diff --git a/plugins/kolab_files/kolab_files.js b/plugins/kolab_files/kolab_files.js
index c7116e0b..8081f432 100644
--- a/plugins/kolab_files/kolab_files.js
+++ b/plugins/kolab_files/kolab_files.js
@@ -1,3785 +1,3786 @@
 /**
  * Kolab files plugin
  *
  * @author Aleksander Machniak <machniak@kolabsys.com>
  *
  * @licstart  The following is the entire license notice for the
  * JavaScript code in this file.
  *
  * Copyright (C) 2011-2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  *
  * @licend  The above is the entire license notice
  * for the JavaScript code in this file.
  */
 
 window.rcmail && window.files_api && rcmail.addEventListener('init', function() {
   if (rcmail.task == 'mail') {
     // mail compose
     if (rcmail.env.action == 'compose') {
       kolab_files_from_cloud_widget($('#compose-attachments > div'));
 
       // register some commands to skip warning message on compose page
       $.merge(rcmail.env.compose_commands, ['files-list', 'files-sort', 'files-search', 'files-search-reset']);
     }
     // mail preview
     else if (rcmail.env.action == 'show' || rcmail.env.action == 'preview') {
       var attachment_list = $('#attachment-list');
 
       if ($('li', attachment_list).length) {
         var link = $('<a href="#" class="button filesaveall">')
           .text(rcmail.gettext('kolab_files.saveall'))
           .click(function() { kolab_directory_selector_dialog(); })
           .insertAfter(attachment_list);
       }
 
       rcmail.addEventListener('menu-open', kolab_files_attach_menu_open);
       rcmail.enable_command('folder-create', true);
     }
     // attachment preview
     else if (rcmail.env.action == 'get') {
       rcmail.enable_command('folder-create', true);
     }
 
     if (!rcmail.env.action || rcmail.env.action == 'show' || rcmail.env.action == 'preview') {
       // add "attach from cloud" button for event/task dialog in mail
       rcmail.addEventListener('plugin.mail2event_dialog', function() {
         if (!$('#calendar-attachment-form input.fromcloud').length)
           kolab_files_from_cloud_widget($('#calendar-attachment-form > div.buttons'));
       });
     }
   }
   else if (rcmail.task == 'calendar') {
     // add "attach from cloud" button for event dialog
     if (!rcmail.env.action)
       kolab_files_from_cloud_widget($('#calendar-attachment-form > div.buttons'));
   }
   else if (rcmail.task == 'tasks') {
     // add "attach from cloud" button for task dialog
     if (!rcmail.env.action)
       kolab_files_from_cloud_widget($('#taskedit-attachment-form > div.buttons'));
   }
   else if (rcmail.task == 'files') {
     if (rcmail.gui_objects.fileslist) {
       rcmail.fileslist = new rcube_list_widget(rcmail.gui_objects.fileslist, {
         multiselect: true,
         draggable: true,
         keyboard: true,
         column_movable: rcmail.env.files_col_movable,
         dblclick_time: rcmail.dblclick_time
       });
 
       rcmail.fileslist.addEventListener('dblclick', function(o) { kolab_files_list_dblclick(o); })
         .addEventListener('select', function(o) { kolab_files_list_select(o); })
         .addEventListener('keypress', function(o) { kolab_files_list_keypress(o); })
         .addEventListener('dragstart', function(e) { kolab_files_drag_start(e); })
         .addEventListener('dragmove', function(e) { kolab_files_drag_move(e); })
         .addEventListener('dragend', function(e) { kolab_files_drag_end(e); })
         .addEventListener('column_replace', function(e) { kolab_files_set_coltypes(e, 'files'); })
         .addEventListener('listupdate', function(e) { rcmail.triggerEvent('listupdate', e); });
 
       rcmail.enable_command('menu-open', 'menu-save', 'files-sort', 'files-search', 'files-search-reset', 'folder-create', true);
 
       rcmail.fileslist.init();
       kolab_files_list_coltypes('files');
       kolab_files_drag_drop_init($(rcmail.gui_objects.fileslist).parents('.droptarget'));
     }
 
     if (rcmail.gui_objects.sessionslist) {
       rcmail.sessionslist = new rcube_list_widget(rcmail.gui_objects.sessionslist, {
         keyboard: true,
         column_movable: rcmail.env.sessions_col_movable,
         dblclick_time: rcmail.dblclick_time
       });
 
