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File Content: `app.js`

/**
 * Roundcube Webmail Client Script
 *
 * This file is part of the Roundcube Webmail client
 *
 * @licstart  The following is the entire license notice for the
 * JavaScript code in this file.
 *
 * Copyright (C) The Roundcube Dev Team
 * Copyright (C) Kolab Systems AG
 *
 * The JavaScript code in this page is free software: you can
 * redistribute it and/or modify it under the terms of the GNU
 * General Public License (GNU GPL) as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option)
 * any later version.  The code is distributed WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU GPL for more details.
 *
 * As additional permission under GNU GPL version 3 section 7, you
 * may distribute non-source (e.g., minimized or compacted) forms of
 * that code without the copy of the GNU GPL normally required by
 * section 4, provided you include this license notice and a URL
 * through which recipients can access the Corresponding Source.
 *
 * @licend  The above is the entire license notice
 * for the JavaScript code in this file.
 *
 * @author Thomas Bruederli <roundcube@gmail.com>
 * @author Aleksander 'A.L.E.C' Machniak <alec@alec.pl>
 * @author Charles McNulty <charles@charlesmcnulty.com>
 *
 * @requires jquery.js, common.js, list.js
 */

function rcube_webmail()
{
  this.labels = {};
  this.buttons = {};
  this.buttons_sel = {};
  this.gui_objects = {};
  this.gui_containers = {};
  this.commands = {};
  this.command_handlers = {};
  this.onloads = [];
  this.messages = {};
  this.group2expand = {};
  this.http_request_jobs = {};
  this.menu_stack = [];
  this.menu_buttons = {};
  this.entity_selectors = [];
  this.image_style = {};
  this.uploads = {};

  // webmail client settings
  this.dblclick_time = 500;
  this.message_time = 5000;
  this.preview_delay_select = 400;
  this.preview_delay_click  = 60;
  this.identifier_expr = /[^0-9a-z_-]/gi;
  this.uploadTimeout = 0; // 0 = no timeout | ajax call timeout for loading attachment


  // environment defaults
  this.env = {
    attachments: {},
    request_timeout: 180,  // seconds
    draft_autosave: 0,     // seconds
    comm_path: './',
    recipients_separator: ',', // @deprecated
    recipients_delimiter: ', ', // @deprecated
    popup_width: 1150,
    popup_width_small: 900,
    thread_padding: '15px'
  };

  // create protected reference to myself
  this.ref = 'rcmail';
  var ref = this;

  // set jQuery ajax options
  $.ajaxSetup({
    cache: false,
    timeout: this.env.request_timeout * 1000,
    error: function(request, status, err){ ref.http_error(request, status, err); },
    beforeSend: function(xmlhttp){ xmlhttp.setRequestHeader('X-Roundcube-Request', ref.env.request_token); }
  });

  // unload fix
  $(window).on('beforeunload', function() { ref.unload = true; });

  // set environment variable(s)
  this.set_env = function(p, value)
  {
    if (p != null && typeof p === 'object' && !value)
      for (var n in p)
        this.env[n] = p[n];
    else
      this.env[p] = value;
  };

  // add a localized label to the client environment
  this.add_label = function(p, value)
  {
    if (typeof p == 'string')
      this.labels[p] = value;
    else if (typeof p == 'object')
      $.extend(this.labels, p);
  };

  // add a button to the button list
  this.register_button = function(command, id, type, act, sel, over)
  {
    var button_prop = {id:id, type:type};

    if (act) button_prop.act = act;
    if (sel) button_prop.sel = sel;
    if (over) button_prop.over = over;

    if (!this.buttons[command])
      this.buttons[command] = [];

    this.buttons[command].push(button_prop);

    if (this.loaded) {
      this.init_button(command, button_prop);
      this.set_button(command, (this.commands[command] ? 'act' : 'pas'));
    }
  };

  // register a button with popup menu, to set its state according to the state of all commands in the menu
  this.register_menu_button = function(button, menu_id)
  {
    if (this.menu_buttons[menu_id]) {
      this.menu_buttons[menu_id][0].push(button);
    }
    else {
      var commands = [];
      $('#' + menu_id).find('a').each(function() {
        var command, link = $(this), onclick = link.attr('onclick');

        if (onclick && String(onclick).match(/rcmail\.command\(\'([^']+)/))
          command = RegExp.$1;
        else
          command = function() { return link.is('.active'); };

        commands.push(command);
      });

      if (commands.length)
        this.menu_buttons[menu_id] = [[button], commands];
    }

    this.set_menu_buttons();
  };

  // set state of a menu button according to state of all menu actions
  this.set_menu_buttons = function()
  {
    // Use timeouts to not block and set menu button states only once
    clearTimeout(this.menu_buttons_timeout);
    this.menu_buttons_timeout = setTimeout(function() {
      $.each(ref.menu_buttons, function() {
        var disabled = true;
        $.each(this[1], function() {
          var is_func = typeof(this) == 'function';
          if ((is_func && this()) || (!is_func && ref.commands[this])) {
            return disabled = false;
          }
        });

        $(this[0]).add($(this[0]).parent('.dropbutton'))
          .addClass(disabled ? 'disabled' : 'active')
          .removeClass(disabled ? 'active' : 'disabled');
      });
    }, 50);
  };

  // register a specific gui object
  this.gui_object = function(name, id)
  {
    this.gui_objects[name] = this.loaded ? rcube_find_object(id) : id;
  };

  // register a container object
  this.gui_container = function(name, id)
  {
    this.gui_containers[name] = id;
  };

  // add a GUI element (html node) to a specified container
  this.add_element = function(elm, container)
  {
    if (this.gui_containers[container] && this.gui_containers[container].jquery)
      this.gui_containers[container].append(elm);
  };

  // register an external handler for a certain command
  this.register_command = function(command, callback, enable)
  {
    this.command_handlers[command] = callback;

    if (enable)
      this.enable_command(command, true);
  };

  // execute the given script on load
  this.add_onload = function(f)
  {
    this.onloads.push(f);
  };

  // initialize webmail client
  this.init = function()
  {
    var n;
    this.task = this.env.task;

    if (!this.env.blankpage)
      this.env.blankpage = 'javascript:false;';

    // find all registered gui containers
    for (n in this.gui_containers)
      this.gui_containers[n] = $('#'+this.gui_containers[n]);

    // find all registered gui objects
    for (n in this.gui_objects)
      this.gui_objects[n] = rcube_find_object(this.gui_objects[n]);

    // init registered buttons
    this.init_buttons();

    // tell parent window that this frame is loaded
    if (this.is_framed()) {
      parent.rcmail.unlock_frame();
    }

    // enable general commands
    this.enable_command('close', 'logout', 'mail', 'addressbook', 'settings', 'save-pref',
      'compose', 'undo', 'about', 'switch-task', 'menu-open', 'menu-close', 'menu-save', true);

    // set active task button
    this.set_button(this.task, 'sel');

    if (this.env.permaurl)
      this.enable_command('permaurl', 'extwin', true);

    switch (this.task) {

      case 'mail':
        // enable mail commands
        this.enable_command('list', 'checkmail', 'add-contact', 'search', 'reset-search', 'collapse-folder', 'import-messages', true);

        if (this.gui_objects.messagelist) {
          // setup message list cols
          this.msglist_setup(this.env.layout);

          this.env.widescreen_list_template = [
            {className: 'threads', cells: ['threads']},
            {className: 'subject', cells: ['fromto', 'date', 'size', 'status', 'subject']},
            {className: 'flags', cells: ['flag', 'attachment']}
          ];

          this.message_list = new rcube_list_widget(this.gui_objects.messagelist, {
            multiselect:true, multiexpand:true, draggable:true, keyboard:true,
            column_movable:this.env.col_movable, dblclick_time:this.dblclick_time
            });
          this.message_list
            .addEventListener('initrow', function(o) { ref.init_message_row(o); })
            .addEventListener('dblclick', function(o) { ref.msglist_dbl_click(o); })
            .addEventListener('keypress', function(o) { ref.msglist_keypress(o); })
            .addEventListener('select', function(o) { ref.msglist_select(o); })
            .addEventListener('dragstart', function(o) { ref.drag_start(o); })
            .addEventListener('dragmove', function(e) { ref.drag_move(e); })
            .addEventListener('dragend', function(e) { ref.drag_end(e); })
            .addEventListener('expandcollapse', function(o) { ref.msglist_expand(o); })
            .addEventListener('column_replace', function(o) { ref.msglist_set_coltypes(o); })
            .init();

          // TODO: this should go into the list-widget code
          $(this.message_list.thead).on('click', 'a.sortcol', function(e){
            return ref.command('sort', $(this).attr('rel'), this);
          });

          this.enable_command('toggle_status', 'toggle_flag', 'sort', true);
          this.enable_command('set-listmode', this.env.threads && !this.is_multifolder_listing());

          // load messages
          var searchfilter = $(this.gui_objects.search_filter).val();
          if (searchfilter && searchfilter != 'ALL')
            this.filter_mailbox(searchfilter);
          else
            this.command('list');

          $(this.gui_objects.qsearchbox).val(this.env.search_text).focusin(function() { ref.message_list.blur(); });
        }

        this.set_button_titles();

        this.env.message_commands = ['show', 'reply', 'reply-all', 'reply-list',
          'move', 'copy', 'delete', 'open', 'mark', 'edit', 'viewsource', 'bounce',
          'print', 'load-attachment', 'download-attachment', 'show-headers', 'hide-headers', 'download',
          'forward', 'forward-inline', 'forward-attachment', 'change-format'];

        if (this.env.action == 'show' || this.env.action == 'preview') {
          this.enable_command(this.env.message_commands, this.env.uid);
          this.enable_command('reply-list', this.env.list_post);

          if (this.env.action == 'show') {
            this.http_request('pagenav', {_uid: this.env.uid, _mbox: this.env.mailbox, _search: this.env.search_request},
              this.display_message('', 'loading'));
          }

          if (this.env.mail_read_time > 0)
            setTimeout(function() {
              ref.http_post('mark', {_uid: ref.env.uid, _flag: 'read', _mbox: ref.env.mailbox, _quiet: 1});
            }, this.env.mail_read_time * 1000);

          if (this.env.blockedobjects) {
            $(this.gui_objects.remoteobjectsmsg).show();
            this.enable_command('load-remote', true);
          }

          // make preview/message frame visible
          if (this.env.action == 'preview' && this.is_framed()) {
            this.enable_command('compose', 'add-contact', false);
            parent.rcmail.show_contentframe(true);
          }

          if ($.inArray('flagged', this.env.message_flags) >= 0) {
            $(document.body).addClass('status-flagged');
          }

          // initialize drag-n-drop on attachments, so they can e.g.
          // be dropped into mail compose attachments in another window
          if (this.gui_objects.attachments)
            $('li > a', this.gui_objects.attachments).not('.drop').on('dragstart', function(e) {
              var n, href = this.href, dt = e.originalEvent.dataTransfer;
              if (dt) {
                // inject username to the uri
                href = href.replace(/^https?:\/\//, function(m) { return m + urlencode(ref.env.username) + '@'});
                // cleanup the node to get filename without the size test
                n = $(this).clone();
                n.children().remove();

                dt.setData('roundcube-uri', href);
                dt.setData('roundcube-name', n.text().trim());
              }
            });

            this.check_mailvelope(this.env.action);
        }
        else if (this.env.action == 'compose') {
          this.env.address_group_stack = [];
          this.env.compose_commands = ['send-attachment', 'remove-attachment', 'send', 'cancel',
            'toggle-editor', 'list-addresses', 'pushgroup', 'search', 'reset-search', 'extwin',
            'insert-response', 'menu-open', 'menu-close', 'load-attachment',
            'download-attachment', 'open-attachment', 'rename-attachment'];

          if (this.env.drafts_mailbox)
            this.env.compose_commands.push('savedraft')

          this.enable_command(this.env.compose_commands, true);

          // add more commands (not enabled)
          $.merge(this.env.compose_commands, ['add-recipient', 'firstpage', 'previouspage', 'nextpage', 'lastpage']);

          if (window.googie) {
            this.env.editor_config.spellchecker = googie;
            this.env.editor_config.spellcheck_observer = function(s) { ref.spellcheck_state(); };

            this.env.compose_commands.push('spellcheck')
            this.enable_command('spellcheck', true);
          }

          // initialize HTML editor
          this.editor_init(null, this.env.composebody);

          // init message compose form
          this.init_messageform();

          this.check_mailvelope(this.env.action);
        }
        else if (this.env.action == 'bounce') {
          this.init_messageform_inputs();
          this.env.compose_commands = [];
        }
        else if (this.env.action == 'get') {
          this.enable_command('download', true);
          this.enable_command('image-scale', 'image-rotate', !!/^image\//.test(this.env.mimetype));

          // Mozilla's PDF.js viewer does not allow printing from host page (#5125)
          // to minimize user confusion we disable the Print button on Firefox < 75
          this.enable_command('print', this.env.mimetype != 'application/pdf' || !bw.mz || bw.vendver >= 75);

          if (this.env.is_message) {
            this.enable_command('reply', 'reply-all', 'edit', 'viewsource',
              'forward', 'forward-inline', 'forward-attachment', 'bounce', true);
            if (this.env.list_post)
              this.enable_command('reply-list', true);
          }

          // center and scale the image in preview frame
          // TODO: Find a better way. Onload is late, also we could use embed.css
          if (this.env.mimetype.startsWith('image/'))
            $(this.gui_objects.messagepartframe).on('load', function() {
              var contents = $(this).contents();

              // do not apply styles to an error page (with no image)
              if (contents.find('img').length) {
                contents.find('img').css({ maxWidth: '100%', maxHeight: '100%' });
                contents.find('body').css({ display: 'flex', alignItems: 'center', justifyContent: 'center', height: '100%', margin: 0 });
                contents.find('html').css({ height: '100%' });
              }
            });
        }
        // show printing dialog unless decryption must be done first
        else if (this.env.action == 'print' && this.env.uid) {
          this.check_mailvelope(this.env.action);
          if (!this.env.is_pgp_content && !this.env.pgp_mime_part) {
            this.print_dialog();
          }
        }

        // get unread count for each mailbox
        if (this.gui_objects.mailboxlist) {
          this.env.unread_counts = {};
          this.gui_objects.folderlist = this.gui_objects.mailboxlist;
          this.http_request('getunread', {_page: this.env.current_page});
        }

        // init address book widget
        if (this.gui_objects.contactslist) {
          this.contact_list = new rcube_list_widget(this.gui_objects.contactslist,
            { multiselect:true, draggable:false, keyboard:true });
          this.contact_list
            .addEventListener('initrow', function(o) { ref.triggerEvent('insertrow', { cid:o.uid, row:o }); })
            .addEventListener('select', function(o) { ref.compose_recipient_select(o); })
            .addEventListener('dblclick', function(o) { ref.compose_add_recipient(); })
            .addEventListener('keypress', function(o) {
              if (o.key_pressed == o.ENTER_KEY) {
                if (!ref.compose_add_recipient()) {
                  // execute link action on <enter> if not a recipient entry
                  if (o.last_selected && String(o.last_selected).charAt(0) == 'G') {
                    $(o.rows[o.last_selected].obj).find('a').first().click();
                  }
                }
              }
            })
            .init();

          // remember last focused address field
          $('#_to,#_cc,#_bcc').focus(function() { ref.env.focused_field = this; });
        }

        if (this.gui_objects.addressbookslist) {
          this.gui_objects.folderlist = this.gui_objects.addressbookslist;
          this.enable_command('list-addresses', true);
        }

        // ask user to send MDN
        if (this.env.mdn_request && this.env.uid) {
            this.mdn_request_dialog(this.env.uid, this.env.mailbox);
        }

        // detect browser capabilities
        if (!this.is_framed() && !this.env.extwin)
          this.browser_capabilities_check();

        break;

      case 'addressbook':
        this.env.address_group_stack = [];

        if (this.gui_objects.folderlist)
          this.env.contactfolders = $.extend($.extend({}, this.env.address_sources), this.env.contactgroups);

        this.enable_command('add', 'import', this.env.writable_source);
        this.enable_command('list', 'listgroup', 'pushgroup', 'popgroup', 'listsearch', 'search', 'reset-search', 'advanced-search', true);

        if (this.gui_objects.contactslist) {
          this.contact_list = new rcube_list_widget(this.gui_objects.contactslist,
            {multiselect:true, draggable:this.gui_objects.folderlist?true:false, keyboard:true});
          this.contact_list
            .addEventListener('initrow', function(o) { ref.triggerEvent('insertrow', { cid:o.uid, row:o }); })
            .addEventListener('keypress', function(o) { ref.list_keypress(o); })
            .addEventListener('select', function(o) { ref.contactlist_select(o); })
            .addEventListener('dragstart', function(o) { ref.drag_start(o); })
            .addEventListener('dragmove', function(e) { ref.drag_move(e); })
            .addEventListener('dragend', function(e) { ref.drag_end(e); })
            .init();

          $(this.gui_objects.qsearchbox).focusin(function() { ref.contact_list.blur(); });

          this.update_group_commands();
          this.command('list');
        }

        if (this.gui_objects.savedsearchlist) {
          this.savedsearchlist = new rcube_treelist_widget(this.gui_objects.savedsearchlist, {
            id_prefix: 'rcmli',
            id_encode: this.html_identifier_encode,
            id_decode: this.html_identifier_decode
          });

          this.savedsearchlist.addEventListener('select', function(node) {
            ref.triggerEvent('selectfolder', { folder:node.id, prefix:'rcmli' }); });
        }

        this.set_page_buttons();

        if (this.env.cid) {
          this.enable_command('show', 'edit', 'qrcode', true);
          // register handlers for group assignment via checkboxes
          if (this.gui_objects.editform) {
            $('input.groupmember').change(function() {
              ref.group_member_change(this.checked ? 'add' : 'del', ref.env.cid, ref.env.source, this.value);
            });
          }
        }

        if (this.gui_objects.editform) {
          this.enable_command('save', true);
          if (this.env.action == 'add' || this.env.action == 'edit' || this.env.action == 'search')
              this.init_contact_form();
        }
        else if (this.env.action == 'print') {
          this.print_dialog();
        }

        break;

      case 'settings':
        this.enable_command('show', 'save', true);

        if (this.env.action == 'identities') {
          this.enable_command('add', this.env.identities_level < 2);
        }
        else if (this.env.action == 'edit-identity' || this.env.action == 'add-identity') {
          this.enable_command('save', 'edit', true);
          this.enable_command('delete', this.env.identities_level < 2);

          if (this.env.action == 'edit-identity') {
            this.check_mailvelope(this.env.action);
          }
        }
        else if (this.env.action == 'folders') {
          this.enable_command('subscribe', 'unsubscribe', 'create-folder', 'rename-folder', true);
        }
        else if (this.env.action == 'edit-folder' && this.gui_objects.editform) {
          this.enable_command('save', 'folder-size', true);
          parent.rcmail.env.exists = this.env.messagecount;
          parent.rcmail.enable_command('purge', this.env.messagecount);
        }
        else if (this.env.action == 'responses') {
          this.enable_command('add', true);
        }

        if (this.gui_objects.identitieslist) {
          this.identity_list = new rcube_list_widget(this.gui_objects.identitieslist,
            {multiselect:false, draggable:false, keyboard:true});
          this.identity_list
            .addEventListener('select', function(o) { ref.identity_select(o); })
            .addEventListener('keypress', function(o) { ref.list_keypress(o); })
            .init()
            .focus();
        }
        else if (this.gui_objects.sectionslist) {
          this.sections_list = new rcube_list_widget(this.gui_objects.sectionslist, {multiselect:false, draggable:false, keyboard:true});
          this.sections_list
            .addEventListener('select', function(o) { ref.section_select(o); })
            .init()
            .focus();
        }
        else if (this.gui_objects.subscriptionlist) {
          this.init_subscription_list();
        }
        else if (this.gui_objects.responseslist) {
          this.responses_list = new rcube_list_widget(this.gui_objects.responseslist, {multiselect:false, draggable:false, keyboard:true});
          this.responses_list
            .addEventListener('select', function(o) { ref.response_select(o); })
            .addEventListener('keypress', function(o) { ref.list_keypress(o); })
            .init()
            .focus();
        }

        break;

      case 'login':
        var tz, tz_name,
            input_user = $('#rcmloginuser'),
            input_tz = $('#rcmlogintz');

        if (input_user.val() == '')
          input_user.focus();
        else
          $('#rcmloginpwd').focus();

        // detect client timezone
        if (window.jstz && (tz = jstz.determine()))
          tz_name = tz.name();

        input_tz.val(tz_name ? tz_name : (new Date().getStdTimezoneOffset() / -60));

        // display 'loading' message on form submit, lock submit button
        $('form').submit(function () {
          $('[type=submit]', this).prop('disabled', true);
          ref.clear_messages();
          ref.display_message('', 'loading');
        });

        break;
    }

    // select first input field in an edit form
    if (this.gui_objects.editform)
      $("input,select,textarea", this.gui_objects.editform)
        .not(':hidden').not(':disabled').first().select().focus();

    // prevent from form submit with Enter key in file input fields
    if (bw.ie)
      $('input[type=file]').keydown(function(e) { if (e.keyCode == '13') e.preventDefault(); });

    // flag object as complete
    this.loaded = true;
    this.env.lastrefresh = new Date();

    // show message
    if (this.pending_message)
      this.display_message.apply(this, this.pending_message);

    // init treelist widget
    if (this.gui_objects.folderlist && window.rcube_treelist_widget
      // some plugins may load rcube_treelist_widget and there's one case
      // when this will cause problems - addressbook widget in compose,
      // which already has been initialized using rcube_list_widget
      && this.gui_objects.folderlist != this.gui_objects.addressbookslist
    ) {
      this.treelist = new rcube_treelist_widget(this.gui_objects.folderlist, {
          selectable: true,
          id_prefix: 'rcmli',
          parent_focus: true,
          id_encode: this.html_identifier_encode,
          id_decode: this.html_identifier_decode,
          check_droptarget: function(node) { return !node.virtual && ref.check_droptarget(node.id) }
      });

      this.treelist
        .addEventListener('collapse', function(node) { ref.folder_collapsed(node) })
        .addEventListener('expand', function(node) { ref.folder_collapsed(node) })
        .addEventListener('beforeselect', function(node) { return !ref.busy; })
        .addEventListener('select', function(node) {
          ref.triggerEvent('selectfolder', { folder:node.id, prefix:'rcmli' });
          ref.mark_all_read_state();
        });
    }

    // activate html5 file drop feature (if browser supports it and if configured)
    if (this.gui_objects.filedrop && this.env.filedrop && window.FormData) {
      $(document.body).on('dragover dragleave drop', function(e) { return ref.document_drag_hover(e, e.type == 'dragover'); });
      $(this.gui_objects.filedrop).addClass('droptarget')
        .on('dragover dragleave', function(e) { return ref.file_drag_hover(e, e.type == 'dragover'); })
        .get(0).addEventListener('drop', function(e) { return ref.file_dropped(e); }, false);
    }

    // catch document (and iframe) mouse clicks
    var body_mouseup = function(e) { return ref.doc_mouse_up(e); };
    $(document.body)
      .mouseup(body_mouseup)
      .keydown(function(e) { return ref.doc_keypress(e); });

    rcube_webmail.set_iframe_events({mouseup: body_mouseup});

    // trigger init event hook
    this.triggerEvent('init', { task:this.task, action:this.env.action });

    // execute all foreign onload scripts
    // @deprecated
    for (n in this.onloads) {
      if (typeof this.onloads[n] === 'string')
        eval(this.onloads[n]);
      else if (typeof this.onloads[n] === 'function')
        this.onloads[n]();
    }

    // register menu buttons
    $('[data-popup]').each(function() { ref.register_menu_button(this, $(this).data('popup')); });

    // start keep-alive and refresh intervals
    this.start_refresh();
    this.start_keepalive();
  };

  this.log = function(msg)
  {
    if (this.env.devel_mode && window.console && console.log)
      console.log(msg);
  };

  /*********************************************************/
  /*********       client command interface        *********/
  /*********************************************************/

  // execute a specific command on the web client
  this.command = function(command, props, obj, event, allow_disabled)
  {
    var ret;

    if (obj && obj.blur && !(event && rcube_event.is_keyboard(event)))
      obj.blur();

    // do nothing if interface is locked by another command
    // with exception for searching reset and menu
    if (this.busy && !(command == 'reset-search' && this.last_command == 'search') && !command.match(/^menu-/))
      return false;

    // let the browser handle this click (shift/ctrl usually opens the link in a new window/tab)
    if ((obj && obj.href && String(obj.href).indexOf('#') < 0) && rcube_event.get_modifier(event)) {
      return true;
    }

    // command not supported or allowed
    if (!allow_disabled && !this.commands[command]) {
      // pass command to parent window
      if (this.is_framed())
        parent.rcmail.command(command, props);

      return false;
    }

    // check input before leaving compose step
    if (this.task == 'mail' && this.env.action == 'compose' && !this.env.server_error && command != 'save-pref'
      && ($.inArray(command, this.env.compose_commands) < 0 || command.startsWith('compose-encrypted') && ref.mailvelope_editor)
      && !this.compose_skip_unsavedcheck
    ) {
      if (!this.env.is_sent && this.cmp_hash != this.compose_field_hash()) {
        this.confirm_dialog(this.get_label('notsentwarning'), 'discard', function() {
            // remove copy from local storage if compose screen is left intentionally
            ref.remove_compose_data(ref.env.compose_id);
            ref.compose_skip_unsavedcheck = true;
            ref.command(command, props, obj, event);
          });

        return false;
      }
    }

    this.last_command = command;
    this.command_aborted = false;

    // trigger plugin hooks
    this.triggerEvent('actionbefore', {props: props, action: command, originalEvent: event});

    if ((ret = this.triggerEvent('before' + command, props || event)) !== undefined) {
      // abort if one of the handlers returned false
      if (ret === false)
        return false;

      props = ret;
    }

    // process external commands
    if (typeof this.command_handlers[command] === 'function') {
      ret = this.command_handlers[command](props, obj, event);
    }
    else if (typeof this.command_handlers[command] === 'string') {
      ret = window[this.command_handlers[command]](props, obj, event);
    }
    // process internal commands
    else {
      ret = this.command_handler(command, props, obj, event);
    }

    if (!this.command_aborted && this.triggerEvent('after' + command, props) === false)
      ret = false;

    this.triggerEvent('actionafter', {props: props, action: command, aborted: this.command_aborted, ret: ret, originalEvent: event});

    if (ret === false)
      return false;

    if ((obj && ret !== true) || this.command_aborted === true)
      return false;

    return true;
  };

  // execute a specific known command
  this.command_handler = function(command, props, obj, event)
  {
    var uid, cid, url, flag;

    // process internal command
    switch (command) {

      // commands to switch task
      case 'logout':
      case 'mail':
      case 'addressbook':
      case 'settings':
        this.switch_task(command);
        break;

      case 'about':
        this.redirect('?_task=settings&_action=about', false);
        break;

      case 'permaurl':
        if (obj && obj.href && obj.target)
          return true;
        if (this.env.permaurl)
          parent.location.href = this.env.permaurl;
        break;

      case 'extwin':
        if (this.env.action == 'compose') {
          var form = this.gui_objects.messageform,
            win = this.open_window('');

          if (win) {
            this.save_compose_form_local();
            this.compose_skip_unsavedcheck = true;
            $("[name='_action']", form).val('compose');
            form.action = this.url('mail/compose', { _id: this.env.compose_id, _extwin: 1 });
            form.target = win.name;
            form.submit();
          }
        }
        else {
          this.open_window(this.env.permaurl, true);
        }
        break;

      case 'change-format':
        url = this.env.permaurl + '&_format=' + props;

        if (this.env.action == 'preview')
          url = url.replace(/_action=show/, '_action=preview') + '&_framed=1';
        if (this.env.extwin)
          url += '&_extwin=1';

        location.href = url;
        break;

      case 'menu-open':
        if (props && props.menu == 'attachmentmenu') {
          var mimetype = this.env.attachments[props.id];
          if (mimetype && mimetype.mimetype) // in compose format is different
            mimetype = mimetype.mimetype;
          this.enable_command('open-attachment', mimetype && this.env.mimetypes && $.inArray(mimetype, this.env.mimetypes) >= 0);
        }
        this.show_menu(props, props.show || undefined, event);
        break;

      case 'menu-close':
        this.hide_menu(props, event);
        break;

      case 'menu-save':
        this.triggerEvent(command, {props:props, originalEvent:event});
        return false;

      case 'open':
        if (uid = this.get_single_uid()) {
          obj.href = this.url('show', this.params_from_uid(uid, {_extwin: 1}));
          return true;
        }
        break;

      case 'close':
        if (this.env.extwin)
          window.close();
        break;

      case 'list':
        if (props && props != '') {
          this.reset_qsearch(true);
        }
        if (this.env.action == 'compose' && this.env.extwin) {
          window.close();
        }
        else if (this.task == 'mail') {
          this.list_mailbox(props, props ? 1 : '');
          this.set_button_titles();
        }
        else if (this.task == 'addressbook')
          this.list_contacts(props);
        break;

      case 'set-listmode':
        this.set_list_options(null, undefined, undefined, props == 'threads' ? 1 : 0);
        break;

      case 'sort':
        var sort_order = this.env.sort_order,
          sort_col = !this.env.disabled_sort_col ? props : this.env.sort_col;

        if (!this.env.disabled_sort_order)
          sort_order = this.env.sort_col == sort_col && sort_order == 'ASC' ? 'DESC' : 'ASC';

        // set table header and update env
        this.set_list_sorting(sort_col, sort_order);

        // reload message list
        this.list_mailbox('', '', sort_col+'_'+sort_order);
        break;

      case 'nextpage':
        this.list_page('next');
        break;

      case 'lastpage':
        this.list_page('last');
        break;

      case 'previouspage':
        this.list_page('prev');
        break;

      case 'firstpage':
        this.list_page('first');
        break;

      case 'expunge':
        if (this.env.exists)
          this.expunge_mailbox(this.env.mailbox);
        break;

      case 'purge':
      case 'empty-mailbox':
        if (this.env.exists)
          this.purge_mailbox(this.env.mailbox);
        break;

      // common commands used in multiple tasks
      case 'show':
        if (this.task == 'mail') {
          uid = this.get_single_uid();
          if (uid && (!this.env.uid || uid != this.env.uid)) {
            var mbox = this.get_message_mailbox(uid);
            if (mbox == this.env.drafts_mailbox)
              this.open_compose_step({_draft_uid: uid, _mbox: mbox});
            else
              this.show_message(uid);
          }
        }
        else if (this.task == 'addressbook') {
          cid = props ? props : this.get_single_cid();
          if (cid && !(this.env.action == 'show' && cid == this.env.cid))
            this.load_contact(cid, 'show');
        }
        else if (this.task == 'settings') {
          this.goto_url('settings/' + props, {_framed: 0});
        }
        break;

      case 'add':
        if (this.task == 'addressbook')
          this.load_contact(0, 'add');
        else if (this.task == 'settings' && this.env.action == 'responses')
          this.load_response(0, 'add-response');
        else if (this.task == 'settings')
          this.load_identity(0, 'add-identity');
        break;

      case 'edit':
        if (this.task == 'addressbook' && (cid = this.get_single_cid()))
          this.load_contact(cid, 'edit');
        else if (this.task == 'mail' && (uid = this.get_single_uid())) {
          url = { _mbox: this.get_message_mailbox(uid) };
          url[url._mbox == this.env.drafts_mailbox && props != 'new' ? '_draft_uid' : '_uid'] = uid;
          this.open_compose_step(url);
        }
        break;

      case 'save':
        var input, form = this.gui_objects.editform;
        if (form) {
          // user prefs
          if ((input = $("[name='_pagesize']", form)) && input.length && isNaN(parseInt(input.val()))) {
            this.alert_dialog(this.get_label('nopagesizewarning'), function() {
              input.focus();
            });
            break;
          }
          // contacts/identities
          else {
            // reload form
            if (props == 'reload') {
              form.action += '&_reload=1';
            }
            else if (this.task == 'settings' && (this.env.identities_level % 2) == 0  &&
              (input = $("[name='_email']", form)) && input.length && !rcube_check_email(input.val())
            ) {
              this.alert_dialog(this.get_label('noemailwarning'), function() {
                input.focus();
              });
              break;
            }
          }

          // add selected source (on the list)
          if (parent.rcmail && parent.rcmail.env.source)
            form.action = this.add_url(form.action, '_orig_source', parent.rcmail.env.source);

          form.submit();
        }
        break;

      case 'delete':
        // mail task
        if (this.task == 'mail')
          this.delete_messages(event);
        // addressbook task
        else if (this.task == 'addressbook')
          this.delete_contacts();
        // settings: canned response
        else if (this.task == 'settings' && this.env.action == 'responses')
          this.delete_response();
        // settings: user identities
        else if (this.task == 'settings')
          this.delete_identity();
        break;

      // mail task commands
      case 'move':
      case 'moveto': // deprecated
        if (this.task == 'mail')
          this.move_messages(props, event);
        else if (this.task == 'addressbook')
          this.move_contacts(props, event);
        break;

      case 'copy':
        if (this.task == 'mail')
          this.copy_messages(props, event);
        else if (this.task == 'addressbook')
          this.copy_contacts(props, event);
        break;

      case 'mark':
        if (props)
          this.mark_message(props);
        break;

      case 'toggle_status':
      case 'toggle_flag':
        flag = command == 'toggle_flag' ? 'flagged' : 'read';

        if (uid = props) {
          // toggle flagged/unflagged
          if (flag == 'flagged') {
            if (this.message_list.rows[uid].flagged)
              flag = 'unflagged';
          }
          // toggle read/unread
          else if (this.message_list.rows[uid].deleted)
            flag = 'undelete';
          else if (!this.message_list.rows[uid].unread)
            flag = 'unread';

          this.mark_message(flag, uid);
        }

        break;

      case 'add-contact':
        this.add_contact(props);
        break;

      case 'load-remote':
        if (this.env.uid) {
          if (props && this.env.sender) {
            this.add_contact(this.env.sender, true, props);
            break;
          }

          this.show_message(this.env.uid, true, this.env.action == 'preview');
        }
        break;

      case 'load-attachment':
      case 'open-attachment':
      case 'download-attachment':
        var params, mimetype = this.env.attachments[props];

        if (this.env.action == 'compose') {
          params = {_file: props, _id: this.env.compose_id};
          mimetype = mimetype ? mimetype.mimetype : '';
        }
        else {
          params = {_mbox: this.env.mailbox, _uid: this.env.uid, _part: props};
        }

        // open attachment in frame if it's of a supported mimetype
        if (command != 'download-attachment' && mimetype && this.env.mimetypes && $.inArray(mimetype, this.env.mimetypes) >= 0) {
          // Note: We disable _framed for proper X-Frame-Options:deny support (#6688)
          if (this.open_window(this.url('get', $.extend({_frame: 1, _framed: 0}, params))))
            return true;
        }

        params._download = 1;

        // prevent from page unload warning in compose
        this.compose_skip_unsavedcheck = 1;
        this.goto_url('get', params, false, true);
        this.compose_skip_unsavedcheck = 0;

        return true;

      case 'select-all':
        this.select_all_mode = props ? false : true;
        this.dummy_select = true; // prevent msg opening if there's only one msg on the list
        var list = this[this.task == 'addressbook' ? 'contact_list' : 'message_list'];
        if (props == 'invert')
          list.invert_selection();
        else
          list.select_all(props == 'page' ? '' : props);
        this.dummy_select = null;
        break;

      case 'select-none':
        this.select_all_mode = false;
        this[this.task == 'addressbook' ? 'contact_list' : 'message_list'].clear_selection();
        break;

      case 'expand-all':
        this.env.autoexpand_threads = 1;
        this.message_list.expand_all();
        break;

      case 'expand-unread':
        this.env.autoexpand_threads = 2;
        this.message_list.collapse_all();
        this.expand_unread();
        break;

      case 'collapse-all':
        this.env.autoexpand_threads = 0;
        this.message_list.collapse_all();
        break;

      case 'nextmessage':
        if (this.env.next_uid)
          this.show_message(this.env.next_uid, false, this.env.action == 'preview');
        break;

      case 'lastmessage':
        if (this.env.last_uid)
          this.show_message(this.env.last_uid);
        break;

      case 'previousmessage':
        if (this.env.prev_uid)
          this.show_message(this.env.prev_uid, false, this.env.action == 'preview');
        break;

      case 'firstmessage':
        if (this.env.first_uid)
          this.show_message(this.env.first_uid);
        break;

      case 'compose':
        url = {};

        if (this.task == 'mail') {
          url = {_mbox: this.env.mailbox, _search: this.env.search_request};
          if (props)
            url._to = props;
        }
        // modify url if we're in addressbook
        else if (this.task == 'addressbook') {
          // switch to mail compose step directly
          if (props && props.indexOf('@') > 0) {
            url._to = props;
          }
          else {
            var a_cids = [];
            // use contact id passed as command parameter
            if (props)
              a_cids.push(props);
            // get selected contacts
            else if (this.contact_list)
              a_cids = this.contact_list.get_selection();

            if (a_cids.length) {
              this.http_post('mailto', { _cid: a_cids.join(','), _source: this.env.source }, true);
              break;
            }
            else if (this.env.group && this.env.pagecount) {
              this.http_post('mailto', { _gid: this.env.group, _source: this.env.source }, true);
              break;
            }
          }
        }
        else if (props && typeof props == 'string') {
          url._to = props;
        }
        else if (props && typeof props == 'object') {
          $.extend(url, props);
        }

        this.open_compose_step(url);
        break;

      case 'spellcheck':
        if (this.spellcheck_state()) {
          this.editor.spellcheck_stop();
        }
        else {
          this.editor.spellcheck_start();
        }
        break;

      case 'savedraft':
        // Reset the auto-save timer
        clearTimeout(this.save_timer);

