url = m4; + var title = m7; + + if (!title) title = ""; + + if (url == "") { + if (link_id == "") { + // lower-case and turn embedded newlines into spaces + link_id = alt_text.toLowerCase().replace(/ ?\n/g, " "); + } + url = "#" + link_id; + + if (g_urls.get(link_id) != undefined) { + url = g_urls.get(link_id); + if (g_titles.get(link_id) != undefined) { + title = g_titles.get(link_id); + } + } + else { + return whole_match; + } + } + + alt_text = alt_text.replace(/"/g, """); + url = escapeCharacters(url, "*_"); + var result = "\""" + _RunSpanGamut(m1) + "\n\n"; } + ); + + text = text.replace(/^(.+)[ \t]*\n-+[ \t]*\n+/gm, + function (matchFound, m1) { return "

" + _RunSpanGamut(m1) + "

\n\n"; } + ); + + // atx-style headers: + // # Header 1 + // ## Header 2 + // ## Header 2 with closing hashes ## + // ... + // ###### Header 6 + // + + /* + text = text.replace(/ + ^(\#{1,6}) // $1 = string of #'s + [ \t]* + (.+?) // $2 = Header text + [ \t]* + \#* // optional closing #'s (not counted) + \n+ + /gm, function() {...}); + */ + + text = text.replace(/^(\#{1,6})[ \t]*(.+?)[ \t]*\#*\n+/gm, + function (wholeMatch, m1, m2) { + var h_level = m1.length; + return "" + _RunSpanGamut(m2) + "\n\n"; + } + ); + + return text; + } + + function _DoLists(text) { + // + // Form HTML ordered (numbered) and unordered (bulleted) lists. + // + + // attacklab: add sentinel to hack around khtml/safari bug: + // http://bugs.webkit.org/show_bug.cgi?id=11231 + text += "~0"; + + // Re-usable pattern to match any entirel ul or ol list: + + /* + var whole_list = / + ( // $1 = whole list + ( // $2 + [ ]{0,3} // attacklab: g_tab_width - 1 + ([*+-]|\d+[.]) // $3 = first list item marker + [ \t]+ + ) + [^\r]+? + ( // $4 + ~0 // sentinel for workaround; should be $ + | + \n{2,} + (?=\S) + (?! // Negative lookahead for another list item marker + [ \t]* + (?:[*+-]|\d+[.])[ \t]+ + ) + ) + ) + /g + */ + var whole_list = /^(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/gm; + + if (g_list_level) { + text = text.replace(whole_list, function (wholeMatch, m1, m2) { + var list = m1; + var list_type = (m2.search(/[*+-]/g) > -1) ? "ul" : "ol"; + + var result = _ProcessListItems(list, list_type); + + // Trim any trailing whitespace, to put the closing `` + // up on the preceding line, to get it past the current stupid + // HTML block parser. This is a hack to work around the terrible + // hack that is the HTML block parser. + result = result.replace(/\s+$/, ""); + result = "<" + list_type + ">" + result + "\n"; + return result; + }); + } else { + whole_list = /(\n\n|^\n?)(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/g; + text = text.replace(whole_list, function (wholeMatch, m1, m2, m3) { + var runup = m1; + var list = m2; + + var list_type = (m3.search(/[*+-]/g) > -1) ? "ul" : "ol"; + var result = _ProcessListItems(list, list_type); + result = runup + "<" + list_type + ">\n" + result + "\n"; + return result; + }); + } + + // attacklab: strip sentinel + text = text.replace(/~0/, ""); + + return text; + } + + var _listItemMarkers = { ol: "\\d+[.]", ul: "[*+-]" }; + + function _ProcessListItems(list_str, list_type) { + // + // Process the contents of a single ordered or unordered list, splitting it + // into individual list items. + // + // list_type is either "ul" or "ol". + + // The $g_list_level global keeps track of when we're inside a list. + // Each time we enter a list, we increment it; when we leave a list, + // we decrement. If it's zero, we're not in a list anymore. + // + // We do this because when we're not inside a list, we want to treat + // something like this: + // + // I recommend upgrading to version + // 8. Oops, now this line is treated + // as a sub-list. + // + // As a single paragraph, despite the fact that the second line starts + // with a digit-period-space sequence. + // + // Whereas when we're inside a list (or sub-list), that line will be + // treated as the start of a sub-list. What a kludge, huh? This is + // an aspect of Markdown's syntax that's hard to parse perfectly + // without resorting to mind-reading. Perhaps the solution is to + // change the syntax rules such that sub-lists must start with a + // starting cardinal number; e.g. "1." or "a.". + + g_list_level++; + + // trim trailing blank lines: + list_str = list_str.replace(/\n{2,}$/, "\n"); + + // attacklab: add sentinel to emulate \z + list_str += "~0"; + + // In the original attacklab showdown, list_type was not given to this function, and anything + // that matched /[*+-]|\d+[.]/ would just create the next
  • , causing this mismatch: + // + // Markdown rendered by WMD rendered by MarkdownSharp + // ------------------------------------------------------------------ + // 1. first 1. first 1. first + // 2. second 2. second 2. second + // - third 3. third * third + // + // We changed this to behave identical to MarkdownSharp. This is the constructed RegEx, + // with {MARKER} being one of \d+[.] or [*+-], depending on list_type: + + /* + list_str = list_str.replace(/ + (^[ \t]*) // leading whitespace = $1 + ({MARKER}) [ \t]+ // list marker = $2 + ([^\r]+? // list item text = $3 + (\n+) + ) + (?= + (~0 | \2 ({MARKER}) [ \t]+) + ) + /gm, function(){...}); + */ + + var marker = _listItemMarkers[list_type]; + var re = new RegExp("(^[ \\t]*)(" + marker + ")[ \\t]+([^\\r]+?(\\n+))(?=(~0|\\1(" + marker + ")[ \\t]+))", "gm"); + var last_item_had_a_double_newline = false; + list_str = list_str.replace(re, + function (wholeMatch, m1, m2, m3) { + var item = m3; + var leading_space = m1; + var ends_with_double_newline = /\n\n$/.test(item); + var contains_double_newline = ends_with_double_newline || item.search(/\n{2,}/) > -1; + + if (contains_double_newline || last_item_had_a_double_newline) { + item = _RunBlockGamut(_Outdent(item), /* doNotUnhash = */true); + } + else { + // Recursion for sub-lists: + item = _DoLists(_Outdent(item)); + item = item.replace(/\n$/, ""); // chomp(item) + item = _RunSpanGamut(item); + } + last_item_had_a_double_newline = ends_with_double_newline; + return "
  • " + item + "
    • \n"; + } + ); + + // attacklab: strip sentinel + list_str = list_str.replace(/~0/g, ""); + + g_list_level--; + return list_str; + } + + function _DoCodeBlocks(text) { + // + // Process Markdown `
    ` blocks.
+            //  
+
+            /*
+            text = text.replace(/
+                (?:\n\n|^)
+                (                               // $1 = the code block -- one or more lines, starting with a space/tab
+                    (?:
+                        (?:[ ]{4}|\t)           // Lines must start with a tab or a tab-width of spaces - attacklab: g_tab_width
+                        .*\n+
+                    )+
+                )
+                (\n*[ ]{0,3}[^ \t\n]|(?=~0))    // attacklab: g_tab_width
+            /g ,function(){...});
+            */
+
+            // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
+            text += "~0";
+
+            text = text.replace(/(?:\n\n|^)((?:(?:[ ]{4}|\t).*\n+)+)(\n*[ ]{0,3}[^ \t\n]|(?=~0))/g,
+                function (wholeMatch, m1, m2) {
+                    var codeblock = m1;
+                    var nextChar = m2;
+
+                    codeblock = _EncodeCode(_Outdent(codeblock));
+                    codeblock = _Detab(codeblock);
+                    codeblock = codeblock.replace(/^\n+/g, ""); // trim leading newlines
+                    codeblock = codeblock.replace(/\n+$/g, ""); // trim trailing whitespace
+
+                    codeblock = "
    " + codeblock + "\n
    ";
+
+                    return "\n\n" + codeblock + "\n\n" + nextChar;
+                }
+            );
+
+            // attacklab: strip sentinel
+            text = text.replace(/~0/, "");
+
+            return text;
+        }
+
+        function hashBlock(text) {
+            text = text.replace(/(^\n+|\n+$)/g, "");
+            return "\n\n~K" + (g_html_blocks.push(text) - 1) + "K\n\n";
+        }
+
+        function _DoCodeSpans(text) {
+            //
+            // * Backtick quotes are used for  spans.
