Reopens tabs you've closed recently.

undo-closed-tabs.ubiq.js

const Name = 'undo-closed-tabs',
SS = Cc['@mozilla.org/browser/sessionstore;1'].getService(Ci.nsISessionStore),
Style = <style>{<><![CDATA[
  @, @* {margin:0; padding:0}
  @button {border-width:1px;
    font:bold 112% "Consolas",monospace; vertical-align:top}
  @li {list-style-type:none}
  @img {width:16px; height:16px}
  @span.url {display:inline-block; white-space:pre; font-size:88%}
  @img, @span {vertical-align:middle}
  ]]></>.toString().replace(/@/g, '.'+ Name +' ')}</style>;
CmdUtils.CreateCommand({
  name: Name,
  synonyms: ['uct'],
  icon: 'chrome://ubiquity/skin/icons/arrow_undo.png',
  description: "Reopens tabs you've closed recently.",
  help: (''+<ul style="list-style-image:none">
         <li>Use accesskey or click to undo.</li>
         <li>Type <abbr title="Regular Expression">regex</abbr>
         to filter by title and/or url.</li></ul>),
  takes: {regex: {_name: '/re/i', suggest: function(txt, htm, cb, sx){
    if(sx) return [];
    try { var re = RegExp(txt, 'i') } catch(_){ re = /^/ }
    return [{text: txt, data: re, summary: re}];
  }}},
  execute: function({data}){
    for each(var {id} in this._find(data)) this._undo(id);
  },
  preview: function(pbl, {data}){
    if(!SS.getClosedTabCount(context.chromeWindow))
      return this._puts(pbl, 'No closed tabs found.');
    var ol = this._find(data).reduce(function(ol, {id, title, image, url}, i){
      var k = String.fromCharCode(i + 65);
      ol.li += (<li><label for={id}><span class="title"><button id={id}
                accesskey={k}>{k}</button><img src={image}
                />{title}</span><span class="url">{url}</span></label></li>);
      return ol;
    }, <ol class={Name}></ol>);
    if(!('li' in ol)) return this._puts(pbl, 'No tabs matched.');
    (jQuery(pbl).html(Style + ol +'')
     .find('button').each(function(me){
       this.addEventListener('focus', function(e){
         var li = this.parentNode.parentNode.parentNode;
         li.parentNode.removeChild(li);
         me._undo(+this.id);
         e.preventDefault(), e.stopPropagation();
       }, true);
     }, [this]));
  },
  previewDelay: 333,
  _puts: function(pbl, msg){
    pbl.innerHTML = <i>{msg}</i>.toXMLString() + this.help;
  },
  _find: function(re){
    var ls = this._list = eval(SS.getClosedTabData(context.chromeWindow));
    ls.forEach(function(t, i){ t.id = i; [{url: t.url}] = t.state.entries });
    return re ? ls.filter(function(t) re.test(t.title) || re.test(t.url)) : ls;
  },
  _undo: function(id){
    this._list.every(function(t, i, l){
      if(id !== t.id) return 1;
      SS.undoCloseTab(context.chromeWindow, i);
      l.splice(i, 1);
    });
  },
  author: ['powchin'.link('http://friendfeed.com/powchin'),
           'satyr'.link('http://d.hatena.ne.jp/murky-satyr')].join(', '),
  license: 'MIT',
});