        // compose form did not change (and draft wasn't saved already)
        if (this.env.draft_id && this.cmp_hash == this.compose_field_hash()) {
          this.auto_save_start();
          break;
        }

        this.submit_messageform(true);
        break;

      case 'send':
        if (!props.nocheck && !this.env.is_sent && !this.check_compose_input(command))
          break;

        // Reset the auto-save timer
        clearTimeout(this.save_timer);

        this.submit_messageform();
        break;

      case 'send-attachment':
        // Reset the auto-save timer
        clearTimeout(this.save_timer);

        if (!(flag = this.upload_file(props || this.gui_objects.uploadform, 'upload'))) {
          if (flag !== false)
            this.alert_dialog(this.get_label('selectimportfile'));
          aborted = true;
        }
        break;

      case 'insert-sig':
        this.change_identity($("[name='_from']")[0], true);
        break;

      case 'list-addresses':
        this.list_contacts(props);
        this.enable_command('add-recipient', false);
        break;

      case 'add-recipient':
        this.compose_add_recipient(props);
        break;

      case 'reply-all':
      case 'reply-list':
      case 'reply':
        if (uid = this.get_single_uid()) {
          url = {_reply_uid: uid, _mbox: this.get_message_mailbox(uid), _search: this.env.search_request};
          if (command == 'reply-all')
            // do reply-list, when list is detected and popup menu wasn't used
            url._all = (!props && this.env.reply_all_mode == 1 && this.commands['reply-list'] ? 'list' : 'all');
          else if (command == 'reply-list')
            url._all = 'list';

          this.open_compose_step(url);
        }
        break;

      case 'forward-attachment':
      case 'forward-inline':
      case 'forward':
        var uids = this.env.uid ? [this.env.uid] : (this.message_list ? this.message_list.get_selection() : []);
        if (uids.length) {
          url = { _forward_uid: this.uids_to_list(uids), _mbox: this.env.mailbox, _search: this.env.search_request };
          if (command == 'forward-attachment' || (!props && this.env.forward_attachment) || uids.length > 1)
            url._attachment = 1;
          this.open_compose_step(url);
        }
        break;

      case 'print':
        if (this.task == 'addressbook') {
          if (uid = this.get_single_cid()) {
            url = '&_action=print&_cid=' + uid;
            if (this.env.source)
              url += '&_source=' + urlencode(this.env.source);
            this.open_window(this.env.comm_path + url, true, true);
          }
        }
        else if (this.env.action == 'get' && !this.env.is_message) {
          this.gui_objects.messagepartframe.contentWindow.print();
        }
        else if (uid = this.get_single_uid()) {
          url = this.url('print', this.params_from_uid(uid, {_safe: this.env.safemode ? 1 : 0}));
          if (this.open_window(url, true, true)) {
            if (this.env.action != 'show' && this.env.action != 'get')
              this.mark_message('read', uid);
          }
        }
        break;

      case 'viewsource':
        if (uid = this.get_single_uid())
          this.open_window(this.url('viewsource', this.params_from_uid(uid)), true, true);
        break;

      case 'download':
        if (this.env.action == 'get') {
          location.href = this.secure_url(location.href.replace(/_frame=/, '_download='));
        }
        else if (uid = this.get_single_uid()) {
          this.goto_url('viewsource', this.params_from_uid(uid, {_save: 1}), false, true);
        }
        break;

      // quicksearch
      case 'search':
        return this.qsearch(props);

      // reset quicksearch
      case 'reset-search':
        var n, s = this.env.search_request || this.env.qsearch;

        this.reset_qsearch(true);

        if (s && this.env.action == 'compose') {
          if (this.contact_list)
            this.list_contacts_clear();
        }
        else if (s && this.env.mailbox) {
          this.list_mailbox(this.env.mailbox, 1);
        }
        else if (s && this.task == 'addressbook') {
          this.env.source = this.env.last_source || '';
          this.env.group = this.env.last_group || '';
          this.list_contacts(this.env.source, this.env.group, 1);
        }
        break;

      case 'pushgroup':
        // add group ID and current search to stack
        var group = {
          id: props.id,
          search_request: this.env.search_request,
          page: this.env.current_page,
          search: this.env.search_request && this.gui_objects.qsearchbox ? this.gui_objects.qsearchbox.value : null
        };

        this.env.address_group_stack.push(group);
        if (obj && event)
          rcube_event.cancel(event);

        // FIXME: no break?

      case 'listgroup':
        this.reset_qsearch();
        this.list_contacts(props.source, props.id, 1, group);
        break;

      case 'popgroup':
        if (this.env.address_group_stack.length) {
          var old = this.env.address_group_stack.pop();
          this.reset_qsearch();

          if (old.search_request) {
            // this code is executed when going back to the search result
            if (old.search && this.gui_objects.qsearchbox)
              $(this.gui_objects.qsearchbox).val(old.search);
            this.env.search_request = old.search_request;
            this.list_contacts_remote(null, null, this.env.current_page = old.page);
          }
          else
            this.list_contacts(props.source, this.env.address_group_stack[this.env.address_group_stack.length-1].id);
        }
        break;

      case 'import-messages':
        var form = props || this.gui_objects.importform,
          importlock = this.set_busy(true, 'importwait');

        if (!(flag = this.upload_file(form, 'import', importlock))) {
          this.set_busy(false, null, importlock);
          if (flag !== false)
            this.alert_dialog(this.get_label('selectimportfile'));
          this.command_aborted = true;
        }
        break;

      case 'import':
        var dialog = $('<iframe>').attr('src', this.url('import', {_framed: 1, _target: this.env.source})),
          import_func = function(e) {
            var win = dialog[0].contentWindow,
              form = null;

            if (win.rcmail.gui_objects.importformmap)
              form = win.rcmail.gui_objects.importformmap;
            else
              form = win.rcmail.gui_objects.importform;

            if (form) {
              var lock, file = win.$('#rcmimportfile')[0];
              if (file && !file.value) {
                win.rcmail.alert_dialog(win.rcmail.get_label('selectimportfile'));
                return;
              }

              lock = win.rcmail.set_busy(true, 'importwait');
              $('[name="_unlock"]', form).val(lock);
              form.submit();
              win.rcmail.lock_form(form, true);
              // disable Import button
              $(e.target).attr('disabled', true).next().focus();
            }
          },
          close_func = function(event, ui) {
            $(this).remove();
            if (ref.import_state == 'reload')
              ref.command('list');
          };

        this.import_state = null;
        this.import_dialog = this.simple_dialog(dialog, 'importcontacts', import_func, {
          close: close_func,
          button: 'import',
          width: 500,
          height: 300
        });

        break;

      case 'export':
        if (this.contact_list.rowcount > 0) {
          this.goto_url('export', { _source: this.env.source, _gid: this.env.group, _search: this.env.search_request }, false, true);
        }
        break;

      case 'export-selected':
        if (this.contact_list.rowcount > 0) {
          this.goto_url('export', { _source: this.env.source, _gid: this.env.group, _cid: this.contact_list.get_selection().join(',') }, false, true);
        }
        break;

      case 'upload-photo':
        this.upload_contact_photo(props || this.gui_objects.uploadform);
        break;

      case 'delete-photo':
        this.replace_contact_photo('-del-');
        break;

      case 'undo':
        this.http_request('undo', '', this.display_message('', 'loading'));
        break;

      // unified command call (command name == function name)
      default:
        var func = command.replace(/-/g, '_');
        if (this[func] && typeof this[func] === 'function') {
          return this[func](props, obj, event);
        }
    }
  };

  // set command(s) enabled or disabled
  this.enable_command = function()
  {
    var i, n, args = Array.prototype.slice.call(arguments),
      enable = args.pop(), cmd;

    for (n=0; n<args.length; n++) {
      cmd = args[n];
      // argument of type array
      if (typeof cmd === 'string') {
        this.commands[cmd] = enable;
        this.set_button(cmd, (enable ? 'act' : 'pas'));
        this.triggerEvent('enable-command', {command: cmd, status: enable});
      }
      // push array elements into commands array
      else {
        for (i in cmd)
          args.push(cmd[i]);
      }
    }

    this.set_menu_buttons();
  };

  this.command_enabled = function(cmd)
  {
    return this.commands[cmd];
  };

  // lock/unlock interface
  this.set_busy = function(a, message, id)
  {
    if (a && message) {
      var msg = this.get_label(message);
      if (msg == message)
        msg = 'Loading...';

      id = this.display_message(msg, 'loading');
    }
    else if (!a && id) {
      this.hide_message(id);
    }

    this.busy = a;

    if (this.gui_objects.editform)
      this.lock_form(this.gui_objects.editform, a);

    return id;
  };

  // return a localized string
  this.get_label = function(name, domain)
  {
    if (domain && this.labels[domain+'.'+name])
      return this.labels[domain+'.'+name];
    else if (this.labels[name])
      return this.labels[name];
    else
      return name;
  };

  // alias for convenience reasons
  this.gettext = this.get_label;

  // switch to another application task
  this.switch_task = function(task)
  {
    var action, path;

    if ((path = task.split('/')).length == 2) {
      task = path[0];
      action = path[1];
    }

    if (this.task === task && task != 'mail')
      return;

    var url = this.get_task_url(task);

    if (action)
      url += '&_action=' + action;

    if (task == 'mail')
      url += '&_mbox=INBOX';
    else if (task == 'logout') {
      url = this.secure_url(url);
      this.clear_compose_data();
    }

    this.redirect(url);
  };

  this.get_task_url = function(task, url)
  {
    if (!url)
      url = this.env.comm_path;

    if (url.match(/[?&]_task=[a-zA-Z0-9_-]+/))
        return url.replace(/_task=[a-zA-Z0-9_-]+/, '_task=' + task);
    else
        return url.replace(/\?.*$/, '') + '?_task=' + task;
  };

  this.reload = function(delay)
  {
    if (this.is_framed())
      parent.rcmail.reload(delay);
    else if (delay)
      setTimeout(function() { ref.reload(); }, delay);
    else if (window.location)
      location.href = this.url('', {_extwin: this.env.extwin});
  };

  // Add variable to GET string, replace old value if exists
  this.add_url = function(url, name, value)
  {
    var urldata, datax, hash = '';

    value = urlencode(value);

    if (/(#[a-z0-9_-]*)$/.test(url)) {
      hash = RegExp.$1;
      url = url.substr(0, url.length - hash.length);
    }

    if (/(\?.*)$/.test(url)) {
      urldata = RegExp.$1;
      datax = RegExp('((\\?|&)'+RegExp.escape(name)+'=[^&]*)');

      if (datax.test(urldata))
        urldata = urldata.replace(datax, RegExp.$2 + name + '=' + value);
      else
        urldata += '&' + name + '=' + value;

      return url.replace(/(\?.*)$/, urldata) + hash;
    }

    return url + '?' + name + '=' + value + hash;
  };

  // append CSRF protection token to the given url
  this.secure_url = function(url)
  {
    return this.add_url(url, '_token', this.env.request_token);
  },

  this.is_framed = function()
  {
    return this.env.framed && parent.rcmail && parent.rcmail != this && typeof parent.rcmail.command == 'function';
  };

  this.save_pref = function(prop)
  {
    var request = {_name: prop.name, _value: prop.value};

    if (prop.session)
      request._session = prop.session;
    if (prop.env)
      this.env[prop.env] = prop.value;

    this.http_post('save-pref', request);
  };

  this.html_identifier = function(str, encode)
  {
    return encode ? this.html_identifier_encode(str) : String(str).replace(this.identifier_expr, '_');
  };

  this.html_identifier_encode = function(str)
  {
    return Base64.encode(String(str)).replace(/=+$/, '').replace(/\+/g, '-').replace(/\//g, '_');
  };

  this.html_identifier_decode = function(str)
  {
    str = String(str).replace(/-/g, '+').replace(/_/g, '/');

    while (str.length % 4) str += '=';

    return Base64.decode(str);
  };


  /*********************************************************/
  /*********        event handling methods         *********/
  /*********************************************************/

  this.drag_menu = function(e, target)
  {
    var modkey = rcube_event.get_modifier(e),
      menu = this.gui_objects.dragmenu;

    if (menu && modkey == SHIFT_KEY && this.commands['copy']) {
      var pos = rcube_event.get_mouse_pos(e);
      this.env.drag_target = target;
      this.show_menu(this.gui_objects.dragmenu.id, true, e);
      $(menu).css({top: (pos.y-10)+'px', left: (pos.x-10)+'px'});
      return true;
    }

    return false;
  };

  this.drag_menu_action = function(action)
  {
    var menu = this.gui_objects.dragmenu;
    if (menu) {
      $(menu).hide();
    }

    this.command(action, this.env.drag_target);
    this.env.drag_target = null;
  };

  this.drag_start = function(list)
  {
    this.drag_active = true;

    if (this.preview_timer)
      clearTimeout(this.preview_timer);

    // prepare treelist widget for dragging interactions
    if (this.treelist)
      this.treelist.drag_start();
  };

  this.drag_end = function(e)
  {
    var list, model;

    if (this.treelist)
      this.treelist.drag_end();

    // execute drag & drop action when mouse was released
    if (list = this.message_list)
      model = this.env.mailboxes;
    else if (list = this.contact_list)
      model = this.env.contactfolders;

    // Note: we accept only mouse events to ignore dragging aborts with ESC key (#6623)
    if (this.drag_active && model && this.env.last_folder_target && !rcube_event.is_keyboard(e)) {
      var target = model[this.env.last_folder_target];
      list.draglayer.hide();

      if (this.contact_list) {
        if (!this.contacts_drag_menu(e, target))
          this.command('move', target);
      }
      else if (!this.drag_menu(e, target))
        this.command('move', target);
    }

    this.drag_active = false;
    this.env.last_folder_target = null;
  };

  this.drag_move = function(e)
  {
    if (this.gui_objects.folderlist) {
      var drag_target, oldclass,
        layerclass = 'draglayernormal',
        mouse = rcube_event.get_mouse_pos(e);

      if (this.contact_list && this.contact_list.draglayer)
        oldclass = this.contact_list.draglayer.attr('class');

      // mouse intersects a valid drop target on the treelist
      if (this.treelist && (drag_target = this.treelist.intersects(mouse, true))) {
        this.env.last_folder_target = drag_target;
        layerclass = 'draglayer' + (this.check_droptarget(drag_target) > 1 ? 'copy' : 'normal');
      }
      else {
        // Clear target, otherwise drag end will trigger move into last valid droptarget
        this.env.last_folder_target = null;
      }

      if (layerclass != oldclass && this.contact_list && this.contact_list.draglayer)
        this.contact_list.draglayer.attr('class', layerclass);
    }
  };

  this.collapse_folder = function(name)
  {
    if (this.treelist)
      this.treelist.toggle(name);
  };

  this.folder_collapsed = function(node)
  {
    if (this.folder_collapsed_timer)
      clearTimeout(this.folder_collapsed_timer);

    var prefname = this.env.task == 'addressbook' ? 'collapsed_abooks' : 'collapsed_folders',
      old = this.env[prefname],
      entry = '&' + urlencode(node.id) + '&';

    this.env[prefname] = old.replace(entry, '');

    if (node.collapsed) {
      this.env[prefname] = this.env[prefname] + entry;

      // select the folder if one of its children is currently selected
      // don't select if it's virtual (#1488346)
      if (!node.virtual && this.env.mailbox && this.env.mailbox.startsWith(node.id + this.env.delimiter))
        this.command('list', node.id);
    }

    if (!this.drag_active) {
      if (old !== this.env[prefname])
        this.folder_collapsed_timer = setTimeout(function() { ref.command('save-pref', { name: prefname, value: ref.env[prefname] }); }, 10);

      if (this.env.unread_counts)
        this.set_unread_count_display(node.id, false);
    }
  };

  // global mouse-click handler to cleanup some UI elements
  this.doc_mouse_up = function(e)
  {
    var list, id, target = rcube_event.get_target(e);

    // ignore event if jquery UI dialog is open
    if ($(target).closest('.ui-dialog, .ui-widget-overlay').length)
      return;

    // remove focus from list widgets
    if (window.rcube_list_widget && rcube_list_widget._instances.length) {
      $.each(rcube_list_widget._instances, function(i,list) {
        if (list && !rcube_mouse_is_over(e, list.list.parentNode))
          list.blur();
      });
    }

    // reset 'pressed' buttons
    if (this.buttons_sel) {
      for (id in this.buttons_sel)
        if (typeof id !== 'function')
          this.button_out(this.buttons_sel[id], id);
      this.buttons_sel = {};
    }

    // reset popup menus; delayed to have updated menu_stack data
    setTimeout(function(e) {
      var obj, skip, config, id, i, parents = $(target).parents();
      for (i = ref.menu_stack.length - 1; i >= 0; i--) {
        id = ref.menu_stack[i];
        obj = $('#' + id);

        if (obj.is(':visible')
          && target != obj.data('opener')
          && target != obj.get(0)  // check if scroll bar was clicked (#1489832)
          && !parents.is(obj.data('opener'))
          && id != skip
          && (obj.attr('data-editable') != 'true' || !$(target).parents('#' + id).length)
          && (obj.attr('data-sticky') != 'true' || !rcube_mouse_is_over(e, obj.get(0)))
        ) {
          ref.hide_menu(id, e);
        }
        skip = obj.data('parent');
      }
    }, 10, e);
  };

  // global keypress event handler
  this.doc_keypress = function(e)
  {
    // Helper method to move focus to the next/prev active menu item
    var focus_menu_item = function(dir) {
      var obj, item, mod = dir < 0 ? 'prevAll' : 'nextAll', limit = dir < 0 ? 'last' : 'first';
      if (ref.focused_menu && (obj = $('#'+ref.focused_menu))) {
        item = obj.find(':focus').closest('li')[mod]().has(':not([aria-disabled=true])').find('a,input')[limit]();
        if (!item.length)
          item = obj.find(':focus').closest('ul')[mod]().has(':not([aria-disabled=true])').find('a,input')[limit]();
        return item.focus().length;
      }

      return 0;
    };

    var target = e.target || {},
      keyCode = rcube_event.get_keycode(e);

    if (e.keyCode != 27 && (!this.menu_keyboard_active || target.nodeName == 'TEXTAREA' || target.nodeName == 'SELECT')) {
      return true;
    }

    switch (keyCode) {
      case 38:
      case 40:
      case 63232: // "up", in safari keypress
      case 63233: // "down", in safari keypress
        focus_menu_item(keyCode == 38 || keyCode == 63232 ? -1 : 1);
        return rcube_event.cancel(e);

      case 9:   // tab
        if (this.focused_menu) {
          var mod = rcube_event.get_modifier(e);
          if (!focus_menu_item(mod == SHIFT_KEY ? -1 : 1)) {
            this.hide_menu(this.focused_menu, e);
          }
        }
        return rcube_event.cancel(e);

      case 27:  // esc
        if (this.menu_stack.length)
          this.hide_menu(this.menu_stack[this.menu_stack.length-1], e);
        break;
    }

    return true;
  }

  // Common handler for a keypress event on a list widget
  this.list_keypress = function(list, conf)
  {
    if (list.modkey == CONTROL_KEY)
      return;

    if (list.key_pressed == list.DELETE_KEY || list.key_pressed == list.BACKSPACE_KEY)
      this.command(conf && conf.del ? conf.del : 'delete');
    else if (list.key_pressed == 33)
      this.command(conf && conf.prev ? conf.prev : 'previouspage');
    else if (list.key_pressed == 34)
      this.command(conf && conf.next ? conf.next : 'nextpage');
  };

  // Handler for a keypress event on a messages list widget
  this.msglist_keypress = function(list)
  {
    // On Enter open the message in list layout mode (no preview frame)
    if (list.key_pressed == list.ENTER_KEY && !this.env.contentframe)
      this.command('show');
    else
      this.list_keypress(list);
  };

  this.msglist_select = function(list)
  {
    if (this.preview_timer)
      clearTimeout(this.preview_timer);

    var isDraft = false,
      selected = list.get_single_selection(),
      selection = list.get_selection(false),
      selected_count = selection.length;

    this.enable_command(this.env.message_commands, selected != null);

    // Find out whether any of the selected messages comes from the Drafts folder
    if (selected_count > 0) {
      if (!this.env.multifolder_listing) {
        isDraft = this.env.mailbox == this.env.drafts_mailbox
      }
      else {
        $.each(selection, function(i, v) {
          if (ref.get_message_mailbox(v) == ref.env.drafts_mailbox) {
            isDraft = true;
            return false;
          }
        });
      }
    }

    // Disable some actions enabled above
    if (selected) {
      if (isDraft) {
        this.enable_command('reply', 'reply-all', 'reply-list', 'forward', 'forward-inline',
          'forward-attachment', 'bounce', false);
      }
      else {
        var msg = this.env.messages[selected];
        if (!msg.ml)
          this.enable_command('reply-list', false);
      }
    }

    // Multi-message commands
    this.enable_command('delete', 'move', 'copy', 'mark', selected_count > 0);
    this.enable_command('forward', 'forward-attachment', !isDraft && selected_count > 0);

    // reset all-pages-selection
    if (selected || (selected_count && selected_count != list.rowcount))
      this.select_all_mode = false;

    // start timer for message preview (wait for double click)
    if (selected && this.env.contentframe && !list.multi_selecting && !this.dummy_select) {
      // try to be responsive and try not to overload the server when user is pressing up/down key repeatedly
      var now = new Date().getTime(),
        time_diff = now - (this._last_msglist_select_time || 0),
        preview_pane_delay = this.preview_delay_click;

      // user is selecting messages repeatedly, wait until this ends (use larger delay)
      if (time_diff < this.preview_delay_select) {
        preview_pane_delay = this.preview_delay_select;
        if (this.preview_timer) {
          clearTimeout(this.preview_timer);
        }
        if (this.env.contentframe) {
          this.show_contentframe(false);
        }
      }

      this._last_msglist_select_time = now;
      this.preview_timer = setTimeout(function() { ref.msglist_get_preview(); }, preview_pane_delay);
    }
    else if (this.env.contentframe) {
      this.show_contentframe(false);
    }
  };

  this.msglist_dbl_click = function(list)
  {
    if (this.preview_timer)
      clearTimeout(this.preview_timer);

    var mbox, uid = list.get_single_selection();

    // TODO: Here we should just use this.command('show') but we can't
    // because at this point this.busy=true (set by msglist_get_preview())

    if (uid) {
      mbox = this.get_message_mailbox(uid);
      if (mbox == this.env.drafts_mailbox)
        this.open_compose_step({_draft_uid: uid, _mbox: mbox});
      else
        this.show_message(uid);
    }
  };

  this.msglist_get_preview = function()
  {
    var uid = this.get_single_uid();
    if (uid && this.env.contentframe && !this.drag_active)
      this.show_message(uid, false, true);
    else if (this.env.contentframe)
      this.show_contentframe(false);
  };

  this.msglist_expand = function(row)
  {
    if (this.env.messages[row.uid])
      this.env.messages[row.uid].expanded = row.expanded;
    $(row.obj)[row.expanded?'addClass':'removeClass']('expanded');
  };

  this.msglist_set_coltypes = function(list)
  {
    var i, found, name, cols = list.thead.rows[0].cells;

    this.env.listcols = [];

    for (i=0; i<cols.length; i++)
      if (cols[i].id && cols[i].id.startsWith('rcm')) {
        name = cols[i].id.slice(3);
        this.env.listcols.push(name);
      }

    // update message list setup
    this.msglist_setup(this.env.layout);

    if ((found = $.inArray('flag', this.env.listcols)) >= 0)
      this.env.flagged_col = found;

    if ((found = $.inArray('subject', this.env.listcols)) >= 0)
      this.env.subject_col = found;

    this.command('save-pref', { name: 'list_cols', value: this.env.listcols, session: 'list_attrib/columns' });
  };

  this.msglist_setup = function(layout)
  {
    var ret, listcols;

    // allow plugins or skins to override default list layout
    if (ret = this.triggerEvent('msglist_layout', layout))
      layout = ret;

    listcols = this.env[layout == 'widescreen' ? 'listcols_widescreen' : 'listcols'];

    if (layout == 'widescreen' && !this.env.threading)
      listcols = $.grep(listcols, function(value) { return value != 'threads'; });

    // set env vars for message list
    this.env.msglist_layout = layout;
    this.env.msglist_cols = listcols;

    // Set sort-* class on the list element
    var list = this.gui_objects.messagelist,
      classes = list.className.split(' ').filter(function(v) { return !v.startsWith('sort-'); });

    classes.push('sort-' + (this.env.sort_col || 'none'));
    list.className = classes.join(' ');
  };

  this.check_droptarget = function(id)
  {
    switch (this.task) {
      case 'mail':
        return (this.env.mailboxes[id]
            && !this.env.mailboxes[id].virtual
            && (this.env.mailboxes[id].id != this.env.mailbox || this.is_multifolder_listing())) ? 1 : 0;

      case 'addressbook':
        var target;
        if (id != this.env.source && (target = this.env.contactfolders[id])) {
          // droptarget is a group
          if (target.type == 'group') {
            if (target.id != this.env.group && !this.env.contactfolders[target.source].readonly) {
              var is_other = this.env.selection_sources.length > 1 || $.inArray(target.source, this.env.selection_sources) == -1;
              return !is_other || this.commands.move ? 1 : 2;
            }
          }
          // droptarget is a (writable) addressbook and it's not the source
          else if (!target.readonly && (this.env.selection_sources.length > 1 || $.inArray(id, this.env.selection_sources) == -1)) {
            return this.commands.move ? 1 : 2;
          }
        }
    }

    return 0;
  };

  // open popup window
  this.open_window = function(url, small, toolbar)
  {
    var wname = 'rcmextwin' + new Date().getTime();

    url += (url.match(/\?/) ? '&' : '?') + '_extwin=1';

    if (this.env.standard_windows)
      var extwin = window.open(url, wname);
    else {
      var win = this.is_framed() ? parent.window : window,
        page = $(win),
        page_width = page.width(),
        page_height = bw.mz ? $('body', win).height() : page.height(),
        w = Math.min(small ? this.env.popup_width_small : this.env.popup_width, page_width),
        h = page_height, // always use same height
        l = (win.screenLeft || win.screenX) + 20,
        t = (win.screenTop || win.screenY) + 20,
        extwin = window.open(url, wname,
          'width='+w+',height='+h+',top='+t+',left='+l+',resizable=yes,location=no,scrollbars=yes'
          +(toolbar ? ',toolbar=yes,menubar=yes,status=yes' : ',toolbar=no,menubar=no,status=no'));
    }

    // detect popup blocker (#1489618)
    // don't care this might not work with all browsers
    if (!extwin || extwin.closed) {
      this.display_message('windowopenerror', 'warning');
      return;
    }

    // write loading... message to empty windows
    if (!url && extwin.document) {
      extwin.document.write('<html><body>' + this.get_label('loading') + '</body></html>');
    }

    // allow plugins to grab the window reference (#1489413)
    this.triggerEvent('openwindow', { url:url, handle:extwin });

    // focus window, delayed to bring to front
    setTimeout(function() { extwin && extwin.focus(); }, 10);

    return extwin;
  };


  /*********************************************************/
  /*********     (message) list functionality      *********/
  /*********************************************************/

  this.init_message_row = function(row)
  {
    var i, fn = {}, uid = row.uid,
      status_icon = (this.env.status_col != null ? 'status' : 'msg') + 'icn' + row.id;

    if (uid && this.env.messages[uid])
      $.extend(row, this.env.messages[uid]);

    // set eventhandler to status icon
    if (row.icon = document.getElementById(status_icon)) {
      fn.icon = function(e) { ref.command('toggle_status', uid); };
    }

    // save message icon position too
    if (this.env.status_col != null)
      row.msgicon = document.getElementById('msgicn'+row.id);
    else
      row.msgicon = row.icon;

    // set eventhandler to flag icon
    if (this.env.flagged_col != null && (row.flagicon = document.getElementById('flagicn'+row.id))) {
      fn.flagicon = function(e) { ref.command('toggle_flag', uid); };
    }

    // set event handler to thread expand/collapse icon
    if (!row.depth && row.has_children && (row.expando = document.getElementById('rcmexpando'+row.id))) {
      fn.expando = function(e) { ref.expand_message_row(e, uid); };
    }

    // attach events
    $.each(fn, function(i, f) {
      row[i].onclick = function(e) { f(e); return rcube_event.cancel(e); };
      if (bw.touch && row[i].addEventListener) {
        row[i].addEventListener('touchend', function(e) {
          if (e.changedTouches.length == 1) {
            f(e);
            return rcube_event.cancel(e);
          }
        }, false);
      }
    });

    this.triggerEvent('insertrow', { uid:uid, row:row });
  };

  // create a table row in the message list
  this.add_message_row = function(uid, cols, flags, attop)
  {
    if (!this.gui_objects.messagelist || !this.message_list)
      return false;

    // Prevent from adding messages from different folder (#1487752)
    if (flags.mbox != this.env.mailbox && !flags.skip_mbox_check)
      return false;

    // When deleting messages fast it may happen that the same message
    // from the next page could be added many times, we prevent this here
    if (this.message_list.rows[uid])
      return false;

    if (!this.env.messages[uid])
      this.env.messages[uid] = {};

    // merge flags over local message object
    $.extend(this.env.messages[uid], {
      deleted: flags.deleted?1:0,
      replied: flags.answered?1:0,
      unread: !flags.seen?1:0,
      forwarded: flags.forwarded?1:0,
      flagged: flags.flagged?1:0,
      has_children: flags.has_children?1:0,
      depth: flags.depth?flags.depth:0,
      unread_children: flags.unread_children || 0,
      flagged_children: flags.flagged_children || 0,
      parent_uid: flags.parent_uid || 0,
      selected: this.select_all_mode || this.message_list.in_selection(uid),
      ml: flags.ml?1:0,
      ctype: flags.ctype,
      mbox: flags.mbox,
      // flags from plugins
      flags: flags.extra_flags
    });

    var c, n, col, html, css_class, label, status_class = '', status_label = '',
      tree = '', expando = '',
      list = this.message_list,
      rows = list.rows,
      message = this.env.messages[uid],
      msg_id = this.html_identifier(uid,true),
      row_class = 'message'
        + (!flags.seen ? ' unread' : '')
        + (flags.deleted ? ' deleted' : '')
        + (flags.flagged ? ' flagged' : '')
        + (message.selected ? ' selected' : ''),
      row = { cols:[], style:{}, id:'rcmrow'+msg_id, uid:uid },
      layout = this.env.msglist_layout,
      listcols = this.env.msglist_cols;

    // widescreen layout does not have a separate status column
    if (layout == 'widescreen')
      this.env.status_col = null;
    else if ((n = $.inArray('status', listcols)) >= 0)
      this.env.status_col = n;

    // message status icons
    css_class = 'msgicon';
    if (this.env.status_col === null) {
      css_class += ' status';
      if (flags.deleted) {
        status_class += ' deleted';
        status_label += this.get_label('deleted') + ' ';
      }
      else if (!flags.seen) {
        status_class += ' unread';
        status_label += this.get_label('unread') + ' ';
      }
      else if (flags.unread_children > 0) {
        status_class += ' unreadchildren';
      }
    }
    if (flags.answered) {
      status_class += ' replied';
      status_label += this.get_label('replied') + ' ';
    }
    if (flags.forwarded) {
      status_class += ' forwarded';
      status_label += this.get_label('forwarded') + ' ';
    }

    // update selection
    if (message.selected && !list.in_selection(uid))
      list.selection.push(uid);

    // threads
    if (this.env.threading) {
      if (message.depth) {
        // This assumes that div width is hardcoded to 15px,
        tree += '<span id="rcmtab' + msg_id + '" class="branch" style="width:' + (message.depth * 15) + 'px;">&nbsp;&nbsp;</span>';

        if ((rows[message.parent_uid] && rows[message.parent_uid].expanded === false)
          || ((this.env.autoexpand_threads == 0 || this.env.autoexpand_threads == 2) &&
            (!rows[message.parent_uid] || !rows[message.parent_uid].expanded))
        ) {
          row.style.display = 'none';
          message.expanded = false;
        }
        else
          message.expanded = true;

        row_class += ' thread expanded';
      }
      else if (message.has_children) {
        if (message.expanded === undefined && (this.env.autoexpand_threads == 1 || (this.env.autoexpand_threads == 2 && message.unread_children))) {
          message.expanded = true;
        }

        expando = '<div id="rcmexpando' + row.id + '" class="' + (message.expanded ? 'expanded' : 'collapsed') + '">&nbsp;&nbsp;</div>';
        row_class += ' thread' + (message.expanded ? ' expanded' : '');
      }

      if (flags.unread_children && flags.seen && !message.expanded)
        row_class += ' unroot';

      if (flags.flagged_children && !message.expanded)
        row_class += ' flaggedroot';
    }

    tree += '<span id="msgicn'+row.id+'" class="'+css_class+status_class+'" title="'+status_label+'"></span>';
    row.className = row_class;

    // build subject link
    if (cols.subject) {
      var action  = flags.mbox == this.env.drafts_mailbox ? 'compose' : 'show',
        uid_param = flags.mbox == this.env.drafts_mailbox ? '_draft_uid' : '_uid',
        query = { _mbox: flags.mbox };
      query[uid_param] = uid;
      cols.subject = '<a href="' + this.url(action, query) + '" onclick="return rcube_event.keyboard_only(event)"' +
        ' onmouseover="rcube_webmail.long_subject_title(this)" tabindex="-1"><span>'+cols.subject+'</span></a>';
    }

    // add each submitted col
    for (n in listcols) {
      c = listcols[n];
      col = {className: String(c).toLowerCase(), events:{}};

      if (this.env.coltypes[c] && this.env.coltypes[c].hidden) {
        col.className += ' hidden';
      }

      if (c == 'flag') {
        css_class = (flags.flagged ? 'flagged' : 'unflagged');
        label = this.get_label(css_class);
        html = '<span id="flagicn'+row.id+'" class="'+css_class+'" title="'+label+'"></span>';
      }
      else if (c == 'attachment') {
        label = this.get_label('withattachment');
        if (flags.attachmentClass)
          html = '<span class="'+flags.attachmentClass+'" title="'+label+'"></span>';
        else if (flags.ctype == 'multipart/report')
          html = '<span class="report"></span>';
        else if (flags.ctype == 'multipart/encrypted' || flags.ctype == 'application/pkcs7-mime')
          html = '<span class="encrypted"></span>';
        else if (flags.hasattachment || (!flags.hasnoattachment && /application\/|multipart\/(m|signed)/.test(flags.ctype)))
          html = '<span class="attachment" title="'+label+'"></span>';
        else
          html = '&nbsp;';
      }
      else if (c == 'status') {
        label = '';
        if (flags.deleted) {
          css_class = 'deleted';
          label = this.get_label('deleted');
        }
        else if (!flags.seen) {
          css_class = 'unread';
          label = this.get_label('unread');
        }
        else if (flags.unread_children > 0) {
          css_class = 'unreadchildren';
        }
        else
          css_class = 'msgicon';
        html = '<span id="statusicn'+row.id+'" class="'+css_class+status_class+'" title="'+label+'"></span>';
      }
      else if (c == 'threads')
        html = expando;
      else if (c == 'subject') {
        html = tree + cols[c];
      }
      else if (c == 'priority') {
        if (flags.prio > 0 && flags.prio < 6) {
          label = this.get_label('priority') + ' ' + flags.prio;
          html = '<span class="prio'+flags.prio+'" title="'+label+'"></span>';
        }
        else
          html = '&nbsp;';
      }
      else if (c == 'folder') {
        html = '<span onmouseover="rcube_webmail.long_subject_title(this)">' + cols[c] + '<span>';
      }
      else
        html = cols[c];

      col.innerHTML = html;
      row.cols.push(col);
    }

    if (layout == 'widescreen')
      row = this.widescreen_message_row(row, uid, message);

    list.insert_row(row, attop);

    // remove 'old' row
    if (attop && this.env.pagesize && list.rowcount > this.env.pagesize) {
      var uid = list.get_last_row();
      list.remove_row(uid);
      list.clear_selection(uid);
    }
  };