+            // 
+            // * You can use multiple backticks as the delimiters if you want to
+            //   include literal backticks in the code span. So, this input:
+            //     
+            //      Just type ``foo `bar` baz`` at the prompt.
+            //     
+            //   Will translate to:
+            //     
+            //      
    Just type foo `bar` baz at the prompt.
    
+            //     
+            //   There's no arbitrary limit to the number of backticks you
+            //   can use as delimters. If you need three consecutive backticks
+            //   in your code, use four for delimiters, etc.
+            //
+            // * You can use spaces to get literal backticks at the edges:
+            //     
+            //      ... type `` `bar` `` ...
+            //     
+            //   Turns to:
+            //     
+            //      ... type `bar` ...
+            //
+
+            /*
+            text = text.replace(/
+                (^|[^\\])       // Character before opening ` can't be a backslash
+                (`+)            // $2 = Opening run of `
+                (               // $3 = The code block
+                    [^\r]*?
+                    [^`]        // attacklab: work around lack of lookbehind
+                )
+                \2              // Matching closer
+                (?!`)
+            /gm, function(){...});
+            */
+
+            text = text.replace(/(^|[^\\])(`+)([^\r]*?[^`])\2(?!`)/gm,
+                function (wholeMatch, m1, m2, m3, m4) {
+                    var c = m3;
+                    c = c.replace(/^([ \t]*)/g, ""); // leading whitespace
+                    c = c.replace(/[ \t]*$/g, ""); // trailing whitespace
+                    c = _EncodeCode(c);
+                    return m1 + "" + c + "";
+                }
+            );
+
+            return text;
+        }
+
+        function _EncodeCode(text) {
+            //
+            // Encode/escape certain characters inside Markdown code runs.
+            // The point is that in code, these characters are literals,
+            // and lose their special Markdown meanings.
+            //
+            // Encode all ampersands; HTML entities are not
+            // entities within a Markdown code span.
+            text = text.replace(/&/g, "&");
+
+            // Do the angle bracket song and dance:
+            text = text.replace(//g, ">");
+
+            // Now, escape characters that are magic in Markdown:
+            text = escapeCharacters(text, "\*_{}[]\\", false);
+
+            // jj the line above breaks this:
+            //---
+
+            //* Item
+
+            //   1. Subitem
+
+            //            special char: *
+            //---
+
+            return text;
+        }
+
+        function _DoItalicsAndBold(text) {
+
+            //  must go first:
+            text = text.replace(/([\W_]|^)(\*\*|__)(?=\S)([^\r]*?\S[\*_]*)\2([\W_]|$)/g,
+            "$1$3$4");
+
+            text = text.replace(/([\W_]|^)(\*|_)(?=\S)([^\r\*_]*?\S)\2([\W_]|$)/g,
+            "$1$3$4");
+
+            return text;
+        }
+
+        function _DoBlockQuotes(text) {
+
+            /*
+            text = text.replace(/
+                (                           // Wrap whole match in $1
+                    (
+                        ^[ \t]*>[ \t]?      // '>' at the start of a line
+                        .+\n                // rest of the first line
+                        (.+\n)*             // subsequent consecutive lines
+                        \n*                 // blanks
+                    )+
+                )
+            /gm, function(){...});
+            */
+
+            text = text.replace(/((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)/gm,
+                function (wholeMatch, m1) {
+                    var bq = m1;
+
+                    // attacklab: hack around Konqueror 3.5.4 bug:
+                    // "----------bug".replace(/^-/g,"") == "bug"
+
+                    bq = bq.replace(/^[ \t]*>[ \t]?/gm, "~0"); // trim one level of quoting
+
+                    // attacklab: clean up hack
+                    bq = bq.replace(/~0/g, "");
+
+                    bq = bq.replace(/^[ \t]+$/gm, "");     // trim whitespace-only lines
+                    bq = _RunBlockGamut(bq);             // recurse
+
+                    bq = bq.replace(/(^|\n)/g, "$1  ");
+                    // These leading spaces screw with 
     content, so we need to fix that:
+                    bq = bq.replace(
+                            /(\s*
    [^\r]+?<\/pre>)/gm,
+                        function (wholeMatch, m1) {
+                            var pre = m1;
+                            // attacklab: hack around Konqueror 3.5.4 bug:
+                            pre = pre.replace(/^  /mg, "~0");
+                            pre = pre.replace(/~0/g, "");
+                            return pre;
+                        });
+
+                    return hashBlock("
    \n" + bq + "\n
    ");
+                }
+            );
+            return text;
+        }
+
+        function _FormParagraphs(text, doNotUnhash) {
+            //
+            //  Params:
+            //    $text - string to process with html 
     tags
+            //
+
+            // Strip leading and trailing lines:
+            text = text.replace(/^\n+/g, "");
+            text = text.replace(/\n+$/g, "");
+
+            var grafs = text.split(/\n{2,}/g);
+            var grafsOut = [];
+
+            //
+            // Wrap 
     tags.
+            //
+            var end = grafs.length;
+            for (var i = 0; i < end; i++) {
+                var str = grafs[i];
+
+                // if this is an HTML marker, copy it
+                if (str.search(/~K(\d+)K/g) >= 0) {
+                    grafsOut.push(str);
+                }
+                else if (str.search(/\S/) >= 0) {
+                    str = _RunSpanGamut(str);
+                    str = str.replace(/^([ \t]*)/g, "
    ");
+                    str += "
    "
+                    grafsOut.push(str);
+                }
+
+            }
+            //
+            // Unhashify HTML blocks
+            //
+            if (!doNotUnhash) {
+                end = grafsOut.length;
+                for (var i = 0; i < end; i++) {
+                    // if this is a marker for an html block...
+                    while (grafsOut[i].search(/~K(\d+)K/) >= 0) {
+                        var blockText = g_html_blocks[RegExp.$1];
+                        blockText = blockText.replace(/\$/g, "$$$$"); // Escape any dollar signs
+                        grafsOut[i] = grafsOut[i].replace(/~K\d+K/, blockText);
+                    }
+                }
+            }
+            return grafsOut.join("\n\n");
+        }
+
+        function _EncodeAmpsAndAngles(text) {
+            // Smart processing for ampersands and angle brackets that need to be encoded.
+
+            // Ampersand-encoding based entirely on Nat Irons's Amputator MT plugin:
+            //   http://bumppo.net/projects/amputator/
+            text = text.replace(/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/g, "&");
+
+            // Encode naked <'s
+            text = text.replace(/<(?![a-z\/?\$!])/gi, "<");
+
+            return text;
+        }
+
+        function _EncodeBackslashEscapes(text) {
+            //
+            //   Parameter:  String.
+            //   Returns:    The string, with after processing the following backslash
+            //               escape sequences.
+            //
+
+            // attacklab: The polite way to do this is with the new
+            // escapeCharacters() function:
+            //
+            //     text = escapeCharacters(text,"\\",true);
+            //     text = escapeCharacters(text,"`*_{}[]()>#+-.!",true);
+            //
+            // ...but we're sidestepping its use of the (slow) RegExp constructor
+            // as an optimization for Firefox.  This function gets called a LOT.