       rcmail.sessionslist.addEventListener('dblclick', function(o) { kolab_files_sessions_list_dblclick(o); })
         .addEventListener('select', function(o) { kolab_files_sessions_list_select(o); })
         .addEventListener('keypress', function(o) { kolab_files_sessions_list_keypress(o); })
         .addEventListener('column_replace', function(e) { kolab_files_set_coltypes(e, 'sessions'); })
         .addEventListener('listupdate', function(e) { rcmail.triggerEvent('listupdate', e); });
 
       rcmail.sessionslist.init();
       kolab_files_list_coltypes('sessions');
     }
 
     // "one file only" commands
     rcmail.env.file_commands = ['files-get', 'files-rename'];
     // "one or more file" commands
     rcmail.env.file_commands_all = ['files-delete', 'files-move', 'files-copy'];
 
     if (rcmail.env.action == 'open' || rcmail.env.action == 'edit') {
       rcmail.enable_command('files-get', true);
       rcmail.enable_command('files-delete', rcmail.env.file_data.writable);
     }
     else {
       rcmail.enable_command('folder-mount', rcmail.env.external_sources);
     }
   }
 
   kolab_files_init();
 });
 
 
 /**********************************************************/
 /*********          Shared functionality         **********/
 /**********************************************************/
 
 // Initializes API object
 function kolab_files_init()
 {
   if (window.file_api)
     return;
 
   var editor_config = {};
 
   // Initialize application object (don't change var name!)
   file_api = $.extend(new files_api(), new kolab_files_ui());
 
   file_api.set_env({
     token: kolab_files_token(),
     url: rcmail.env.files_url,
     sort_col: 'name',
     sort_reverse: false,
     search_threads: rcmail.env.search_threads,
     resources_dir: rcmail.assets_path('program/resources'),
     caps: rcmail.env.files_caps,
     supported_mimetypes: rcmail.env.file_mimetypes
   });
 
   file_api.translations = rcmail.labels;
 
   if (rcmail.task == 'files') {
     if (rcmail.env.action == 'edit' && rcmail.env.editor_type) {
       // Extract the domain here, it can't be done by Chwala
       // when using WOPI, which does not set iframe src attribute
       var domain, href = rcmail.env.file_data.viewer.href;
       if (href && /^(https?:\/\/[^/]+)/i.test(href))
         domain = RegExp.$1;
 
       editor_config = {
         // UI elements
         iframe: $('#fileframe').get(0),
         domain: domain,
         export_menu: rcmail.gui_objects.exportmenu ? $('ul', rcmail.gui_objects.exportmenu).get(0) : null,
         title_input: $('#document-title').get(0),
         members_list: $('#members').get(0),
         photo_url: '?_task=addressbook&_action=photo&_error=1&_email=%email',
         photo_default_url: rcmail.env.photo_placeholder,
         // events
         ready: function(data) { document_editor_init(); },
         sessionClosed: function(data) { return document_editor_close(); }
       };
 
       if (rcmail.env.file_data.writable)
         editor_config.documentChanged = function(data) { rcmail.enable_command('document-save', true); };
     }
     else if (rcmail.env.action == 'open') {
       // initialize folders list (for dialogs)
       file_api.folder_list();
 
       // get ongoing sessions
       file_api.request('folder_info', {folder: file_api.file_path(rcmail.env.file), sessions: 1}, 'folder_info_response');
     }
     else {
       file_api.env.folder = rcmail.env.folder;
       file_api.env.collection = rcmail.env.collection;
       file_api.folder_list();
       file_api.browser_capabilities_check();
     }
   }
 
   if (rcmail.env.files_caps && !rcmail.env.framed && rcmail.env.files_caps.DOCEDIT)
     $.extend(editor_config, {
       // invitation notifications
       api: file_api,
       owner: rcmail.env.files_user,
       interval: rcmail.env.files_interval || 60,
       invitationMore: true,
       invitationChange: document_editor_invitation_handler
     });
 
   $.extend(editor_config, {
     // notifications/alerts
     gettext: function(label) { return rcmail.get_label('kolab_files.' + label); },
     set_busy: function(state, message) { return rcmail.set_busy(state, message ? 'kolab_files.' + message : ''); },
     hide_message: function(id) { return rcmail.hide_message(id); },
     display_message: function(label, type, is_txt, timeout) {
       if (!is_txt)
         label = 'kolab_files.' + label;
       return rcmail.display_message(label, type, timeout * 1000);
     }
   });
 
   if (window.document_editor_api)
     document_editor = new document_editor_api(editor_config);
   else
     document_editor = new manticore_api(editor_config);
 };
 