  // Converts standard message list record into "widescreen" (3-column) layout
  this.widescreen_message_row = function(row, uid, message)
  {
    var domrow = document.createElement('tr');

    domrow.id = row.id;
    domrow.uid = row.uid;
    domrow.className = row.className;
    if (row.style) $.extend(domrow.style, row.style);

    $.each(this.env.widescreen_list_template, function() {
      if (!ref.env.threading && this.className == 'threads')
        return;

      var i, n, e, col, domcol,
        domcell = document.createElement('td');

      if (this.className) domcell.className = this.className;

      for (i=0; this.cells && i < this.cells.length; i++) {
        for (n=0; row.cols && n < row.cols.length; n++) {
          if (this.cells[i] == row.cols[n].className) {
            col = row.cols[n];
            domcol = document.createElement('span');
            domcol.className = this.cells[i];
            if (this.className == 'subject' && domcol.className != 'subject')
              domcol.className += ' skip-on-drag';
            if (col.innerHTML)
              domcol.innerHTML = col.innerHTML;
            domcell.appendChild(domcol);
            break;
          }
        }
      }

      domrow.appendChild(domcell);
    });

    if (this.env.threading && message.depth) {
      n = this.calculate_thread_padding(message.depth);
      $('td.subject', domrow).attr('style', 'padding-left:' + n + ' !important');
      $('span.branch', domrow).remove();
    }

    return domrow;
  };

  this.calculate_thread_padding = function(level)
  {
     ref.env.thread_padding.match(/^([0-9.]+)(.+)/);
     return (Math.min(6, level) * parseFloat(RegExp.$1)) + RegExp.$2;
  };

  this.set_list_sorting = function(sort_col, sort_order)
  {
    var sort_old = this.env.sort_col == 'arrival' ? 'date' : this.env.sort_col,
      sort_new = sort_col == 'arrival' ? 'date' : sort_col;

    // set table header class
    $('#rcm' + sort_old).removeClass('sorted' + this.env.sort_order.toUpperCase());
    if (sort_new)
      $('#rcm' + sort_new).addClass('sorted' + sort_order);

    // if sorting by 'arrival' is selected, click on date column should not switch to 'date'
    $('#rcmdate > a').prop('rel', sort_col == 'arrival' ? 'arrival' : 'date');

    this.env.sort_col = sort_col;
    this.env.sort_order = sort_order;
  };

  this.set_list_options = function(cols, sort_col, sort_order, threads, layout)
  {
    var update, post_data = {};

    if (sort_col === undefined)
      sort_col = this.env.sort_col;
    if (!sort_order)
      sort_order = this.env.sort_order;

    if (this.env.sort_col != sort_col || this.env.sort_order != sort_order) {
      update = 1;
      this.set_list_sorting(sort_col, sort_order);
    }

    if (this.env.threading != threads) {
      update = 1;
      post_data._threads = threads;
    }

    if (layout && this.env.layout != layout) {
      this.triggerEvent('layout-change', {old_layout: this.env.layout, new_layout: layout});
      update = 1;
      this.env.layout = post_data._layout = layout;

      // update message list setup
      this.msglist_setup(this.env.layout);
    }

    if (cols && cols.length) {
      // make sure new columns are added at the end of the list
      var i, idx, name, newcols = [], oldcols = this.env.listcols;

      for (i=0; i<oldcols.length; i++) {
        name = oldcols[i];
        idx = $.inArray(name, cols);
        if (idx != -1) {
          newcols.push(name);
          delete cols[idx];
        }
      }
      for (i=0; i<cols.length; i++)
        if (cols[i])
          newcols.push(cols[i]);

      if (newcols.join() != oldcols.join()) {
        update = 1;
        post_data._cols = newcols.join(',');
      }
    }

    if (update)
      this.list_mailbox('', '', sort_col+'_'+sort_order, post_data);
  };

  // when user double-clicks on a row
  this.show_message = function(id, safe, preview)
  {
    if (!id)
      return;

    var win, target = window,
      url = this.params_from_uid(id, {_caps: this.browser_capabilities()});

    if (preview && (win = this.get_frame_window(this.env.contentframe))) {
      target = win;
      url._framed = 1;
    }

    if (safe)
      url._safe = 1;

    // also send search request to get the right messages
    if (this.env.search_request)
      url._search = this.env.search_request;

    if (this.env.extwin)
      url._extwin = 1;

    url = this.url(preview ? 'preview': 'show', url);

    if (preview)
      this.preview_id = id;

    if (preview && String(target.location.href).indexOf(url) >= 0) {
      this.show_contentframe(true);
    }
    else {
      if (!preview && this.env.message_extwin && !this.env.extwin)
        this.open_window(url, true);
      else {
        // "Allow remote resources" reloads the page, we remove this request from the history,
        // so Back button works as expected, i.e. ignores the reload request (#6620)
        if (safe && document.referrer && window.history.replaceState)
          window.history.replaceState({}, '', document.referrer);

        this.location_href(url, target, true);
      }
    }
  };

  // update message status and unread counter after marking a message as read
  this.set_unread_message = function(id, folder)
  {
    var self = this;

    // find window with messages list
    if (!self.message_list)
      self = self.opener();

    if (!self && window.parent)
      self = parent.rcmail;

    if (!self || !self.message_list)
      return;

    // this may fail in multifolder mode
    if (self.set_message(id, 'unread', false) === false)
      self.set_message(id + '-' + folder, 'unread', false);

    if (self.env.unread_counts[folder] > 0) {
      self.env.unread_counts[folder] -= 1;
      self.set_unread_count(folder, self.env.unread_counts[folder], folder == 'INBOX' && !self.is_multifolder_listing());
    }
  };

  this.show_contentframe = function(show)
  {
    var frame, win, name = this.env.contentframe;

    if (frame = this.get_frame_element(name)) {
      if (!show && (win = this.get_frame_window(name))) {
        if (win.location.href.indexOf(this.env.blankpage) < 0) {
          if (win.stop)
            win.stop();
          else // IE
            win.document.execCommand('Stop');

          win.location.href = this.env.blankpage;
        }
      }
      else if (!bw.safari && !bw.konq)
        $(frame)[show ? 'show' : 'hide']();
    }

    if (!show) {
      this.unlock_frame();
      delete this.preview_id;
    }
  };

  this.get_frame_element = function(id)
  {
    var frame;

    if (id && (frame = document.getElementById(id)))
      return frame;
  };

  this.get_frame_window = function(id)
  {
    var frame = this.get_frame_element(id);

    if (frame && frame.name && window.frames)
      return window.frames[frame.name];
  };

  this.lock_frame = function(target)
  {
    var rc = this.is_framed() ? parent.rcmail : this;

    if (!rc.env.frame_lock)
      rc.env.frame_lock = rc.set_busy(true, 'loading');

    try {
      if (target.frameElement)
        $(target.frameElement).on('load.lock', function(e) {
          rc.unlock_frame();
          $(this).off('load.lock');
        });
    } catch(e) { /* Ignore permission denied error */ };
  };

  this.unlock_frame = function()
  {
    if (this.env.frame_lock) {
      this.set_busy(false, null, this.env.frame_lock);
      this.env.frame_lock = null;
    }
  };

  // list a specific page
  this.list_page = function(page)
  {
    if (page == 'next')
      page = this.env.current_page+1;
    else if (page == 'last')
      page = this.env.pagecount;
    else if (page == 'prev' && this.env.current_page > 1)
      page = this.env.current_page-1;
    else if (page == 'first' && this.env.current_page > 1)
      page = 1;

    if (page > 0 && page <= this.env.pagecount) {
      this.env.current_page = page;

      if (this.task == 'addressbook' || this.contact_list)
        this.list_contacts(this.env.source, this.env.group, page);
      else if (this.task == 'mail')
        this.list_mailbox(this.env.mailbox, page);
    }
  };

  // sends request to check for recent messages
  this.checkmail = function()
  {
    var lock = this.set_busy(true, 'checkingmail'),
      params = this.check_recent_params();

    this.http_post('check-recent', params, lock);
  };

  // list messages of a specific mailbox using filter
  this.filter_mailbox = function(filter)
  {
    if (this.filter_disabled)
      return;

    var params = this.search_params(false, filter),
      lock = this.set_busy(true, 'searching');

    this.clear_message_list();

    // reset vars
    this.env.current_page = 1;
    this.env.search_filter = filter;
    this.http_request('search', params, lock);
    this.update_state({_mbox: params._mbox, _filter: filter, _scope: params._scope});
  };

  // reload the current message listing
  this.refresh_list = function()
  {
    this.list_mailbox(this.env.mailbox, this.env.current_page || 1, null, { _clear:1 }, true);
    if (this.message_list)
      this.message_list.clear_selection();
  };

  // list messages of a specific mailbox
  this.list_mailbox = function(mbox, page, sort, url, update_only)
  {
    var win, target = window;

    if (typeof url != 'object')
      url = {};

    if (!mbox)
      mbox = this.env.mailbox ? this.env.mailbox : 'INBOX';

    // add sort to url if set
    if (sort)
      url._sort = sort;

    // folder change, reset page, search scope, etc.
    if (this.env.mailbox != mbox) {
      page = 1;
      this.env.current_page = page;
      this.env.search_scope = 'base';
      this.select_all_mode = false;
      this.reset_search_filter();
    }
    // also send search request to get the right messages
    else if (this.env.search_request)
      url._search = this.env.search_request;

    if (!update_only) {
      // unselect selected messages and clear the list and message data
      this.clear_message_list();

      if (mbox != this.env.mailbox || (mbox == this.env.mailbox && !page && !sort))
        url._refresh = 1;

      this.select_folder(mbox, '', true);
      this.unmark_folder(mbox, 'recent', '', true);
      this.env.mailbox = mbox;
    }

    // load message list remotely
    if (this.gui_objects.messagelist) {
      this.list_mailbox_remote(mbox, page, url);
      return;
    }

    if (win = this.get_frame_window(this.env.contentframe)) {
      target = win;
      url._framed = 1;
    }

    if (this.env.uid)
      url._uid = this.env.uid;

    if (page)
      url._page = page;

    // load message list to target frame/window
    if (mbox) {
      url._mbox = mbox;
      this.set_busy(true, 'loading');
      this.location_href(url, target);
    }
  };

  this.clear_message_list = function()
  {
    this.env.messages = {};

    this.show_contentframe(false);
    if (this.message_list)
      this.message_list.clear(true);
  };

  // send remote request to load message list
  this.list_mailbox_remote = function(mbox, page, url)
  {
    var lock = this.set_busy(true, 'loading');

    if (typeof url != 'object')
      url = {};

    url._layout = this.env.layout
    url._mbox = mbox;
    url._page = page;

    this.http_request('list', url, lock);
    this.update_state({ _mbox: mbox, _page: (page && page > 1 ? page : null) });
  };

  // removes messages that doesn't exists from list selection array
  this.update_selection = function()
  {
    var list = this.message_list,
      selected = list.selection,
      rows = list.rows,
      i, selection = [];

    for (i in selected)
      if (rows[selected[i]])
        selection.push(selected[i]);

    list.selection = selection;

    // reset preview frame, if currently previewed message is not selected (has been removed)
    try {
      var win = this.get_frame_window(this.env.contentframe),
        id = win.rcmail.env.uid;

      if (id && !list.in_selection(id))
        this.show_contentframe(false);
    }
    catch (e) {};
  };

  // expand all threads with unread children
  this.expand_unread = function()
  {
    var r, tbody = this.message_list.tbody,
      new_row = tbody.firstChild;

    while (new_row) {
      if (new_row.nodeType == 1 && (r = this.message_list.rows[new_row.uid]) && r.unread_children) {
        this.message_list.expand_all(r);
        this.set_unread_children(r.uid);
      }

      new_row = new_row.nextSibling;
    }

    return false;
  };

  // thread expanding/collapsing handler
  this.expand_message_row = function(e, uid)
  {
    var row = this.message_list.rows[uid];

    // handle unread_children/flagged_children mark
    row.expanded = !row.expanded;
    this.set_unread_children(uid);
    this.set_flagged_children(uid);
    row.expanded = !row.expanded;

    this.message_list.expand_row(e, uid);
  };

  // message list expanding
  this.expand_threads = function()
  {
    if (!this.env.threading || !this.env.autoexpand_threads || !this.message_list)
      return;

    switch (this.env.autoexpand_threads) {
      case 2: this.expand_unread(); break;
      case 1: this.message_list.expand_all(); break;
    }
  };

  // Initializes threads indicators/expanders after list update
  this.init_threads = function(roots, mbox)
  {
    // #1487752
    if (mbox && mbox != this.env.mailbox)
      return false;

    for (var n=0, len=roots.length; n<len; n++)
      this.add_tree_icons(roots[n]);
    this.expand_threads();
  };

  // adds threads tree icons to the list (or specified thread)
  this.add_tree_icons = function(root)
  {
    var i, l, r, n, len, pos, tmp = [], uid = [],
      row, rows = this.message_list.rows;

    if (root)
      row = rows[root] ? rows[root].obj : null;
    else
      row = this.message_list.tbody.firstChild;

    while (row) {
      if (row.nodeType == 1 && (r = rows[row.uid])) {
        if (r.depth) {
          for (i=tmp.length-1; i>=0; i--) {
            len = tmp[i].length;
            if (len > r.depth) {
              pos = len - r.depth;
              if (!(tmp[i][pos] & 2))
                tmp[i][pos] = tmp[i][pos] ? tmp[i][pos]+2 : 2;
            }
            else if (len == r.depth) {
              if (!(tmp[i][0] & 2))
                tmp[i][0] += 2;
            }
            if (r.depth > len)
              break;
          }

          tmp.push(new Array(r.depth));
          tmp[tmp.length-1][0] = 1;
          uid.push(r.uid);
        }
        else {
          if (tmp.length) {
            for (i in tmp) {
              this.set_tree_icons(uid[i], tmp[i]);
            }
            tmp = [];
            uid = [];
          }
          if (root && row != rows[root].obj)
            break;
        }
      }
      row = row.nextSibling;
    }

    if (tmp.length) {
      for (i in tmp) {
        this.set_tree_icons(uid[i], tmp[i]);
      }
    }
  };

  // adds tree icons to specified message row
  this.set_tree_icons = function(uid, tree)
  {
    var i, divs = [], html = '', len = tree.length;

    for (i=0; i<len; i++) {
      if (tree[i] > 2)
        divs.push({'class': 'l3', width: 15});
      else if (tree[i] > 1)
        divs.push({'class': 'l2', width: 15});
      else if (tree[i] > 0)
        divs.push({'class': 'l1', width: 15});
      // separator div
      else if (divs.length && !divs[divs.length-1]['class'])
        divs[divs.length-1].width += 15;
      else
        divs.push({'class': null, width: 15});
    }

    for (i=divs.length-1; i>=0; i--) {
      if (divs[i]['class'])
        html += '<div class="tree '+divs[i]['class']+'" />';
      else
        html += '<div style="width:'+divs[i].width+'px" />';
    }

    if (html)
      $('#rcmtab'+this.html_identifier(uid, true)).html(html);
  };

  // update parent in a thread
  this.update_thread_root = function(uid, flag)
  {
    if (!this.env.threading)
      return;

    var root = this.message_list.find_root(uid);

    if (uid == root)
      return;

    var p = this.message_list.rows[root];

    if (flag == 'read' && p.unread_children) {
      p.unread_children--;
    }
    else if (flag == 'unread' && p.has_children) {
      // unread_children may be undefined
      p.unread_children = (p.unread_children || 0) + 1;
    }
    else if (flag == 'unflagged' && p.flagged_children) {
      p.flagged_children--;
    }
    else if (flag == 'flagged' && p.has_children) {
      p.flagged_children = (p.flagged_children || 0) + 1;
    }
    else {
      return;
    }

    this.set_message_icon(root);
    this.set_unread_children(root);
    this.set_flagged_children(root);
  };

  // update thread indicators for all messages in a thread below the specified message
  // return number of removed/added root level messages
  this.update_thread = function(uid)
  {
    if (!this.env.threading || !this.message_list.rows[uid])
      return 0;

    var r, parent, count = 0,
      list = this.message_list,
      rows = list.rows,
      row = rows[uid],
      depth = rows[uid].depth,
      roots = [];

    if (!row.depth) // root message: decrease roots count
      count--;

    // update unread_children for thread root
    if (row.depth && row.unread) {
      parent = list.find_root(uid);
      rows[parent].unread_children--;
      this.set_unread_children(parent);
    }

    // update unread_children for thread root
    if (row.depth && row.flagged) {
      parent = list.find_root(uid);
      rows[parent].flagged_children--;
      this.set_flagged_children(parent);
    }

    parent = row.parent_uid;

    // children
    row = row.obj.nextSibling;
    while (row) {
      if (row.nodeType == 1 && (r = rows[row.uid])) {
        if (!r.depth || r.depth <= depth)
          break;

        r.depth--; // move left
        // reset width and clear the content of a tab, icons will be added later
        $('#rcmtab'+r.id).width(r.depth * 15).html('');
        if (!r.depth) { // a new root
          count++; // increase roots count
          r.parent_uid = 0;
          if (r.has_children) {
            // replace 'leaf' with 'collapsed'
            $('#' + r.id + ' .leaf').first()
              .attr('id', 'rcmexpando' + r.id)
              .attr('class', (r.obj.style.display != 'none' ? 'expanded' : 'collapsed'))
              .mousedown({uid: r.uid}, function(e) {
                return ref.expand_message_row(e, e.data.uid);
              });

            r.unread_children = 0;
            roots.push(r);
          }
          // show if it was hidden
          if (r.obj.style.display == 'none')
            $(r.obj).show();
        }
        else {
          if (r.depth == depth)
            r.parent_uid = parent;
          if (r.unread && roots.length)
            roots[roots.length-1].unread_children++;
        }
      }
      row = row.nextSibling;
    }

    // update unread_children/flagged_children for roots
    for (r=0; r<roots.length; r++) {
      this.set_unread_children(roots[r].uid);
      this.set_flagged_children(roots[r].uid);
    }

    return count;
  };

  this.delete_excessive_thread_rows = function()
  {
    var rows = this.message_list.rows,
      tbody = this.message_list.tbody,
      row = tbody.firstChild,
      cnt = this.env.pagesize + 1;

    while (row) {
      if (row.nodeType == 1 && (r = rows[row.uid])) {
        if (!r.depth && cnt)
          cnt--;

        if (!cnt)
          this.message_list.remove_row(row.uid);
      }
      row = row.nextSibling;
    }
  };

  // set message icon
  this.set_message_icon = function(uid)
  {
    var css_class, label = '',
      row = this.message_list.rows[uid];

    if (!row)
      return false;

    if (row.icon) {
      css_class = 'msgicon';
      if (row.deleted) {
        css_class += ' deleted';
        label += this.get_label('deleted') + ' ';
      }
      else if (row.unread) {
        css_class += ' unread';
        label += this.get_label('unread') + ' ';
      }
      else if (row.unread_children)
        css_class += ' unreadchildren';
      if (row.msgicon == row.icon) {
        if (row.replied) {
          css_class += ' replied';
          label += this.get_label('replied') + ' ';
        }
        if (row.forwarded) {
          css_class += ' forwarded';
          label += this.get_label('forwarded') + ' ';
        }
        css_class += ' status';
      }

      $(row.icon).attr({'class': css_class, title: label});
    }

    if (row.msgicon && row.msgicon != row.icon) {
      label = '';
      css_class = 'msgicon';
      if (!row.unread && row.unread_children) {
        css_class += ' unreadchildren';
      }
      if (row.replied) {
        css_class += ' replied';
        label += this.get_label('replied') + ' ';
      }
      if (row.forwarded) {
        css_class += ' forwarded';
        label += this.get_label('forwarded') + ' ';
      }

      $(row.msgicon).attr({'class': css_class, title: label});
    }

    if (row.flagicon) {
      css_class = (row.flagged ? 'flagged' : 'unflagged');
      label = this.get_label(css_class);
      $(row.flagicon).attr('class', css_class)
        .attr({'aria-label': label, title: label});
    }
  };

  // set message status
  this.set_message_status = function(uid, flag, status)
  {
    var row = this.message_list.rows[uid];

    if (!row)
      return false;

    if (flag == 'unread') {
      if (row.unread != status)
        this.update_thread_root(uid, status ? 'unread' : 'read');
    }
    else if (flag == 'flagged') {
      this.update_thread_root(uid, status ? 'flagged' : 'unflagged');
    }

    if ($.inArray(flag, ['unread', 'deleted', 'replied', 'forwarded', 'flagged']) > -1)
      row[flag] = status;
  };

  // set message row status, class and icon
  this.set_message = function(uid, flag, status)
  {
    var row = this.message_list && this.message_list.rows[uid];

    if (!row)
      return false;

    if (flag)
      this.set_message_status(uid, flag, status);

    if ($.inArray(flag, ['unread', 'deleted', 'flagged']) > -1)
      $(row.obj)[row[flag] ? 'addClass' : 'removeClass'](flag);

    this.set_unread_children(uid);
    this.set_message_icon(uid);
  };

  // sets unroot (unread_children) class of parent row
  this.set_unread_children = function(uid)
  {
    var row = this.message_list.rows[uid];

    if (row.parent_uid)
      return;

    var enable = !row.unread && row.unread_children && !row.expanded;
    $(row.obj)[enable ? 'addClass' : 'removeClass']('unroot');
  };

  // sets flaggedroot (flagged_children) class of parent row
  this.set_flagged_children = function(uid)
  {
    var row = this.message_list.rows[uid];

    if (row.parent_uid)
      return;

    var enable = row.flagged_children && !row.expanded;
    $(row.obj)[enable ? 'addClass' : 'removeClass']('flaggedroot');
  };

  // copy selected messages to the specified mailbox
  this.copy_messages = function(mbox, event, uids)
  {
    if (mbox && typeof mbox === 'object') {
      if (mbox.uids) uids = mbox.uids;
      mbox = mbox.id;
    }
    else if (!mbox) {
      uids = this.env.uid ? [this.env.uid] : this.message_list.get_selection();
      return this.folder_selector(event, function(folder, obj) {
        ref.command('copy', {id: folder, uids: uids}, obj, event, true);
      });
    }

    // exit if current or no mailbox specified
    if (!mbox || mbox == this.env.mailbox)
      return;

    var post_data = this.selection_post_data({_target_mbox: mbox, _uid: uids});

    // exit if selection is empty
    if (!post_data._uid)
      return;

    // send request to server
    this.http_post('copy', post_data, this.display_message('copyingmessage', 'loading'));
  };

  // move selected messages to the specified mailbox
  this.move_messages = function(mbox, event, uids)
  {
    if (mbox && typeof mbox === 'object') {
      if (mbox.uids) uids = mbox.uids;
      mbox = mbox.id;
    }
    else if (!mbox) {
      uids = this.env.uid ? [this.env.uid] : this.message_list.get_selection();
      return this.folder_selector(event, function(folder, obj) {
        ref.command('move', {id: folder, uids: uids}, obj, event, true);
      });
    }

    // exit if current or no mailbox specified
    if (!mbox || (mbox == this.env.mailbox && !this.is_multifolder_listing()))
      return;

    var lock = false, post_data = this.selection_post_data({_target_mbox: mbox, _uid: uids});

    // exit if selection is empty
    if (!post_data._uid)
      return;

    // show wait message
    if (this.env.action == 'show')
      lock = this.set_busy(true, 'movingmessage');

    // Hide message command buttons until a message is selected
    this.enable_command(this.env.message_commands, false);

    this.with_selected_messages('move', post_data, lock);

    if (this.env.action != 'show')
      this.show_contentframe(false);
  };

  // delete selected messages from the current mailbox
  this.delete_messages = function(event)
  {
    var list = this.message_list, trash = this.env.trash_mailbox;

    // if config is set to flag for deletion
    if (this.env.flag_for_deletion) {
      this.mark_message('delete');
      return false;
    }
    // if there isn't a defined trash mailbox or we are in it
    else if (!trash || this.env.mailbox == trash)
      this.permanently_remove_messages();
    // we're in Junk folder and delete_junk is enabled
    else if (this.env.delete_junk && this.env.junk_mailbox && this.env.mailbox == this.env.junk_mailbox)
      this.permanently_remove_messages();
    // if there is a trash mailbox defined and we're not currently in it
    else {
      // if shift was pressed delete it immediately
      if ((list && list.modkey == SHIFT_KEY) || (event && rcube_event.get_modifier(event) == SHIFT_KEY)) {
        this.confirm_dialog(this.get_label('deletemessagesconfirm'), 'delete', function() {
            ref.permanently_remove_messages();
          });
      }
      else
        this.move_messages(trash);
    }

    return true;
  };

  // delete the selected messages permanently
  this.permanently_remove_messages = function()
  {
    var post_data = this.selection_post_data();

    // exit if selection is empty
    if (!post_data._uid)
      return;

    this.with_selected_messages('delete', post_data);
    this.show_contentframe(false);
  };

  // Send a specific move/delete request with UIDs of all selected messages
  this.with_selected_messages = function(action, post_data, lock, http_action)
  {
    var count = 0, msg,
      remove = (action == 'delete' || !this.is_multifolder_listing());

    // update the list (remove rows, clear selection)
    if (this.message_list) {
      var n, len, id, root, roots = [],
        selection = post_data._uid,
        display_next = this.check_display_next();

      if (selection === '*')
        selection = this.message_list.get_selection();
      else if (typeof selection == 'string')
        selection = selection.split(',');

      for (n=0, len=selection.length; n<len; n++) {
        id = selection[n];

        if (this.env.threading) {
          count += this.update_thread(id);
          root = this.message_list.find_root(id);
          if (root != id && $.inArray(root, roots) < 0) {
            roots.push(root);
          }
        }

        if (remove)
          this.message_list.remove_row(id, display_next && n == selection.length-1);
      }

      // make sure there are no selected rows
      if (!display_next && remove)
        this.message_list.clear_selection();

      // update thread tree icons
      for (n=0, len=roots.length; n<len; n++) {
        this.add_tree_icons(roots[n]);
      }
    }

    if (count < 0)
      post_data._count = (count*-1);
    // remove threads from the end of the list
    else if (count > 0 && remove)
      this.delete_excessive_thread_rows();

    if (!remove)
      post_data._refresh = 1;

    if (!lock) {
      msg = action == 'move' ? 'movingmessage' : 'deletingmessage';
      lock = this.display_message(msg, 'loading');
    }

    // send request to server
    this.http_post(http_action || action, post_data, lock);
  };

  // build post data for message delete/move/copy/flag requests
  this.selection_post_data = function(data)
  {
    if (typeof(data) != 'object')
      data = {};

    if (!data._uid)
      data._uid = this.env.uid ? [this.env.uid] : this.message_list.get_selection();

    data._mbox = this.env.mailbox;
    data._uid = this.uids_to_list(data._uid);

    if (this.env.action)
      data._from = this.env.action;

    // also send search request to get the right messages
    if (this.env.search_request)
      data._search = this.env.search_request;

    if (this.env.display_next && this.env.next_uid)
      data._next_uid = this.env.next_uid;

    return data;
  };

  this.check_display_next = function()
  {
    return this.env.display_next && (this.preview_id || !this.env.contentframe);
  };

  // set a specific flag to one or more messages
  this.mark_message = function(flag, uid)
  {
    var a_uids = [], r_uids = [], len, n, id,
      list = this.message_list;

    if (uid)
      a_uids.push(uid);
    else if (this.env.uid)
      a_uids.push(this.env.uid);
    else if (list)
      a_uids = list.get_selection();

    if (!list)
      r_uids = a_uids;
    else {
      list.focus();
      for (n=0, len=a_uids.length; n<len; n++) {
        id = a_uids[n];
        if ((flag == 'read' && list.rows[id].unread)
            || (flag == 'unread' && !list.rows[id].unread)
            || (flag == 'delete' && !list.rows[id].deleted)
            || (flag == 'undelete' && list.rows[id].deleted)
            || (flag == 'flagged' && !list.rows[id].flagged)
            || (flag == 'unflagged' && list.rows[id].flagged)
        ) {
          r_uids.push(id);
        }
      }
    }

    // nothing to do
    if (!r_uids.length && !this.select_all_mode)
      return;

    switch (flag) {
        case 'read':
        case 'unread':
          this.toggle_read_status(flag, r_uids);
          break;
        case 'delete':
        case 'undelete':
          this.toggle_delete_status(r_uids);
          break;
        case 'flagged':
        case 'unflagged':
          this.toggle_flagged_status(flag, a_uids);
          break;
    }
  };

  // set class to read/unread
  this.toggle_read_status = function(flag, a_uids)
  {
    var i, len = a_uids.length,
      post_data = this.selection_post_data({_uid: a_uids, _flag: flag}),
      lock = this.display_message('markingmessage', 'loading');

    // mark all message rows as read/unread
    for (i=0; i<len; i++)
      this.set_message(a_uids[i], 'unread', (flag == 'unread' ? true : false));

    this.http_post('mark', post_data, lock);
  };

  // set image to flagged or unflagged
  this.toggle_flagged_status = function(flag, a_uids)
  {
    var i, len = a_uids.length,
      win = this.env.contentframe ? this.get_frame_window(this.env.contentframe) : window,
      post_data = this.selection_post_data({_uid: a_uids, _flag: flag}),
      lock = this.display_message('markingmessage', 'loading');

    // mark all message rows as flagged/unflagged
    for (i=0; i<len; i++)
      this.set_message(a_uids[i], 'flagged', (flag == 'flagged' ? true : false));

    if (this.env.action == 'show' || $.inArray(this.preview_id, a_uids) >= 0)
      $(win.document.body)[flag == 'flagged' ? 'addClass' : 'removeClass']('status-flagged');

    this.http_post('mark', post_data, lock);
  };

  // mark all message rows as deleted/undeleted
  this.toggle_delete_status = function(a_uids)
  {
    var i, uid, all_deleted = true,
      len = a_uids.length,
      rows = this.message_list ? this.message_list.rows : {};

    if (len == 1) {
      if (!this.message_list || (rows[a_uids[0]] && !rows[a_uids[0]].deleted))
        this.flag_as_deleted(a_uids);
      else
        this.flag_as_undeleted(a_uids);

      return true;
    }

    for (i=0; i<len; i++) {
      uid = a_uids[i];
      if (rows[uid] && !rows[uid].deleted) {
        all_deleted = false;
        break;
      }
    }

    if (all_deleted)
      this.flag_as_undeleted(a_uids);
    else
      this.flag_as_deleted(a_uids);

    return true;
  };

  this.flag_as_undeleted = function(a_uids)
  {
    var i, len = a_uids.length,
      post_data = this.selection_post_data({_uid: a_uids, _flag: 'undelete'}),
      lock = this.display_message('markingmessage', 'loading');

    for (i=0; i<len; i++)
      this.set_message(a_uids[i], 'deleted', false);

    this.http_post('mark', post_data, lock);
  };

  this.flag_as_deleted = function(a_uids)
  {
    var r_uids = [],
      post_data = this.selection_post_data({_uid: a_uids, _flag: 'delete'}),
      lock = this.display_message('markingmessage', 'loading'),
      list = this.message_list,
      rows = list ? list.rows : {},
      count = 0,
      display_next = this.check_display_next();

    for (var i=0, len=a_uids.length; i<len; i++) {
      uid = a_uids[i];
      if (rows[uid]) {
        if (rows[uid].unread)
          r_uids[r_uids.length] = uid;

        if (this.env.skip_deleted) {
          count += this.update_thread(uid);
          list.remove_row(uid, display_next && i == list.get_selection(false).length-1);
        }
        else
          this.set_message(uid, 'deleted', true);
      }
    }

    // make sure there are no selected rows
    if (this.env.skip_deleted && list) {
      if (!display_next || !list.rowcount)
        list.clear_selection();
      if (count < 0)
        post_data._count = (count*-1);
      else if (count > 0)
        // remove threads from the end of the list
        this.delete_excessive_thread_rows();
    }

    // set of messages to mark as seen
    if (r_uids.length)
      post_data._ruid = this.uids_to_list(r_uids);

    if (this.env.skip_deleted && this.env.display_next && this.env.next_uid)
      post_data._next_uid = this.env.next_uid;

    this.http_post('mark', post_data, lock);
  };

  // flag as read without mark request (called from backend)
  // argument should be a coma-separated list of uids
  this.flag_deleted_as_read = function(uids)
  {
    var uid, i, len,
      rows = this.message_list ? this.message_list.rows : {};

    if (typeof uids == 'string')
      uids = uids.split(',');

    for (i=0, len=uids.length; i<len; i++) {
      uid = uids[i];
      if (rows[uid])
        this.set_message(uid, 'unread', false);
    }
  };

  // Converts array of message UIDs to comma-separated list for use in URL
  // with select_all mode checking
  this.uids_to_list = function(uids)
  {
    if (this.select_all_mode)
      return '*';

    // multi-folder list of uids cannot be passed as a string (#6845)
    if ($.isArray(uids) && (uids.length == 1 || String(uids[0]).indexOf('-') == -1))
      uids = uids.join(',');

    return uids;
  };

  // Sets title of the delete button
  this.set_button_titles = function()
  {
    var label = 'deletemessage';

    if (!this.env.flag_for_deletion
      && this.env.trash_mailbox && this.env.mailbox != this.env.trash_mailbox
      && (!this.env.delete_junk || !this.env.junk_mailbox || this.env.mailbox != this.env.junk_mailbox)
    )
      label = 'movemessagetotrash';

    this.set_alttext('delete', label);
  };

  // Initialize input element for list page jump
  this.init_pagejumper = function(element)
  {
    $(element).addClass('rcpagejumper')
      .on('focus', function(e) {
        // create and display popup with page selection
        var i, html = '';

        for (i = 1; i <= ref.env.pagecount; i++)
          html += '<li>' + i + '</li>';

        html = '<ul class="toolbarmenu menu">' + html + '</ul>';

        if (!ref.pagejump) {
          ref.pagejump = $('<div id="pagejump-selector" class="popupmenu"></div>')
            .appendTo(document.body)
            .on('click', 'li', function() {
              if (!ref.busy)
                $(element).val($(this).text()).change();
            });
        }

        if (ref.pagejump.data('count') != i)
          ref.pagejump.html(html);

        ref.pagejump.attr('rel', '#' + this.id).data('count', i);

        // display page selector
        ref.show_menu('pagejump-selector', true, e);
      })
      // keyboard navigation
      .on('keydown keyup click', function(e) {
        var current, selector = $('#pagejump-selector'),
          ul = $('ul', selector),
          list = $('li', ul),
          height = ul.height(),
          p = parseInt(this.value);

        if (e.which != 27 && e.which != 9 && e.which != 13 && !selector.is(':visible'))
          return ref.show_menu('pagejump-selector', true, e);

        if (e.type == 'keydown') {
          // arrow-down
          if (e.which == 40) {
            if (list.length > p)
              this.value = (p += 1);
          }
          // arrow-up
          else if (e.which == 38) {
            if (p > 1 && list.length > p - 1)
              this.value = (p -= 1);
          }
          // enter
          else if (e.which == 13) {
            return $(this).change();
          }
          // esc, tab
          else if (e.which == 27 || e.which == 9) {
            ref.hide_menu('pagejump-selector', e);
            return $(element).val(ref.env.current_page);
          }
        }

        $('li.selected', ul).removeClass('selected');

        if ((current = $(list[p - 1])).length) {
          current.addClass('selected');
          $('#pagejump-selector').scrollTop(((ul.height() / list.length) * (p - 1)) - selector.height() / 2);
        }
      })
      .on('change', function(e) {
        // go to specified page
        var p = parseInt(this.value);
        if (p && p != ref.env.current_page && !ref.busy) {
          ref.hide_menu('pagejump-selector', e);
          ref.list_page(p);
        }
      });
  };

  // Update page-jumper state on list updates
  this.update_pagejumper = function()
  {
    $('input.rcpagejumper').val(this.env.current_page).prop('disabled', this.env.pagecount < 2);
  };

  // check for mailvelope API
  this.check_mailvelope = function(action)
  {
    if (window.mailvelope) {
      this.mailvelope_load(action);
    }
    else {
      $(window).on('mailvelope', function() {
        ref.mailvelope_load(action);
      });
    }
  };

  // Load Mailvelope functionality (and initialize keyring if needed)
  this.mailvelope_load = function(action)
  {
    var keyring = this.env.mailvelope_main_keyring ? undefined : this.env.user_id,
      fn = function(kr) {
        ref.mailvelope_keyring = kr;
        ref.mailvelope_init(action, kr);
      };

    mailvelope.getVersion().then(function(v) {
      mailvelope.VERSION = v;
      mailvelope.VERSION_MAJOR = Math.floor(parseFloat(v));
      return mailvelope.getKeyring(keyring);
    }).then(fn, function(err) {
      if (keyring) {
        // attempt to create a new keyring for this app/user
        mailvelope.createKeyring(keyring).then(fn, function(err) {
          console.error(err);
        });
      } else {
        console.error(err);
      }
    });
  };