+
+            text = text.replace(/\\(\\)/g, escapeCharacters_callback);
+            text = text.replace(/\\([`*_{}\[\]()>#+-.!])/g, escapeCharacters_callback);
+            return text;
+        }
+
+        function _DoAutoLinks(text) {
+
+            // note that at this point, all other URL in the text are already hyperlinked as     
+            // *except* for the  case
+
+            // automatically add < and > around unadorned raw hyperlinks
+            // must be preceded by space/BOF and followed by non-word/EOF character    
+            text = text.replace(/(^|\s)(https?|ftp)(:\/\/[-A-Z0-9+&@#\/%?=~_|\[\]\(\)!:,\.;]*[-A-Z0-9+&@#\/%=~_|\[\]])($|\W)/gi, "$1<$2$3>$4");
+
+            //  autolink anything like 
+            
+            var replacer = function (wholematch, m1) { return "" + pluginHooks.plainLinkText(m1) + ""; }
+            text = text.replace(/<((https?|ftp):[^'">\s]+)>/gi, replacer);
+
+            // Email addresses: 
+            /*
+            text = text.replace(/
+                <
+                (?:mailto:)?
+                (
+                    [-.\w]+
+                    \@
+                    [-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
+                )
+                >
+            /gi, _DoAutoLinks_callback());
+            */
+
+            /* disabling email autolinking, since we don't do that on the server, either
+            text = text.replace(/<(?:mailto:)?([-.\w]+\@[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+)>/gi,
+                function(wholeMatch,m1) {
+                    return _EncodeEmailAddress( _UnescapeSpecialChars(m1) );
+                }
+            );
+            */
+            return text;
+        }
+
+        function _UnescapeSpecialChars(text) {
+            //
+            // Swap back in all the special characters we've hidden.
+            //
+            text = text.replace(/~E(\d+)E/g,
+                function (wholeMatch, m1) {
+                    var charCodeToReplace = parseInt(m1);
+                    return String.fromCharCode(charCodeToReplace);
+                }
+            );
+            return text;
+        }
+
+        function _Outdent(text) {
+            //
+            // Remove one level of line-leading tabs or spaces
+            //
+
+            // attacklab: hack around Konqueror 3.5.4 bug:
+            // "----------bug".replace(/^-/g,"") == "bug"
+
+            text = text.replace(/^(\t|[ ]{1,4})/gm, "~0"); // attacklab: g_tab_width
+
+            // attacklab: clean up hack
+            text = text.replace(/~0/g, "")
+
+            return text;
+        }
+
+        function _Detab(text) {
+            if (!/\t/.test(text))
+                return text;
+
+            var spaces = ["    ", "   ", "  ", " "],
+            skew = 0,
+            v;
+
+            return text.replace(/[\n\t]/g, function (match, offset) {
+                if (match === "\n") {
+                    skew = offset + 1;
+                    return match;
+                }
+                v = (offset - skew) % 4;
+                skew = offset + 1;
+                return spaces[v];
+            });
+        }
+
+        //
+        //  attacklab: Utility functions
+        //
+
+        var _problemUrlChars = /(?:["'*()[\]:]|~D)/g;
+
+        // hex-encodes some unusual "problem" chars in URLs to avoid URL detection problems 
+        function encodeProblemUrlChars(url) {
+            if (!url)
+                return "";
+
+            var len = url.length;
+
+            return url.replace(_problemUrlChars, function (match, offset) {
+                if (match == "~D") // escape for dollar
+                    return "%24";
+                if (match == ":") {
+                    if (offset == len - 1 || /[0-9\/]/.test(url.charAt(offset + 1)))
+                        return ":"
+                }
+                return "%" + match.charCodeAt(0).toString(16);
+            });
+        }
+
+
+        function escapeCharacters(text, charsToEscape, afterBackslash) {
+            // First we have to escape the escape characters so that
+            // we can build a character class out of them
+            var regexString = "([" + charsToEscape.replace(/([\[\]\\])/g, "\\$1") + "])";
+
+            if (afterBackslash) {
+                regexString = "\\\\" + regexString;
+            }
+
+            var regex = new RegExp(regexString, "g");
+            text = text.replace(regex, escapeCharacters_callback);
+
+            return text;
+        }
+
+
+        function escapeCharacters_callback(wholeMatch, m1) {
+            var charCodeToEscape = m1.charCodeAt(0);
+            return "~E" + charCodeToEscape + "E";
+        }
+
+    }; // end of the Markdown.Converter constructor
+
+})();
diff --git a/Markdown.Editor.js b/Markdown.Editor.js
new file mode 100644
index 0000000..ba2e1b7
--- /dev/null
+++ b/Markdown.Editor.js
@@ -0,0 +1,2116 @@
+// needs Markdown.Converter.js at the moment
+
+(function () {
+
+    var util = {},
+        position = {},
+        ui = {},
+        doc = top.document,
+        re = top.RegExp,
+        nav = top.navigator,
+        SETTINGS = { lineLength: 72 },
+
+    // Used to work around some browser bugs where we can't use feature testing.
+        uaSniffed = {
+            isIE: /msie/.test(nav.userAgent.toLowerCase()),
+            isIE_5or6: /msie 6/.test(nav.userAgent.toLowerCase()) || /msie 5/.test(nav.userAgent.toLowerCase()),
+            isOpera: /opera/.test(nav.userAgent.toLowerCase())
+        };
+
+
+    // -------------------------------------------------------------------
+    //  YOUR CHANGES GO HERE
+    //
+    // I've tried to localize the things you are likely to change to 
+    // this area.
+    // -------------------------------------------------------------------
+
+    // The text that appears on the upper part of the dialog box when
+    // entering links.
+    var linkDialogText = "
    Insert Hyperlink
    http://example.com/ \"optional title\"
    ";
+    var imageDialogText = "
    Insert Image
    http://example.com/images/diagram.jpg \"optional title\"

    Need free image hosting?
    ";
+
+    // The default text that appears in the dialog input box when entering
+    // links.
+    var imageDefaultText = "http://";
+    var linkDefaultText = "http://";
+
+    var defaultHelpHoverTitle = "Markdown Editing Help";
+
+    // -------------------------------------------------------------------
+    //  END OF YOUR CHANGES
+    // -------------------------------------------------------------------
+
+    // help, if given, should have a property "handler", the click handler for the help button,
+    // and can have an optional property "title" for the button's tooltip (defaults to "Markdown Editing Help").
+    // If help isn't given, not help button is created.
+    //
+    // The constructed editor object has the methods:
+    // - getConverter() returns the markdown converter object that was passed to the constructor
+    // - run() actually starts the editor; should be called after all necessary plugins are registered. Calling this more than once is a no-op.
+    // - refreshPreview() forces the preview to be updated. This method is only available after run() was called.
+    Markdown.Editor = function (markdownConverter, idPostfix, help) {
+
+        idPostfix = idPostfix || "";
+
+        var hooks = this.hooks = new Markdown.HookCollection();
+        hooks.addNoop("onPreviewRefresh");       // called with no arguments after the preview has been refreshed
+        hooks.addNoop("postBlockquoteCreation"); // called with the user's selection *after* the blockquote was created; should return the actual to-be-inserted text
+        hooks.addFalse("insertImageDialog");     /* called with one parameter: a callback to be called with the URL of the image. If the application creates
+                                                  * its own image insertion dialog, this hook should return true, and the callback should be called with the chosen
+                                                  * image url (or null if the user cancelled). If this hook returns false, the default dialog will be used.
+                                                  */
+
+        this.getConverter = function () { return markdownConverter; }
+
+        var that = this,
+            panels;
+
+        this.run = function () {
+            if (panels)
+                return; // already initialized
+
+            panels = new PanelCollection(idPostfix);
+            var commandManager = new CommandManager(hooks);
+            var previewManager = new PreviewManager(markdownConverter, panels, function () { hooks.onPreviewRefresh(); });
+            var undoManager, uiManager;
+
+            if (!/\?noundo/.test(doc.location.href)) {
+                undoManager = new UndoManager(function () {
+                    previewManager.refresh();
+                    if (uiManager) // not available on the first call
+                        uiManager.setUndoRedoButtonStates();
+                }, panels);
+            }
+
+            uiManager = new UIManager(idPostfix, panels, undoManager, previewManager, commandManager, help);
+            uiManager.setUndoRedoButtonStates();
+
+            var forceRefresh = that.refreshPreview = function () { previewManager.refresh(true); };
+
+            forceRefresh();
+        };
+
+    }
+
+    // before: contains all the text in the input box BEFORE the selection.