 // returns API authorization token
 function kolab_files_token()
 {
   // consider the token from parent window more reliable (fresher) than in framed window
   // it's because keep-alive is not requested in frames
   return window.parent && parent.rcmail && parent.rcmail.env.files_token ? parent.rcmail.env.files_token : rcmail.env.files_token;
 };
 
 function kolab_files_from_cloud_widget(elem)
 {
   var input = $('<input class="button fromcloud" type="button">')
       .attr('tabindex', $('input', elem).attr('tabindex') || 0)
       .val(rcmail.gettext('kolab_files.fromcloud'))
       .click(function() { kolab_files_selector_dialog(); })
       .appendTo(elem);
 
   if (rcmail.gui_objects.fileslist) {
     rcmail.fileslist = new rcube_list_widget(rcmail.gui_objects.fileslist, {
       multiselect: true,
       keyboard: true,
       column_movable: false,
       dblclick_time: rcmail.dblclick_time
     });
     rcmail.fileslist.addEventListener('select', function(o) { kolab_files_list_select(o); })
       .addEventListener('listupdate', function(e) { rcmail.triggerEvent('listupdate', e); });
 
     rcmail.enable_command('files-sort', 'files-search', 'files-search-reset', true);
 
     rcmail.fileslist.init();
     kolab_files_list_coltypes();
   }
 }
 
 // folder selection dialog
 function kolab_directory_selector_dialog(id)
 {
   var dialog = $('#files-dialog'),
     input = $('#file-save-as-input'),
     form = $('#file-save-as'),
     list = $('#folderlistbox'),
     buttons = {}, label = 'saveto',
     win = window, fn;
 
   // attachment is specified
   if (id) {
     var attach = $('#attach' + id + '> a').first(),
       filename = attach.attr('title');
 
     if (!filename) {
       attach = attach.clone();
       $('.attachment-size', attach).remove();
       filename = $.trim(attach.text());
     }
 
     form.show();
     dialog.addClass('saveas');
     input.val(filename);
   }
   // attachment preview page
   else if (rcmail.env.action == 'get') {
     id = rcmail.env.part;
     form.show();
     dialog.addClass('saveas');
     input.val(rcmail.env.filename);
   }
   else {
     form.hide();
     dialog.removeClass('saveas');
     label = 'saveall';
   }
 
   $('#foldercreatelink').attr('tabindex', 0);
 
   buttons[rcmail.gettext('kolab_files.save')] = function () {
     if (!file_api.env.folder)
       return;
 
     var lock = rcmail.set_busy(true, 'saving'),
       request = {
         act: 'save-file',
         source: rcmail.env.mailbox,
         uid: rcmail.env.uid,
         dest: file_api.env.folder
       };
 
     if (id) {
       request.id = id;
       request.name = input.val();
     }
 
     rcmail.http_post('plugin.kolab_files', request, lock);
     kolab_dialog_close(this);
   };
 
   buttons[rcmail.gettext('kolab_files.cancel')] = function () {
     kolab_dialog_close(this);
   };
 
   if (!rcmail.env.folders_loaded) {
     fn = function() {
       rcmail.env.folder_list_selector = '#files-dialog #files-folder-list';
       rcmail.env.folder_search_selector = '#files-dialog #foldersearch';
       file_api.folder_list({writable: 1});
       rcmail.env.folders_loaded = true;
     };
   }
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.' + label),
     buttons: buttons,
     button_classes: ['mainaction'],
     minWidth: 250,
     minHeight: 300,
     height: 400,
     width: 300
   }, fn);
 
   // "enable" folder creation when dialog is displayed in parent window
   if (rcmail.is_framed()) {
     parent.rcmail.enable_command('folder-create', true);
     parent.rcmail.folder_create = function() {
       win.kolab_files_folder_create_dialog();
     };
   }
 };
 
 // file selection dialog
 function kolab_files_selector_dialog()
 {
   var dialog = $('#files-compose-dialog'), buttons = {};
 
   buttons[rcmail.gettext('kolab_files.attachsel')] = function () {
     var list = [];
     $('#filelist tr.selected').each(function() {
       list.push($(this).data('file'));
     });
 
     kolab_dialog_close(this);
 
     if (list.length) {
       // display upload indicator and cancel button
       var content = '<span>' + rcmail.get_label('kolab_files.attaching') + '</span>',
         id = new Date().getTime();
 
       rcmail.add2attachment_list(id, {name:'', html:content, classname:'uploading', complete:false});
 