  // Initializes Mailvelope editor or display container
  this.mailvelope_init = function(action, keyring)
  {
    if (!window.mailvelope)
      return;

    if (action == 'show' || action == 'preview' || action == 'print') {
      // decrypt text body
      if (this.env.is_pgp_content) {
        var data = $(this.env.is_pgp_content).text();
        ref.mailvelope_display_container(this.env.is_pgp_content, data, keyring);
      }
      // load pgp/mime message and pass it to the mailvelope display container
      else if (this.env.pgp_mime_part) {
        var msgid = this.display_message('loadingdata', 'loading'),
          selector = this.env.pgp_mime_container;

        $.ajax({
          type: 'GET',
          url: this.url('get', { '_mbox': this.env.mailbox, '_uid': this.env.uid, '_part': this.env.pgp_mime_part }),
          error: function(o, status, err) {
            ref.http_error(o, status, err, msgid);
          },
          success: function(data) {
            ref.mailvelope_display_container(selector, data, keyring, msgid);
          }
        });
      }
    }
    else if (action == 'compose') {
      this.env.compose_commands.push('compose-encrypted');

      var sign_supported = mailvelope.VERSION_MAJOR >= 2;
      var is_html = $('[name="_is_html"]').val() > 0;

      if (sign_supported)
        this.env.compose_commands.push('compose-encrypted-signed');

      if (this.env.pgp_mime_message) {
        // fetch PGP/Mime part and open load into Mailvelope editor
        var lock = this.set_busy(true, this.get_label('loadingdata'));

        $.ajax({
          type: 'GET',
          url: this.url('get', this.env.pgp_mime_message),
          error: function(o, status, err) {
            ref.http_error(o, status, err, lock);
            ref.enable_command('compose-encrypted', !is_html);
            if (sign_supported)
              ref.enable_command('compose-encrypted-signed', !is_html);
          },
          success: function(data) {
            ref.set_busy(false, null, lock);

            if (is_html) {
              ref.command('toggle-editor', {html: false, noconvert: true});
              $('#' + ref.env.composebody).val('');
            }

            ref.compose_encrypted({ quotedMail: data });
            ref.enable_command('compose-encrypted', true);
            ref.enable_command('compose-encrypted-signed', false);
          }
        });
      }
      else {
        // enable encrypted compose toggle
        this.enable_command('compose-encrypted', !is_html);
        if (sign_supported)
          this.enable_command('compose-encrypted-signed', !is_html);
      }

      // make sure to disable encryption button after toggling editor into HTML mode
      this.addEventListener('actionafter', function(args) {
        if (args.ret && args.action == 'toggle-editor') {
          ref.enable_command('compose-encrypted', !args.props.html);
        if (sign_supported)
          ref.enable_command('compose-encrypted-signed', !args.props.html);
        }
      });
    } else if (action == 'edit-identity') {
      ref.mailvelope_identity_keygen();
    }
  };

  // handler for the 'compose-encrypted-signed' command
  this.compose_encrypted_signed = function(props)
  {
    props = props || {};
    props.signMsg = true;
    this.compose_encrypted(props);
  };

  // handler for the 'compose-encrypted' command
  this.compose_encrypted = function(props)
  {
    var options, container = $('#' + this.env.composebody).parent();

    // remove Mailvelope editor if active
    if (ref.mailvelope_editor) {
      ref.mailvelope_editor = null;
      ref.set_button('compose-encrypted', 'act');

      container.removeClass('mailvelope').find('iframe:not([aria-hidden=true])').remove();
      $('#' + ref.env.composebody).show();
      $("[name='_pgpmime']").remove();

      // re-enable commands that operate on the compose body
      ref.enable_command('toggle-editor', 'insert-response', true);
      ref.enable_command('spellcheck', !!window.googie);
      ref.enable_command('insert-sig', !!(ref.env.signatures && ref.env.identity && ref.env.signatures[ref.env.identity]));

      ref.triggerEvent('compose-encrypted', { active:false });
    }
    // embed Mailvelope editor container
    else {
      if (this.spellcheck_state())
        this.editor.spellcheck_stop();

      if (props.quotedMail) {
        options = { quotedMail: props.quotedMail, quotedMailIndent: false };
      }
      else {
        options = { predefinedText: $('#' + this.env.composebody).val() };
      }

      if (props.signMsg) {
        options.signMsg = props.signMsg;
      }

      if (this.env.compose_mode == 'reply') {
        options.quotedMailIndent = true;
        options.quotedMailHeader = this.env.compose_reply_header;
      }

      mailvelope.createEditorContainer('#' + container.attr('id'), ref.mailvelope_keyring, options).then(function(editor) {
        ref.mailvelope_editor = editor;
        ref.set_button('compose-encrypted', 'sel');

        container.addClass('mailvelope');
        $('#' + ref.env.composebody).hide();

        // disable commands that operate on the compose body
        ref.enable_command('spellcheck', 'insert-sig', 'toggle-editor', 'insert-response', false);
        ref.triggerEvent('compose-encrypted', { active:true });

        if (!$.isEmptyObject(ref.env.attachments)) {
          // notify user if losing attachments
          if (ref.env.compose_mode != 'draft'
            || Object.keys(ref.env.attachments).length != 1
            || ref.env.attachments[Object.keys(ref.env.attachments)[0]].name != 'encrypted.asc'
          ) {
            ref.alert_dialog(ref.get_label('encryptnoattachments'));
          }

          $.each(ref.env.attachments, function(name, attach) {
            ref.remove_from_attachment_list(name);
          });
        }
      }, function(err) {
        console.error(err);
        console.log(options);
      });
    }
  };

  // callback to replace the message body with the full armored
  this.mailvelope_submit_messageform = function(draft, saveonly)
  {
    // get recipients
    var recipients = [];
    $.each(['to', 'cc', 'bcc'], function(i,field) {
      var pos, rcpt, val = $('[name="_' + field + '"]').val().trim();
      while (val.length && rcube_check_email(val, true)) {
        rcpt = RegExp.$2.replace(/^<+/, '').replace(/>+$/, '');
        recipients.push(rcpt);
        val = val.substr(val.indexOf(rcpt) + rcpt.length + 1).replace(/^\s*,\s*/, '');
      }
    });

    // check if we have keys for all recipients
    var isvalid = recipients.length > 0;
    ref.mailvelope_keyring.validKeyForAddress(recipients).then(function(status) {
      var missing_keys = [];
      $.each(status, function(k,v) {
        if (v === false) {
          isvalid = false;
          missing_keys.push(k);
        }
      });

      // list recipients with missing keys
      if (!isvalid && missing_keys.length) {
        // display dialog with missing keys
        ref.simple_dialog(
          ref.get_label('nopubkeyfor').replace('$email', missing_keys.join(', ')) +
            '<p>' + ref.get_label('searchpubkeyservers') + '</p>',
          'encryptedsendialog',
          function() {
            ref.mailvelope_search_pubkeys(missing_keys, function() {
              return true; // close dialog
            });
          },
          {button: 'search'}
        );
        return false;
      }

      if (!isvalid) {
        if (!recipients.length) {
          ref.alert_dialog(ref.get_label('norecipientwarning'), function() {
            $("[name='_to']").focus();
          });
        }
        return false;
      }

      // add sender identity to recipients to be able to decrypt our very own message
      var senders = [], selected_sender = ref.env.identities[$("[name='_from'] option:selected").val()];
      $.each(ref.env.identities, function(k, sender) {
        senders.push(sender.email);
      });

      ref.mailvelope_keyring.validKeyForAddress(senders).then(function(status) {
        valid_sender = null;
        $.each(status, function(k,v) {
          if (v !== false) {
            valid_sender = k;
            if (valid_sender == selected_sender) {
              return false;  // break
            }
          }
        });

        if (!valid_sender) {
          if (!confirm(ref.get_label('nopubkeyforsender'))) {
            return false;
          }
        }

        recipients.push(valid_sender);

        ref.mailvelope_editor.encrypt(recipients).then(function(armored) {
          // all checks passed, send message
          var form = ref.gui_objects.messageform,
            hidden = $("[name='_pgpmime']", form),
            msgid = ref.set_busy(true, draft || saveonly ? 'savingmessage' : 'sendingmessage');

          form.target = ref.get_save_target(msgid);
          form._draft.value = draft ? '1' : '';
          form.action = ref.add_url(form.action, '_unlock', msgid);
          form.action = ref.add_url(form.action, '_framed', 1);

          if (saveonly) {
            form.action = ref.add_url(form.action, '_saveonly', 1);
          }

          // send pgp content via hidden field
          if (!hidden.length) {
            hidden = $('<input type="hidden" name="_pgpmime">').appendTo(form);
          }
          hidden.val(armored);

          form.submit();

        }, function(err) {
          console.log(err);
        });  // mailvelope_editor.encrypt()

      }, function(err) {
        console.error(err);
      });  // mailvelope_keyring.validKeyForAddress(senders)

    }, function(err) {
      console.error(err);
    });  // mailvelope_keyring.validKeyForAddress(recipients)

    return false;
  };

  // wrapper for the mailvelope.createDisplayContainer API call
  this.mailvelope_display_container = function(selector, data, keyring, msgid)
  {
    var error_handler = function(error) {
      // remove mailvelope frame with the error message
      $(selector + ' > iframe').remove();
      ref.hide_message(msgid);
      ref.display_message(error.message, 'error');
    };

    mailvelope.createDisplayContainer(selector, data, keyring, { senderAddress: this.env.sender }).then(function(status) {
      if (status.error && status.error.message) {
        return error_handler(status.error);
      }

      ref.hide_message(msgid);
      $(selector).children().not('iframe').hide();
      $(ref.gui_objects.messagebody).addClass('mailvelope');

      // on success we can remove encrypted part from the attachments list
      if (ref.env.pgp_mime_part)
        $('#attach' + ref.env.pgp_mime_part).remove();

      setTimeout(function() { $(window).resize(); }, 10);
    }, error_handler);
  };

  // subroutine to query keyservers for public keys
  this.mailvelope_search_pubkeys = function(emails, resolve, import_handler)
  {
    // query with publickey.js
    var deferred = [],
      pk = new PublicKey(this.env.keyservers),
      lock = ref.display_message('', 'loading');

    $.each(emails, function(i, email) {
      var d = $.Deferred();
      pk.search(email, function(results, errorCode) {
        if (errorCode !== null) {
          // rejecting would make all fail
          // d.reject(email);
          d.resolve([email]);
        }
        else {
          d.resolve([email].concat(results));
        }
      });
      deferred.push(d);
    });

    $.when.apply($, deferred).then(function() {
      var missing_keys = [],
        key_selection = [];

      // analyze results of all queries
      $.each(arguments, function(i, result) {
        var email = result.shift();
        if (!result.length) {
          missing_keys.push(email);
        }
        else {
          key_selection = key_selection.concat(result);
        }
      });

      ref.hide_message(lock);
      resolve(true);

      // show key import dialog
      if (key_selection.length) {
        ref.mailvelope_key_import_dialog(key_selection, import_handler);
      }
      // some keys could not be found
      if (missing_keys.length) {
        ref.display_message(ref.get_label('nopubkeyfor').replace('$email', missing_keys.join(', ')), 'warning');
      }
    }).fail(function() {
      console.error('Pubkey lookup failed with', arguments);
      ref.hide_message(lock);
      ref.display_message('pubkeysearcherror', 'error');
      resolve(false);
    });
  };

  // list the given public keys in a dialog with options to import
  // them into the local Mailvelope keyring
  this.mailvelope_key_import_dialog = function(candidates, import_handler)
  {
    var ul = $('<div>').addClass('listing pgpkeyimport');

    $.each(candidates, function(i, keyrec) {
      var li = $('<div>').addClass('key');

      if (keyrec.revoked)  li.addClass('revoked');
      if (keyrec.disabled) li.addClass('disabled');
      if (keyrec.expired)  li.addClass('expired');

      li.append($('<label>').addClass('keyid').text(ref.get_label('keyid')));
      li.append($('<a>').text(keyrec.keyid.substr(-8).toUpperCase())
        .attr({href: keyrec.info, target: '_blank', tabindex: '-1'}));

      li.append($('<label>').addClass('keylen').text(ref.get_label('keylength')));
      li.append($('<span>').text(keyrec.keylen));

      if (keyrec.expirationdate) {
        li.append($('<label>').addClass('keyexpired').text(ref.get_label('keyexpired')));
        li.append($('<span>').text(new Date(keyrec.expirationdate * 1000).toDateString()));
      }

      if (keyrec.revoked) {
        li.append($('<span>').addClass('keyrevoked').text(ref.get_label('keyrevoked')));
      }

      var ul_ = $('<ul>').addClass('uids');
      $.each(keyrec.uids, function(j, uid) {
        var li_ = $('<li>').addClass('uid');
        if (uid.revoked)  li_.addClass('revoked');
        if (uid.disabled) li_.addClass('disabled');
        if (uid.expired)  li_.addClass('expired');

        ul_.append(li_.text(uid.uid));
      });

      li.append(ul_);
      li.append($('<button>')
        .attr('rel', keyrec.keyid)
        .text(ref.get_label('import'))
        .addClass('button import importkey')
        .prop('disabled', keyrec.revoked || keyrec.disabled || keyrec.expired));

      ul.append(li);
    });

    // display dialog with missing keys
    ref.simple_dialog(
      $('<div>')
        .append($('<p>').html(ref.get_label('encryptpubkeysfound')))
        .append(ul),
      'importpubkeys',
      null,
      {cancel_label: 'close', cancel_button: 'close'}
    );

    // delegate handler for import button clicks
    ul.on('click', 'button.importkey', function() {
      var btn = $(this),
        keyid = btn.attr('rel'),
        pk = new PublicKey(ref.env.keyservers),
        lock = ref.display_message('', 'loading');

        // fetch from keyserver and import to Mailvelope keyring
        pk.get(keyid, function(armored, errorCode) {
          ref.hide_message(lock);

          if (errorCode) {
            ref.display_message('keyservererror', 'error');
            return;
          }

          if (import_handler) {
            import_handler(armored);
            return;
          }

          // import to keyring
          ref.mailvelope_keyring.importPublicKey(armored).then(function(status) {
            if (status === 'REJECTED') {
              // ref.alert_dialog(ref.get_label('Key import was rejected'));
            }
            else {
              var $key = keyid.substr(-8).toUpperCase();
              btn.closest('.key').fadeOut();
              ref.display_message(ref.get_label('keyimportsuccess').replace('$key', $key), 'confirmation');
            }
          }, function(err) {
            console.log(err);
          });
        });
    });
  };

  // enable key management for identity
  this.mailvelope_identity_keygen = function()
  {
    var container = $(this.gui_objects.editform).find('.identity-encryption').first();
    var identity_email = $(this.gui_objects.editform).find('.ff_email').val().trim();

    if (!container.length || !identity_email || !this.mailvelope_keyring.createKeyGenContainer)
      return;

    var key_fingerprint;
    this.mailvelope_keyring.validKeyForAddress([identity_email])
      .then(function(keys) {
        var private_keys = [];

        if (keys && keys[identity_email] && Array.isArray(keys[identity_email].keys)) {
          var checks = [];
          for (var j=0; j < keys[identity_email].keys.length; j++) {
            checks.push((function(key) {
              return ref.mailvelope_keyring.hasPrivateKey(key.fingerprint)
                .then(function(found) {
                  if (found) {
                    private_keys.push(key);
                  }
                });
            })(keys[identity_email].keys[j]));
          }
          return Promise.all(checks)
            .then(function() {
              return private_keys;
            });
        }

        return private_keys;
      }).then(function(private_keys) {
        var content = container.find('.identity-encryption-block').empty();
        if (private_keys && private_keys.length) {
          // show private key information
          $('<p>').text(ref.get_label('encryptionprivkeysinmailvelope').replace('$nr', private_keys.length)).appendTo(content);
          var ul = $('<ul>').addClass('keylist').appendTo(content);
          $.each(private_keys, function(i, key) {
            $('<li>').appendTo(ul)
              .append($('<strong>').addClass('fingerprint').text(String(key.fingerprint).toUpperCase()))
              .append($('<span>').addClass('identity').text('<' + identity_email + '> '));
          });
        } else {
          $('<p>').text(ref.get_label('encryptionnoprivkeysinmailvelope')).appendTo(content);
        }

        // show button to create a new key
        $('<button>')
          .attr('type', 'button')
          .addClass('button create')
          .text(ref.get_label('encryptioncreatekey'))
          .appendTo(content)
          .on('click', function() { ref.mailvelope_show_keygen_container(content, identity_email); });
        $('<span>').addClass('space').html('&nbsp;').appendTo(content);
        $('<button>')
          .attr('type', 'button')
          .addClass('button settings')
          .text(ref.get_label('openmailvelopesettings'))
          .appendTo(content)
          .on('click', function() { ref.mailvelope_keyring.openSettings(); });

        container.show();
        ref.triggerEvent('identity-encryption-show', { container: container });
      })
      .catch(function(err) {
        console.error('Mailvelope keyring error', err);
      })
  };

  // start pgp key generation using Mailvelope
  this.mailvelope_show_keygen_container = function(container, identity_email)
  {
    var cid = new Date().getTime();
    var user_id = {email: identity_email, fullName: $(ref.gui_objects.editform).find('.ff_name').val().trim()};
    var options = {userIds: [user_id], keySize: this.env.mailvelope_keysize};

    $('<div>').attr('id', 'mailvelope-keygen-container-' + cid)
      .css({height: '245px', marginBottom: '10px'})
      .appendTo(container.empty());

    this.mailvelope_keyring.createKeyGenContainer('#mailvelope-keygen-container-' + cid, options)
      .then(function(generator) {
        if (generator instanceof Error) {
          throw generator;
        }

        // append button to start key generation
        $('<button>')
          .attr('type', 'button')
          .addClass('button mainaction generate')
          .text(ref.get_label('generate'))
          .appendTo(container)
          .on('click', function() {
            var btn = $(this).prop('disabled', true);
            generator.generate()
              .then(function(result) {
                if (typeof result === 'string' && result.indexOf('BEGIN PGP') > 0) {
                  ref.display_message(ref.get_label('keypaircreatesuccess').replace('$identity', identity_email), 'confirmation');
                  // reset keygen view
                  ref.mailvelope_identity_keygen();
                }
              })
              .catch(function(err) {
                debugger;
                ref.display_message(err.message || 'errortitle', 'error');
                btn.prop('disabled', false);
            });
          });

        $('<span>').addClass('space').html('&nbsp;').appendTo(container);

        $('<button>')
          .attr('type', 'button')
          .addClass('button cancel')
          .text(ref.get_label('cancel'))
          .appendTo(container)
          .on('click', function() { ref.mailvelope_identity_keygen(); });

        ref.triggerEvent('identity-encryption-update', { container: container });
      })
      .catch(function(err) {
        ref.display_message('errortitle', 'error');
        // start over
        ref.mailvelope_identity_keygen();
      });
  };

  this.mdn_request_dialog = function(uid, mailbox)
  {
    var props = {
        action: 'mark',
        data: { _uid: uid, _mbox: mailbox, _flag: 'mdnsent' }
      },
      buttons = [
        {
          text: this.get_label('send'),
          'class': 'mainaction send',
          click: function(e, ui, dialog) {
            props.action = 'sendmdn';
            (ref.is_framed() ? parent.$ : $)(dialog || this).dialog('close');
          }
        },
        {
          text: this.get_label('ignore'),
          'class': 'cancel',
          click: function(e, ui, dialog) {
            (ref.is_framed() ? parent.$ : $)(dialog || this).dialog('close');
          }
        }
      ],
      mdn_func = function(event, ui) {
        ref.http_post(props.action, props.data);
        // from default close function
        $(this).remove();
      };

    if (this.env.mdn_request_save) {
      buttons.unshift({
        text: this.get_label('sendalwaysto').replace('$email', this.env.mdn_request_sender.mailto),
        'class': 'mainaction send',
        click: function(e, ui, dialog) {
          props.data._save = ref.env.mdn_request_save;
          props.data._address = ref.env.mdn_request_sender.string;
          $(e.target).next().click();
        }
      });
    }

    this.show_popup_dialog(this.get_label('mdnrequest'), this.get_label('sendreceipt'), buttons, { close: mdn_func });
  };


  /*********************************************************/
  /*********       mailbox folders methods         *********/
  /*********************************************************/

  this.expunge_mailbox = function(mbox)
  {
    var lock, post_data = {_mbox: mbox};

    // lock interface if it's the active mailbox
    if (mbox == this.env.mailbox) {
      lock = this.set_busy(true, 'loading');
      post_data._reload = 1;
      if (this.env.search_request)
        post_data._search = this.env.search_request;
    }

    // send request to server
    this.http_post('expunge', post_data, lock);
  };

  this.purge_mailbox = function(mbox)
  {
    this.confirm_dialog(this.get_label('purgefolderconfirm'), 'delete', function() {
        var lock, post_data = {_mbox: mbox};

        // lock interface if it's the active mailbox
        if (mbox == ref.env.mailbox) {
           lock = ref.set_busy(true, 'loading');
           post_data._reload = 1;
        }

        // send request to server
        ref.http_post('purge', post_data, lock);
      });

    return false;
  };

  // Mark all messages as read in:
  //   - selected folder (mode=cur)
  //   - selected folder and its subfolders (mode=sub)
  //   - all folders (mode=all)
  this.mark_all_read = function(mbox, mode)
  {
    var state, content, nodes = [],
      list = this.message_list,
      folder = mbox || this.env.mailbox,
      post_data = {_uid: '*', _flag: 'read', _mbox: folder, _folders: mode};

    if (typeof mode != 'string') {
      state = this.mark_all_read_state(folder);
      if (!state)
        return;

      if (state > 1) {
        // build content of the dialog
        $.each({cur: 1, sub: 2, all: 4}, function(i, v) {
          var id = 'readallmode' + i,
            label = $('<label>').attr('for', id).text(ref.get_label('folders-' + i)),
            input = $('<input>').attr({type: 'radio', value: i, name: 'mode', id: id, disabled: !(state & v)});

          nodes.push($('<li>').append([input, label]));
        });

        content = $('<ul class="proplist">').append(nodes);
        $('input:not([disabled])', content).first().attr('checked', true);

        this.simple_dialog(content, 'markallread',
          function() {
            ref.mark_all_read(folder, $('input:checked', content).val());
            return true;
          },
          {button: 'mark', button_class: 'save'}
        );

        return;
      }

      post_data._folders = 'cur'; // only current folder has unread messages
    }

    // mark messages on the list
    $.each(list ? list.rows : [], function(uid, row) {
      if (!row.unread)
        return;

      var mbox = ref.env.messages[uid].mbox;
      if (mode == 'all' || mbox == ref.env.mailbox
          || (mode == 'sub' && mbox.startsWith(ref.env.mailbox + ref.env.delimiter))
      ) {
        ref.set_message(uid, 'unread', false);
      }
    });

    // send the request
    this.http_post('mark', post_data, this.display_message('markingmessage', 'loading'));
  };

  // Enable/disable mark-all-read action depending on folders state
  this.mark_all_read_state = function(mbox)
  {
    var state = 0,
      li = this.treelist.get_item(mbox || this.env.mailbox),
      folder_item = $(li).is('.unread') ? 1 : 0,
      subfolder_items = $('li.unread', li).length,
      all_items = $('li.unread', ref.gui_objects.folderlist).length;

    state += folder_item;
    state += subfolder_items ? 2 : 0;
    state += all_items > folder_item + subfolder_items ? 4 : 0;

    this.enable_command('mark-all-read', state > 0);

    return state;
  };

  // Display "bounce message" dialog
  this.bounce = function(props, obj, event)
  {
    // get message uid and folder
    var uid = this.get_single_uid(),
      url = this.url('bounce', {_framed: 1, _uid: uid, _mbox: this.get_message_mailbox(uid)}),
      dialog = $('<iframe>').attr('src', url),
      get_form = function() {
        var rc = $('iframe', dialog)[0].contentWindow.rcmail;
        return {rc: rc, form: rc.gui_objects.messageform};
      },
      post_func = function() {
        var post = {}, form = get_form();

        $.each($(form.form).serializeArray(), function() { post[this.name] = this.value; });

        post._uid = form.rc.env.uid;
        post._mbox = form.rc.env.mailbox;
        delete post._action;
        delete post._task;

        if (post._to || post._cc || post._bcc) {
          ref.http_post('bounce', post, ref.set_busy(true, 'sendingmessage'));
          dialog.dialog('close');
        }
      },
      submit_func = function() {
        var form = get_form();

        if (typeof form.form != 'object')
          return false;

        if (!form.rc.check_compose_address_fields(post_func, form.form))
          return false;

        return post_func();
      };

    this.hide_menu('forwardmenu', event);

    dialog = this.simple_dialog(dialog, 'bouncemsg', submit_func, {
      button: 'bounce',
      width: 400,
      height: 300
    });

    return true;
  };


  /*********************************************************/
  /*********        message compose methods        *********/
  /*********************************************************/

  this.open_compose_step = function(p)
  {
    var url = this.url('mail/compose', p);

    // open new compose window
    if (this.env.compose_extwin && !this.env.extwin) {
      this.open_window(url);
    }
    else {
      this.redirect(url);
      if (this.env.extwin)
        window.resizeTo(Math.max(this.env.popup_width, $(window).width()), $(window).height() + 24);
    }
  };

  // init message compose form: set focus and eventhandlers
  this.init_messageform = function()
  {
    if (!this.gui_objects.messageform)
      return false;

    var elem, pos,
      input_from = $("[name='_from']"),
      input_to = $("[name='_to']"),
      input_subject = $("[name='_subject']"),
      input_message = $("[name='_message']").get(0),
      html_mode = $("[name='_is_html']").val() == '1',
      opener_rc = this.opener();

    // close compose step in opener
    if (opener_rc && opener_rc.env.action == 'compose') {
      setTimeout(function() {
        if (opener.history.length > 1)
          opener.history.back();
        else
          opener_rc.redirect(opener_rc.get_task_url('mail'));
      }, 100);
      this.env.opened_extwin = true;
    }

    if (!html_mode) {
      // On Back button Chrome will overwrite textarea with old content
      // causing e.g. the same signature is added twice (#5809)
      if (input_message.value && input_message.defaultValue !== undefined)
        input_message.value = input_message.defaultValue;

      pos = this.env.top_posting && this.env.compose_mode ? 0 : input_message.value.length;

      // add signature according to selected identity
      // if we have HTML editor, signature is added in a callback
      if (input_from.prop('type') == 'select-one') {
        // for some reason the caret initially is not at pos=0 in Firefox 51 (#5628)
        this.set_caret_pos(input_message, 0);
        this.change_identity(input_from[0]);
      }

      // set initial cursor position
      this.set_caret_pos(input_message, pos);

      // scroll to the bottom of the textarea (#1490114)
      if (pos) {
        $(input_message).scrollTop(input_message.scrollHeight);
      }
    }

    // check for locally stored compose data
    if (this.env.save_localstorage)
      this.compose_restore_dialog(0, html_mode)

    if (input_to.val() == '')
      elem = input_to;
    else if (input_subject.val() == '')
      elem = input_subject;
    else if (input_message)
      elem = input_message;

    this.env.compose_focus_elem = this.init_messageform_inputs(elem);

    // get summary of all field values
    this.compose_field_hash(true);

    // start the auto-save timer
    this.auto_save_start();
  };

  // init autocomplete events on compose form inputs
  this.init_messageform_inputs = function(focused)
  {
    var i,
      input_to = $("[name='_to']"),
      ac_fields = ['cc', 'bcc', 'replyto', 'followupto'];

    // init live search events
    this.init_address_input_events(input_to);
    for (i in ac_fields) {
      this.init_address_input_events($("[name='_"+ac_fields[i]+"']"));
    }

    if (!focused)
      focused = input_to;

    // focus first empty element (and return it)
    return $(focused).focus().get(0);
  };

  this.compose_restore_dialog = function(j, html_mode)
  {
    var i, key, formdata, index = this.local_storage_get_item('compose.index', []);

    var show_next = function(i) {
      if (++i < index.length)
        ref.compose_restore_dialog(i, html_mode)
    }

    for (i = j || 0; i < index.length; i++) {
      key = index[i];
      formdata = this.local_storage_get_item('compose.' + key, null, true);
      if (!formdata) {
        continue;
      }
      // restore saved copy of current compose_id
      if (formdata.changed && key == this.env.compose_id) {
        this.restore_compose_form(key, html_mode);
        break;
      }
      // skip records from 'other' drafts
      if (this.env.draft_id && formdata.draft_id && formdata.draft_id != this.env.draft_id) {
        continue;
      }
      // skip records on reply
      if (this.env.reply_msgid && formdata.reply_msgid != this.env.reply_msgid) {
        continue;
      }
      // show dialog asking to restore the message
      if (formdata.changed && formdata.session != this.env.session_id) {
        this.show_popup_dialog(
          this.get_label('restoresavedcomposedata')
            .replace('$date', new Date(formdata.changed).toLocaleString())
            .replace('$subject', formdata._subject)
            .replace(/\n/g, '<br/>'),
          this.get_label('restoremessage'),
          [{
            text: this.get_label('restore'),
            'class': 'mainaction restore',
            click: function(){
              ref.restore_compose_form(key, html_mode);
              ref.remove_compose_data(key);  // remove old copy
              ref.save_compose_form_local();  // save under current compose_id
              $(this).dialog('close');
            }
          },
          {
            text: this.get_label('delete'),
            'class': 'delete',
            click: function(){
              ref.remove_compose_data(key);
              $(this).dialog('close');
              show_next(i);
            }
          },
          {
            text: this.get_label('ignore'),
            'class': 'cancel',
            click: function(){
              $(this).dialog('close');
              show_next(i);
            }
          }]
        );
        break;
      }
    }
  }

  this.init_address_input_events = function(obj, props)
  {
    // configure parallel autocompletion
    if (!props && this.env.autocomplete_threads > 0) {
      props = {
        threads: this.env.autocomplete_threads,
        sources: this.env.autocomplete_sources
      };
    }

    obj.keydown(function(e) { return ref.ksearch_keydown(e, this, props); })
      .attr({autocomplete: 'off', 'aria-autocomplete': 'list', 'aria-expanded': 'false', role: 'combobox'});

    var callback = function(e) {
      if (ref.ksearch_pane && e.target === ref.ksearch_pane.get(0)) {
        return;
      }
      ref.ksearch_hide();
    };

    // hide the popup on any click
    $(document).on('click', callback);
    // and on scroll (that cannot be jQuery.on())
    document.addEventListener('scroll', callback, true);
  };

  this.submit_messageform = function(draft, saveonly)
  {
    var form = this.gui_objects.messageform;

    if (!form)
      return;

    // the message has been sent but not saved, ask the user what to do
    if (!saveonly && this.env.is_sent) {
      return this.simple_dialog(this.get_label('messageissent'), '', // TODO: dialog title
        function() {
          ref.submit_messageform(false, true);
          return true;
        }
      );
    }

    // delegate sending to Mailvelope routine
    if (this.mailvelope_editor) {
      return this.mailvelope_submit_messageform(draft, saveonly);
    }

    // all checks passed, send message
    var msgid = this.set_busy(true, draft || saveonly ? 'savingmessage' : 'sendingmessage'),
      lang = this.spellcheck_lang(),
      files = [];

    // send files list
    $('li', this.gui_objects.attachmentlist).each(function() { files.push(this.id.replace(/^rcmfile/, '')); });
    $('[name="_attachments"]', form).val(files.join());

    form.target = this.get_save_target(msgid);
    form._draft.value = draft ? '1' : '';
    form.action = this.add_url(form.action, '_unlock', msgid);
    form.action = this.add_url(form.action, '_framed', 1);

    if (lang)
        form.action = this.add_url(form.action, '_lang', lang);
    if (saveonly)
      form.action = this.add_url(form.action, '_saveonly', 1);

    // register timer to notify about connection timeout
    this.submit_timer = setTimeout(function() {
      ref.set_busy(false, null, msgid);
      ref.display_message('requesttimedout', 'error');
    }, this.env.request_timeout * 1000);

    form.submit();
  };

  this.compose_recipient_select = function(list)
  {
    var id, n, recipients = 0, selection = list.get_selection();
    for (n=0; n < selection.length; n++) {
      id = selection[n];
      if (this.env.contactdata[id])
        recipients++;
    }
    this.enable_command('add-recipient', recipients);
  };

  this.compose_add_recipient = function(field)
  {
    // find last focused field name
    if (!field) {
      field = $(this.env.focused_field).filter(':visible');
      field = field.length ? field.attr('id').replace('_', '') : 'to';
    }

    var recipients = [], input = $('#_' + field), selection = this.contact_list.get_selection();

    if (this.contact_list && selection.length) {
      var data, name, n, id;
      for (n = 0; n < selection.length; n++) {
        if ((id = selection[n]) && (data = this.env.contactdata[id])) {
          name = data.name || data

          // group is added, expand it
          if (id.charAt(0) == 'E' && input.length) {
            // We wrap the group name with invisible markers to prevent from problems with group expanding (#7569)
            name = '\u200b' + name + '\u200b';
            var gid = id.substr(1);
            this.group2expand[gid] = {name: name, input: input.get(0)};
            this.http_request('group-expand', {_source: data.source || this.env.source, _gid: gid}, false);
          }

          recipients.push(name);
        }
      }
    }

    if (recipients.length && input.length) {
      var oldval = input.val();
      if (oldval && !/[,;]\s*$/.test(oldval))
        oldval += ', ';
      input.val(oldval + recipients.join(', ') + ', ').change();
      this.triggerEvent('add-recipient', { field:field, recipients:recipients });
    }

    return recipients.length;
  };

  // checks the input fields before sending a message
  this.check_compose_input = function(cmd)
  {
    var key,
      input_subject = $("[name='_subject']");

    // check if all files has been uploaded
    for (key in this.env.attachments) {
      if (typeof this.env.attachments[key] === 'object' && !this.env.attachments[key].complete) {
        this.alert_dialog(this.get_label('notuploadedwarning'));
        return false;
      }
    }

    // display localized warning for missing subject
    if (!this.env.nosubject_warned && input_subject.val() == '') {
      var dialog,
        prompt_value = $('<input>').attr({type: 'text', size: 40, 'data-submit': 'true'}),
        myprompt = $('<div class="prompt">')
          .append($('<p class="message">').text(this.get_label('nosubjectwarning')))
          .append(prompt_value),
        save_func = function() {
          input_subject.val(prompt_value.val());
          dialog.dialog('close');
          if (ref.check_compose_input(cmd))
            ref.command(cmd, { nocheck:true });  // repeat command which triggered this
        };

      dialog = this.show_popup_dialog(
        myprompt,
        this.get_label('nosubjecttitle'),
        [{
            text: this.get_label('sendmessage'),
            'class': 'mainaction send',
            click: function() { save_func(); }
          }, {
            text: this.get_label('cancel'),
            'class': 'cancel',
            click: function() {
              input_subject.focus();
              dialog.dialog('close');
            }
          }],
        {dialogClass: 'warning'}
      );

      this.env.nosubject_warned = true;
      return false;
    }

    // check for empty body (only possible if not mailvelope encrypted)
    if (!this.mailvelope_editor && !this.editor.get_content() && !confirm(this.get_label('nobodywarning'))) {
      this.editor.focus();
      return false;
    }

    if (!this.check_compose_address_fields(cmd))
      return false;

    // move body from html editor to textarea (just to be sure, #1485860)
    this.editor.save();

    return true;
  };

  this.check_compose_address_fields = function(cmd, form)
  {
    if (!form)
      form = window.document;

    // check input fields
    var key, recipients, dialog,
      limit = this.env.max_disclosed_recipients,
      input_to = $("[name='_to']", form),
      input_cc = $("[name='_cc']", form),
      input_bcc = $("[name='_bcc']", form),
      input_from = $("[name='_from']", form),
      get_recipients = function(fields) {
        fields = $.map(fields, function(v) {
          v = v.val().trim();
          return v.length ? v : null;
        });
        return fields.join(',').replace(/^[\s,;]+/, '').replace(/[\s,;]+$/, '');
      };

    // check sender (if have no identities)
    if (input_from.prop('type') == 'text' && !rcube_check_email(input_from.val(), true)) {
      this.alert_dialog(this.get_label('nosenderwarning'), function() {
        input_from.focus();
      });
      return false;
    }

    // check for empty recipient
    if (!rcube_check_email(get_recipients([input_to, input_cc, input_bcc]), true)) {
      this.alert_dialog(this.get_label('norecipientwarning'), function() {
        input_to.focus();
      });
      return false;
    }