+    // after: contains all the text in the input box AFTER the selection.
+    function Chunks() { }
+
+    // startRegex: a regular expression to find the start tag
+    // endRegex: a regular expresssion to find the end tag
+    Chunks.prototype.findTags = function (startRegex, endRegex) {
+
+        var chunkObj = this;
+        var regex;
+
+        if (startRegex) {
+
+            regex = util.extendRegExp(startRegex, "", "$");
+
+            this.before = this.before.replace(regex,
+                function (match) {
+                    chunkObj.startTag = chunkObj.startTag + match;
+                    return "";
+                });
+
+            regex = util.extendRegExp(startRegex, "^", "");
+
+            this.selection = this.selection.replace(regex,
+                function (match) {
+                    chunkObj.startTag = chunkObj.startTag + match;
+                    return "";
+                });
+        }
+
+        if (endRegex) {
+
+            regex = util.extendRegExp(endRegex, "", "$");
+
+            this.selection = this.selection.replace(regex,
+                function (match) {
+                    chunkObj.endTag = match + chunkObj.endTag;
+                    return "";
+                });
+
+            regex = util.extendRegExp(endRegex, "^", "");
+
+            this.after = this.after.replace(regex,
+                function (match) {
+                    chunkObj.endTag = match + chunkObj.endTag;
+                    return "";
+                });
+        }
+    };
+
+    // If remove is false, the whitespace is transferred
+    // to the before/after regions.
+    //
+    // If remove is true, the whitespace disappears.
+    Chunks.prototype.trimWhitespace = function (remove) {
+
+        this.selection = this.selection.replace(/^(\s*)/, "");
+
+        if (!remove) {
+            this.before += re.$1;
+        }
+
+        this.selection = this.selection.replace(/(\s*)$/, "");
+
+        if (!remove) {
+            this.after = re.$1 + this.after;
+        }
+    };
+
+
+    Chunks.prototype.skipLines = function (nLinesBefore, nLinesAfter, findExtraNewlines) {
+
+        if (nLinesBefore === undefined) {
+            nLinesBefore = 1;
+        }
+
+        if (nLinesAfter === undefined) {
+            nLinesAfter = 1;
+        }
+
+        nLinesBefore++;
+        nLinesAfter++;
+
+        var regexText;
+        var replacementText;
+
+        // chrome bug ... documented at: http://meta.stackoverflow.com/questions/63307/blockquote-glitch-in-editor-in-chrome-6-and-7/65985#65985
+        if (navigator.userAgent.match(/Chrome/)) {
+            "X".match(/()./);
+        }
+
+        this.selection = this.selection.replace(/(^\n*)/, "");
+
+        this.startTag = this.startTag + re.$1;
+
+        this.selection = this.selection.replace(/(\n*$)/, "");
+        this.endTag = this.endTag + re.$1;
+        this.startTag = this.startTag.replace(/(^\n*)/, "");
+        this.before = this.before + re.$1;
+        this.endTag = this.endTag.replace(/(\n*$)/, "");
+        this.after = this.after + re.$1;
+
+        if (this.before) {
+
+            regexText = replacementText = "";
+
+            while (nLinesBefore--) {
+                regexText += "\\n?";
+                replacementText += "\n";
+            }
+
+            if (findExtraNewlines) {
+                regexText = "\\n*";
+            }
+            this.before = this.before.replace(new re(regexText + "$", ""), replacementText);
+        }
+
+        if (this.after) {
+
+            regexText = replacementText = "";
+
+            while (nLinesAfter--) {
+                regexText += "\\n?";
+                replacementText += "\n";
+            }
+            if (findExtraNewlines) {
+                regexText = "\\n*";
+            }
+
+            this.after = this.after.replace(new re(regexText, ""), replacementText);
+        }
+    };
+
+    // end of Chunks 
+
+    // A collection of the important regions on the page.
+    // Cached so we don't have to keep traversing the DOM.
+    // Also holds ieRetardedClick and ieCachedRange, where necessary; working around
+    // this issue:
+    // Internet explorer has problems with CSS sprite buttons that use HTML
+    // lists.  When you click on the background image "button", IE will 
+    // select the non-existent link text and discard the selection in the
+    // textarea.  The solution to this is to cache the textarea selection
+    // on the button's mousedown event and set a flag.  In the part of the
+    // code where we need to grab the selection, we check for the flag
+    // and, if it's set, use the cached area instead of querying the
+    // textarea.
+    //
+    // This ONLY affects Internet Explorer (tested on versions 6, 7
+    // and 8) and ONLY on button clicks.  Keyboard shortcuts work
+    // normally since the focus never leaves the textarea.
+    function PanelCollection(postfix) {
+        this.buttonBar = doc.getElementById("wmd-button-bar" + postfix);
+        this.preview = doc.getElementById("wmd-preview" + postfix);
+        this.input = doc.getElementById("wmd-input" + postfix);
+    };
+
+    // Returns true if the DOM element is visible, false if it's hidden.
+    // Checks if display is anything other than none.
+    util.isVisible = function (elem) {
+
+        if (window.getComputedStyle) {
+            // Most browsers
+            return window.getComputedStyle(elem, null).getPropertyValue("display") !== "none";
+        }
+        else if (elem.currentStyle) {
+            // IE
+            return elem.currentStyle["display"] !== "none";
+        }
+    };
+
+
+    // Adds a listener callback to a DOM element which is fired on a specified
+    // event.
+    util.addEvent = function (elem, event, listener) {
+        if (elem.attachEvent) {
+            // IE only.  The "on" is mandatory.
+            elem.attachEvent("on" + event, listener);
+        }
+        else {
+            // Other browsers.
+            elem.addEventListener(event, listener, false);
+        }
+    };
+
+
+    // Removes a listener callback from a DOM element which is fired on a specified
+    // event.
+    util.removeEvent = function (elem, event, listener) {
+        if (elem.detachEvent) {
+            // IE only.  The "on" is mandatory.
+            elem.detachEvent("on" + event, listener);
+        }
+        else {
+            // Other browsers.
+            elem.removeEventListener(event, listener, false);
+        }
+    };
+
+    // Converts \r\n and \r to \n.
+    util.fixEolChars = function (text) {
+        text = text.replace(/\r\n/g, "\n");
+        text = text.replace(/\r/g, "\n");
+        return text;
+    };
+
+    // Extends a regular expression.  Returns a new RegExp
+    // using pre + regex + post as the expression.
+    // Used in a few functions where we have a base
+    // expression and we want to pre- or append some
+    // conditions to it (e.g. adding "$" to the end).
+    // The flags are unchanged.
+    //
+    // regex is a RegExp, pre and post are strings.
+    util.extendRegExp = function (regex, pre, post) {
+
+        if (pre === null || pre === undefined) {
+            pre = "";
+        }
+        if (post === null || post === undefined) {
+            post = "";
+        }
+
+        var pattern = regex.toString();
+        var flags;
+
+        // Replace the flags with empty space and store them.
+        pattern = pattern.replace(/\/([gim]*)$/, "");
+        flags = re.$1;
+
+        // Remove the slash delimiters on the regular expression.
+        pattern = pattern.replace(/(^\/|\/$)/g, "");
+        pattern = pre + pattern + post;
+
+        return new re(pattern, flags);
+    }
+
+    // UNFINISHED
+    // The assignment in the while loop makes jslint cranky.
+    // I'll change it to a better loop later.
+    position.getTop = function (elem, isInner) {
+        var result = elem.offsetTop;
+        if (!isInner) {
+            while (elem = elem.offsetParent) {
+                result += elem.offsetTop;
+            }
+        }
+        return result;
+    };
+
+    position.getHeight = function (elem) {
+        return elem.offsetHeight || elem.scrollHeight;
+    };
+
+    position.getWidth = function (elem) {
+        return elem.offsetWidth || elem.scrollWidth;
+    };
+
+    position.getPageSize = function () {
+
+        var scrollWidth, scrollHeight;
+        var innerWidth, innerHeight;
+
+        // It's not very clear which blocks work with which browsers.