       // send request
       rcmail.http_post('plugin.kolab_files', {
         act: 'attach-file',
         files: list,
         id: rcmail.env.compose_id,
         uploadid: id
       });
     }
   };
 
   buttons[rcmail.gettext('kolab_files.cancel')] = function () {
     kolab_dialog_close(this);
   };
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.selectfiles'),
     buttons: buttons,
     button_classes: ['mainaction'],
     minWidth: 500,
     minHeight: 300,
     width: 700,
     height: 500
   }, function() { rcmail.fileslist.resize(); });
 
   if (!rcmail.env.files_loaded) {
     rcmail.env.folder_list_selector = '#files-compose-dialog #files-folder-list';
     rcmail.env.folder_search_selector = '#files-compose-dialog #foldersearch';
     file_api.folder_list();
     rcmail.env.files_loaded = true;
   }
   else {
     rcmail.fileslist.clear_selection();
   }
 };
 
 function kolab_files_attach_menu_open(p)
 {
   if (!p || !p.props || p.props.menu != 'attachmentmenu')
     return;
 
   var id = p.props.id;
 
   $('#attachmenusaveas').unbind('click').attr('onclick', '').click(function(e) {
     return kolab_directory_selector_dialog(id);
   });
 };
 
 // folder creation dialog
 function kolab_files_folder_create_dialog()
 {
   var dialog = $('#files-folder-create-dialog'),
     buttons = {},
     select = $('select[name="parent"]', dialog).html(''),
     input = $('input[name="name"]', dialog).val('');
 
   buttons[rcmail.gettext('kolab_files.create')] = function () {
     var folder = '', name = input.val(), parent = select.val();
 
     if (!name)
       return;
 
     if (parent)
       folder = parent + file_api.env.directory_separator;
 
     folder += name;
 
     file_api.folder_create(folder);
     kolab_dialog_close(this);
   };
 
   buttons[rcmail.gettext('kolab_files.cancel')] = function () {
     kolab_dialog_close(this);
   };
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.foldercreate'),
     buttons: buttons,
     button_classes: ['mainaction']
   });
 
   // Fix submitting form with Enter
   $('form', dialog).submit(kolab_dialog_submit_handler);
 
   // build parent selector
   file_api.folder_select_element(select, {empty: true, writable: true});
 };
 
 // folder edit dialog
 function kolab_files_folder_edit_dialog()
 {
   var dialog = $('#files-folder-edit-dialog'),
     buttons = {},
     separator = file_api.env.directory_separator,
     arr = file_api.env.folder.split(separator),
     folder = arr.pop(),
     path = arr.join(separator),
     select = $('select[name="parent"]', dialog).html(''),
     input = $('input[name="name"]', dialog).val(folder);
 
   buttons[rcmail.gettext('kolab_files.save')] = function () {
     var folder = '', name = input.val(), parent = select.val();
 
     if (!name)
       return;
 
     if (parent)
       folder = parent + separator;
 
     folder += name;
 
     file_api.folder_rename(file_api.env.folder, folder);
     kolab_dialog_close(this);
   };
 
   buttons[rcmail.gettext('kolab_files.cancel')] = function () {
     kolab_dialog_close(this);
   };
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.folderedit'),
     buttons: buttons,
     button_classes: ['mainaction']
   });
 
   // Fix submitting form with Enter
   $('form', dialog).submit(kolab_dialog_submit_handler);
 
   // build parent selector
   file_api.folder_select_element(select, {selected: path, empty: true});
 };
 
 // folder mounting dialog
 function kolab_files_folder_mount_dialog()
 {
   var args = {buttons: {}, title: rcmail.gettext('kolab_files.foldermount')},
     dialog = $('#files-folder-mount-dialog'),
     input = $('#folder-mount-name').val('');
 
   args.buttons[rcmail.gettext('kolab_files.save')] = function () {
     var args = {}, folder = input.val(),
       driver = $('input[name="driver"]:checked', dialog).val();
 
     if (!folder || !driver)
       return;
 
     args.folder = folder;
     args.driver = driver;
 
     $('#source-' + driver + ' input').each(function() {
       if (this.name.startsWith(driver + '[')) {
         args[this.name.substring(driver.length + 1, this.name.length - 1)] = this.value;
       }
     });
 