    // check disclosed recipients limit
    if (limit && !this.env.disclosed_recipients_warned
      && rcube_check_email(recipients = get_recipients([input_to, input_cc]), true, true) > limit
    ) {
      var save_func = function(move_to_bcc) {
          if (move_to_bcc) {
            var bcc = input_bcc.val();
            input_bcc.val((bcc ? (bcc + ', ') : '') + recipients).change();
            input_to.val('').change();
            input_cc.val('').change();
          }

          dialog.dialog('close');

          if (typeof cmd == 'function')
            cmd();
          else if (cmd)
            ref.command(cmd, { nocheck:true });  // repeat command which triggered this
        };

      dialog = this.show_popup_dialog(
        this.get_label('disclosedrecipwarning'),
        this.get_label('disclosedreciptitle'),
        [{
            text: this.get_label('sendmessage'),
            click: function() { save_func(false); },
            'class': 'mainaction'
          }, {
            text: this.get_label('bccinstead'),
            click: function() { save_func(true); }
          }, {
            text: this.get_label('cancel'),
            click: function() { dialog.dialog('close'); },
            'class': 'cancel'
          }],
        {dialogClass: 'warning'}
      );

      this.env.disclosed_recipients_warned = true;
      return false;
    }

    return true;
  };

  this.toggle_editor = function(props, obj, e)
  {
    // @todo: this should work also with many editors on page
    var mode, result = this.editor.toggle(props.html, props.noconvert || false),
      control = $('#' + this.editor.id).data('control') || $(e ? e.target : []);

    if (result)
      mode = props.html ? 'html' : 'plain';
    else
      mode = props.html ? 'plain' : 'html';

    // update internal format flag
    $("[name='_is_html']").val(mode == 'html' ? 1 : 0);

    if (control.is('[type=checkbox]'))
      control.prop('checked', mode == 'html');
    else
      control.val(mode);

    return result;
  };

  // Inserts a predefined response to the compose editor
  this.insert_response = function(response)
  {
    if (typeof response == 'object') {
      var replace = {};
      replace[response.is_html ? 'html' : 'text'] = response.data;

      this.editor.replace(replace);
      this.display_message('responseinserted', 'confirmation');
    }
    else {
      var lock = this.display_message('', 'loading');
      this.http_get('settings/response-get', {_id: response, _is_html: this.editor.is_html() ? 1 : 0}, lock);
    }
  };

  // updates spellchecker buttons on state change
  this.spellcheck_state = function()
  {
    var active = this.editor.spellcheck_state();

    $.each(this.buttons.spellcheck || [], function(i, v) {
      $('#' + v.id)[active ? 'addClass' : 'removeClass']('selected');
    });

    return active;
  };

  // get selected language
  this.spellcheck_lang = function()
  {
    return this.editor.get_language();
  };

  this.spellcheck_lang_set = function(lang)
  {
    this.editor.set_language(lang);
  };

  // resume spellchecking, highlight provided misspellings without new ajax request
  this.spellcheck_resume = function(data)
  {
    this.editor.spellcheck_resume(data);
  };

  this.set_draft_id = function(id)
  {
    if (id && id != this.env.draft_id) {
      var filter = {task: 'mail', action: ''},
        rc = this.opener(false, filter) || this.opener(true, filter);

      // refresh the drafts folder in the opener window
      if (rc && rc.env.mailbox == this.env.drafts_mailbox)
        rc.command('checkmail');

      this.env.draft_id = id;
      $("[name='_draft_saveid']").val(id);
    }

    // always remove local copy upon saving as draft
    this.remove_compose_data(this.env.compose_id);
    this.compose_skip_unsavedcheck = false;
  };

  // Create (attach) 'savetarget' iframe before use
  this.get_save_target = function(unlock)
  {
    // Removing the frame on load/error to workaround issues with window history
    this.dummy_iframe('savetarget', 'javascript:false;')
      .on('load error', function() {
        // catch invalid/error response from server and unlock the UI (#7494, #7488, #7522)
        if (unlock && $(this).contents().find('meta[name="generator"][content="Roundcube"]').length == 0) {
          ref.iframe_loaded(unlock);
          ref.display_message('connerror', 'error');
        }

        $(this).remove();
      });

    return 'savetarget';
  };

  this.auto_save_start = function()
  {
    if (this.env.draft_autosave) {
      this.save_timer = setTimeout(function() {
          ref.command("savedraft");
      }, this.env.draft_autosave * 1000);
    }

    // save compose form content to local storage every 5 seconds
    if (!this.local_save_timer && window.localStorage && this.env.save_localstorage) {
      // track typing activity and only save on changes
      this.compose_type_activity = this.compose_type_activity_last = 0;
      $(document).keypress(function(e) { ref.compose_type_activity++; });

      this.local_save_timer = setInterval(function(){
        if (ref.compose_type_activity > ref.compose_type_activity_last) {
          ref.save_compose_form_local();
          ref.compose_type_activity_last = ref.compose_type_activity;
        }
      }, 5000);

      $(window).on('unload', function() {
        // remove copy from local storage if compose screen is left after warning
        if (!ref.env.server_error)
          ref.remove_compose_data(ref.env.compose_id);
      });
    }

    // check for unsaved changes before leaving the compose page
    if (!window.onbeforeunload) {
      window.onbeforeunload = function() {
        if (!ref.compose_skip_unsavedcheck && ref.cmp_hash != ref.compose_field_hash()) {
          return ref.get_label('notsentwarning');
        }
      };
    }

    // Unlock interface now that saving is complete
    this.busy = false;
  };

  this.compose_field_hash = function(save)
  {
    // check input fields
    var i, id, val, str = '', hash_fields = ['to', 'cc', 'bcc', 'subject'];

    for (i=0; i<hash_fields.length; i++)
      if (val = $('[name="_' + hash_fields[i] + '"]').val())
        str += val + ':';

    str += this.editor.get_content({refresh: false});

    for (id in this.env.attachments)
      str += id;

    // we can't detect changes in the Mailvelope editor so assume it changed
    if (this.mailvelope_editor) {
      str += ';' + new Date().getTime();
    }

    if (save)
      this.cmp_hash = str;

    return str;
  };

  // store the contents of the compose form to localstorage
  this.save_compose_form_local = function()
  {
    // feature is disabled
    if (!this.env.save_localstorage)
      return;

    var formdata = { session:this.env.session_id, changed:new Date().getTime() },
      ed, empty = true;

    // get fresh content from editor
    this.editor.save();

    if (this.env.draft_id) {
      formdata.draft_id = this.env.draft_id;
    }
    if (this.env.reply_msgid) {
      formdata.reply_msgid = this.env.reply_msgid;
    }

    $('input, select, textarea', this.gui_objects.messageform).each(function(i, elem) {
      switch (elem.tagName.toLowerCase()) {
        case 'input':
          if (elem.type == 'button' || elem.type == 'submit' || (elem.type == 'hidden' && elem.name != '_is_html')) {
            break;
          }
          formdata[elem.name] = elem.type != 'checkbox' || elem.checked ? $(elem).val() : '';

          if (formdata[elem.name] != '' && elem.type != 'hidden')
            empty = false;
          break;

        case 'select':
          formdata[elem.name] = $('option:checked', elem).val();
          break;

        default:
          formdata[elem.name] = $(elem).val();
          if (formdata[elem.name] != '')
            empty = false;
      }
    });

    if (!empty) {
      var index = this.local_storage_get_item('compose.index', []),
        key = this.env.compose_id;

      if ($.inArray(key, index) < 0) {
        index.push(key);
      }

      this.local_storage_set_item('compose.' + key, formdata, true);
      this.local_storage_set_item('compose.index', index);
    }
  };

  // write stored compose data back to form
  this.restore_compose_form = function(key, html_mode)
  {
    var ed, formdata = this.local_storage_get_item('compose.' + key, true);

    if (formdata && typeof formdata == 'object') {
      $.each(formdata, function(k, value) {
        if (k[0] == '_') {
          var elem = $("[name=" + k + "]");
          if (elem[0] && elem[0].type == 'checkbox') {
            elem.prop('checked', value != '');
          }
          else {
            elem.val(value).change();
          }
        }
      });

      // initialize HTML editor
      if ((formdata._is_html == '1' && !html_mode) || (formdata._is_html != '1' && html_mode)) {
        this.command('toggle-editor', {id: this.env.composebody, html: !html_mode, noconvert: true});
      }
    }
  };

  // remove stored compose data from localStorage
  this.remove_compose_data = function(key)
  {
    var index = this.local_storage_get_item('compose.index', []);

    if ($.inArray(key, index) >= 0) {
      this.local_storage_remove_item('compose.' + key);
      this.local_storage_set_item('compose.index', $.grep(index, function(val,i) { return val != key; }));
    }
  };

  // clear all stored compose data of this user
  this.clear_compose_data = function()
  {
    var i, index = this.local_storage_get_item('compose.index', []);

    for (i=0; i < index.length; i++) {
      this.local_storage_remove_item('compose.' + index[i]);
    }

    this.local_storage_remove_item('compose.index');
  };

  this.change_identity = function(obj, show)
  {
    if (!obj || !obj.options)
      return false;

    var id = $(obj).val(),
      got_sig = this.env.signatures && this.env.signatures[id],
      sig = this.env.identity,
      show_sig = show ? show : this.env.show_sig;

    // enable manual signature insert
    if (got_sig) {
      this.enable_command('insert-sig', true);
      this.env.compose_commands.push('insert-sig');
      got_sig = true;
    }
    else
      this.enable_command('insert-sig', false);

    // first function execution
    if (!this.env.identities_initialized) {
      this.env.identities_initialized = true;
      if (this.env.show_sig_later)
        this.env.show_sig = true;
      if (this.env.opened_extwin)
        return;
    }

    // update reply-to/bcc fields with addresses defined in identities
    $.each(['replyto', 'bcc'], function() {
      var rx, key = this,
        old_val = sig && ref.env.identities[sig] ? ref.env.identities[sig][key] : '',
        new_val = id && ref.env.identities[id] ? ref.env.identities[id][key] : '',
        input = $('[name="_'+key+'"]'), input_val = input.val();

      // remove old address(es)
      if (old_val && input_val) {
        rx = new RegExp('\\s*' + RegExp.escape(old_val) + '\\s*');
        input_val = input_val.replace(rx, '');
      }

      // cleanup
      input_val = String(input_val).replace(/[,;]\s*[,;]/g, ',').replace(/^[\s,;]+/, '');

      // add new address(es)
      if (new_val && input_val.indexOf(new_val) == -1 && input_val.indexOf(new_val.replace(/"/g, '')) == -1) {
        if (input_val) {
          input_val = input_val.replace(/[,;\s]+$/, '') + ', ';
        }

        input_val += new_val + ', ';
      }

      if (old_val || new_val)
        input.val(input_val).change();
    });

    if (this.editor)
      this.editor.change_signature(id, show_sig);

    if (show && got_sig)
      this.display_message('siginserted', 'confirmation');

    this.env.identity = id;
    this.triggerEvent('change_identity');

    return true;
  };

  // Open file selection dialog for defined upload form
  // Works only on click and only with smart-upload forms
  this.upload_input = function(name)
  {
    $('#' + name + ' input[type="file"]').click();
  };

  // upload (attachment) file
  this.upload_file = function(form, action, lock)
  {
    if (form) {
      var fname, files = [];
      $('input', form).each(function() {
        if (this.files) {
          fname = this.name;
          for (var i=0; i < this.files.length; i++)
            files.push(this.files[i]);
        }
      });

      return this.file_upload(files, {_id: this.env.compose_id || ''}, {
        name: fname,
        action: action,
        lock: lock
      });
    }
  };

  // add file name to attachment list
  // called from upload page
  this.add2attachment_list = function(name, att, upload_id)
  {
    if (upload_id)
      this.triggerEvent('fileuploaded', {name: name, attachment: att, id: upload_id});

    if (upload_id && this.env.attachments[upload_id])
      delete this.env.attachments[upload_id];

    this.env.attachments[name] = att;

    if (!this.gui_objects.attachmentlist)
      return false;

    var label, indicator, li = $('<li>');

    if (!att.complete && att.html.indexOf('<') < 0)
      att.html = '<span class="uploading">' + att.html + '</span>';

    if (!att.complete && this.env.loadingicon)
      att.html = '<img src="'+this.env.loadingicon+'" alt="" class="uploading" />' + att.html;

    if (!att.complete) {
      label = this.get_label('cancel');
      att.html = '<a title="'+label+'" onclick="return rcmail.cancel_attachment_upload(\''+name+'\');" href="#cancelupload" class="cancelupload">'
        + (this.env.cancelicon ? '<img src="'+this.env.cancelicon+'" alt="'+label+'" />' : '<span class="inner">' + label + '</span>') + '</a>' + att.html;
    }

    li.attr('id', name).addClass(att.classname).html(att.html)
      .find('.attachment-name').on('mouseover', function() { rcube_webmail.long_subject_title_ex(this); });

    // replace indicator's li
    if (upload_id && (indicator = document.getElementById(upload_id))) {
      li.replaceAll(indicator);
    }
    else { // add new li
      li.appendTo(this.gui_objects.attachmentlist);
    }

    // set tabindex attribute
    var tabindex = $(this.gui_objects.attachmentlist).attr('data-tabindex') || '0';
    li.find('a').attr('tabindex', tabindex);

    this.triggerEvent('fileappended', {name: name, attachment: att, id: upload_id, item: li});

    return true;
  };

  this.remove_from_attachment_list = function(name)
  {
    delete this.env.attachments[name];
    $('#'+name).remove();
  };

  this.remove_attachment = function(name)
  {
    if (name && this.env.attachments[name])
      this.http_post('remove-attachment', { _id:this.env.compose_id, _file:name });

    return false;
  };

  this.cancel_attachment_upload = function(name)
  {
    if (!name || !this.uploads[name])
      return false;

    this.remove_from_attachment_list(name);
    this.uploads[name].abort();
    return false;
  };

  // rename uploaded attachment (in compose)
  this.rename_attachment = function(id)
  {
    var attachment = this.env.attachments[id];

    if (!attachment)
      return;

    var input = $('<input>').attr({type: 'text', size: 50}).val(attachment.name),
      content = $('<label>').text(this.get_label('namex')).append(input);

    this.simple_dialog(content, 'attachmentrename', function() {
        var name;
        if ((name = input.val()) && name != attachment.name) {
          ref.http_post('rename-attachment', {_id: ref.env.compose_id, _file: id, _name: name},
          ref.set_busy(true, 'loading'));
          return true;
        }
      }
    );
  };

  // update attachments list with the new name
  this.rename_attachment_handler = function(id, name)
  {
    var attachment = this.env.attachments[id];

    if (!attachment || !name)
      return;

    attachment.name = name;

    $('#' + id + ' .attachment-name').text(name).attr('title', '');
  };

  // send remote request to add a new contact
  this.add_contact = function(value, reload, source)
  {
    if (value)
      this.http_post('addcontact', {_address: value, _reload: reload, _source: source});
  };

  // send remote request to search mail or contacts
  this.qsearch = function(value)
  {
    // Note: Some plugins would like to do search without value,
    // so we keep value != '' check to allow that use-case. Which means
    // e.g. that qsearch() with no argument will execute the search.
    if (value != '' || $(this.gui_objects.qsearchbox).val() || $(this.gui_objects.search_interval).val()) {
      var r, lock = this.set_busy(true, 'searching'),
        url = this.search_params(value),
        action = this.env.action == 'compose' && this.contact_list ? 'search-contacts' : 'search';

      if (this.message_list)
        this.clear_message_list();
      else if (this.contact_list)
        this.list_contacts_clear();

      if (this.env.source)
        url._source = this.env.source;
      if (this.env.group)
        url._gid = this.env.group;

      // reset vars
      this.env.current_page = 1;

      r = this.http_request(action, url, lock);

      this.env.qsearch = {lock: lock, request: r};
      this.enable_command('set-listmode', this.env.threads && (this.env.search_scope || 'base') == 'base');

      return true;
    }

    return false;
  };

  this.continue_search = function(request_id)
  {
    var lock = this.set_busy(true, 'stillsearching');

    setTimeout(function() {
      var url = ref.search_params();
      url._continue = request_id;
      ref.env.qsearch = { lock: lock, request: ref.http_request('search', url, lock) };
    }, 100);
  };

  // build URL params for search
  this.search_params = function(search, filter)
  {
    var n, url = {}, mods_arr = [],
      mods = this.env.search_mods,
      scope = this.env.search_scope || 'base',
      mbox = this.env.mailbox;

    if (!filter && this.gui_objects.search_filter)
      filter = this.gui_objects.search_filter.value;

    if (!search && this.gui_objects.qsearchbox)
      search = this.gui_objects.qsearchbox.value;

    if (this.gui_objects.search_interval)
      url._interval = $(this.gui_objects.search_interval).val();

    if (search) {
      url._q = search;

      if (mods && this.message_list)
        mods = mods[mbox] || mods['*'];

      if (mods) {
        for (n in mods)
          mods_arr.push(n);
        url._headers = mods_arr.join(',');
      }
    }

    url._layout = this.env.layout;
    url._filter = filter;
    url._scope = scope;
    url._mbox = mbox;

    return url;
  };

  // reset search filter
  this.reset_search_filter = function()
  {
    this.filter_disabled = true;
    if (this.gui_objects.search_filter)
      $(this.gui_objects.search_filter).val('ALL').change();
    this.filter_disabled = false;
  };

  // reset quick-search form
  this.reset_qsearch = function(all)
  {
    if (this.gui_objects.qsearchbox)
      this.gui_objects.qsearchbox.value = '';

    if (this.gui_objects.search_interval)
      $(this.gui_objects.search_interval).val('');

    if (this.env.qsearch)
      this.abort_request(this.env.qsearch);

    if (all) {
      this.env.search_scope = 'base';
      this.reset_search_filter();
    }

    this.env.qsearch = null;
    this.env.search_request = null;
    this.env.search_id = null;
    this.select_all_mode = false;

    this.enable_command('set-listmode', this.env.threads);
  };

  this.set_searchscope = function(scope)
  {
    this.env.search_scope = scope;
  };

  this.set_searchinterval = function(interval)
  {
    this.env.search_interval = interval;
  };

  this.set_searchmods = function(mods)
  {
    var mbox = this.env.mailbox,
      scope = this.env.search_scope || 'base';

    if (!this.env.search_mods)
      this.env.search_mods = {};

    if (mbox)
      this.env.search_mods[mbox] = mods;
  };

  this.is_multifolder_listing = function()
  {
    return this.env.multifolder_listing !== undefined ? this.env.multifolder_listing :
      (this.env.search_request && (this.env.search_scope || 'base') != 'base');
  };

  // action executed after mail is sent
  this.sent_successfully = function(type, msg, folders, save_error)
  {
    this.display_message(msg, type);
    this.compose_skip_unsavedcheck = true;

    if (this.env.extwin) {
      if (!save_error)
        this.lock_form(this.gui_objects.messageform);

      var filter = {task: 'mail', action: ''},
        rc = this.opener(false, filter) || this.opener(true, filter);

      if (rc) {
        rc.display_message(msg, type);
        // refresh the folder where sent message was saved or replied message comes from
        if (folders && $.inArray(rc.env.mailbox, folders) >= 0) {
          rc.command('checkmail');
        }
      }

      if (!save_error)
        setTimeout(function() { window.close(); }, 1000);
    }
    else if (!save_error) {
      // before redirect we need to wait some time for Chrome (#1486177)
      setTimeout(function() { ref.list_mailbox(); }, 500);
    }

    if (save_error)
      this.env.is_sent = true;
  };

  this.image_rotate = function()
  {
    var curr = this.image_style ? (this.image_style.rotate || 0) : 0;

    this.image_style.rotate = curr > 180 ? 0 : curr + 90;
    this.apply_image_style();
  };

  this.image_scale = function(prop)
  {
    var curr = this.image_style ? (this.image_style.scale || 1) : 1;

    this.image_style.scale = Math.max(0.1, curr + 0.1 * (prop == '-' ? -1 : 1));
    this.apply_image_style();
  };

  this.apply_image_style = function()
  {
    var style = [],
      img = $(this.gui_objects.messagepartframe).contents().find('img');

    $.each({scale: '', rotate: 'deg'}, function(i, v) {
      var val = ref.image_style[i];
      if (val)
        style.push(i + '(' + val + v + ')');
    });

    img.css('transform', style.join(' '));
  };

  // Update import dialog state
  this.import_state_set = function(state)
  {
    if (this.import_dialog) {
      this.import_state = state;

      var button = $(this.import_dialog).parent().find('.ui-dialog-buttonset > button').first();

      if (state != 'error') {
        // replace Import/Cancel buttons with Close button
        button.hide();
        button.next().text(this.gettext('close')).focus();
      }
      else {
        // activate the Import button
        button.prop('disabled', false);
      }
    }
  };


  /*********************************************************/
  /*********     keyboard live-search methods      *********/
  /*********************************************************/

  // handler for keyboard events on address-fields
  this.ksearch_keydown = function(e, obj, props)
  {
    if (this.ksearch_timer)
      clearTimeout(this.ksearch_timer);

    var key = rcube_event.get_keycode(e);

    switch (key) {
      case 38:  // arrow up
      case 40:  // arrow down
        if (!this.ksearch_visible())
          return;

        var dir = key == 38 ? 1 : 0,
          highlight = this.ksearch_pane.find('li.selected')[0];

        if (!highlight)
          highlight = this.ksearch_pane.__ul.firstChild;

        if (highlight)
          this.ksearch_select(dir ? highlight.previousSibling : highlight.nextSibling);

        return rcube_event.cancel(e);

      case 9:   // tab
        if (rcube_event.get_modifier(e) == SHIFT_KEY || !this.ksearch_visible()) {
          this.ksearch_hide();
          return;
        }

      case 13:  // enter
        if (!this.ksearch_visible())
          return false;

        // insert selected address and hide ksearch pane
        this.insert_recipient(this.ksearch_selected);
        this.ksearch_hide();

        // Don't cancel on Tab, we want to jump to the next field (#5659)
        return key == 9 ? null : rcube_event.cancel(e);

      case 27:  // escape
        this.ksearch_hide();
        return;

      case 37:  // left
      case 39:  // right
        return;
    }

    // start timer
    this.ksearch_timer = setTimeout(function() { ref.ksearch_get_results(props); }, 200);
    this.ksearch_input = obj;

    return true;
  };

  this.ksearch_visible = function()
  {
    return this.ksearch_selected !== null && this.ksearch_selected !== undefined && this.ksearch_value;
  };

  this.ksearch_select = function(node)
  {
    if (this.ksearch_pane && node) {
      this.ksearch_pane.find('li.selected').removeClass('selected').removeAttr('aria-selected');
    }

    if (node) {
      $(node).addClass('selected').attr('aria-selected', 'true');
      this.ksearch_selected = node._rcm_id;
      $(this.ksearch_input).attr('aria-activedescendant', 'rcmkSearchItem' + this.ksearch_selected);
    }
  };

  this.insert_recipient = function(id)
  {
    if (id === null || !this.env.contacts[id] || !this.ksearch_input)
      return;

    var trigger = false, insert = '', delim = ', ',
      contact = this.env.contacts[id];

    this.ksearch_destroy();

    // insert all members of a group
    if (typeof contact === 'object' && contact.type == 'group' && !contact.email && contact.id) {
      // We wrap the group name with invisible markers to prevent from problems with group expanding (#7569)
      var name = '\u200b' + contact.name + '\u200b';
      insert = name + delim;
      this.group2expand[contact.id] = {name: name, input: this.ksearch_input};
      this.http_request('mail/group-expand', {_source: contact.source, _gid: contact.id}, false);
    }
    else if (typeof contact === 'object' && contact.name) {
      insert = contact.name + delim;
      trigger = true;
    }
    else if (typeof contact === 'string') {
      insert = contact + delim;
      trigger = true;
    }

    this.ksearch_input_replace(this.ksearch_value, insert, null, trigger);

    if (trigger) {
      this.triggerEvent('autocomplete_insert', {
          field: this.ksearch_input,
          insert: insert,
          data: contact,
          search: this.ksearch_value_last,
          result_type: 'person'
      });

      this.ksearch_value_last = null;
      this.compose_type_activity++;
    }
  };

  this.replace_group_recipients = function(id, recipients)
  {
    var data = this.group2expand[id];

    if (data) {
      this.ksearch_input_replace(data.name, recipients, data.input);

      this.triggerEvent('autocomplete_insert', {
          field: data.input,
          insert: recipients,
          data: data,
          search: this.ksearch_value_last,
          result_type: 'group'
      });

      this.ksearch_value_last = null;
      this.group2expand[id] = null;
      this.compose_type_activity++;
    }
  };

  // address search processor
  this.ksearch_get_results = function(props)
  {
    if (this.ksearch_pane && this.ksearch_pane.is(":visible"))
      this.ksearch_pane.hide();

    // get string from cursor position back to the last comma or semicolon
    var q = this.ksearch_input_get(),
      min = this.env.autocomplete_min_length,
      data = this.ksearch_data;

    // trim query string
    q = q.trim();

    // Don't (re-)search if the last results are still active
    if (q == this.ksearch_value)
      return;

    this.ksearch_destroy();

    if (q.length && q.length < min) {
      if (!this.ksearch_info) {
        this.ksearch_info = this.display_message(this.get_label('autocompletechars').replace('$min', min));
      }
      return;
    }

    var old_value = this.ksearch_value;
    this.ksearch_value = q;
    this.ksearch_value_last = q;   // Group expansion clears ksearch_value before calling autocomplete_insert trigger, therefore store it in separate variable for later consumption.

    // ...string is empty
    if (!q.length)
      return;

    // ...new search value contains old one and previous search was not finished or its result was empty
    if (old_value && old_value.length && q.startsWith(old_value) && (!data || data.num <= 0) && this.env.contacts && !this.env.contacts.length)
      return;

    var sources = props && props.sources ? props.sources : [''];
    var reqid = this.multi_thread_http_request({
      items: sources,
      threads: props && props.threads ? props.threads : 1,
      action:  props && props.action ? props.action : 'mail/autocomplete',
      postdata: { _search:q, _source:'%s' },
      lock: this.display_message('searching', 'loading')
    });

    this.ksearch_data = { id:reqid, sources:sources.slice(), num:sources.length };
  };

  this.ksearch_query_results = function(results, search, reqid)
  {
    // trigger multi-thread http response callback
    this.multi_thread_http_response(results, reqid);

    // search stopped in meantime?
    if (!this.ksearch_value)
      return;

    // ignore this outdated search response
    if (this.ksearch_input && search != this.ksearch_value)
      return;

    // display search results
    var i, id, len, ul, text, type, init,
      is_framed = this.is_framed(),
      value = this.ksearch_value,
      maxlen = this.env.autocomplete_max ? this.env.autocomplete_max : 15;

    // create results pane if not present
    if (!this.ksearch_pane) {
      ul = $('<ul>');
      this.ksearch_pane = $('<div>')
        .attr({id: 'rcmKSearchpane', role: 'listbox', 'class': 'select-menu inline'})
        .css({position: 'absolute', 'z-index': 30000})
        .append(ul)
        .appendTo(is_framed ? parent.document.body : document.body);

      this.ksearch_pane.__ul = ul[0];
      this.triggerEvent('autocomplete_create', {obj: this.ksearch_pane});
    }

    ul = this.ksearch_pane.__ul;

    // remove all search results or add to existing list if parallel search
    if (reqid && this.ksearch_pane.data('reqid') == reqid) {
      maxlen -= ul.childNodes.length;
    }
    else {
      this.ksearch_pane.data('reqid', reqid);
      init = 1;
      // reset content
      ul.innerHTML = '';
      this.env.contacts = [];

      // Calculate the results pane position and size
      // Elastic: On small screen we use the width/position of the whole .ac-input element (input's parent)
      var is_composite_input = $('html').is('.layout-small,.layout-phone') && $(this.ksearch_input).parents('.ac-input').length == 1,
        input = is_composite_input ? $(this.ksearch_input).parents('.ac-input')[0] : $(this.ksearch_input)[0],
        pos = $(input).offset();

      // ... consider scroll position
      pos.left -= $(document.documentElement).scrollLeft();
      pos.top -= $(document.documentElement).scrollTop();

      // ... consider iframe position
      if (is_framed) {
        try {
          parent.$('iframe').each(function() {
            if (this.contentWindow == window) {
              var offset = $(this).offset();
              pos.left += offset.left;
              pos.top += offset.top;
            }
          });
        }
        catch(e) {}
      }

      var w = $(is_framed ? parent : window).width(),
        input_width = $(input).outerWidth(),
        left = w - pos.left > 200 ? pos.left : w - 200,
        top = (pos.top + input.offsetHeight + 1),
        width = Math.min(400, w - left);

      this.ksearch_pane.css({
        left: (is_composite_input ? pos.left : left) + 'px',
        top: top + 'px',
        maxWidth: (is_composite_input ? input_width : width) + 'px',
        minWidth: '200px',
        width: is_composite_input ? (input_width + 'px') : 'auto',
        display: 'none'
      });
    }

    // add each result line to list
    if (results && (len = results.length)) {
      for (i=0; i < len && maxlen > 0; i++) {
        text = typeof results[i] === 'object' ? (results[i].display || results[i].name) : results[i];
        type = typeof results[i] === 'object' ? results[i].type : '';
        id = i + this.env.contacts.length;
        $('<li>').attr({id: 'rcmkSearchItem' + id, role: 'option'})
          .html('<i class="icon"></i>' + this.quote_html(text.replace(new RegExp('('+RegExp.escape(value)+')', 'ig'), '##$1%%')).replace(/##([^%]+)%%/g, '<b>$1</b>'))
          .addClass(type || '')
          .appendTo(ul)
          .mouseover(function() { ref.ksearch_select(this); })
          .mouseup(function() { ref.ksearch_click(this); })
          .get(0)._rcm_id = id;
        maxlen -= 1;
      }
    }

    if (ul.childNodes.length) {
      // set the right aria-* attributes to the input field
      $(this.ksearch_input)
        .attr({'aria-haspopup': 'true', 'aria-expanded': 'true', 'aria-owns': 'rcmKSearchpane'});

      this.ksearch_pane.show();

      // select the first
      if (!this.env.contacts.length) {
        this.ksearch_select($('li', ul)[0]);
      }
    }

    if (len)
      this.env.contacts = this.env.contacts.concat(results);

    if (this.ksearch_data.id == reqid)
      this.ksearch_data.num--;
  };

  // Getter for input value
  // returns a string from the last comma to current cursor position
  this.ksearch_input_get = function()
  {
    if (!this.ksearch_input)
      return '';

    var cp = this.get_caret_pos(this.ksearch_input);

    return this.ksearch_input.value.substr(0, cp).split(/[,;]/).pop();
  };

  // Setter for input value
  // replaces 'from' string with 'to' and sets cursor position at the end
  this.ksearch_input_replace = function(from, to, input, trigger)
  {
    if (!this.ksearch_input && !input)
      return;

    if (!input)
      input = this.ksearch_input;

    var cpos = this.get_caret_pos(input),
      p = input.value.lastIndexOf(from, cpos),
      pre = input.value.substring(0, p),
      end = input.value.substring(p + from.length, input.value.length);

    input.value = pre + to + end;

    // set caret to insert pos
    this.set_caret_pos(input, cpos + to.length - from.length);

    // run onchange action on the element
    $(input).trigger('change', [true, trigger]);
  };

  this.ksearch_click = function(node)
  {
    if (this.ksearch_input)
      this.ksearch_input.focus();

    this.insert_recipient(node._rcm_id);
    this.ksearch_hide();
  };

  this.ksearch_blur = function()
  {
    if (this.ksearch_timer)
      clearTimeout(this.ksearch_timer);

    this.ksearch_input = null;
    this.ksearch_hide();
  };

  this.ksearch_hide = function()
  {
    this.ksearch_selected = null;
    this.ksearch_value = '';

    if (this.ksearch_pane)
      this.ksearch_pane.hide();

    $(this.ksearch_input)
      .attr({'aria-haspopup': 'false', 'aria-expanded': 'false'})
      .removeAttr('aria-activedescendant')
      .removeAttr('aria-owns');

    this.ksearch_destroy();
  };

  // Clears autocomplete data/requests
  this.ksearch_destroy = function()
  {
    if (this.ksearch_data)
      this.multi_thread_request_abort(this.ksearch_data.id);

    if (this.ksearch_info)
      this.hide_message(this.ksearch_info);

    if (this.ksearch_msg)
      this.hide_message(this.ksearch_msg);

    this.ksearch_data = null;
    this.ksearch_info = null;
    this.ksearch_msg = null;
  };


  /*********************************************************/
  /*********         address book methods          *********/
  /*********************************************************/

  this.contactlist_select = function(list)
  {
    if (this.preview_timer)
      clearTimeout(this.preview_timer);

    var id, targets,
      groupcount = 0,
      writable = false,
      deletable = false,
      copy_writable = false,
      selected = list.get_selection().length,
      source = this.env.source ? this.env.address_sources[this.env.source] : null;

    // we don't have dblclick handler here, so use 50 instead of this.dblclick_time
    if (this.env.contentframe && !list.multi_selecting && (id = list.get_single_selection()))
      this.preview_timer = setTimeout(function() { ref.load_contact(id, 'show'); }, this.preview_delay_click);
    else if (this.env.contentframe)
      this.show_contentframe(false);

    if (selected) {
      list.draggable = false;

      // no source = search result, we'll need to detect if any of
      // selected contacts are in writable addressbook to enable edit/delete
      // we'll also need to know sources used in selection for copy
      // and group-addmember operations (drag&drop)
      this.env.selection_sources = [];

      if (source) {
        this.env.selection_sources.push(this.env.source);
      }

      $.each(list.get_selection(), function(i, v) {
        var book, sid, contact = list.data[v];
        if (!source) {
          sid = String(v).replace(/^[^-]+-/, '');
          book = sid ? ref.env.address_sources[sid] : null;

          if (book) {
            writable = writable || (!book.readonly && !contact.readonly);
            deletable = deletable || book.deletable === true;
            ref.env.selection_sources.push(sid);
          }
        }
        else {
          writable = writable || (!source.readonly && !contact.readonly);
          deletable = deletable || source.deletable === true;
        }

        if (contact._type != 'group')
          list.draggable = true;
      });

      this.env.selection_sources = $.unique(this.env.selection_sources);

      if (source && source.groups)
        $.each(this.env.contactgroups, function() { if (this.source === ref.env.source) groupcount++; });

      targets = $.map(this.env.address_sources, function(v, i) { return v.readonly ? null : i; });
      copy_writable = $.grep(targets, function(v) { return jQuery.inArray(v, ref.env.selection_sources) < 0; }).length > 0;
    }

    // if a group is currently selected, and there is at least one contact selected
    // we can enable the group-remove-selected command
    this.enable_command('group-assign-selected', groupcount > 0 && writable);
    this.enable_command('group-remove-selected', this.env.group && writable);
    this.enable_command('print', 'qrcode', selected == 1);
    this.enable_command('export-selected', selected > 0);
    this.enable_command('edit', id && writable);
    this.enable_command('delete', 'move', writable || deletable);
    this.enable_command('copy', copy_writable);

    return false;
  };

  this.list_contacts = function(src, group, page, search)
  {
    var win, folder, index = -1, url = {},
      refresh = src === undefined && group === undefined && page === undefined,
      target = window;

    if (!src)
      src = this.env.source;

    if (refresh)
      group = this.env.group;

    if (src != this.env.source) {
      page = this.env.current_page = 1;
      this.reset_qsearch();
    }
    else if (!refresh && group != this.env.group)
      page = this.env.current_page = 1;

    if (this.env.search_id)
      folder = 'S'+this.env.search_id;
    else if (!this.env.search_request)
      folder = group ? 'G'+src+group : src;

    this.env.source = this.env.last_source = src;
    this.env.group = this.env.last_group = group;

    // truncate groups listing stack
    $.each(this.env.address_group_stack, function(i, v) {
      if (ref.env.group == v.id) {
        index = i;
        return false;
      }
    });

    this.env.address_group_stack = index < 0 ? [] : this.env.address_group_stack.slice(0, index);

    // remove cached contact group selector
    this.destroy_entity_selector('contactgroup-selector');

    // make sure the current group is on top of the stack
    if (this.env.group) {
      if (!search) search = {};
      search.id = this.env.group;
      this.env.address_group_stack.push(search);

      // mark the first group on the stack as selected in the directory list
      folder = 'G'+src+this.env.address_group_stack[0].id;
    }
    else if (this.gui_objects.addresslist_title) {
        $(this.gui_objects.addresslist_title).text(this.get_label('contacts'));
    }

    if (!this.env.search_id)
      this.select_folder(folder, '', true);

    // load contacts remotely
    if (this.gui_objects.contactslist) {
      this.list_contacts_remote(src, group, page);
      return;
    }

    if (win = this.get_frame_window(this.env.contentframe)) {
      target = win;
      url._framed = 1;
    }

    if (group)
      url._gid = group;
    if (page)
      url._page = page;
    if (src)
      url._source = src;

    // also send search request to get the correct listing
    if (this.env.search_request)
      url._search = this.env.search_request;

    this.set_busy(true, 'loading');
    this.location_href(url, target);
  };

  // send remote request to load contacts list
  this.list_contacts_remote = function(src, group, page)
  {
    // clear message list first
    this.list_contacts_clear();

    // send request to server
    var url = {}, lock = this.set_busy(true, 'loading');

    if (src)
      url._source = src;
    if (page)
      url._page = page;
    if (group)
      url._gid = group;

    this.env.source = src;
    this.env.group = group;