+        if (self.innerHeight && self.scrollMaxY) {
+            scrollWidth = doc.body.scrollWidth;
+            scrollHeight = self.innerHeight + self.scrollMaxY;
+        }
+        else if (doc.body.scrollHeight > doc.body.offsetHeight) {
+            scrollWidth = doc.body.scrollWidth;
+            scrollHeight = doc.body.scrollHeight;
+        }
+        else {
+            scrollWidth = doc.body.offsetWidth;
+            scrollHeight = doc.body.offsetHeight;
+        }
+
+        if (self.innerHeight) {
+            // Non-IE browser
+            innerWidth = self.innerWidth;
+            innerHeight = self.innerHeight;
+        }
+        else if (doc.documentElement && doc.documentElement.clientHeight) {
+            // Some versions of IE (IE 6 w/ a DOCTYPE declaration)
+            innerWidth = doc.documentElement.clientWidth;
+            innerHeight = doc.documentElement.clientHeight;
+        }
+        else if (doc.body) {
+            // Other versions of IE
+            innerWidth = doc.body.clientWidth;
+            innerHeight = doc.body.clientHeight;
+        }
+
+        var maxWidth = Math.max(scrollWidth, innerWidth);
+        var maxHeight = Math.max(scrollHeight, innerHeight);
+        return [maxWidth, maxHeight, innerWidth, innerHeight];
+    };
+
+    // Handles pushing and popping TextareaStates for undo/redo commands.
+    // I should rename the stack variables to list.
+    function UndoManager(callback, panels) {
+
+        var undoObj = this;
+        var undoStack = []; // A stack of undo states
+        var stackPtr = 0; // The index of the current state
+        var mode = "none";
+        var lastState; // The last state
+        var timer; // The setTimeout handle for cancelling the timer
+        var inputStateObj;
+
+        // Set the mode for later logic steps.
+        var setMode = function (newMode, noSave) {
+            if (mode != newMode) {
+                mode = newMode;
+                if (!noSave) {
+                    saveState();
+                }
+            }
+
+            if (!uaSniffed.isIE || mode != "moving") {
+                timer = top.setTimeout(refreshState, 1);
+            }
+            else {
+                inputStateObj = null;
+            }
+        };
+
+        var refreshState = function (isInitialState) {
+            inputStateObj = new TextareaState(panels, isInitialState);
+            timer = undefined;
+        };
+
+        this.setCommandMode = function () {
+            mode = "command";
+            saveState();
+            timer = top.setTimeout(refreshState, 0);
+        };
+
+        this.canUndo = function () {
+            return stackPtr > 1;
+        };
+
+        this.canRedo = function () {
+            if (undoStack[stackPtr + 1]) {
+                return true;
+            }
+            return false;
+        };
+
+        // Removes the last state and restores it.
+        this.undo = function () {
+
+            if (undoObj.canUndo()) {
+                if (lastState) {
+                    // What about setting state -1 to null or checking for undefined?
+                    lastState.restore();
+                    lastState = null;
+                }
+                else {
+                    undoStack[stackPtr] = new TextareaState(panels);
+                    undoStack[--stackPtr].restore();
+
+                    if (callback) {
+                        callback();
+                    }
+                }
+            }
+
+            mode = "none";
+            panels.input.focus();
+            refreshState();
+        };
+
+        // Redo an action.
+        this.redo = function () {
+
+            if (undoObj.canRedo()) {
+
+                undoStack[++stackPtr].restore();
+
+                if (callback) {
+                    callback();
+                }
+            }
+
+            mode = "none";
+            panels.input.focus();
+            refreshState();
+        };
+
+        // Push the input area state to the stack.
+        var saveState = function () {
+            var currState = inputStateObj || new TextareaState(panels);
+
+            if (!currState) {
+                return false;
+            }
+            if (mode == "moving") {
+                if (!lastState) {
+                    lastState = currState;
+                }
+                return;
+            }
+            if (lastState) {
+                if (undoStack[stackPtr - 1].text != lastState.text) {
+                    undoStack[stackPtr++] = lastState;
+                }
+                lastState = null;
+            }
+            undoStack[stackPtr++] = currState;
+            undoStack[stackPtr + 1] = null;
+            if (callback) {
+                callback();
+            }
+        };
+
+        var handleCtrlYZ = function (event) {
+
+            var handled = false;
+
+            if (event.ctrlKey || event.metaKey) {
+
+                // IE and Opera do not support charCode.
+                var keyCode = event.charCode || event.keyCode;
+                var keyCodeChar = String.fromCharCode(keyCode);
+
+                switch (keyCodeChar) {
+
+                    case "y":
+                        undoObj.redo();
+                        handled = true;
+                        break;
+
+                    case "z":
+                        if (!event.shiftKey) {
+                            undoObj.undo();
+                        }
+                        else {
+                            undoObj.redo();
+                        }
+                        handled = true;
+                        break;
+                }
+            }
+
+            if (handled) {
+                if (event.preventDefault) {
+                    event.preventDefault();
+                }
+                if (top.event) {
+                    top.event.returnValue = false;
+                }
+                return;
+            }
+        };
+
+        // Set the mode depending on what is going on in the input area.
+        var handleModeChange = function (event) {
+
+            if (!event.ctrlKey && !event.metaKey) {
+
+                var keyCode = event.keyCode;
+
+                if ((keyCode >= 33 && keyCode <= 40) || (keyCode >= 63232 && keyCode <= 63235)) {
+                    // 33 - 40: page up/dn and arrow keys
+                    // 63232 - 63235: page up/dn and arrow keys on safari
+                    setMode("moving");
+                }
+                else if (keyCode == 8 || keyCode == 46 || keyCode == 127) {
+                    // 8: backspace
+                    // 46: delete
+                    // 127: delete
+                    setMode("deleting");
+                }
+                else if (keyCode == 13) {
+                    // 13: Enter
+                    setMode("newlines");
+                }
+                else if (keyCode == 27) {
+                    // 27: escape
+                    setMode("escape");
+                }
+                else if ((keyCode < 16 || keyCode > 20) && keyCode != 91) {
+                    // 16-20 are shift, etc. 
+                    // 91: left window key
+                    // I think this might be a little messed up since there are
+                    // a lot of nonprinting keys above 20.
+                    setMode("typing");
+                }
+            }
+        };
+
+        var setEventHandlers = function () {
+            util.addEvent(panels.input, "keypress", function (event) {
+                // keyCode 89: y
+                // keyCode 90: z
+                if ((event.ctrlKey || event.metaKey) && (event.keyCode == 89 || event.keyCode == 90)) {
+                    event.preventDefault();
+                }
+            });
+
+            var handlePaste = function () {
+                if (uaSniffed.isIE || (inputStateObj && inputStateObj.text != panels.input.value)) {
+                    if (timer == undefined) {
+                        mode = "paste";
+                        saveState();
+                        refreshState();
+                    }
+                }
+            };
+
+            util.addEvent(panels.input, "keydown", handleCtrlYZ);
+            util.addEvent(panels.input, "keydown", handleModeChange);
+            util.addEvent(panels.input, "mousedown", function () {
+                setMode("moving");
+            });
+
+            panels.input.onpaste = handlePaste;
+            panels.input.ondrop = handlePaste;
+        };
+
+        var init = function () {
+            setEventHandlers();
+            refreshState(true);
+            saveState();
+        };
+
+        init();
+    }
+
+    // end of UndoManager
+
+    // The input textarea state/contents.
+    // This is used to implement undo/redo by the undo manager.