    // also send search request to get the right records
    if (this.env.search_request)
      url._search = this.env.search_request;

    this.http_request(this.env.task == 'mail' ? 'list-contacts' : 'list', url, lock);

    if (this.env.task != 'mail')
      this.update_state({_source: src, _page: page && page > 1 ? page : null, _gid: group});
  };

  this.list_contacts_clear = function()
  {
    this.contact_list.data = {};
    this.contact_list.clear(true);
    this.show_contentframe(false);
    this.enable_command('delete', 'move', 'copy', 'print', false);
  };

  this.set_group_prop = function(prop)
  {
    if (this.gui_objects.addresslist_title) {
      var boxtitle = $(this.gui_objects.addresslist_title).html('');  // clear contents

      // add link to pop back to parent group
      if (this.env.address_group_stack.length > 1
        || (this.env.address_group_stack.length == 1 && this.env.address_group_stack[0].search_request)
      ) {
        var link = $('<a href="#list">...</a>')
          .attr({title: this.get_label('uponelevel'), 'class': 'poplink'})
          .click(function() { return ref.command('popgroup', '', this); });

        boxtitle.append(link).append('&nbsp;&raquo;&nbsp;');
      }

      boxtitle.append($('<span>').text(prop ? prop.name : this.get_label('contacts')));
    }
  };

  // load contact record
  this.load_contact = function(cid, action, framed)
  {
    var win, url = {}, target = window,
      rec = this.contact_list ? this.contact_list.data[cid] : null;

    if (win = this.get_frame_window(this.env.contentframe)) {
      url._framed = 1;
      target = win;
      this.show_contentframe(true);

      // load dummy content, unselect selected row(s)
      if (!cid)
        this.contact_list.clear_selection();

      this.enable_command('export-selected', 'print', rec && rec._type != 'group');
    }
    else if (framed)
      return false;

    if (action && (cid || action == 'add') && !this.drag_active) {
      if (this.env.group)
        url._gid = this.env.group;

      if (this.env.search_request)
        url._search = this.env.search_request;

      if (cid)
        url._cid = this.preview_id = cid;

      url._action = action;
      url._source = this.env.source;

      this.location_href(url, target, true);
    }

    return true;
  };

  // add/delete member to/from the group
  this.group_member_change = function(what, cid, source, gid)
  {
    if (what != 'add')
      what = 'del';

    var lock = this.display_message(what == 'add' ? 'addingmember' : 'removingmember', 'loading'),
      post_data = {_cid: cid, _source: source, _gid: gid};

    this.http_post('group-'+what+'members', post_data, lock);
  };

  this.contacts_drag_menu = function(e, to)
  {
    var dest = to.type == 'group' ? to.source : to.id,
      source = this.env.source;

    if (!this.env.address_sources[dest] || this.env.address_sources[dest].readonly)
      return true;

    // search result may contain contacts from many sources, but if there is only one...
    if (source == '' && this.env.selection_sources.length == 1)
      source = this.env.selection_sources[0];

    if (to.type == 'group' && dest == source) {
      var cid = this.contact_list.get_selection().join(',');
      this.group_member_change('add', cid, dest, to.id);
      return true;
    }
    // move action is not possible, "redirect" to copy if menu wasn't requested
    else if (!this.commands.move && rcube_event.get_modifier(e) != SHIFT_KEY) {
      this.copy_contacts(to);
      return true;
    }

    return this.drag_menu(e, to);
  };

  // copy contact(s) to the specified target (group or directory)
  this.copy_contacts = function(to, event, cid)
  {
    if (!to) {
      cid = this.contact_list.get_selection();
      return this.addressbook_selector(event, function(to, obj) {
          var to = $(obj).data('source') ? ref.env.contactgroups['G' + $(obj).data('source') + $(obj).data('gid')] : ref.env.address_sources[to];
          ref.copy_contacts(to, null, cid);
        });
    }

    var dest = to.type == 'group' ? to.source : to.id,
      source = this.env.source,
      group = this.env.group ? this.env.group : '';

    cid = cid ? cid.join(',') : this.contact_list.get_selection().join(',');

    if (!cid || !this.env.address_sources[dest] || this.env.address_sources[dest].readonly)
      return;

    // search result may contain contacts from many sources, but if there is only one...
    if (source == '' && this.env.selection_sources.length == 1)
      source = this.env.selection_sources[0];

    // target is a group
    if (to.type == 'group') {
      if (dest == source)
        return;

      var lock = this.display_message('copyingcontact', 'loading'),
        post_data = {_cid: cid, _source: this.env.source, _to: dest, _togid: to.id, _gid: group};

      this.http_post('copy', post_data, lock);
    }
    // target is an addressbook
    else if (to.id != source) {
      var lock = this.display_message('copyingcontact', 'loading'),
        post_data = {_cid: cid, _source: this.env.source, _to: to.id, _gid: group};

      this.http_post('copy', post_data, lock);
    }
  };

  // move contact(s) to the specified target (group or directory)
  this.move_contacts = function(to, event, cid)
  {
    if (!to) {
      cid = this.contact_list.get_selection();
      return this.addressbook_selector(event, function(to, obj) {
          var to = $(obj).data('source') ? ref.env.contactgroups['G' + $(obj).data('source') + $(obj).data('gid')] : ref.env.address_sources[to];
          ref.move_contacts(to, null, cid);
        });
    }

    var dest = to.type == 'group' ? to.source : to.id,
      source = this.env.source,
      group = this.env.group ? this.env.group : '';

    if (!this.env.address_sources[dest] || this.env.address_sources[dest].readonly)
      return;

    if (!cid)
      cid = this.contact_list.get_selection();

    // search result may contain contacts from many sources, but if there is only one...
    if (source == '' && this.env.selection_sources.length == 1)
      source = this.env.selection_sources[0];

    if (to.type == 'group') {
      if (dest == source)
        return;

      this._with_selected_contacts('move', {_to: dest, _togid: to.id, _cid: cid});
    }
    // target is an addressbook
    else if (to.id != source)
      this._with_selected_contacts('move', {_to: to.id, _cid: cid});
  };

  // delete contact(s)
  this.delete_contacts = function()
  {
    var undelete = this.env.source && this.env.address_sources[this.env.source].undelete;

    if (undelete) {
      this._with_selected_contacts('delete', {_cid: this.contact_list.get_selection()});
    }
    else {
      var cid = this.contact_list.get_selection();
      this.confirm_dialog(this.get_label('deletecontactconfirm'), 'delete', function() {
        ref._with_selected_contacts('delete', {_cid: cid});
      });
    }
  };

  this._with_selected_contacts = function(action, post_data)
  {
    var selection = post_data._cid;

    // exit if no contact specified or if selection is empty
    if (!selection.length && !this.env.cid)
      return;

    var n, a_cids = [],
      label = action == 'delete' ? 'contactdeleting' : 'movingcontact',
      lock = this.display_message(label, 'loading'),
      display_next = this.check_display_next();

    if (this.env.cid)
      a_cids.push(this.env.cid);
    else {
      for (n=0; n<selection.length; n++) {
        id = selection[n];
        a_cids.push(id);
        this.contact_list.remove_row(id, display_next && n == selection.length-1);
      }

      if (!display_next)
        this.contact_list.clear_selection();
    }

    if (!post_data)
      post_data = {};

    post_data._source = this.env.source;
    post_data._from = this.env.action;
    post_data._cid = a_cids.join(',');

    if (this.env.group)
      post_data._gid = this.env.group;

    // also send search request to get the right records from the next page
    if (this.env.search_request)
      post_data._search = this.env.search_request;

    // send request to server
    this.http_post(action, post_data, lock)

    return true;
  };

  // update a contact record in the list
  this.update_contact_row = function(cid, cols_arr, newcid, source, data)
  {
    var list = this.contact_list;

    cid = this.html_identifier(cid);

    // when in searching mode, concat cid with the source name
    if (!list.rows[cid]) {
      cid = cid + '-' + source;
      if (newcid)
        newcid = newcid + '-' + source;
    }

    list.update_row(cid, cols_arr, newcid, true);
    list.data[cid] = data;
  };

  // add row to contacts list
  this.add_contact_row = function(cid, cols, classes, data)
  {
    if (!this.gui_objects.contactslist)
      return false;

    var c, col, list = this.contact_list,
      row = { cols:[] };

    row.id = 'rcmrow' + this.html_identifier(cid);
    row.className = 'contact ' + (classes || '');

    if (list.in_selection(cid))
      row.className += ' selected';

    // add each submitted col
    for (c in cols) {
      col = {};
      col.className = String(c).toLowerCase();
      col.innerHTML = cols[c];
      row.cols.push(col);
    }

    // store data in list member
    list.data[cid] = data;
    list.insert_row(row);

    this.enable_command('export', list.rowcount > 0);
  };

  this.init_contact_form = function()
  {
    var col;

    if (this.env.coltypes) {
      this.set_photo_actions($('#ff_photo').val());
      for (col in this.env.coltypes)
        this.init_edit_field(col, null);
    }

    $('.contactfieldgroup .row a.deletebutton').click(function() {
      ref.delete_edit_field(this);
      return false;
    });

    $('select.addfieldmenu').change(function() {
      ref.insert_edit_field($(this).val(), $(this).attr('rel'), this);
      this.selectedIndex = 0;
    });

    // enable date pickers on date fields
    if ($.datepicker && this.env.date_format) {
      $.datepicker.setDefaults({
        dateFormat: this.env.date_format,
        changeMonth: true,
        changeYear: true,
        yearRange: '-120:+10',
        showOtherMonths: true,
        selectOtherMonths: true
      });
      $('input.datepicker').datepicker();
    }

    // Submit search form on Enter
    if (this.env.action == 'search')
      $(this.gui_objects.editform).append($('<input type="submit">').hide())
        .submit(function() { $('input.mainaction').click(); return false; });
  };

  // group creation dialog
  this.group_create = function()
  {
    var input = $('<input>').attr({type: 'text', 'data-submit': 'true'}),
      content = $('<label>').text(this.get_label('namex')).append(input),
      source = this.env.source;

    this.simple_dialog(content, 'newgroup', function() {
        var name;
        if (name = input.val()) {
          ref.http_post('group-create', {_source: source, _name: name},
            ref.set_busy(true, 'loading'));
          return true;
        }
      });
  };

  // group rename dialog
  this.group_rename = function()
  {
    if (!this.env.group)
      return;

    var group_name = this.env.contactgroups['G' + this.env.source + this.env.group].name,
      input = $('<input>').attr({type: 'text', 'data-submit': 'true'}).val(group_name),
      content = $('<label>').text(this.get_label('namex')).append(input),
      source = this.env.source,
      group = this.env.group;

    this.simple_dialog(content, 'grouprename', function() {
        var name;
        if ((name = input.val()) && name != group_name) {
          ref.http_post('group-rename', {_source: source, _gid: group, _name: name},
          ref.set_busy(true, 'loading'));
          return true;
        }
      });
  };

  this.group_delete = function()
  {
    if (this.env.group) {
      var group = this.env.group;
      this.confirm_dialog(this.get_label('deletegroupconfirm'), 'delete', function() {
          var lock = ref.set_busy(true, 'groupdeleting');
          ref.http_post('group-delete', {_source: ref.env.source, _gid: group}, lock);
        });
    }
  };

  // callback from server upon group-delete command
  this.remove_group_item = function(prop)
  {
    var key = 'G' + prop.source + prop.id;

    if (this.treelist.remove(key)) {
      // make sure there is no cached address book or contact group selectors
      this.destroy_entity_selector('addressbook-selector');
      this.destroy_entity_selector('contactgroup-selector');

      this.triggerEvent('group_delete', { source:prop.source, id:prop.id });
      delete this.env.contactfolders[key];
      delete this.env.contactgroups[key];
    }

    if (prop.source == this.env.source && prop.id == this.env.group)
      this.list_contacts(prop.source, 0);
  };

  //assign selected contacts to a group
  this.group_assign_selected = function(props, obj, event)
  {
    var cid = ref.contact_list.get_selection();
    var source = ref.env.source;
    this.contactgroup_selector(event, function(to) { ref.group_member_change('add', cid, source, to); });
  };

  //remove selected contacts from current active group
  this.group_remove_selected = function()
  {
    this.http_post('group-delmembers', {_cid: this.contact_list.get_selection(),
      _source: this.env.source, _gid: this.env.group});
  };

  //callback after deleting contact(s) from current group
  this.remove_group_contacts = function(props)
  {
    if (this.env.group !== undefined && (this.env.group === props.gid)) {
      var n, selection = this.contact_list.get_selection(),
        display_next= this.check_display_next();

      for (n=0; n<selection.length; n++) {
        id = selection[n];
        this.contact_list.remove_row(id, display_next && n == selection.length-1);
      }

      if (!display_next)
        this.contact_list.clear_selection();
    }
  };

  // callback for creating a new contact group
  this.insert_contact_group = function(prop)
  {
    prop.type = 'group';

    var key = 'G'+prop.source+prop.id,
      link = $('<a>').attr({href: '#', rel: prop.source + ':' + prop.id})
        .click(function() { return ref.command('listgroup', prop, this); })
        .text(prop.name);

    this.env.contactfolders[key] = this.env.contactgroups[key] = prop;
    this.treelist.insert({ id:key, html:link, classes:['contactgroup'] }, prop.source, 'contactgroup');

    // make sure there is no cached address book or contact group selectors
    this.destroy_entity_selector('addressbook-selector');
    this.destroy_entity_selector('contactgroup-selector');

    this.triggerEvent('group_insert', { id:prop.id, source:prop.source, name:prop.name, li:this.treelist.get_item(key) });
  };

  // callback for renaming a contact group
  this.update_contact_group = function(prop)
  {
    var key = 'G'+prop.source+prop.id,
      newnode = {};

    // group ID has changed, replace link node and identifiers
    if (prop.newid) {
      var newkey = 'G'+prop.source+prop.newid,
        newprop = $.extend({}, prop);

      this.env.contactfolders[newkey] = this.env.contactfolders[key];
      this.env.contactfolders[newkey].id = prop.newid;
      this.env.group = prop.newid;

      delete this.env.contactfolders[key];
      delete this.env.contactgroups[key];

      newprop.id = prop.newid;
      newprop.type = 'group';

      newnode.id = newkey;
      newnode.html = $('<a>').attr({href: '#', rel: prop.source + ':' + prop.newid})
        .click(function() { return ref.command('listgroup', newprop, this); })
        .text(prop.name);
    }
    // update displayed group name
    else {
      $(this.treelist.get_item(key)).children().first().text(prop.name);
      this.env.contactfolders[key].name = this.env.contactgroups[key].name = prop.name;

      if (prop.source == this.env.source && prop.id == this.env.group)
        this.set_group_prop(prop);
    }

    // update list node and re-sort it
    this.treelist.update(key, newnode, true);

    // make sure there is no cached address book or contact group selectors
    this.destroy_entity_selector('addressbook-selector');
    this.destroy_entity_selector('contactgroup-selector');

    this.triggerEvent('group_update', { id:prop.id, source:prop.source, name:prop.name, li:this.treelist.get_item(key), newid:prop.newid });
  };

  this.update_group_commands = function()
  {
    var source = this.env.source != '' ? this.env.address_sources[this.env.source] : null,
      supported = source && source.groups && !source.readonly;

    this.enable_command('group-create', supported);
    this.enable_command('group-rename', 'group-delete', supported && this.env.group);
  };

  this.init_edit_field = function(col, elem)
  {
    var label = this.env.coltypes[col].label;

    if (!elem)
      elem = $('.ff_' + col);

    if (label && !$('label[for="ff_' + col + '"]').length)
      elem.placeholder(label);
  };

  this.insert_edit_field = function(col, section, menu)
  {
    // just make pre-defined input field visible
    var elem = $('#ff_' + col);
    if (elem.length) {
      $('label[for="ff_' + col + '"]').parent().show();
      elem.show().focus();
      $(menu).children('option[value="' + col + '"]').prop('disabled', true);
    }
    else {
      var lastelem = $('.ff_' + col),
        appendcontainer = $('#contactsection'+section+' .contactcontroller'+col);

      if (!appendcontainer.length) {
        var sect = $('#contactsection'+section),
          lastgroup = $('.contactfieldgroup', sect).last();
        appendcontainer = $('<fieldset>').addClass('contactfieldgroup contactcontroller'+col);
        if (lastgroup.length)
          appendcontainer.insertAfter(lastgroup);
        else
          sect.prepend(appendcontainer);
      }

      if (appendcontainer.get(0).nodeName == 'FIELDSET') {
        var label, input,
          colprop = this.env.coltypes[col],
          name_suffix = colprop.limit != 1 ? '[]' : '',
          compact = $(menu).data('compact') ? true : false,
          input_id = 'ff_' + col + (colprop.count || 0),
          row = $('<div>').addClass('row input-group'),
          cell = $('<div>').addClass('contactfieldcontent ' + colprop.type);

        // Field label
        if (colprop.subtypes_select) {
          label = $(colprop.subtypes_select);
          if (!compact)
            label = $('<div>').addClass('contactfieldlabel label').append(label);
          else
            label.addClass('input-group-prepend');
        }
        else {
          label = $('<label>').addClass('contactfieldlabel label input-group-text')
            .attr('for', input_id).text(colprop.label);

          if (compact)
            label = $('<span class="input-group-prepend">').append(label);
        }

        // Field input
        if (colprop.type == 'text' || colprop.type == 'date') {
          input = $('<input>')
            .addClass('form-control ff_' + col)
            .attr({type: 'text', name: '_'+col+name_suffix, size: colprop.size, id: input_id});

          this.init_edit_field(col, input);

          if (colprop.type == 'date' && $.datepicker)
            input.addClass('datepicker').datepicker();
        }
        else if (colprop.type == 'textarea') {
          input = $('<textarea>')
            .addClass('form-control ff_' + col)
            .attr({ name: '_' + col + name_suffix, cols: colprop.size, rows: colprop.rows, id: input_id });

          this.init_edit_field(col, input);
        }
        else if (colprop.type == 'composite') {
          var i, childcol, cp, first, templ, cols = [], suffices = [], content = cell;

          row.addClass('composite');

          if (compact)
            content = $('<div class="content input-group-text">');

          // read template for composite field order
          if (templ = this.env[col + '_template']) {
            for (i=0; i < templ.length; i++) {
              cols.push(templ[i][1]);
              suffices.push(templ[i][2]);
            }
          }
          else {  // list fields according to appearance in colprop
            for (childcol in colprop.childs)
              cols.push(childcol);
          }

          for (i=0; i < cols.length; i++) {
            childcol = cols[i];
            cp = colprop.childs[childcol];
            input = $('<input>')
              .addClass('form-control ff_' + childcol)
              .attr({ type: 'text', name: '_' + childcol + name_suffix, size: cp.size })
              .appendTo(content);

            if (!compact)
              content.append(suffices[i] || " ");

            this.init_edit_field(childcol, input);
            if (!first) first = input;
          }

          if (compact)
            input = content;
          else
            input = first;  // set focus to the first of this composite fields
        }
        else if (colprop.type == 'select') {
          input = $('<select>')
            .addClass('custom-select ff_' + col)
            .attr({ name: '_' + col + name_suffix, id: input_id });

          var options = input.attr('options');
          options[options.length] = new Option('---', '');
          if (colprop.options)
            $.each(colprop.options, function(i, val) { options[options.length] = new Option(val, i); });
        }

        if (input) {
          var delbutton = $('<a href="#del"></a>')
            .addClass('contactfieldbutton deletebutton input-group-text icon delete')
            .attr({title: this.get_label('delete'), rel: col})
            .html(this.env.delbutton)
            .click(function() { ref.delete_edit_field(this); return false; });

          row.append(label);

          if (!compact) {
            if (colprop.type != 'composite')
              cell.append(input);
            row.append(cell.append(delbutton));
          }
          else {
            row.append(input).append(delbutton);
            delbutton.wrap('<span class="input-group-append">');
          }

          row.appendTo(appendcontainer.show());

          if (input.is('div'))
            input.find('input').first().focus();
          else
            input.first().focus();

          // disable option if limit reached
          if (!colprop.count) colprop.count = 0;
          if (++colprop.count == colprop.limit && colprop.limit)
            $(menu).children('option[value="' + col + '"]').prop('disabled', true);

          this.triggerEvent('insert-edit-field', input);
        }
      }
    }
  };

  this.delete_edit_field = function(elem)
  {
    var col = $(elem).attr('rel'),
      colprop = this.env.coltypes[col],
      input_group = $(elem).parents('div.row'),
      fieldset = $(elem).parents('fieldset.contactfieldgroup'),
      addmenu = fieldset.parent().find('select.addfieldmenu');

    // just clear input but don't hide the last field
    if (--colprop.count <= 0 && colprop.visible)
      input_group.find('input').val('').blur();
    else {
      input_group.remove();
      // hide entire fieldset if no more rows
      if (!fieldset.children('div.row').length)
        fieldset.hide();
    }

    // enable option in add-field selector or insert it if necessary
    if (addmenu.length) {
      var option = addmenu.children('option[value="'+col+'"]');
      if (option.length)
        option.prop('disabled', false);
      else
        option = $('<option>').attr('value', col).html(colprop.label).appendTo(addmenu);
      addmenu.show();
    }
  };

  this.upload_contact_photo = function(form)
  {
    if (form && form.elements._photo.value) {
      this.async_upload_form(form, 'upload-photo', function(e) {
        ref.set_busy(false, null, ref.file_upload_id);
      });

      // display upload indicator
      this.file_upload_id = this.set_busy(true, 'uploading');
    }
  };

  this.replace_contact_photo = function(id)
  {
    var img_src = id == '-del-' ? this.env.photo_placeholder :
      this.env.comm_path + '&_action=photo&_source=' + this.env.source + '&_cid=' + (this.env.cid || 0) + '&_photo=' + id;

    this.set_photo_actions(id);
    $(this.gui_objects.contactphoto).children('img').attr('src', img_src);
  };

  this.photo_upload_end = function()
  {
    this.set_busy(false, null, this.file_upload_id);
    delete this.file_upload_id;
  };

  this.set_photo_actions = function(id)
  {
    var n, buttons = this.buttons['upload-photo'];
    for (n=0; buttons && n < buttons.length; n++)
      $('a#'+buttons[n].id).html(this.get_label(id == '-del-' ? 'addphoto' : 'replacephoto'));

    $('#ff_photo').val(id);
    this.enable_command('upload-photo', this.env.coltypes.photo ? true : false);
    this.enable_command('delete-photo', this.env.coltypes.photo && id != '-del-');
  };

  // load advanced search page
  this.advanced_search = function()
  {
    var dialog = $('<iframe>').attr('src', this.url('search', {_form: 1, _framed: 1})),
      search_func = function() {
        var valid = false, form = {_adv: 1};

        $.each($(dialog[0].contentWindow.rcmail.gui_objects.editform).serializeArray(), function() {
          if (this.name.match(/^_search/) && this.value != '') {
            form[this.name] = this.value;
            valid = true;
          }
        });

        if (valid) {
          ref.http_post('search', form, ref.set_busy(true, 'searching'));
          return true;
        }
      };

    this.simple_dialog(dialog, 'advsearch', search_func, {
      button: 'search',
      width: 600,
      height: 500
    });

    return true;
  };

  // unselect directory/group
  this.unselect_directory = function()
  {
    this.select_folder('');
    this.enable_command('search-delete', false);
  };

  // callback for creating a new saved search record
  this.insert_saved_search = function(name, id)
  {
    var key = 'S'+id,
      link = $('<a>').attr({href: '#', rel: id})
        .click(function() { return ref.command('listsearch', id, this); })
        .html(name),
      prop = { name:name, id:id };

    this.savedsearchlist.insert({ id:key, html:link, classes:['contactsearch'] }, null, 'contactsearch');
    this.select_folder(key,'',true);
    this.enable_command('search-delete', true);
    this.env.search_id = id;

    this.triggerEvent('abook_search_insert', prop);
  };

  // creates a dialog for saved search
  this.search_create = function()
  {
    var input = $('<input>').attr('type', 'text'),
      content = $('<label>').text(this.get_label('namex')).append(input);

    this.simple_dialog(content, 'searchsave',
      function() {
        var name;
        if (name = input.val()) {
          ref.http_post('search-create', {_search: ref.env.search_request, _name: name},
            ref.set_busy(true, 'loading'));
          return true;
        }
      }
    );
  };

  this.search_delete = function()
  {
    if (this.env.search_request) {
      var lock = this.set_busy(true, 'savedsearchdeleting');
      this.http_post('search-delete', {_sid: this.env.search_id}, lock);
    }
  };

  // callback from server upon search-delete command
  this.remove_search_item = function(id)
  {
    if (this.savedsearchlist.remove('S' + id)) {
      this.triggerEvent('search_delete', {id: id});
    }

    this.env.search_id = null;
    this.env.search_request = null;
    this.list_contacts_clear();
    this.reset_qsearch();
    this.enable_command('search-delete', 'search-create', false);
  };

  this.listsearch = function(id)
  {
    var lock = this.set_busy(true, 'searching');

    if (this.contact_list) {
      this.list_contacts_clear();
    }

    this.reset_qsearch();

    if (this.savedsearchlist) {
      this.treelist.select('');
      this.savedsearchlist.select('S'+id);
    }
    else
      this.select_folder('S'+id, '', true);

    // reset vars
    this.env.current_page = 1;
    this.http_request('search', {_sid: id}, lock);
  };

  // display a dialog with QR code image
  this.qrcode = function()
  {
    var img = new Image(300, 300);

    img.src = this.url('addressbook/qrcode', {_source: this.env.source, _cid: this.get_single_cid()});

    return this.simple_dialog(img, 'qrcode', null, {
        button: false,
        cancel_button: 'close',
        width: 300,
        height: 300
    });
  };


  /*********************************************************/
  /*********        user settings methods          *********/
  /*********************************************************/

  // preferences section select and load options frame
  this.section_select = function(list)
  {
    var win, id = list.get_single_selection();

    if (id && (win = this.get_frame_window(this.env.contentframe))) {
      this.location_href({_action: 'edit-prefs', _section: id, _framed: 1}, win, true);
    }
  };

  this.response_select = function(list)
  {
    var id = list.get_single_selection();

    this.enable_command('delete', !!id && $.inArray(id, this.env.readonly_responses) < 0);

    if (id) {
      this.load_response(id, 'edit-response');
    }
  };

  // load response record
  this.load_response = function(id, action)
  {
    var win;

    if (win = this.get_frame_window(this.env.contentframe)) {
      if (id || action == 'add-response') {
        if (!id)
          this.responses_list.clear_selection();

        this.location_href({_action: action, _id: id, _framed: 1}, win, true);
      }
    }
  };

  this.identity_select = function(list)
  {
    var id = list.get_single_selection();

    this.enable_command('delete', !!id && list.rowcount > 1 && this.env.identities_level < 2);

    if (id) {
      this.load_identity(id, 'edit-identity');
    }
  };

  // load identity record
  this.load_identity = function(id, action)
  {
    var win;

    if (win = this.get_frame_window(this.env.contentframe)) {
      if (id || action == 'add-identity') {
        if (!id)
          this.identity_list.clear_selection();

        this.location_href({_action: action, _iid: id, _framed: 1}, win, true);
      }
    }
  };

  this.delete_identity = function(id)
  {
    if (!id && this.identity_list)
      id = this.identity_list.get_single_selection();

    if (id) {
      this.confirm_dialog(this.get_label('deleteidentityconfirm'), 'delete', function() {
          ref.http_post('settings/delete-identity', {_iid: id}, true);
      });
    }
  };

  this.delete_response = function(id)
  {
    if (!id && this.responses_list) {
      id = this.responses_list.get_single_selection();
    }

    if (id) {
      this.confirm_dialog(this.get_label('deleteresponseconfirm'), 'delete', function() {
          ref.http_post('settings/delete-response', {_id: id}, true);
      });
    }
  };

  // Update indetities list (add or update a record)
  this.update_identity_row = function(id, name, add)
  {
    var list = this.identity_list,
      rid = this.html_identifier(id);

    if (add) {
      list.insert_row({id: 'rcmrow' + rid, cols: [{className: 'mail', innerHTML: name}]});
      list.select(rid);
    }
    else {
      list.update_row(rid, [name]);
    }
  };

  // Update responses list (add or update a record)
  this.update_response_row = function(id, name, add)
  {
    var list = this.responses_list;

    if (add) {
      list.insert_row({id: 'rcmrow' + id, cols: [{className: 'name', innerHTML: name}]});
      list.select(id);
    }
    else {
      list.update_row(id, [name]);
    }
  };

  // Remove response record from the responses list
  this.remove_response = function(id)
  {
    if (this.responses_list) {
      this.responses_list.remove_row(id);
      this.show_contentframe(false);
    }

    this.enable_command('delete', false);
  };

  // Remove identity record from the identities list
  this.remove_identity = function(id)
  {
    var list = this.identity_list,
      rid = this.html_identifier(id);

    if (list && id) {
      list.remove_row(rid);
      this.show_contentframe(false);
    }

    this.enable_command('delete', false);
  };


  /*********************************************************/
  /*********        folder manager methods         *********/
  /*********************************************************/

  this.init_subscription_list = function()
  {
    var delim = RegExp.escape(this.env.delimiter);

    this.last_sub_rx = RegExp('['+delim+']?[^'+delim+']+$');

    this.subscription_list = new rcube_treelist_widget(this.gui_objects.subscriptionlist, {
        selectable: true,
        tabexit: false,
        parent_focus: true,
        id_prefix: 'rcmli',
        id_encode: this.html_identifier_encode,
        id_decode: this.html_identifier_decode,
        searchbox: '#foldersearch'
    });

    this.subscription_list
      .addEventListener('select', function(node) { ref.subscription_select(node.id); })
      .addEventListener('collapse', function(node) { ref.folder_collapsed(node) })
      .addEventListener('expand', function(node) { ref.folder_collapsed(node) })
      .addEventListener('search', function(p) { if (p.query) ref.subscription_select(); })
      .draggable({cancel: 'li.mailbox.root,input,div.treetoggle,.custom-control'})
      .droppable({
        // @todo: find better way, accept callback is executed for every folder
        // on the list when dragging starts (and stops), this is slow, but
        // I didn't find a method to check droptarget on over event
        accept: function(node) {
          if (!node.is('.mailbox'))
            return false;

          var source_folder = ref.folder_id2name(node.attr('id')),
            dest_folder = ref.folder_id2name(this.id),
            source = ref.env.subscriptionrows[source_folder],
            dest = ref.env.subscriptionrows[dest_folder];

          return source && !source[2]
            && dest_folder != source_folder.replace(ref.last_sub_rx, '')
            && !dest_folder.startsWith(source_folder + ref.env.delimiter);
        },
        drop: function(e, ui) {
          var source = ref.folder_id2name(ui.draggable.attr('id')),
            dest = ref.folder_id2name(this.id);

          ref.subscription_move_folder(source, dest);
        }
      });
  };

  this.folder_id2name = function(id)
  {
    return id ? ref.html_identifier_decode(id.replace(/^rcmli/, '')) : null;
  };

  this.subscription_select = function(id)
  {
    var folder;

    if (id && id != '*' && (folder = this.env.subscriptionrows[id])) {
      this.env.mailbox = id;
      this.show_folder(id);
      this.enable_command('delete-folder', !folder[2]);
    }
    else {
      this.env.mailbox = null;
      this.show_contentframe(false);
      this.subscription_list.select('');
      this.enable_command('delete-folder', 'purge', false);
    }
  };

  this.subscription_move_folder = function(from, to)
  {
    if (from && to !== null && from != to && to != from.replace(this.last_sub_rx, '')) {
      var path = from.split(this.env.delimiter),
        basename = path.pop(),
        newname = to === '' || to === '*' ? basename : to + this.env.delimiter + basename;

      if (newname != from) {
        this.confirm_dialog(this.get_label('movefolderconfirm'), 'move', function() {
          ref.http_post('rename-folder', {_folder_oldname: from, _folder_newname: newname},
            ref.set_busy(true, 'foldermoving'));
        }, {button_class: 'save move'});
      }
    }
  };

  // tell server to create and subscribe a new mailbox
  this.create_folder = function()
  {
    this.show_folder('', this.env.mailbox);
  };

  // delete a specific mailbox with all its messages
  this.delete_folder = function(name)
  {
    if (!name)
      name = this.env.mailbox;

    if (name) {
      this.confirm_dialog(this.get_label('deletefolderconfirm'), 'delete', function() {
          ref.http_post('delete-folder', {_mbox: name}, ref.set_busy(true, 'folderdeleting'));
        });
    }
  };

  // Add folder row to the table and initialize it
  this.add_folder_row = function (id, name, display_name, is_protected, subscribed, class_name, refrow, subfolders)
  {
    if (!this.gui_objects.subscriptionlist)
      return false;

    // reset searching
    if (this.subscription_list.is_search()) {
      this.subscription_select();
      this.subscription_list.reset_search();
    }

    // disable drag-n-drop temporarily
    // some skins disable dragging in mobile mode, so we have to check if it is still draggable
    if (this.subscription_list.is_draggable())
      this.subscription_list.draggable('destroy').droppable('destroy');

    var row, n, tmp, tmp_name, rowid, collator, pos, p, parent = '',
      folders = [], list = [], slist = [],
      list_element = $(this.gui_objects.subscriptionlist);
      row = refrow ? refrow : $($('li', list_element).get(1)).clone(true);

    if (!row.length) {
      // Refresh page if we don't have a table row to clone
      this.goto_url('folders');
      return false;
    }

    // set ID, reset css class
    row.attr({id: 'rcmli' + this.html_identifier_encode(id), 'class': class_name});

    if (!refrow || !refrow.length) {
      // remove old data, subfolders and toggle
      $('ul,div.treetoggle', row).remove();
      row.removeData('filtered');
    }

    // set folder name
    $('a', row).first().text(display_name).removeAttr('title');

    // update subscription checkbox
    $('input[name="_subscribed[]"]', row).first().val(id)
      .prop({checked: subscribed ? true : false, disabled: is_protected ? true : false});

    // add to folder/row-ID map
    this.env.subscriptionrows[id] = [name, display_name, false];

    // copy folders data to an array for sorting
    $.each(this.env.subscriptionrows, function(k, v) { v[3] = k; folders.push(v); });

    try {
      // use collator if supported (FF29, IE11, Opera15, Chrome24)
      collator = new Intl.Collator(this.env.locale.replace('_', '-'));
    }
    catch (e) {};

    // sort folders
    folders.sort(function(a, b) {
      var i, f1, f2,
        path1 = a[0].split(ref.env.delimiter),
        path2 = b[0].split(ref.env.delimiter),
        len = path1.length;

      for (i=0; i<len; i++) {
        f1 = path1[i];
        f2 = path2[i];

        if (f1 !== f2) {
          if (f2 === undefined)
            return 1;
          if (collator)
            return collator.compare(f1, f2);
          else
            return f1 < f2 ? -1 : 1;
        }
        else if (i == len-1) {
          return -1
        }
      }
    });

    for (n in folders) {
      p = folders[n][3];
      // protected folder
      if (folders[n][2]) {
        tmp_name = p + this.env.delimiter;
        // prefix namespace cannot have subfolders (#1488349)
        if (tmp_name == this.env.prefix_ns)
          continue;
        slist.push(p);
        tmp = tmp_name;
      }
      // protected folder's child
      else if (tmp && p.startsWith(tmp))
        slist.push(p);
      // other
      else {
        list.push(p);
        tmp = null;
      }
    }

    // check if subfolder of a protected folder
    for (n=0; n<slist.length; n++) {
      if (id.startsWith(slist[n] + this.env.delimiter))
        rowid = slist[n];
    }

    // find folder position after sorting
    for (n=0; !rowid && n<list.length; n++) {
      if (n && list[n] == id)
        rowid = list[n-1];
    }

    // add row to the table
    if (rowid && (n = this.subscription_list.get_item(rowid, true))) {
      // find parent folder
      if (pos = id.lastIndexOf(this.env.delimiter)) {
        parent = id.substring(0, pos);
        parent = this.subscription_list.get_item(parent, true);

        // add required tree elements to the parent if not already there
        if (!$('div.treetoggle', parent).length) {
          $('<div>&nbsp;</div>').addClass('treetoggle collapsed').appendTo(parent);
        }
        if (!$('ul', parent).length) {
          $('<ul>').css('display', 'none').appendTo(parent);
        }
      }

      if (parent && n == parent) {
        $('ul', parent).first().append(row);
      }
      else {
        while (p = $(n).parent().parent().get(0)) {
          if (parent && p == parent)
            break;
          if (!$(p).is('li.mailbox'))
            break;
          n = p;
        }

        $(n).after(row);
      }
    }
    else {
      list_element.append(row);
    }

    // add subfolders
    $.extend(this.env.subscriptionrows, subfolders || {});

    // update list widget
    this.subscription_list.reset(true);
    this.subscription_select();

    // expand parent
    if (parent) {
      this.subscription_list.expand(this.folder_id2name(parent.id));
    }

    row = row.show().get(0);
    if (row.scrollIntoView)
      row.scrollIntoView(false);

    // Let skins to do their magic, e.g. Elastic will fix pretty checkbox
    if (!refrow)
      this.triggerEvent('clonerow', {row: row, id: id});

    return row;
  };

  // replace an existing table row with a new folder line (with subfolders)
  this.replace_folder_row = function(oldid, id, name, display_name, is_protected, class_name)
  {
    if (!this.gui_objects.subscriptionlist) {
      if (this.is_framed()) {
        // @FIXME: for some reason this 'parent' variable need to be prefixed with 'window.'
        return window.parent.rcmail.replace_folder_row(oldid, id, name, display_name, is_protected, class_name);
      }

      return false;
    }

    // reset searching
    if (this.subscription_list.is_search()) {
      this.subscription_select();
      this.subscription_list.reset_search();
    }

    var subfolders = {},
      row = this.subscription_list.get_item(oldid, true),
      parent = $(row).parent(),
      old_folder = this.env.subscriptionrows[oldid],
      prefix_len_id = oldid.length,
      prefix_len_name = old_folder[0].length,
      subscribed = $('input[name="_subscribed[]"]', row).first().prop('checked');

    // no renaming, only update class_name
    if (oldid == id) {
      $(row).attr('class', class_name || '');
      return;
    }

    // update subfolders
    $('li', row).each(function() {
      var fname = ref.folder_id2name(this.id),
        folder = ref.env.subscriptionrows[fname],
        newid = id + fname.slice(prefix_len_id);

      this.id = 'rcmli' + ref.html_identifier_encode(newid);
      $('input[name="_subscribed[]"]', this).first().val(newid);
      folder[0] = name + folder[0].slice(prefix_len_name);

      subfolders[newid] = folder;
      delete ref.env.subscriptionrows[fname];
    });

    // get row off the list
    row = $(row).detach();

    delete this.env.subscriptionrows[oldid];

    // remove parent list/toggle elements if not needed
    if (parent.get(0) != this.gui_objects.subscriptionlist && !$('li', parent).length) {
      $('ul,div.treetoggle', parent.parent()).remove();
    }

    // move the existing table row
    this.add_folder_row(id, name, display_name, is_protected, subscribed, class_name, row, subfolders);
  };

  // remove the table row of a specific mailbox from the table
  this.remove_folder_row = function(folder)
  {
    // reset searching
    if (this.subscription_list.is_search()) {
      this.subscription_select();
      this.subscription_list.reset_search();
    }

    var list = [], row = this.subscription_list.get_item(folder, true);

    // get subfolders if any
    $('li', row).each(function() { list.push(ref.folder_id2name(this.id)); });

    // remove folder row (and subfolders)
    this.subscription_list.remove(folder);

    // update local list variable
    list.push(folder);
    $.each(list, function(i, v) { delete ref.env.subscriptionrows[v]; });
  };

  this.subscribe = function(folder)
  {
    this.change_subscription_state(folder, true);
  };

  this.unsubscribe = function(folder)
  {
    this.change_subscription_state(folder, false);
  };

  this.change_subscription_state = function(folder, state)
  {
    if (folder) {
      var prefix = state ? '' : 'un',
        lock = this.display_message('folder' + prefix + 'subscribing', 'loading');

      this.http_post(prefix + 'subscribe', {_mbox: folder}, lock);

      // in case this was a list of search results, update also the main list
      $(this.gui_objects.subscriptionlist).find('input[value="' + folder + '"]').prop('checked', state);
    }
  };


  // when user select a folder in manager
  this.show_folder = function(folder, path, force)
  {
    var win, target = window,
      action = folder === '' ? 'add' : 'edit',
      url = '&_action=' + action + '-folder&_mbox=' + urlencode(folder);

    if (path)
      url += '&_path='+urlencode(path);

    if (win = this.get_frame_window(this.env.contentframe)) {
      target = win;
      url += '&_framed=1';
    }

    if (action == 'add')
      this.subscription_select('');

    if (String(target.location.href).indexOf(url) >= 0 && !force)
      this.show_contentframe(true);
    else
      this.location_href(this.env.comm_path+url, target, true);
  };

  // disables subscription checkbox (for protected folder)
  this.disable_subscription = function(folder)
  {
    var row = this.subscription_list.get_item(folder, true);
    if (row)
      $('input[name="_subscribed[]"]', row).first().prop('disabled', true);
  };

  // resets state of subscription checkbox (e.g. on error)
  this.reset_subscription = function(folder, state)
  {
    var row = this.subscription_list.get_item(folder, true);
    if (row)
      $('input[name="_subscribed[]"]', row).first().prop('checked', state);
  };

  this.folder_size = function(folder)
  {
    var lock = this.set_busy(true, 'loading');
    this.http_post('folder-size', {_mbox: folder}, lock);
  };

  this.folder_size_update = function(size)
  {
    $('#folder-size').replaceWith(size);
  };

  // filter folders by namespace
  this.folder_filter = function(prefix)
  {
    this.subscription_list.reset_search();

    this.subscription_list.container.children('li').each(function() {
      var i, folder = ref.folder_id2name(this.id);
      // show all folders
      if (prefix == '---') {
      }
      // got namespace prefix
      else if (prefix) {
        if (folder !== prefix) {
          $(this).data('filtered', true).hide();
          return
        }
      }
      // no namespace prefix, filter out all other namespaces
      else {
        // first get all namespace roots
        for (i in ref.env.ns_roots) {
          if (folder === ref.env.ns_roots[i]) {
            $(this).data('filtered', true).hide();
            return;
          }
        }
      }

      $(this).removeData('filtered').show();
    });
  };

  /*********************************************************/
  /*********           GUI functionality           *********/
  /*********************************************************/

  this.init_button = function(cmd, prop)
  {
    var elm = document.getElementById(prop.id);
    if (!elm)
      return;

    var preload = false;
    if (prop.type == 'image') {
      elm = elm.parentNode;
      preload = true;
    }

    elm._command = cmd;
    elm._id = prop.id;
    if (prop.sel) {
      elm.onmousedown = function(e) { return ref.button_sel(this._command, this._id); };
      elm.onmouseup = function(e) { return ref.button_out(this._command, this._id); };
      if (preload)
        new Image().src = prop.sel;
    }
    if (prop.over) {
      elm.onmouseover = function(e) { return ref.button_over(this._command, this._id); };
      elm.onmouseout = function(e) { return ref.button_out(this._command, this._id); };
      if (preload)
        new Image().src = prop.over;
    }
  };

  // set event handlers on registered buttons
  this.init_buttons = function()
  {
    for (var cmd in this.buttons) {
      if (typeof cmd !== 'string')
        continue;

      for (var i=0; i<this.buttons[cmd].length; i++) {
        this.init_button(cmd, this.buttons[cmd][i]);
      }
    }
  };

  // set button to a specific state
  this.set_button = function(command, state)
  {
    var n, button, obj, a_buttons = this.buttons[command],
      len = a_buttons ? a_buttons.length : 0;

    for (n=0; n<len; n++) {
      button = a_buttons[n];
      obj = document.getElementById(button.id);

      if (!obj || button.status === state)
        continue;

      // get default/passive setting of the button
      if (button.type == 'image' && !button.status) {
        button.pas = obj._original_src ? obj._original_src : obj.src;
        // respect PNG fix on IE browsers
        if (obj.runtimeStyle && obj.runtimeStyle.filter && obj.runtimeStyle.filter.match(/src=['"]([^'"]+)['"]/))
          button.pas = RegExp.$1;
      }
      else if (!button.status)
        button.pas = String(obj.className);

      button.status = state;

      // set image according to button state
      if (button.type == 'image' && button[state]) {
        obj.src = button[state];
      }
      // set class name according to button state
      else if (button[state] !== undefined) {
        obj.className = button[state];
      }

      // disable/enable input buttons
      if (button.type == 'input' || button.type == 'button') {
        obj.disabled = state == 'pas';
      }
      else {
        $(obj).attr({
          tabindex: state == 'pas' || state == 'sel' ? '-1' : ($(obj).attr('data-tabindex') || '0'),
          'aria-disabled': state == 'pas' || state == 'sel' ? 'true' : 'false'
        });
      }
    }
  };

  // display a specific alttext
  this.set_alttext = function(command, label)
  {
    var n, button, obj, link, label,
      a_buttons = this.buttons[command],
      len = a_buttons ? a_buttons.length : 0;

    for (n=0; n<len; n++) {
      button = a_buttons[n];
      obj = document.getElementById(button.id);
      label = this.get_label(label);

      if (obj && button.type == 'image') {
        obj.setAttribute('alt', label);
        if ((link = obj.parentNode) && link.tagName.toLowerCase() == 'a')
          link.setAttribute('title', label);
      }
      else if (obj)
        obj.setAttribute('title', label);
    }
  };

  // mouse over button
  this.button_over = function(command, id)
  {
    this.button_event(command, id, 'over');
  };

  // mouse down on button
  this.button_sel = function(command, id)
  {
    this.button_event(command, id, 'sel');
  };

  // mouse out of button
  this.button_out = function(command, id)
  {
    this.button_event(command, id, 'act');
  };

  // event of button
  this.button_event = function(command, id, event)
  {
    var n, button, obj, a_buttons = this.buttons[command],
      len = a_buttons ? a_buttons.length : 0;

    for (n=0; n<len; n++) {
      button = a_buttons[n];
      if (button.id == id && button.status == 'act') {
        if (button[event] && (obj = document.getElementById(button.id))) {
          obj[button.type == 'image' ? 'src' : 'className'] = button[event];
        }

        if (event == 'sel') {
          this.buttons_sel[id] = command;
        }
      }
    }
  };

  // write to the document/window title
  this.set_pagetitle = function(title)
  {
    if (title && document.title)
      document.title = title;
  };

  // display a system message, list of types in common.css (below #message definition)
  this.display_message = function(msg, type, timeout, key)
  {
    if (msg && msg.length && /^[a-z._]+$/.test(msg))
      msg = this.get_label(msg);

    // pass command to parent window
    if (this.is_framed())
      return parent.rcmail.display_message(msg, type, timeout);

    if (!this.gui_objects.message) {
      // save message in order to display after page loaded
      if (type != 'loading')
        this.pending_message = [msg, type, timeout, key];
      return 1;
    }

    if (!type)
      type = 'notice';
    else if (type == 'loading') {
      if (!key)
        key = 'loading';
      if (!timeout)
        timeout = this.env.request_timeout * 1000;
      if (!msg)
        msg = this.get_label('loading');
    }

    if (!key)
      key = this.html_identifier(msg);

    var date = new Date(),
      id = type + date.getTime();

    if (!timeout) {
      switch (type) {
        case 'error':
        case 'warning':
          timeout = this.message_time * 2;
          break;

        case 'uploading':
          timeout = 0;
          break;

        default:
          timeout = this.message_time;
      }
    }

    // The same message is already displayed
    if (this.messages[key]) {
      // replace label
      if (this.messages[key].obj)
        $('div.content', this.messages[key].obj).html(msg);
      // store label in stack
      if (type == 'loading') {
        this.messages[key].labels.push({'id': id, 'msg': msg});
      }
      // add element and set timeout
      this.messages[key].elements.push(id);
      setTimeout(function() { ref.hide_message(id, type == 'loading'); }, timeout);
      return id;
    }

    // create DOM object and display it
    var obj = $('<div>').addClass(type + ' content').html(msg).data('key', key),
      cont = $(this.gui_objects.message).append(obj).show();

    this.messages[key] = {'obj': obj, 'elements': [id]};

    if (type == 'loading') {
      this.messages[key].labels = [{'id': id, 'msg': msg}];
    }
    else if (type != 'uploading') {
      obj.click(function() { return ref.hide_message(obj); })
        .attr('role', 'alert');
    }

    this.triggerEvent('message', { message:msg, type:type, timeout:timeout, object:obj });

    if (timeout > 0)
      setTimeout(function() { ref.hide_message(id, type != 'loading'); }, timeout);

    return id;
  };

  // make a message to disappear
  this.hide_message = function(obj, fade)
  {
    // pass command to parent window
    if (this.is_framed())
      return parent.rcmail.hide_message(obj, fade);

    if (!this.gui_objects.message)
      return;

    var k, n, i, o, m = this.messages;

    // Hide message by object, don't use for 'loading'!
    if (typeof obj === 'object') {
      o = $(obj);
      k = o.data('key');
      this.hide_message_object(o, fade);
      if (m[k])
        delete m[k];
    }
    // Hide message by id
    else {
      for (k in m) {
        for (n in m[k].elements) {
          if (m[k] && m[k].elements[n] == obj) {
            m[k].elements.splice(n, 1);
            // hide DOM element if last instance is removed
            if (!m[k].elements.length) {
              this.hide_message_object(m[k].obj, fade);
              delete m[k];
            }
            // set pending action label for 'loading' message
            else if (k == 'loading') {
              for (i in m[k].labels) {
                if (m[k].labels[i].id == obj) {
                  delete m[k].labels[i];
                }
                else {
                  o = m[k].labels[i].msg;
                  $('div.content', m[k].obj).html(o);
                }
              }
            }
          }
        }
      }
    }
  };

  // hide message object and remove from the DOM
  this.hide_message_object = function(o, fade)
  {
    if (fade)
      o.fadeOut(600, function() { $(this).remove(); });
    else
      o.hide().remove();
  };

  // remove all messages immediately
  this.clear_messages = function()
  {
    // pass command to parent window
    if (this.is_framed())
      return parent.rcmail.clear_messages();

    var k, n, m = this.messages;

    for (k in m)
      for (n in m[k].elements)
        if (m[k].obj)
          this.hide_message_object(m[k].obj);

    this.messages = {};
  };

  // display uploading message with progress indicator
  // data should contain: name, total, current, percent, text
  this.display_progress = function(data)
  {
    if (!data || !data.name)
      return;

    var msg = this.messages['progress' + data.name];

    if (!data.label)
      data.label = this.get_label('uploadingmany');

    if (!msg) {
      if (!data.percent || data.percent < 100)
        this.display_message(data.label, 'uploading', 0, 'progress' + data.name);
      return;
    }

    if (!data.total || data.percent >= 100) {
      this.hide_message(msg.obj);
      return;
    }

    if (data.text)
      data.label += ' ' + data.text;

    msg.obj.text(data.label);
  };

  // open a jquery UI dialog with the given content
  this.show_popup_dialog = function(content, title, buttons, options)
  {
    // forward call to parent window
    if (this.is_framed()) {
      return parent.rcmail.show_popup_dialog(content, title, buttons, options);
    }

    var popup = $('<div class="popup">');

    if (typeof content == 'object') {
      popup.append(content);
      if ($(content).is('iframe'))
        popup.addClass('iframe');
    }
    else
      popup.html(content);

    // assign special classes to dialog buttons
    var i = 0, fn = function(button, classes, idx) {
        if (typeof button == 'function') {
          button = {
            click: button,
            text: idx,
            'class': classes
          };
        }
        else {
          buttons['class'] = classes;
        }

        return button;
      };

    if (options && options.button_classes)
      $.each(buttons, function(idx, button) {
        var cl = options.button_classes[i];
        if (cl)
          buttons[idx] = fn(button, cl, idx);
        i++;
      });

    options = $.extend({
        title: title,
        buttons: buttons,
        modal: true,
        resizable: true,
        width: 500,
        close: function(event, ui) { $(this).remove(); }
      }, options || {});

    popup.dialog(options);

    // Remember the jQuery instance (window), useful when closing the dialog
    popup[0].jqref = $;

    if (options.width)
      popup.width(options.width);
    if (options.height)
      popup.height(options.height);

    var dialog = popup.parent();

    if (!options.noresize) {
      // resize and center popup
      var win = $(window), w = win.width(), h = win.height(),
        width = popup.width(),
        height = options.height || (popup[0].scrollHeight + 20),
        titlebar_height = $('.ui-dialog-titlebar', dialog).outerHeight() || 0,
        buttonpane_height = $('.ui-dialog-buttonpane', dialog).outerHeight() || 0,
        padding = (parseInt(dialog.css('padding-top')) + parseInt(popup.css('padding-top'))) * 2;

      popup.dialog('option', {
        height: Math.min(h - 40, height + titlebar_height + buttonpane_height + padding + 2),
        width: Math.min(w - 20, width + 28)
      });
    }
    else {
      popup.css('width', 'auto');
    }

    // Don't propagate keyboard events to the UI below the dialog (#6055)
    dialog.on('keydown keyup', function(e) { e.stopPropagation(); });

    // Add Enter key handler to the input, click the 'mainaction' button
    dialog.find('input[data-submit]').on('keydown', function(e) {
      if (e.which == 13) {
        dialog.find('.ui-dialog-buttonpane button.mainaction').click();
      }
    });

    this.triggerEvent('dialog-open', {obj: popup});

    return popup;
  };

  // show_popup_dialog() wrapper for simple dialogs with action and Cancel buttons
  this.simple_dialog = function(content, title, action_func, options)
  {
    if (!options)
      options = {};

    var title = this.get_label(title),
      save_label = options.button || 'save',
      save_class = options.button_class || save_label.replace(/^[^\.]+\./i, ''),
      cancel_label = options.cancel_button || 'cancel',
      cancel_class = options.cancel_class || cancel_label.replace(/^[^\.]+\./i, ''),
      close_func = function(e, ui, dialog) {
        if (!dialog)
          dialog = this;

        // The dialog might got open in the current window, but also any of its parents (#8627)
        // We have to use the jQuery object that did invoke the dialog, set in show_popup_dialog()
        dialog.jqref(dialog).dialog('close');
        if (options.cancel_func) options.cancel_func(e, ref);
      },
      buttons = [{
        text: this.get_label(cancel_label),
        'class': cancel_class.replace(/close/i, 'cancel'),
        click: close_func
      }];

    if (!action_func)
      buttons[0]['class'] += ' mainaction';
    else
      buttons.unshift({
        text: this.get_label(save_label),
        'class': 'mainaction ' + save_class,
        click: function(e, ui) { if (action_func(e, ref)) close_func(e, ui, this); }
      });

    return this.show_popup_dialog(content, title, buttons, options);
  };

  // show_popup_dialog() wrapper for alert() type dialogs
  this.alert_dialog = function(content, action, options)
  {
    options = $.extend(options || {}, {
        cancel_button: 'ok',
        cancel_class: 'save',
        cancel_func: action,
        noresize: true
      });

    return this.simple_dialog(content, options.title || 'alerttitle', null, options);
  };

  // simple_dialog() wrapper for confirm() type dialogs
  this.confirm_dialog = function(content, button_label, action, options)
  {
    var action_func = function(e, ref) { action(e, ref); return true; };

    options = $.extend(options || {}, {
        button: button_label || 'continue',
        noresize: true
      });

    return this.simple_dialog(content, options.title || 'confirmationtitle', action_func, options);
  };

  // enable/disable buttons for page shifting
  this.set_page_buttons = function()
  {
    this.enable_command('nextpage', 'lastpage', this.env.pagecount > this.env.current_page);
    this.enable_command('previouspage', 'firstpage', this.env.current_page > 1);

    this.update_pagejumper();
  };

  // mark a mailbox as selected and set environment variable
  this.select_folder = function(name, prefix, encode)
  {
    if (this.savedsearchlist) {
      this.savedsearchlist.select('');
    }

    if (this.treelist) {
      this.treelist.select(name);
    }
    else if (this.gui_objects.folderlist) {
      $('li.selected', this.gui_objects.folderlist).removeClass('selected');
      $(this.get_folder_li(name, prefix, encode)).addClass('selected');

      // trigger event hook
      this.triggerEvent('selectfolder', { folder:name, prefix:prefix });
    }
  };

  // adds a class to selected folder
  this.mark_folder = function(name, class_name, prefix, encode)
  {
    $(this.get_folder_li(name, prefix, encode)).addClass(class_name);
    this.triggerEvent('markfolder', {folder: name, mark: class_name, status: true});
  };

  // adds a class to selected folder
  this.unmark_folder = function(name, class_name, prefix, encode)
  {
    $(this.get_folder_li(name, prefix, encode)).removeClass(class_name);
    this.triggerEvent('markfolder', {folder: name, mark: class_name, status: false});
  };

  // helper method to find a folder list item
  this.get_folder_li = function(name, prefix, encode)
  {
    if (!prefix)
      prefix = 'rcmli';

    if (this.gui_objects.folderlist) {
      name = this.html_identifier(name, encode);
      return document.getElementById(prefix+name);
    }
  };

  // for reordering column array (Konqueror workaround)
  // and for setting some message list global variables
  this.set_message_coltypes = function(cols, repl, smart_col)
  {
    // update list mode columns list
    this.env.listcols = cols;

    // reset message list cols
    this.msglist_setup(this.env.layout);

    var list = this.message_list,
      thead = list ? list.thead : null,
      repl, cell, col, c, n, len, tr,
      listcols = this.env.msglist_cols;

    if (!this.env.coltypes)
      this.env.coltypes = {};

    // replace old column headers
    if (thead) {
      if (repl) {
        thead.innerHTML = '';
        tr = document.createElement('tr');

        for (n in listcols) {
          c = listcols[n];
          cell = document.createElement('th');
          cell.innerHTML = repl[c].html || '';
          if (repl[c].id) cell.id = repl[c].id;
          if (repl[c].className) cell.className = repl[c].className;
          tr.appendChild(cell);
        }

        if (list.checkbox_selection)
          list.insert_checkbox(tr, 'thead');

        thead.appendChild(tr);
      }

      for (n = 0, len = listcols.length; n < len; n++) {
        col = listcols[list.checkbox_selection ? n-1 : n];
        if ((cell = thead.rows[0].cells[n]) && (col == 'from' || col == 'to' || col == 'fromto')) {
          $(cell).attr('rel', col).find('span,a').text(this.get_label(col == 'fromto' ? smart_col : col));
        }
      }
    }

    this.env.subject_col = null;
    this.env.flagged_col = null;
    this.env.status_col = null;

    if (this.env.coltypes.folder)
      this.env.coltypes.folder.hidden = !(this.env.search_request || this.env.search_id) || this.env.search_scope == 'base';

    if ((n = $.inArray('subject', listcols)) >= 0) {
      this.env.subject_col = n;
      if (list)
        list.subject_col = n;
    }
    if ((n = $.inArray('flag', listcols)) >= 0)
      this.env.flagged_col = n;
    if ((n = $.inArray('status', listcols)) >= 0)
      this.env.status_col = n;

    if (list) {
      list.hide_column('folder', (this.env.coltypes.folder && this.env.coltypes.folder.hidden) || $.inArray('folder', listcols) < 0);
      list.init_header();
    }
  };

  // replace content of row count display
  this.set_rowcount = function(text, mbox)
  {
    // #1487752
    if (mbox && mbox != this.env.mailbox)
      return false;

    $(this.gui_objects.countdisplay).html(text);

    // update page navigation buttons
    this.set_page_buttons();
  };

  // replace content of mailboxname display
  this.set_mailboxname = function(content)
  {
    if (this.gui_objects.mailboxname && content)
      this.gui_objects.mailboxname.innerHTML = content;
  };

  // replace content of quota display
  this.set_quota = function(content)
  {
    if (this.gui_objects.quotadisplay && content && content.type == 'text')
      $(this.gui_objects.quotadisplay).text((content.percent||0) + '%').attr('title', content.title || '');

    this.triggerEvent('setquota', content);
    this.env.quota_content = content;
  };

  // update trash folder state
  this.set_trash_count = function(count)
  {
    this[(count ? 'un' : '') + 'mark_folder'](this.env.trash_mailbox, 'empty', '', true);
  };

  // update the mailboxlist
  this.set_unread_count = function(mbox, count, set_title, mark)
  {
    if (!this.gui_objects.mailboxlist)
      return false;

    this.env.unread_counts[mbox] = count;
    this.set_unread_count_display(mbox, set_title);

    if (mark)
      this.mark_folder(mbox, mark, '', true);
    else if (!count)
      this.unmark_folder(mbox, 'recent', '', true);

    this.mark_all_read_state();
  };

  // update the mailbox count display
  this.set_unread_count_display = function(mbox, set_title)
  {
    var reg, link, text_obj, item, mycount, childcount, div;

    if (item = this.get_folder_li(mbox, '', true)) {
      mycount = this.env.unread_counts[mbox] ? this.env.unread_counts[mbox] : 0;
      link = $(item).children('a').eq(0);
      text_obj = link.children('span.unreadcount');
      if (!text_obj.length && mycount)
        text_obj = $('<span>').addClass('unreadcount skip-content').appendTo(link);
      reg = /\s+\([0-9]+\)$/i;

      childcount = 0;
      if ((div = item.getElementsByTagName('div')[0]) &&
          div.className.match(/collapsed/)) {
        // add children's counters
        for (var k in this.env.unread_counts)
          if (k.startsWith(mbox + this.env.delimiter))
            childcount += this.env.unread_counts[k];
      }

      if (mycount && text_obj.length)
        text_obj.html(this.env.unreadwrap.replace(/%[sd]/, mycount));
      else if (text_obj.length)
        text_obj.remove();

      // set parent's display
      reg = new RegExp(RegExp.escape(this.env.delimiter) + '[^' + RegExp.escape(this.env.delimiter) + ']+$');
      if (mbox.match(reg))
        this.set_unread_count_display(mbox.replace(reg, ''), false);

      // set the right classes
      if ((mycount+childcount)>0)
        $(item).addClass('unread');
      else
        $(item).removeClass('unread');
    }

    // set unread count to window title
    reg = /^\([0-9]+\)\s+/i;
    if (set_title && document.title) {
      var new_title = '',
        doc_title = String(document.title);

      if (mycount && doc_title.match(reg))
        new_title = doc_title.replace(reg, '('+mycount+') ');
      else if (mycount)
        new_title = '('+mycount+') '+doc_title;
      else
        new_title = doc_title.replace(reg, '');

      this.set_pagetitle(new_title);
    }
  };

  // display fetched raw headers
  this.set_headers = function(content)
  {
    if (this.gui_objects.all_headers_box && content)
      $(this.gui_objects.all_headers_box).html(content).show();
  };

  // display all-headers row and fetch raw message headers
  this.show_headers = function(props, elem)
  {
    if (!this.gui_objects.all_headers_row || !this.gui_objects.all_headers_box || !this.env.uid)
      return;

    $(elem).removeClass('show-headers').addClass('hide-headers');
    $(this.gui_objects.all_headers_row).show();
    elem.onclick = function() { ref.command('hide-headers', '', elem); };

    // fetch headers only once
    if (!this.gui_objects.all_headers_box.innerHTML) {
      this.http_request('headers', {_uid: this.env.uid, _mbox: this.env.mailbox},
        this.display_message('', 'loading')
      );
    }
  };

  // hide all-headers row
  this.hide_headers = function(props, elem)
  {
    if (!this.gui_objects.all_headers_row || !this.gui_objects.all_headers_box)
      return;

    $(elem).removeClass('hide-headers').addClass('show-headers');
    $(this.gui_objects.all_headers_row).hide();
    elem.onclick = function() { ref.command('show-headers', '', elem); };
  };

  // create folder selector popup
  this.folder_selector = function(event, callback)
  {
    this.entity_selector('folder-selector', callback, this.env.mailboxes_list, function(obj, a) {
      var n = 0, s = 0,
        delim = ref.env.delimiter,
        folder = ref.env.mailboxes[obj],
        id = folder.id,
        row = $('<li>');

      if (folder.virtual)
        a.addClass('virtual').attr({'aria-disabled': 'true', tabindex: '-1'});
      else
        a.addClass('active').data('id', folder.id);

      if (folder['class'])
        row.addClass(folder['class']);

      // calculate/set indentation level
      while ((s = id.indexOf(delim, s)) >= 0) {
        n++; s++;
      }
      a.css('padding-left', n ? (n * 16) + 'px' : 0);

      // add folder name element
      a.append($('<span>').text(folder.name));

      return row.append(a);
    }, event);
  };

  // create addressbook selector popup
  this.addressbook_selector = function(event, callback)
  {
    // build addressbook + groups list
    var combined_sources = [];

    // check we really need it before processing
    if (!this.entity_selectors['addressbook-selector']) {
      $.each(this.env.address_sources, function() {
        if (!this.readonly) {
          var source = this;
          combined_sources.push(source);

          $.each(ref.env.contactgroups, function() {
            if (source.id === this.source) {
              combined_sources.push(this);
            }
          });
        }
      });
    }

    this.entity_selector('addressbook-selector', callback, combined_sources, function(obj, a) {
      if (obj.type == 'group') {
        a.attr('rel', obj.source + ':' + obj.id)
          .addClass('contactgroup active')
          .data({source: obj.source, gid: obj.id, id: obj.source + ':' + obj.id})
          .css('padding-left', '16px');
      }
      else {
        a.addClass('addressbook active').data('id', obj.id);
      }
      a.append($('<span>').text(obj.name));

      return $('<li>').append(a);
    }, event);
  };

  // create contactgroup selector popup
  this.contactgroup_selector = function(event, callback)
  {
    this.entity_selector('contactgroup-selector', callback, this.env.contactgroups, function(obj, a) {
      if (ref.env.source === obj.source) {
        a.addClass('contactgroup active')
            .data({id: obj.id})
            .append($('<span>').text(obj.name));

        return $('<li>').append(a);
      }
    }, event);
  };

  // create selector popup (eg for folders or address books), position and display it
  this.entity_selector = function(name, click_callback, entity_list, list_callback, event)
  {
    var container = this.entity_selectors[name];

    if (!container) {
      var rows = [],
        container = $('<div>').attr('id', name).addClass('popupmenu'),
        ul = $('<ul>').addClass('toolbarmenu menu'),
        link = document.createElement('a');

      link.href = '#';
      link.className = 'icon';

      // loop over entity list
      $.each(entity_list, function(i) {
        var a = $(link.cloneNode(false)).attr('rel', this.id);
        rows.push(list_callback(this, a, i));
      });

      ul.append(rows).appendTo(container);

      // temporarily show element to calculate its size
      container.css({left: '-1000px', top: '-1000px'})
        .appendTo(document.body).show();

      // set max-height if the list is long
      if (rows.length > 10)
        container.css('max-height', $('li', container)[0].offsetHeight * 10 + 9);

      // register delegate event handler for folder item clicks
      container.on('click', 'a.active', function(e) {
        container.data('callback')($(this).data('id'), this);
      });

      this.entity_selectors[name] = container;
    }

    container.data('callback', click_callback);

    // position menu on the screen
    this.show_menu(name, true, event);
  };

  this.destroy_entity_selector = function(name)
  {
    $("#" + name).remove();
    delete this.entity_selectors[name];
    this.triggerEvent('destroy-entity-selector', { name: name });
  };

  /***********************************************/
  /*********    popup menu functions     *********/
  /***********************************************/

  // Show/hide a specific popup menu
  this.show_menu = function(prop, show, event)
  {
    var name = typeof prop == 'object' ? prop.menu : prop,
      obj = $('#'+name),
      ref = event && event.target ? $(event.target) : $(obj.attr('rel') || '#'+name+'link'),
      keyboard = rcube_event.is_keyboard(event),
      align = obj.attr('data-align') || '',
      stack = false;

    // find "real" button element
    if (ref.get(0).tagName != 'A' && ref.closest('a').length)
      ref = ref.closest('a');

    if (typeof prop == 'string')
      prop = { menu:name };

    // let plugins or skins provide the menu element
    if (!obj.length) {
      obj = this.triggerEvent('menu-get', { name:name, props:prop, originalEvent:event });
    }

    if (!obj || !obj.length) {
      // just delegate the action to subscribers
      return this.triggerEvent(show === false ? 'menu-close' : 'menu-open', { name:name, props:prop, originalEvent:event });
    }

    // move element to top for proper absolute positioning
    obj.appendTo(document.body);

    if (typeof show == 'undefined')
      show = obj.is(':visible') ? false : true;

    if (show && ref.length) {
      var win = $(window),
        pos = ref.offset(),
        above = align.indexOf('bottom') >= 0;

      stack = ref.attr('role') == 'menuitem' || ref.closest('[role=menuitem]').length > 0;

      ref.offsetWidth = ref.outerWidth();
      ref.offsetHeight = ref.outerHeight();
      if (!above && pos.top + ref.offsetHeight + obj.height() > win.height()) {
        above = true;
      }
      if (align.indexOf('right') >= 0) {
        pos.left = pos.left + ref.outerWidth() - obj.width();
      }
      else if (stack) {
        pos.left = pos.left + ref.offsetWidth - 5;
        pos.top -= ref.offsetHeight;
      }
      if (pos.left + obj.width() > win.width()) {
        pos.left = win.width() - obj.width() - 12;
      }
      pos.top = Math.max(0, pos.top + (above ? -obj.height() : ref.offsetHeight));
      obj.css({ left:pos.left+'px', top:pos.top+'px' });
    }

    // add menu to stack
    if (show) {
      // truncate stack down to the one containing the ref link
      for (var i = this.menu_stack.length - 1; stack && i >= 0; i--) {
        if (!$(ref).parents('#'+this.menu_stack[i]).length && $(event.target).parent().attr('role') != 'menuitem')
          this.hide_menu(this.menu_stack[i], event);
      }
      if (stack && this.menu_stack.length) {
        obj.data('parent', $.last(this.menu_stack));
        obj.css('z-index', ($('#'+$.last(this.menu_stack)).css('z-index') || 0) + 1);
      }
      else if (!stack && this.menu_stack.length) {
        this.hide_menu(this.menu_stack[0], event);
      }

      obj.show().attr('aria-hidden', 'false').data('opener', ref.attr('aria-expanded', 'true').get(0));
      this.triggerEvent('menu-open', { name:name, obj:obj, props:prop, originalEvent:event });
      this.menu_stack.push(name);

      this.menu_keyboard_active = show && keyboard;
      if (this.menu_keyboard_active) {
        this.focused_menu = name;
        obj.find('a,input:not(:disabled)').not('[aria-disabled=true]').first().focus();
      }
    }
    else {  // close menu
      this.hide_menu(name, event);
    }

    return show;
  };

  // hide the given popup menu (and its children)
  this.hide_menu = function(name, event)
  {
    if (!this.menu_stack.length) {
      // delegate to subscribers
      this.triggerEvent('menu-close', { name:name, props:{ menu:name }, originalEvent:event });
      return;
    }

    var obj, keyboard = rcube_event.is_keyboard(event);
    for (var j=this.menu_stack.length-1; j >= 0; j--) {
      obj = $('#' + this.menu_stack[j]).hide().attr('aria-hidden', 'true').data('parent', false);
      this.triggerEvent('menu-close', { name:this.menu_stack[j], obj:obj, props:{ menu:this.menu_stack[j] }, originalEvent:event });
      if (this.menu_stack[j] == name) {
        j = -1;  // stop loop
        if (obj.data('opener')) {
          $(obj.data('opener')).attr('aria-expanded', 'false');
          if (keyboard)
            obj.data('opener').focus();
        }
      }
      this.menu_stack.pop();
    }

    // focus previous menu in stack
    if (this.menu_stack.length && keyboard) {
      this.menu_keyboard_active = true;
      this.focused_menu = $.last(this.menu_stack);
      if (!obj || !obj.data('opener'))
        $('#'+this.focused_menu).find('a,input:not(:disabled)').not('[aria-disabled=true]').first().focus();
    }
    else {
      this.focused_menu = null;
      this.menu_keyboard_active = false;
    }
  };

  // position a menu element on the screen in relation to other object
  this.element_position = function(element, obj)
  {
    var obj = $(obj), win = $(window),
      width = obj.outerWidth(),
      height = obj.outerHeight(),
      menu_pos = obj.data('menu-pos'),
      win_height = win.height(),
      elem_height = $(element).height(),
      elem_width = $(element).width(),
      pos = obj.offset(),
      top = pos.top,
      left = pos.left + width;

    if (menu_pos == 'bottom') {
      top += height;
      left -= width;
    }
    else
      left -= 5;

    if (top + elem_height > win_height) {
      top -= elem_height - height;
      if (top < 0)
        top = Math.max(0, (win_height - elem_height) / 2);
    }

    if (left + elem_width > win.width())
      left -= elem_width + width;

    element.css({left: left + 'px', top: top + 'px'});
  };

  // initialize HTML editor
  this.editor_init = function(config, id)
  {
    this.editor = new rcube_text_editor(config || this.env.editor_config, id);
  };


  /********************************************************/
  /*********  html to text conversion functions   *********/
  /********************************************************/

  this.html2plain = function(html, func)
  {
    return this.format_converter(html, 'html', func);
  };

  this.plain2html = function(plain, func)
  {
    return this.format_converter(plain, 'plain', func);
  };

  this.format_converter = function(text, format, func)
  {
    // warn the user (if converted content is not empty)
    if (!text
      || (format == 'html' && !(text.replace(/<[^>]+>|&nbsp;|\xC2\xA0|\s/g, '')).length)
      || (format != 'html' && !(text.replace(/\xC2\xA0|\s/g, '')).length)
    ) {
      // without setTimeout() here, textarea is filled with initial (onload) content
      if (func)
        setTimeout(function() { func(''); }, 50);
      return true;
    }

    var confirmed = this.env.editor_warned || confirm(this.get_label('editorwarning'));

    this.env.editor_warned = true;

    if (!confirmed)
      return false;

    var url = '?_task=utils&_action=' + (format == 'html' ? 'html2text' : 'text2html'),
      lock = this.set_busy(true, 'converting');