+    function TextareaState(panels, isInitialState) {
+
+        // Aliases
+        var stateObj = this;
+        var inputArea = panels.input;
+        this.init = function () {
+            if (!util.isVisible(inputArea)) {
+                return;
+            }
+            if (!isInitialState && doc.activeElement && doc.activeElement !== inputArea) { // this happens when tabbing out of the input box
+                return;
+            }
+
+            this.setInputAreaSelectionStartEnd();
+            this.scrollTop = inputArea.scrollTop;
+            if (!this.text && inputArea.selectionStart || inputArea.selectionStart === 0) {
+                this.text = inputArea.value;
+            }
+
+        }
+
+        // Sets the selected text in the input box after we've performed an
+        // operation.
+        this.setInputAreaSelection = function () {
+
+            if (!util.isVisible(inputArea)) {
+                return;
+            }
+
+            if (inputArea.selectionStart !== undefined && !uaSniffed.isOpera) {
+
+                inputArea.focus();
+                inputArea.selectionStart = stateObj.start;
+                inputArea.selectionEnd = stateObj.end;
+                inputArea.scrollTop = stateObj.scrollTop;
+            }
+            else if (doc.selection) {
+
+                if (doc.activeElement && doc.activeElement !== inputArea) {
+                    return;
+                }
+
+                inputArea.focus();
+                var range = inputArea.createTextRange();
+                range.moveStart("character", -inputArea.value.length);
+                range.moveEnd("character", -inputArea.value.length);
+                range.moveEnd("character", stateObj.end);
+                range.moveStart("character", stateObj.start);
+                range.select();
+            }
+        };
+
+        this.setInputAreaSelectionStartEnd = function () {
+
+            if (!panels.ieRetardedClick && (inputArea.selectionStart || inputArea.selectionStart === 0)) {
+
+                stateObj.start = inputArea.selectionStart;
+                stateObj.end = inputArea.selectionEnd;
+            }
+            else if (doc.selection) {
+
+                stateObj.text = util.fixEolChars(inputArea.value);
+
+                // IE loses the selection in the textarea when buttons are
+                // clicked.  On IE we cache the selection and set a flag
+                // which we check for here.
+                var range;
+                if (panels.ieRetardedClick && panels.ieCachedRange) {
+                    range = panels.ieCachedRange;
+                    panels.ieRetardedClick = false;
+                }
+                else {
+                    range = doc.selection.createRange();
+                }
+
+                var fixedRange = util.fixEolChars(range.text);
+                var marker = "\x07";
+                var markedRange = marker + fixedRange + marker;
+                range.text = markedRange;
+                var inputText = util.fixEolChars(inputArea.value);
+
+                range.moveStart("character", -markedRange.length);
+                range.text = fixedRange;
+
+                stateObj.start = inputText.indexOf(marker);
+                stateObj.end = inputText.lastIndexOf(marker) - marker.length;
+
+                var len = stateObj.text.length - util.fixEolChars(inputArea.value).length;
+
+                if (len) {
+                    range.moveStart("character", -fixedRange.length);
+                    while (len--) {
+                        fixedRange += "\n";
+                        stateObj.end += 1;
+                    }
+                    range.text = fixedRange;
+                }
+
+                this.setInputAreaSelection();
+            }
+        };
+
+        // Restore this state into the input area.
+        this.restore = function () {
+
+            if (stateObj.text != undefined && stateObj.text != inputArea.value) {
+                inputArea.value = stateObj.text;
+            }
+            this.setInputAreaSelection();
+            inputArea.scrollTop = stateObj.scrollTop;
+        };
+
+        // Gets a collection of HTML chunks from the inptut textarea.
+        this.getChunks = function () {
+
+            var chunk = new Chunks();
+            chunk.before = util.fixEolChars(stateObj.text.substring(0, stateObj.start));
+            chunk.startTag = "";
+            chunk.selection = util.fixEolChars(stateObj.text.substring(stateObj.start, stateObj.end));
+            chunk.endTag = "";
+            chunk.after = util.fixEolChars(stateObj.text.substring(stateObj.end));
+            chunk.scrollTop = stateObj.scrollTop;
+
+            return chunk;
+        };
+
+        // Sets the TextareaState properties given a chunk of markdown.
+        this.setChunks = function (chunk) {
+
+            chunk.before = chunk.before + chunk.startTag;
+            chunk.after = chunk.endTag + chunk.after;
+
+            this.start = chunk.before.length;
+            this.end = chunk.before.length + chunk.selection.length;
+            this.text = chunk.before + chunk.selection + chunk.after;
+            this.scrollTop = chunk.scrollTop;
+        };
+        this.init();
+    };
+
+    function PreviewManager(converter, panels, previewRefreshCallback) {
+
+        var managerObj = this;
+        var timeout;
+        var elapsedTime;
+        var oldInputText;
+        var maxDelay = 3000;
+        var startType = "delayed"; // The other legal value is "manual"
+
+        // Adds event listeners to elements
+        var setupEvents = function (inputElem, listener) {
+
+            util.addEvent(inputElem, "input", listener);
+            inputElem.onpaste = listener;
+            inputElem.ondrop = listener;
+
+            util.addEvent(inputElem, "keypress", listener);
+            util.addEvent(inputElem, "keydown", listener);
+        };
+
+        var getDocScrollTop = function () {
+
+            var result = 0;
+
+            if (top.innerHeight) {
+                result = top.pageYOffset;
+            }
+            else
+                if (doc.documentElement && doc.documentElement.scrollTop) {
+                    result = doc.documentElement.scrollTop;
+                }
+                else
+                    if (doc.body) {
+                        result = doc.body.scrollTop;
+                    }
+
+            return result;
+        };
+
+        var makePreviewHtml = function () {
+
+            // If there is no registered preview panel
+            // there is nothing to do.
+            if (!panels.preview)
+                return;
+
+
+            var text = panels.input.value;
+            if (text && text == oldInputText) {
+                return; // Input text hasn't changed.
+            }
+            else {
+                oldInputText = text;
+            }
+
+            var prevTime = new Date().getTime();
+
+            text = converter.makeHtml(text);
+
+            // Calculate the processing time of the HTML creation.
+            // It's used as the delay time in the event listener.
+            var currTime = new Date().getTime();
+            elapsedTime = currTime - prevTime;
+
+            pushPreviewHtml(text);
+        };
+
+        // setTimeout is already used.  Used as an event listener.
+        var applyTimeout = function () {
+
+            if (timeout) {
+                top.clearTimeout(timeout);
+                timeout = undefined;
+            }
+
+            if (startType !== "manual") {
+
+                var delay = 0;
+
+                if (startType === "delayed") {
+                    delay = elapsedTime;
+                }
+
+                if (delay > maxDelay) {
+                    delay = maxDelay;
+                }
+                timeout = top.setTimeout(makePreviewHtml, delay);
+            }
+        };
+
+        var getScaleFactor = function (panel) {
+            if (panel.scrollHeight <= panel.clientHeight) {
+                return 1;
+            }
+            return panel.scrollTop / (panel.scrollHeight - panel.clientHeight);
+        };
+
+        var setPanelScrollTops = function () {
+            if (panels.preview) {
+                panels.preview.scrollTop = (panels.preview.scrollHeight - panels.preview.clientHeight) * getScaleFactor(panels.preview);
+            }
+        };
+
+        this.refresh = function (requiresRefresh) {
+
+            if (requiresRefresh) {
+                oldInputText = "";
+                makePreviewHtml();
+            }
+            else {
+                applyTimeout();
+            }
+        };
+
+        this.processingTime = function () {
+            return elapsedTime;
+        };
+
+        var isFirstTimeFilled = true;
+
+        // IE doesn't let you use innerHTML if the element is contained somewhere in a table
+        // (which is the case for inline editing) -- in that case, detach the element, set the
+        // value, and reattach. Yes, that *is* ridiculous.