    $.ajax({ type: 'POST', url: url, data: text, contentType: 'application/octet-stream',
      error: function(o, status, err) { ref.http_error(o, status, err, lock); },
      success: function(data) {
        ref.set_busy(false, null, lock);
        if (func) func(data);
      }
    });

    return true;
  };


  /********************************************************/
  /*********        remote request methods        *********/
  /********************************************************/

  // compose a valid url with the given parameters
  this.url = function(action, query)
  {
    var querystring = typeof query === 'string' ? query : '';

    if (typeof action !== 'string')
      query = action;
    else if (!query || typeof query !== 'object')
      query = {};

    if (action)
      query._action = action;
    else if (this.env.action)
      query._action = this.env.action;

    var url = this.env.comm_path, k, param = {};

    // overwrite task name
    if (action && action.match(/([a-z0-9_-]+)\/([a-z0-9-_.]+)/)) {
      query._action = RegExp.$2;
      url = url.replace(/\_task=[a-z0-9_-]+/, '_task=' + RegExp.$1);
    }

    // force _framed=0
    if (query._framed === 0) {
      url = url.replace('&_framed=1', '');
      query._framed = null;
    }

    // remove undefined values
    for (k in query) {
      if (query[k] !== undefined && query[k] !== null)
        param[k] = query[k];
    }

    if (param = $.param(param))
      url += (url.indexOf('?') > -1 ? '&' : '?') + param;

    if (querystring)
      url += (url.indexOf('?') > -1 ? '&' : '?') + querystring;

    return url;
  };

  this.redirect = function(url, lock)
  {
    if (lock !== false)
      this.set_busy(true, 'loading');

    if (this.is_framed()) {
      url = url.replace(/&_framed=1/, '');
      parent.rcmail.redirect(url, lock);
    }
    else {
      if (this.env.extwin) {
        if (typeof url == 'string')
          url += (url.indexOf('?') < 0 ? '?' : '&') + '_extwin=1';
        else
          url._extwin = 1;
      }
      this.location_href(url, window);
    }
  };

  this.goto_url = function(action, query, lock, secure)
  {
    var url = this.url(action, query)
    if (secure) url = this.secure_url(url);
    this.redirect(url, lock);
  };

  this.location_href = function(url, target, frame)
  {
    if (frame)
      this.lock_frame(target);

    if (typeof url == 'object')
      url = this.env.comm_path + '&' + $.param(url);

    // simulate real link click to force IE to send referer header
    if (bw.ie && target == window)
      $('<a>').attr('href', url).appendTo(document.body).get(0).click();
    else
      target.location.href = url;

    // reset keep-alive interval
    this.start_keepalive();
  };

  // update browser location to remember current view
  this.update_state = function(query)
  {
    if (window.history.replaceState)
      try {
        // This may throw security exception in Firefox (#5400)
        window.history.replaceState({}, document.title, rcmail.url('', query));
      }
      catch(e) { /* ignore */ };
  };

  // send a http request to the server
  this.http_request = function(action, data, lock, type)
  {
    if (type != 'POST')
      type = 'GET';

    if (typeof data !== 'object')
      data = rcube_parse_query(data);

    data._remote = 1;
    data._unlock = lock ? lock : 0;

    // trigger plugin hook
    var result = this.triggerEvent('request' + action, data);

    // abort if one of the handlers returned false
    if (result === false) {
      if (data._unlock)
        this.set_busy(false, null, data._unlock);
      return false;
    }
    else if (result && result.getResponseHeader) {
      return result;
    }
    else if (result !== undefined) {
      data = result;
      if (data._action) {
        action = data._action;
        delete data._action;
      }
    }

    var url = this.url(action);

    // reset keep-alive interval
    this.start_keepalive();

    // send request
    return $.ajax({
      type: type, url: url, data: data, dataType: 'json',
      success: function(data) { ref.http_response(data); },
      error: function(o, status, err) { ref.http_error(o, status, err, lock, action); }
    });
  };

  // send a http GET request to the server
  this.http_get = this.http_request;

  // send a http POST request to the server
  this.http_post = function(action, data, lock)
  {
    return this.http_request(action, data, lock, 'POST');
  };

  // aborts ajax request
  this.abort_request = function(r)
  {
    if (r.request)
      r.request.abort();
    if (r.lock)
      this.set_busy(false, null, r.lock);
  };

  // handle HTTP response
  this.http_response = function(response)
  {
    if (!response)
      return;

    if (response.unlock)
      this.set_busy(false, null, response.unlock);

    this.triggerEvent('responsebefore', {response: response});
    this.triggerEvent('responsebefore'+response.action, {response: response});

    // set env vars
    if (response.env)
      this.set_env(response.env);

    var i;

    // we have labels to add
    if (typeof response.texts === 'object') {
      for (i in response.texts)
        if (typeof response.texts[i] === 'string')
          this.add_label(i, response.texts[i]);
    }

    // if we get javascript code from server -> execute it
    if (response.exec) {
      eval(response.exec);
    }

    // execute callback functions of plugins
    if (response.callbacks && response.callbacks.length) {
      for (i=0; i < response.callbacks.length; i++)
        this.triggerEvent(response.callbacks[i][0], response.callbacks[i][1]);
    }

    // process the response data according to the sent action
    switch (response.action) {
      case 'mark':
        // Mark the message as Seen also in the opener/parent
        if ((this.env.action == 'show' || this.env.action == 'preview') && this.env.last_flag == 'SEEN')
          this.set_unread_message(this.env.uid, this.env.mailbox);
        break;

      case 'delete':
        if (this.task == 'addressbook') {
          var sid, uid = this.contact_list.get_selection(), writable = false;

          if (uid && this.contact_list.rows[uid]) {
            // search results, get source ID from record ID
            if (this.env.source == '') {
              sid = String(uid).replace(/^[^-]+-/, '');
              writable = sid && this.env.address_sources[sid] && !this.env.address_sources[sid].readonly;
            }
            else {
              writable = !this.env.address_sources[this.env.source].readonly;
            }
          }
          this.enable_command('delete', 'edit', writable);
          this.enable_command('export', (this.contact_list && this.contact_list.rowcount > 0));
          this.enable_command('export-selected', 'print', false);
        }

      case 'move':
        if (this.env.action == 'show') {
          // re-enable commands on move/delete error
          this.enable_command(this.env.message_commands, true);
          if (!this.env.list_post)
            this.enable_command('reply-list', false);
        }
        else if (this.task == 'addressbook') {
          this.triggerEvent('listupdate', { list:this.contact_list, folder:this.env.source, rowcount:this.contact_list.rowcount });
        }

      case 'purge':
      case 'expunge':
        if (this.task == 'mail') {
          if (!this.env.exists) {
            // clear preview pane content
            if (this.env.contentframe)
              this.show_contentframe(false);
            // disable commands useless when mailbox is empty
            this.enable_command(this.env.message_commands, 'purge', 'expunge',
              'select-all', 'select-none', 'expand-all', 'expand-unread', 'collapse-all', false);
          }
          if (this.message_list)
            this.triggerEvent('listupdate', { list:this.message_list, folder:this.env.mailbox, rowcount:this.message_list.rowcount });
        }
        break;

      case 'refresh':
      case 'check-recent':
        // update message flags
        $.each(this.env.recent_flags || {}, function(uid, flags) {
          ref.set_message(uid, 'deleted', flags.deleted);
          ref.set_message(uid, 'replied', flags.answered);
          ref.set_message(uid, 'unread', !flags.seen);
          ref.set_message(uid, 'forwarded', flags.forwarded);
          ref.set_message(uid, 'flagged', flags.flagged);
        });
        delete this.env.recent_flags;

      case 'getunread':
      case 'search':
        this.env.qsearch = null;
      case 'list':
        if (this.task == 'mail') {
          var is_multifolder = this.is_multifolder_listing(),
            list = this.message_list,
            uid = this.env.list_uid;

          this.enable_command('show', 'select-all', 'select-none', this.env.messagecount > 0);
          this.enable_command('expunge', 'purge', this.env.exists && !is_multifolder);
          this.enable_command('import-messages', !is_multifolder);
          this.enable_command('expand-all', 'expand-unread', 'collapse-all', this.env.threading && this.env.messagecount && !is_multifolder);

          if (list) {
            if (response.action == 'list' || response.action == 'search') {
              // highlight message row when we're back from message page
              if (uid) {
                if (uid === 'FIRST') {
                  uid = list.get_first_row();
                }
                else if (uid === 'LAST') {
                  uid = list.get_last_row();
                }
                else if (!list.rows[uid]) {
                  uid += '-' + this.env.mailbox;
                }

                if (uid && list.rows[uid]) {
                  list.select(uid);
                }

                delete this.env.list_uid;
              }

              this.enable_command('set-listmode', this.env.threads && !is_multifolder);
              if (list.rowcount > 0 && !$(document.activeElement).is('input,textarea'))
                list.focus();

              // trigger 'select' so all dependent actions update its state
              // e.g. plugins use this event to activate buttons (#1490647)
              list.triggerEvent('select');
            }

            if (response.action != 'getunread')
              this.triggerEvent('listupdate', { list:list, folder:this.env.mailbox, rowcount:list.rowcount });
          }
        }
        else if (this.task == 'addressbook') {
          var list = this.contact_list,
            uid = this.env.list_uid;

          this.enable_command('export', 'select-all', 'select-none', (list && list.rowcount > 0));

          if (response.action == 'list' || response.action == 'search') {
            this.enable_command('search-create', this.env.source == '');
            this.enable_command('search-delete', this.env.search_id);
            this.update_group_commands();

            if (list && uid) {
              if (uid === 'FIRST') {
                uid = list.get_first_row();
              }
              else if (uid === 'LAST') {
                uid = list.get_last_row();
              }

              if (uid && list.rows[uid]) {
                list.select(uid);
              }

              delete this.env.list_uid;

              // trigger 'select' so all dependent actions update its state
              list.triggerEvent('select');
            }

            if (list.rowcount > 0 && !$(document.activeElement).is('input,textarea'))
              list.focus();

            this.triggerEvent('listupdate', { list:list, folder:this.env.source, rowcount:list.rowcount });
          }
        }
        break;

      case 'list-contacts':
      case 'search-contacts':
        if (this.contact_list) {
          if (this.contact_list.rowcount > 0)
            this.contact_list.focus();
          this.triggerEvent('listupdate', { list:this.contact_list, rowcount:this.contact_list.rowcount });
        }
        break;
    }

    if (response.unlock)
      this.hide_message(response.unlock);

    this.triggerEvent('responseafter', {response: response});
    this.triggerEvent('responseafter'+response.action, {response: response});

    // reset keep-alive interval
    this.start_keepalive();
  };

  // handle HTTP request errors
  this.http_error = function(request, status, err, lock, action)
  {
    var errmsg = request.statusText;

    this.set_busy(false, null, lock);
    request.abort();

    // don't display error message on page unload (#1488547)
    if (this.unload)
      return;

    if (request.status && errmsg)
      this.display_message(this.get_label('servererror') + ' (' + errmsg + ')', 'error');
    else if (status == 'timeout')
      this.display_message('requesttimedout', 'error');
    else if (request.status == 0 && status != 'abort')
      this.display_message('connerror', 'error');

    // redirect to url specified in location header if not empty
    var location_url = request.getResponseHeader("Location");
    if (location_url && this.env.action != 'compose')  // don't redirect on compose screen, contents might get lost (#1488926)
      this.redirect(location_url);

    // 403 Forbidden response (CSRF prevention) - reload the page.
    // In case there's a new valid session it will be used, otherwise
    // login form will be presented (#1488960).
    if (request.status == 403) {
      (this.is_framed() ? parent : window).location.reload();
      return;
    }

    // re-send keep-alive requests after 30 seconds
    if (action == 'keep-alive')
      setTimeout(function() { ref.keep_alive(); ref.start_keepalive(); }, 30000);
  };

  // handler for session errors detected on the server
  this.session_error = function(redirect_url)
  {
    this.env.server_error = 401;

    // save message in local storage and do not redirect
    if (this.env.action == 'compose') {
      this.save_compose_form_local();
      this.compose_skip_unsavedcheck = true;
      // stop keep-alive and refresh processes
      this.env.session_lifetime = 0;
      if (this._keepalive)
        clearInterval(this._keepalive);
      if (this._refresh)
        clearInterval(this._refresh);
    }
    else if (redirect_url) {
      setTimeout(function() { ref.redirect(redirect_url, true); }, 2000);
    }
  };

  // callback when an iframe finished loading
  this.iframe_loaded = function(unlock)
  {
    if (!unlock)
      unlock = this.env.frame_lock;

    this.set_busy(false, null, unlock);

    if (this.submit_timer)
      clearTimeout(this.submit_timer);
  };

  /**
   Send multi-threaded parallel HTTP requests to the server for a list if items.
   The string '%' in either a GET query or POST parameters will be replaced with the respective item value.
   This is the argument object expected: {
       items: ['foo','bar','gna'],      // list of items to send requests for
       action: 'task/some-action',      // Roundcube action to call
       query: { q:'%s' },               // GET query parameters
       postdata: { source:'%s' },       // POST data (sends a POST request if present)
       threads: 3,                      // max. number of concurrent requests
       onresponse: function(data){ },   // Callback function called for every response received from server
       whendone: function(alldata){ }   // Callback function called when all requests have been sent
   }
  */
  this.multi_thread_http_request = function(prop)
  {
    var i, item, reqid = new Date().getTime(),
      threads = prop.threads || 1;

    prop.reqid = reqid;
    prop.running = 0;
    prop.requests = [];
    prop.result = [];
    prop._items = $.extend([], prop.items);  // copy items

    if (!prop.lock)
      prop.lock = this.display_message('', 'loading');

    // add the request arguments to the jobs pool
    this.http_request_jobs[reqid] = prop;

    // start n threads
    for (i=0; i < threads; i++) {
      item = prop._items.shift();
      if (item === undefined)
        break;

      prop.running++;
      prop.requests.push(this.multi_thread_send_request(prop, item));
    }

    return reqid;
  };

  // helper method to send an HTTP request with the given iterator value
  this.multi_thread_send_request = function(prop, item)
  {
    var k, postdata, query;

    // replace %s in post data
    if (prop.postdata) {
      postdata = {};
      for (k in prop.postdata) {
        postdata[k] = String(prop.postdata[k]).replace('%s', item);
      }
      postdata._reqid = prop.reqid;
    }
    // replace %s in query
    else if (typeof prop.query == 'string') {
      query = prop.query.replace('%s', item);
      query += '&_reqid=' + prop.reqid;
    }
    else if (typeof prop.query == 'object' && prop.query) {
      query = {};
      for (k in prop.query) {
        query[k] = String(prop.query[k]).replace('%s', item);
      }
      query._reqid = prop.reqid;
    }

    // send HTTP GET or POST request
    return postdata ? this.http_post(prop.action, postdata) : this.http_request(prop.action, query);
  };

  // callback function for multi-threaded http responses
  this.multi_thread_http_response = function(data, reqid)
  {
    var prop = this.http_request_jobs[reqid];
    if (!prop || prop.running <= 0 || prop.cancelled)
      return;

    prop.running--;

    // trigger response callback
    if (prop.onresponse && typeof prop.onresponse == 'function') {
      prop.onresponse(data);
    }

    prop.result = $.extend(prop.result, data);

    // send next request if prop.items is not yet empty
    var item = prop._items.shift();
    if (item !== undefined) {
      prop.running++;
      prop.requests.push(this.multi_thread_send_request(prop, item));
    }
    // trigger whendone callback and mark this request as done
    else if (prop.running == 0) {
      if (prop.whendone && typeof prop.whendone == 'function') {
        prop.whendone(prop.result);
      }

      this.set_busy(false, '', prop.lock);

      // remove from this.http_request_jobs pool
      delete this.http_request_jobs[reqid];
    }
  };

  // abort a running multi-thread request with the given identifier
  this.multi_thread_request_abort = function(reqid)
  {
    var prop = this.http_request_jobs[reqid];
    if (prop) {
      for (var i=0; prop.running > 0 && i < prop.requests.length; i++) {
        if (prop.requests[i].abort)
          prop.requests[i].abort();
      }

      prop.running = 0;
      prop.cancelled = true;
      this.set_busy(false, '', prop.lock);
    }
  };

  // post the given form to a hidden iframe
  this.async_upload_form = function(form, action, onload)
  {
    // create hidden iframe
    var ts = new Date().getTime(),
      frame_name = 'rcmupload' + ts,
      frame = this.dummy_iframe(frame_name);

    // handle upload errors by parsing iframe content in onload
    frame.on('load', {ts:ts}, onload);

    $(form).attr({
        target: frame_name,
        action: this.url(action, {_id: this.env.compose_id || '', _uploadid: ts, _from: this.env.action}),
        method: 'POST',
        enctype: 'multipart/form-data'
      })
      .submit();

    return frame_name;
  };

  // create hidden iframe element
  this.dummy_iframe = function(name, src)
  {
    return $('<iframe>').attr({
        name: name,
        src: src,
        style: 'width:0;height:0;visibility:hidden',
        'aria-hidden': 'true'
      })
      .appendTo(document.body);
  };

  // html5 file-drop API
  this.document_drag_hover = function(e, over)
  {
    // don't e.preventDefault() here to not block text dragging on the page (#1490619)
    $(this.gui_objects.filedrop)[(over?'addClass':'removeClass')]('active');
  };

  this.file_drag_hover = function(e, over)
  {
    e.preventDefault();
    e.stopPropagation();
    $(this.gui_objects.filedrop)[(over?'addClass':'removeClass')]('hover');
  };

  // handler when files are dropped to a designated area.
  // compose a multipart form data and submit it to the server
  this.file_dropped = function(e)
  {
    // abort event and reset UI
    this.file_drag_hover(e, false);

    // prepare multipart form data composition
    var uri,
      files = e.target.files || e.dataTransfer.files,
      args = {_id: this.env.compose_id || this.env.cid || '', _remote: 1, _from: this.env.action};

    if (!files || !files.length) {
      // Roundcube attachment, pass its uri to the backend and attach
      if (uri = e.dataTransfer.getData('roundcube-uri')) {
        var ts = 'upload' + new Date().getTime(),
          // jQuery way to escape filename (#1490530)
          content = $('<span>').text(e.dataTransfer.getData('roundcube-name') || this.get_label('attaching')).html();

        args._uri = uri;
        args._uploadid = ts;

        // add to attachments list
        if (!this.add2attachment_list(ts, {name: '', html: content, classname: 'uploading', complete: false}))
          this.file_upload_id = this.set_busy(true, 'attaching');

        this.http_post(this.env.filedrop.action || 'upload', args);
      }

      return;
    }

    this.file_upload(files, args, {
      name: (this.env.filedrop.fieldname || '_file') + (this.env.filedrop.single ? '' : '[]'),
      single: this.env.filedrop.single,
      filter: this.env.filedrop.filter,
      action: ref.env.filedrop.action
    });
  };

  // Files upload using ajax
  this.file_upload = function(files, post_args, props)
  {
    if (!window.FormData || !files || !files.length)
      return false;

    var f, i, fname, size = 0, numfiles = 0,
      formdata = new FormData(),
      fieldname = props.name || '_file[]',
      limit = props.single ? 1 : files.length;
      args = $.extend({_remote: 1, _from: this.env.action}, post_args || {});

    // add files to form data
    for (i=0; numfiles < limit && (f = files[i]); i++) {
      // filter by file type if requested
      if (props.filter && !f.type.match(new RegExp(props.filter))) {
        // TODO: show message to user
        continue;
      }

      formdata.append(fieldname, f);
      size += f.size;
      fname = f.name;
      numfiles++;
    }

    if (numfiles) {
      if (this.env.max_filesize && this.env.filesizeerror && size > this.env.max_filesize) {
        this.display_message(this.env.filesizeerror, 'error');
        return false;
      }

      if (this.env.max_filecount && this.env.filecounterror && numfiles > this.env.max_filecount) {
        this.display_message(this.env.filecounterror, 'error');
        return false;
      }

      var ts = 'upload' + new Date().getTime(),
        label = numfiles > 1 ? this.get_label('uploadingmany') : fname,
        // jQuery way to escape filename (#1490530)
        content = $('<span>').text(label).html();

      // add to attachments list
      if (!this.add2attachment_list(ts, {name: '', html: content, classname: 'uploading', complete: false}) && !props.lock)
        props.lock = this.file_upload_id = this.set_busy(true, 'uploading');

      args._uploadid = ts;
      args._unlock = props.lock;

      this.uploads[ts] = $.ajax({
        type: 'POST',
        dataType: 'json',
        url: this.url(props.action || 'upload', args),
        contentType: false,
        processData: false,
        timeout: this.uploadTimeout, // ajax call timeout for loading attachment
        data: formdata,
        headers: {'X-Roundcube-Request': this.env.request_token},
        xhr: function() {
          var xhr = $.ajaxSettings.xhr();
          if (xhr.upload && ref.labels.uploadprogress) {
            xhr.upload.onprogress = function(e) {
              var msg = ref.file_upload_msg(e.loaded, e.total);
              if (msg) {
                $('#' + ts).find('.uploading').text(msg);
              }
            };
          }
          return xhr;
        },
        success: function(data) {
          delete ref.uploads[ts];
          ref.http_response(data);
        },
        error: function(o, status, err) {
          delete ref.uploads[ts];
          ref.remove_from_attachment_list(ts);
          ref.http_error(o, status, err, props.lock, 'attachment');
        }
      });
    }

    return true;
  };

  this.file_upload_msg = function(current, total)
  {
    if (total && current < total) {
      var percent = Math.round(current/total * 100),
        label = ref.get_label('uploadprogress');

      if (total >= 1073741824) {
        total = parseFloat(total/1073741824).toFixed(1) + ' ' . this.get_label('GB');
        current = parseFloat(current/1073741824).toFixed(1);
      }
      else if (total >= 1048576) {
        total = parseFloat(total/1048576).toFixed(1) + ' ' + this.get_label('MB');
        current = parseFloat(current/1048576).toFixed(1);
      }
      else if (total >= 1024) {
        total = parseInt(total/1024) + ' ' + this.get_label('KB');
        current = parseInt(current/1024);
      }
      else {
        total = total + ' ' + this.get_label('B');
      }

      return label.replace('$percent', percent + '%').replace('$current', current).replace('$total', total);
    }
  };

  // starts interval for keep-alive signal
  this.start_keepalive = function()
  {
    if (!this.env.session_lifetime || this.env.framed || this.env.extwin || this.task == 'login' || this.env.action == 'print')
      return;

    if (this._keepalive)
      clearInterval(this._keepalive);

    // use Math to prevent from an integer overflow (#5273)
    // maximum interval is 15 minutes, minimum is 30 seconds
    var interval = Math.min(1800, this.env.session_lifetime) * 0.5 * 1000;
    this._keepalive = setInterval(function() { ref.keep_alive(); }, interval < 30000 ? 30000 : interval);
  };

  // starts interval for refresh signal
  this.start_refresh = function()
  {
    if (!this.env.refresh_interval || this.env.framed || this.env.extwin || this.task == 'login' || this.env.action == 'print')
      return;

    if (this._refresh)
      clearInterval(this._refresh);

    this._refresh = setInterval(function(){ ref.refresh(); }, this.env.refresh_interval * 1000);
  };

  // sends keep-alive signal
  this.keep_alive = function()
  {
    if (!this.busy)
      this.http_request('keep-alive');
  };

  // sends refresh signal
  this.refresh = function()
  {
    if (this.busy) {
      // try again after 10 seconds
      setTimeout(function() { ref.refresh(); ref.start_refresh(); }, 10000);
      return;
    }

    var params = {}, lock = this.set_busy(true, 'refreshing');

    if (this.task == 'mail' && this.gui_objects.mailboxlist)
      params = this.check_recent_params();

    params._last = Math.floor(this.env.lastrefresh.getTime() / 1000);
    this.env.lastrefresh = new Date();

    // plugins should bind to 'requestrefresh' event to add own params
    this.http_post('refresh', params, lock);
  };

  // returns check-recent request parameters
  this.check_recent_params = function()
  {
    var params = {_mbox: this.env.mailbox};

    if (this.gui_objects.mailboxlist)
      params._folderlist = 1;
    if (this.gui_objects.quotadisplay)
      params._quota = 1;
    if (this.env.search_request)
      params._search = this.env.search_request;

    if (this.gui_objects.messagelist) {
      params._list = 1;

      // message uids for flag updates check
      params._uids = $.map(this.message_list.rows, function(row, uid) { return uid; }).join(',');
    }

    return params;
  };


  /********************************************************/
  /*********            helper methods            *********/
  /********************************************************/

  /**
   * Quote html entities
   */
  this.quote_html = function(str)
  {
    return String(str).replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
  };

  // get window.opener.rcmail if available
  this.opener = function(deep, filter)
  {
    var i, win = window.opener;

    // catch Error: Permission denied to access property rcmail
    try {
      if (win && !win.closed && win !== window) {
        // try parent of the opener window, e.g. preview frame
        if (deep && (!win.rcmail || win.rcmail.env.framed) && win.parent && win.parent.rcmail)
          win = win.parent;

        if (win.rcmail && filter)
          for (i in filter)
            if (win.rcmail.env[i] != filter[i])
              return;

        return win.rcmail;
      }
    }
    catch (e) {}
  };

  // check if we're in show mode or if we have a unique selection
  // and return the message uid
  this.get_single_uid = function()
  {
    var uid = this.env.uid || (this.message_list ? this.message_list.get_single_selection() : null);
    var result = ref.triggerEvent('get_single_uid', { uid: uid });
    return result || uid;
  };

  // same as above but for contacts
  this.get_single_cid = function()
  {
    var cid = this.env.cid || (this.contact_list ? this.contact_list.get_single_selection() : null);
    var result = ref.triggerEvent('get_single_cid', { cid: cid });
    return result || cid;
  };

  // get the IMP mailbox of the message with the given UID
  this.get_message_mailbox = function(uid)
  {
    var msg;

    if (this.env.messages && uid && (msg = this.env.messages[uid]) && msg.mbox)
      return msg.mbox;

    if (/^[0-9]+-(.*)$/.test(uid))
      return RegExp.$1;

    return this.env.mailbox;
  };

  // build request parameters from single message id (maybe with mailbox name)
  this.params_from_uid = function(uid, params)
  {
    if (!params)
      params = {};

    params._uid = String(uid).split('-')[0];
    params._mbox = this.get_message_mailbox(uid);

    return params;
  };

  // gets cursor position
  this.get_caret_pos = function(obj)
  {
    if (obj.selectionEnd !== undefined)
      return obj.selectionEnd;

    return obj.value.length;
  };

  // moves cursor to specified position
  this.set_caret_pos = function(obj, pos)
  {
    try {
      if (obj.setSelectionRange)
        obj.setSelectionRange(pos, pos);
    }
    catch(e) {} // catch Firefox exception if obj is hidden
  };

  // get selected text from an input field
  this.get_input_selection = function(obj)
  {
    var start = 0, end = 0, normalizedValue = '';

    if (typeof obj.selectionStart == "number" && typeof obj.selectionEnd == "number") {
      normalizedValue = obj.value;
      start = obj.selectionStart;
      end = obj.selectionEnd;
    }

    return {start: start, end: end, text: normalizedValue.substr(start, end-start)};
  };

  // disable/enable all fields of a form
  this.lock_form = function(form, lock)
  {
    if (!form || !form.elements)
      return;

    if (lock)
      this.disabled_form_elements = [];

    $.each(form.elements, function() {
      if (this.type == 'hidden')
        return;
      // remember which elem was disabled before lock
      if (lock && this.disabled)
        ref.disabled_form_elements.push(this);
      else if (lock || $.inArray(this, ref.disabled_form_elements) < 0)
        this.disabled = lock;
    });
  };

  this.mailto_handler_uri = function()
  {
    return location.href.split('?')[0] + '?_task=mail&_action=compose&_to=%s';
  };

  this.register_protocol_handler = function(name)
  {
    try {
      window.navigator.registerProtocolHandler('mailto', this.mailto_handler_uri(), name);
    }
    catch(e) {
      this.display_message(String(e), 'error');
    }
  };

  this.check_protocol_handler = function(name, elem)
  {
    var nav = window.navigator;

    if (!nav || (typeof nav.registerProtocolHandler != 'function')) {
      $(elem).addClass('disabled').click(function() {
        ref.display_message('nosupporterror', 'error');
        return false;
      });
    }
    else if (typeof nav.isProtocolHandlerRegistered == 'function') {
      var status = nav.isProtocolHandlerRegistered('mailto', this.mailto_handler_uri());
      if (status)
        $(elem).parent().find('.mailtoprotohandler-status').html(status);
    }
    else {
      $(elem).click(function() { ref.register_protocol_handler(name); return false; });
    }
  };

  // Checks browser capabilities e.g. PDF support, TIF support
  this.browser_capabilities_check = function()
  {
    if (!this.env.browser_capabilities)
      this.env.browser_capabilities = {};

    $.each(['pdf', 'flash', 'tiff', 'webp', 'pgpmime'], function() {
      if (ref.env.browser_capabilities[this] === undefined)
        ref.env.browser_capabilities[this] = ref[this + '_support_check']();
    });
  };

  // Returns browser capabilities string
  this.browser_capabilities = function()
  {
    if (!this.env.browser_capabilities)
      return '';

    var n, ret = [];

    for (n in this.env.browser_capabilities)
      ret.push(n + '=' + this.env.browser_capabilities[n]);

    return ret.join();
  };

  this.tiff_support_check = function()
  {
    this.image_support_check('tiff');
    return 0;
  };

  this.webp_support_check = function()
  {
    this.image_support_check('webp');
    return 0;
  };

  this.image_support_check = function(type)
  {
    setTimeout(function() {
      var img = new Image();
      img.onload = function() { ref.env.browser_capabilities[type] = 1; };
      img.onerror = function() { ref.env.browser_capabilities[type] = 0; };
      img.src = ref.assets_path('program/resources/blank.' + type);
    }, 10);
  };

  this.pdf_support_check = function()
  {
    if ('pdfViewerEnabled' in navigator)
      return navigator.pdfViewerEnabled ? 1 : 0;

    var i, plugin = navigator.mimeTypes ? navigator.mimeTypes["application/pdf"] : {},
      regex = /Adobe Reader|PDF|Acrobat/i;

    if (plugin && plugin.enabledPlugin)
        return 1;

    for (i in navigator.plugins) {
      plugin = navigator.plugins[i];
      if (typeof plugin === 'string') {
        if (regex.test(plugin))
          return 1;
      }
      else if (plugin.name && regex.test(plugin.name))
        return 1;
    }

    setTimeout(function() {
      $('<object>').attr({
          data: ref.assets_path('program/resources/dummy.pdf'),
          type: 'application/pdf',
          style: 'position: "absolute"; top: -1000px; height: 1px; width: 1px'
        })
        .on('load error', function(e) {
          ref.env.browser_capabilities.pdf = e.type == 'load' ? 1 : 0;

          // add a short delay before attempting to remove element (#8128)
          var obj = this;
          setTimeout(function() { $(obj).remove(); }, 10);
        })
        .appendTo(document.body);
      }, 10);

    return 0;
  };

  this.flash_support_check = function()
  {
    var plugin = navigator.mimeTypes ? navigator.mimeTypes["application/x-shockwave-flash"] : {};

    if (plugin && plugin.enabledPlugin)
        return 1;

    if ('ActiveXObject' in window) {
      try {
        if (plugin = new ActiveXObject("ShockwaveFlash.ShockwaveFlash"))
          return 1;
      }
      catch (e) {}
    }

    return 0;
  };

  // check for mailvelope API
  this.pgpmime_support_check = function(action)
  {
    if (window.mailvelope)
      return 1;

    $(window).on('mailvelope', function() {
      ref.env.browser_capabilities['pgpmime'] = 1;
    });

    return 0;
  };

  this.assets_path = function(path)
  {
    if (this.env.assets_path && !path.startsWith(this.env.assets_path)) {
      path = this.env.assets_path + path;
    }

    return path;
  };

  // Cookie setter
  this.set_cookie = function(name, value, expires)
  {
    if (expires === false) {
      var expires = new Date();
      expires.setYear(expires.getFullYear() + 1);
    }

    setCookie(name, value, expires, this.env.cookie_path, this.env.cookie_domain, this.env.cookie_secure);
  };

  this.get_local_storage_prefix = function()
  {
    if (!this.local_storage_prefix)
      this.local_storage_prefix = 'roundcube.' + (this.env.user_id || 'anonymous') + '.';

    return this.local_storage_prefix;
  };

  // wrapper for localStorage.getItem(key)
  this.local_storage_get_item = function(key, deflt, encrypted)
  {
    var item, result;

    // TODO: add encryption
    try {
      item = localStorage.getItem(this.get_local_storage_prefix() + key);
      result = JSON.parse(item);
    }
    catch (e) { }

    return result || deflt || null;
  };

  // wrapper for localStorage.setItem(key, data)
  this.local_storage_set_item = function(key, data, encrypted)
  {
    // try/catch to handle no localStorage support, but also error
    // in Safari-in-private-browsing-mode where localStorage exists
    // but can't be used (#1489996)
    try {
      // TODO: add encryption
      localStorage.setItem(this.get_local_storage_prefix() + key, JSON.stringify(data));
      return true;
    }
    catch (e) {
      return false;
    }
  };

  // wrapper for localStorage.removeItem(key)
  this.local_storage_remove_item = function(key)
  {
    try {
      localStorage.removeItem(this.get_local_storage_prefix() + key);
      return true;
    }
    catch (e) {
      return false;
    }
  };

  this.print_dialog = function()
  {
    // setTimeout for Safari
    setTimeout('window.print()', 10);
  };
}  // end object rcube_webmail


// some static methods
rcube_webmail.long_subject_title = function (elem, indent, text_elem) {
    if (!elem.title) {
        var siblings_width = 0, $elem = $(text_elem || elem);

        $elem.siblings().each(function () {
            // Note: width() returns 0 for elements with icons in :before (Elastic)
            siblings_width += $(this).width() + (parseFloat(window.getComputedStyle(this, ':before').width) || 0);
        });

        // Note: 3px to be on the safe side, but also specifically for Elastic
        if ($elem.width() + siblings_width + (indent || 0) * 15 >= $elem.parent().width() - 3) {
            elem.title = rcube_webmail.subject_text($elem[0]);
        }
    }
};

rcube_webmail.long_subject_title_ex = function(elem)
{
  if (!elem.title) {
    var $elem = $(elem),
      txt = $elem.text().trim(),
      indent = $('span.branch', $elem).width() || 0,
      tmp = $('<span>').text(txt)
        .css({position: 'absolute', 'float': 'left', visibility: 'hidden',
          'font-size': $elem.css('font-size'), 'font-weight': $elem.css('font-weight')})
        .appendTo(document.body),
      w = tmp.width();

    tmp.remove();
    if (w + indent * 15 > $elem.width())
      elem.title = rcube_webmail.subject_text(elem);
  }
};

rcube_webmail.subject_text = function(elem)
{
  var t = $(elem).clone();
  t.find('.skip-on-drag,.skip-content,.voice').remove();
  return t.text().trim();
};

// set event handlers on all iframe elements (and their contents)
rcube_webmail.set_iframe_events = function(events)
{
  $('iframe').each(function() {
    var frame = $(this);
    $.each(events, function(event_name, event_handler) {
      frame.on('load', function(e) {
        try { $(this).contents().on(event_name, event_handler); }
        catch (e) {/* catch possible permission error in IE */ }
      });

      try { frame.contents().on(event_name, event_handler); }
      catch (e) {/* catch possible permission error in IE */ }
    });
  });
};

rcube_webmail.prototype.get_cookie = getCookie;

// copy event engine prototype
rcube_webmail.prototype.addEventListener = rcube_event_engine.prototype.addEventListener;
rcube_webmail.prototype.removeEventListener = rcube_event_engine.prototype.removeEventListener;
rcube_webmail.prototype.triggerEvent = rcube_event_engine.prototype.triggerEvent;
Name	Size	Permission
tinymce	---	0755
app.js	320546 bytes	0644
app.min.js	171708 bytes	0644
common.js	22914 bytes	0644
common.min.js	12745 bytes	0644
editor.js	28096 bytes	0644
editor.min.js	14751 bytes	0644
googiespell.js	28704 bytes	0644
googiespell.min.js	17844 bytes	0644
jquery.min.js	90926 bytes	0644
jstz.min.js	13835 bytes	0644
list.js	50228 bytes	0644
list.min.js	28678 bytes	0644
publickey.js	20229 bytes	0644
publickey.min.js	5909 bytes	0644
treelist.js	33795 bytes	0644
treelist.min.js	14105 bytes	0644
File Content: app.js

File Content: `app.js`