+        var ieSafePreviewSet = function (text) {
+            var preview = panels.preview;
+            var parent = preview.parentNode;
+            var sibling = preview.nextSibling;
+            parent.removeChild(preview);
+            preview.innerHTML = text;
+            if (!sibling)
+                parent.appendChild(preview);
+            else
+                parent.insertBefore(preview, sibling);
+        }
+
+        var nonSuckyBrowserPreviewSet = function (text) {
+            panels.preview.innerHTML = text;
+        }
+
+        var previewSetter;
+
+        var previewSet = function (text) {
+            if (previewSetter)
+                return previewSetter(text);
+
+            try {
+                nonSuckyBrowserPreviewSet(text);
+                previewSetter = nonSuckyBrowserPreviewSet;
+            } catch (e) {
+                previewSetter = ieSafePreviewSet;
+                previewSetter(text);
+            }
+        };
+
+        var pushPreviewHtml = function (text) {
+
+            var emptyTop = position.getTop(panels.input) - getDocScrollTop();
+
+            if (panels.preview) {
+                previewSet(text);
+                previewRefreshCallback();
+            }
+
+            setPanelScrollTops();
+
+            if (isFirstTimeFilled) {
+                isFirstTimeFilled = false;
+                return;
+            }
+
+            var fullTop = position.getTop(panels.input) - getDocScrollTop();
+
+            if (uaSniffed.isIE) {
+                top.setTimeout(function () {
+                    top.scrollBy(0, fullTop - emptyTop);
+                }, 0);
+            }
+            else {
+                top.scrollBy(0, fullTop - emptyTop);
+            }
+        };
+
+        var init = function () {
+
+            setupEvents(panels.input, applyTimeout);
+            makePreviewHtml();
+
+            if (panels.preview) {
+                panels.preview.scrollTop = 0;
+            }
+        };
+
+        init();
+    };
+
+    // Creates the background behind the hyperlink text entry box.
+    // And download dialog
+    // Most of this has been moved to CSS but the div creation and
+    // browser-specific hacks remain here.
+    ui.createBackground = function () {
+
+        var background = doc.createElement("div");
+        background.className = "wmd-prompt-background";
+        style = background.style;
+        style.position = "absolute";
+        style.top = "0";
+
+        style.zIndex = "1000";
+
+        if (uaSniffed.isIE) {
+            style.filter = "alpha(opacity=50)";
+        }
+        else {
+            style.opacity = "0.5";
+        }
+
+        var pageSize = position.getPageSize();
+        style.height = pageSize[1] + "px";
+
+        if (uaSniffed.isIE) {
+            style.left = doc.documentElement.scrollLeft;
+            style.width = doc.documentElement.clientWidth;
+        }
+        else {
+            style.left = "0";
+            style.width = "100%";
+        }
+
+        doc.body.appendChild(background);
+        return background;
+    };
+
+    // This simulates a modal dialog box and asks for the URL when you
+    // click the hyperlink or image buttons.
+    //
+    // text: The html for the input box.
+    // defaultInputText: The default value that appears in the input box.
+    // callback: The function which is executed when the prompt is dismissed, either via OK or Cancel.
+    //      It receives a single argument; either the entered text (if OK was chosen) or null (if Cancel
+    //      was chosen).
+    ui.prompt = function (text, defaultInputText, callback) {
+
+        // These variables need to be declared at this level since they are used
+        // in multiple functions.
+        var dialog;         // The dialog box.
+        var input;         // The text box where you enter the hyperlink.
+
+
+        if (defaultInputText === undefined) {
+            defaultInputText = "";
+        }
+
+        // Used as a keydown event handler. Esc dismisses the prompt.
+        // Key code 27 is ESC.
+        var checkEscape = function (key) {
+            var code = (key.charCode || key.keyCode);
+            if (code === 27) {
+                close(true);
+            }
+        };
+
+        // Dismisses the hyperlink input box.
+        // isCancel is true if we don't care about the input text.
+        // isCancel is false if we are going to keep the text.
+        var close = function (isCancel) {
+            util.removeEvent(doc.body, "keydown", checkEscape);
+            var text = input.value;
+
+            if (isCancel) {
+                text = null;
+            }
+            else {
+                // Fixes common pasting errors.
+                text = text.replace('http://http://', 'http://');
+                text = text.replace('http://https://', 'https://');
+                text = text.replace('http://ftp://', 'ftp://');
+
+                if (text.indexOf('http://') === -1 && text.indexOf('ftp://') === -1 && text.indexOf('https://') === -1) {
+                    text = 'http://' + text;
+                }
+            }
+
+            dialog.parentNode.removeChild(dialog);
+
+            callback(text);
+            return false;
+        };
+
+
+
+        // Create the text input box form/window.
+        var createDialog = function () {
+
+            // The main dialog box.
+            dialog = doc.createElement("div");
+            dialog.className = "wmd-prompt-dialog";
+            dialog.style.padding = "10px;";
+            dialog.style.position = "fixed";
+            dialog.style.width = "400px";
+            dialog.style.zIndex = "1001";
+
+            // The dialog text.
+            var question = doc.createElement("div");
+            question.innerHTML = text;
+            question.style.padding = "5px";
+            dialog.appendChild(question);
+
+            // The web form container for the text box and buttons.
+            var form = doc.createElement("form");
+            form.onsubmit = function () { return close(false); };
+            style = form.style;
+            style.padding = "0";
+            style.margin = "0";
+            style.cssFloat = "left";
+            style.width = "100%";
+            style.textAlign = "center";
+            style.position = "relative";
+            dialog.appendChild(form);
+
+            // The input text box
+            input = doc.createElement("input");
+            input.type = "text";
+            input.value = defaultInputText;
+            style = input.style;
+            style.display = "block";
+            style.width = "80%";
+            style.marginLeft = style.marginRight = "auto";
+            form.appendChild(input);
+
+            // The ok button
+            var okButton = doc.createElement("input");
+            okButton.type = "button";
+            okButton.onclick = function () { return close(false); };
+            okButton.value = "OK";
+            style = okButton.style;
+            style.margin = "10px";
+            style.display = "inline";
+            style.width = "7em";
+
+
+            // The cancel button
+            var cancelButton = doc.createElement("input");
+            cancelButton.type = "button";
+            cancelButton.onclick = function () { return close(true); };
+            cancelButton.value = "Cancel";
+            style = cancelButton.style;
+            style.margin = "10px";
+            style.display = "inline";
+            style.width = "7em";
+
+            form.appendChild(okButton);
+            form.appendChild(cancelButton);
+
+            util.addEvent(doc.body, "keydown", checkEscape);
+            dialog.style.top = "50%";
+            dialog.style.left = "50%";
+            dialog.style.display = "block";
+            if (uaSniffed.isIE_5or6) {
+                dialog.style.position = "absolute";
+                dialog.style.top = doc.documentElement.scrollTop + 200 + "px";
+                dialog.style.left = "50%";
+            }
+            doc.body.appendChild(dialog);
+
+            // This has to be done AFTER adding the dialog to the form if you
+            // want it to be centered.
+            dialog.style.marginTop = -(position.getHeight(dialog) / 2) + "px";
+            dialog.style.marginLeft = -(position.getWidth(dialog) / 2) + "px";
+
+        };
+
+        // Why is this in a zero-length timeout?
+        // Is it working around a browser bug?
+        top.setTimeout(function () {
+
+            createDialog();
+
+            var defTextLen = defaultInputText.length;
+            if (input.selectionStart !== undefined) {
+                input.selectionStart = 0;
+                input.selectionEnd = defTextLen;
+            }
+            else if (input.createTextRange) {
+                var range = input.createTextRange();
+                range.collapse(false);
+                range.moveStart("character", -defTextLen);
+                range.moveEnd("character", defTextLen);
+                range.select();
+            }
+
+            input.focus();
+        }, 0);
+    };
+
+    function UIManager(postfix, panels, undoManager, previewManager, commandManager, helpOptions) {
+
+        var inputBox = panels.input,
+            buttons = {}; // buttons.undo, buttons.link, etc. The actual DOM elements.
+
+        makeSpritedButtonRow();
+
+        var keyEvent = "keydown";
+        if (uaSniffed.isOpera) {
+            keyEvent = "keypress";
+        }
+
+        util.addEvent(inputBox, keyEvent, function (key) {
+
+            // Check to see if we have a button key and, if so execute the callback.
+            if ((key.ctrlKey || key.metaKey) && !key.altKey) {
+
+                var keyCode = key.charCode || key.keyCode;
+                var keyCodeStr = String.fromCharCode(keyCode).toLowerCase();
+
+                switch (keyCodeStr) {
+                    case "b":
+                        doClick(buttons.bold);
+                        break;
+                    case "i":
+                        doClick(buttons.italic);
+                        break;
+                    case "l":
+                        doClick(buttons.link);
+                        break;
+                    case "q":
+                        doClick(buttons.quote);
+                        break;
+                    case "k":
+                        doClick(buttons.code);
+                        break;
+                    case "g":
+                        doClick(buttons.image);
+                        break;
+                    case "o":
+                        doClick(buttons.olist);
+                        break;
+                    case "u":
+                        doClick(buttons.ulist);
+                        break;
+                    case "h":
+                        doClick(buttons.heading);
+                        break;
+                    case "r":
+                        doClick(buttons.hr);
+                        break;
+                    case "y":
+                        doClick(buttons.redo);
+                        break;
+                    case "z":
+                        if (key.shiftKey) {
+                            doClick(buttons.redo);
+                        }
+                        else {
+                            doClick(buttons.undo);
+                        }
+                        break;
+                    default:
+                        return;
+                }
+
+
+                if (key.preventDefault) {
+                    key.preventDefault();
+                }
+
+                if (top.event) {
+                    top.event.returnValue = false;
+                }
+            }
+        });
+
+        // Auto-indent on shift-enter
+        util.addEvent(inputBox, "keyup", function (key) {
+            if (key.shiftKey && !key.ctrlKey && !key.metaKey) {
+                var keyCode = key.charCode || key.keyCode;
+                // Character 13 is Enter
+                if (keyCode === 13) {
+                    fakeButton = {};
+                    fakeButton.textOp = bindCommand("doAutoindent");
+                    doClick(fakeButton);
+                }
+            }
+        });
+
+        // special handler because IE clears the context of the textbox on ESC
+        if (uaSniffed.isIE) {
+            util.addEvent(inputBox, "keydown", function (key) {
+                var code = key.keyCode;
+                if (code === 27) {
+                    return false;
+                }
+            });
+        }
+
+
+        // Perform the button's action.
+        function doClick(button) {
+
+            inputBox.focus();
+
+            if (button.textOp) {
+
+                if (undoManager) {
+                    undoManager.setCommandMode();
+                }
+
+                var state = new TextareaState(panels);
+
+                if (!state) {
+                    return;
+                }
+
+                var chunks = state.getChunks();
+
+                // Some commands launch a "modal" prompt dialog.  Javascript
+                // can't really make a modal dialog box and the WMD code
+                // will continue to execute while the dialog is displayed.
+                // This prevents the dialog pattern I'm used to and means
+                // I can't do something like this:
+                //
+                // var link = CreateLinkDialog();
+                // makeMarkdownLink(link);
+                // 
+                // Instead of this straightforward method of handling a
+                // dialog I have to pass any code which would execute
+                // after the dialog is dismissed (e.g. link creation)
+                // in a function parameter.
+                //
+                // Yes this is awkward and I think it sucks, but there's
+                // no real workaround.  Only the image and link code
+                // create dialogs and require the function pointers.
+                var fixupInputArea = function () {
+
+                    inputBox.focus();
+
+                    if (chunks) {
+                        state.setChunks(chunks);
+                    }
+
+                    state.restore();
+                    previewManager.refresh();
+                };
+
+                var noCleanup = button.textOp(chunks, fixupInputArea);
+
+                if (!noCleanup) {
+                    fixupInputArea();
+                }
+
+            }
+
+            if (button.execute) {
+                button.execute(undoManager);
+            }
+        };
+
+        function setupButton(button, isEnabled) {
+
+            var normalYShift = "0px";
+            var disabledYShift = "-20px";
+            var highlightYShift = "-40px";
+            var image = button.getElementsByTagName("span")[0];
+            if (isEnabled) {
+                image.style.backgroundPosition = button.XShift + " " + normalYShift;
+                button.onmouseover = function () {
+                    image.style.backgroundPosition = this.XShift + " " + highlightYShift;
+                };
+
+                button.onmouseout = function () {
+                    image.style.backgroundPosition = this.XShift + " " + normalYShift;
+                };
+
+                // IE tries to select the background image "button" text (it's
+                // implemented in a list item) so we have to cache the selection
+                // on mousedown.
+                if (uaSniffed.isIE) {
+                    button.onmousedown = function () {
+                        if (doc.activeElement && doc.activeElement !== panels.input) { // we're not even in the input box, so there's no selection
+                            return;
+                        }
+                        panels.ieRetardedClick = true;
+                        panels.ieCachedRange = document.selection.createRange();
+                    };
+                }
+
+                if (!button.isHelp) {
+                    button.onclick = function () {
+                        if (this.onmouseout) {
+                            this.onmouseout();
+                        }
+                        doClick(this);
+                        return false;
+                    }
+                }
+            }
+            else {
+                image.style.backgroundPosition = button.XShift + " " + disabledYShift;
+                button.onmouseover = button.onmouseout = button.onclick = function () { };
+            }
+        }
+
+        function bindCommand(method) {
+            if (typeof method === "string")
+                method = commandManager[method];
+            return function () { method.apply(commandManager, arguments); }
+        }
+
+        function makeSpritedButtonRow() {
+
+            var buttonBar = panels.buttonBar;
+
+            var normalYShift = "0px";
+            var disabledYShift = "-20px";
+            var highlightYShift = "-40px";
+
+            var buttonRow = document.createElement("ul");
+            buttonRow.id = "wmd-button-row" + postfix;
+            buttonRow.className = 'wmd-button-row';
+            buttonRow = buttonBar.appendChild(buttonRow);
+            var xPosition = 0;
+            var makeButton = function (id, title, XShift, textOp) {
+                var button = document.createElement("li");
+                button.className = "wmd-button";
+                button.style.left = xPosition + "px";
+                xPosition += 25;
+                var buttonImage = document.createElement("span");
+                button.id = id + postfix;
+                button.appendChild(buttonImage);
+                button.title = title;
+                button.XShift = XShift;
+                if (textOp)
+                    button.textOp = textOp;
+                setupButton(button, true);
+                buttonRow.appendChild(button);
+                return button;
+            };
+            var makeSpacer = function (num) {
+                var spacer = document.createElement("li");
+                spacer.className = "wmd-spacer wmd-spacer" + num;
+                spacer.id = "wmd-spacer" + num + postfix;
+                buttonRow.appendChild(spacer);
+                xPosition += 25;
+            }
+
+            buttons.bold = makeButton("wmd-bold-button", "Strong  Ctrl+B", "0px", bindCommand("doBold"));
+            buttons.italic = makeButton("wmd-italic-button", "Emphasis  Ctrl+I", "-20px", bindCommand("doItalic"));
+            makeSpacer(1);
+            buttons.link = makeButton("wmd-link-button", "Hyperlink  Ctrl+L", "-40px", bindCommand(function (chunk, postProcessing) {
+                return this.doLinkOrImage(chunk, postProcessing, false);
+            }));
+            buttons.quote = makeButton("wmd-quote-button", "Blockquote 
     Ctrl+Q", "-60px", bindCommand("doBlockquote"));
+            buttons.code = makeButton("wmd-code-button", "Code Sample 
     Ctrl+K", "-80px", bindCommand("doCode"));
+            buttons.image = makeButton("wmd-image-button", "Image  Ctrl+G", "-100px", bindCommand(function (chunk, postProcessing) {
+                return this.doLinkOrImage(chunk, postProcessing, true);
+            }));
+            makeSpacer(2);
+            buttons.olist = makeButton("wmd-olist-button", "Numbered List 
       Ctrl+O", "-120px", bindCommand(function (chunk, postProcessing) {
+                this.doList(chunk, postProcessing, true);
+            }));
+            buttons.ulist = makeButton("wmd-ulist-button", "Bulleted List