     $('.auth-options input', dialog).each(function() {
       args[this.name] = this.type == 'checkbox' && !this.checked ? '' : this.value;
     });
 
     file_api.folder_mount(args);
     kolab_dialog_close(this);
   };
 
   args.buttons[rcmail.gettext('kolab_files.cancel')] = function () {
     kolab_dialog_close(this);
   };
 
   // close folderoption menu
   rcmail.hide_menu('folderoptions');
 
   // initialize drivers list
   if (!rcmail.drivers_list_initialized) {
     rcmail.drivers_list_initialized = true;
 
     $('td.source', dialog).each(function() {
       $(this).click(function() {
         $('td.selected', dialog).removeClass('selected');
         dialog.find('.driverform').hide();
         $(this).addClass('selected').find('.driverform').show();
         $('input[type="radio"]', this).prop('checked', true);
      });
    });
   }
 
   args.button_classes = ['mainaction'];
 
   // show dialog window
   kolab_dialog_show(dialog, args, function() {
     $('td.source:first', dialog).click();
     input.focus();
   });
 };
 
 // file edit dialog
 function kolab_files_file_edit_dialog(file, sessions, readonly)
 {
   var content = [], items = [], height = 300,
     dialog = $('#files-file-edit-dialog'),
     buttons = {}, name = file_api.file_name(file),
     title = rcmail.gettext('kolab_files.editfiledialog'),
     mainaction = rcmail.gettext('kolab_files.select'),
     item_fn = function(id, txt, classes) {
         return $('<label>').attr('class', 'session' + (classes ? ' ' + classes : ''))
           .append($('<input>').attr({name: 'opt', value: id, type: 'radio'})).append($('<span>').text(txt));
       },
     select_fn = function(dlg) {
       var session, input = $('input:checked', dialog), id = input.val();
 
       if (dlg)
         kolab_dialog_close(dlg);
 
       if (id && input.parent().is('.session.request')) {
         document_editor.invitation_request({session_id: id});
         return;
       }
 
       if (readonly && (id == 0 || !input.length))
         return kolab_files_file_create_dialog(file);
 
       rcmail.files_edit(id ? id : true);
     };
 
   // Create sessions selection
   if (sessions && sessions.length) {
     items.push($('<div>').text(rcmail.gettext('kolab_files.editfilesessions')));
 
     // first display owned sessions, then invited, other at the end
     $.each(sessions, function() {
       if (this.is_owner) {
         var txt = rcmail.gettext('kolab_files.ownedsession');
         items.push(item_fn(this.id, txt, 'owner'));
       }
     });
 
     if (items.length == 1)
       items.push(item_fn(0, rcmail.gettext('kolab_files.newsession' + (readonly ? 'ro' : ''))));
 
     $.each(sessions, function() {
       if (this.is_invited) {
         var txt = rcmail.gettext('kolab_files.invitedsession')
           .replace('$user', this.owner_name ? this.owner_name : this.owner);
         items.push(item_fn(this.id, txt, 'invited'));
       }
     });
 
     $.each(sessions, function() {
       if (!this.is_owner && !this.is_invited) {
         var txt = rcmail.gettext('kolab_files.joinsession')
           .replace('$user', this.owner_name ? this.owner_name : this.owner);
         items.push(item_fn(this.id, txt, 'request'));
       }
     });
 
     // check the first option
     $('input', items[1]).attr('checked', true);
 
     $('div', dialog).html(items);
 
     // if there's only one session and it's owned, skip the dialog
     if (!readonly && items.length == 2 && $('input:checked', dialog).parent().is('.owner'))
       return select_fn();
   }
   // no ongoing session, folder is readonly warning
   else {
     title = rcmail.gettext('kolab_files.editfilerotitle');
     height = 150;
     $('div', dialog).text(rcmail.gettext('kolab_files.editfilero'));
     mainaction = rcmail.gettext('kolab_files.create');
   }
 
   buttons[mainaction] = function() { select_fn(this); };
   buttons[rcmail.gettext('kolab_files.cancel')] = function () {
     kolab_dialog_close(this);
   };
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: title,
     buttons: buttons,
     button_classes: ['mainaction'],
     minHeight: height - 100,
     height: height
   });
 };
 
 // file rename dialog
 function kolab_files_file_rename_dialog(file)
 {
   var dialog = $('#files-file-rename-dialog'),
     buttons = {}, name = file_api.file_name(file)
     input = $('input[name="name"]', dialog).val(name);
 
   buttons[rcmail.gettext('kolab_files.save')] = function() {
     var folder = file_api.file_path(file), name = input.val();
 
     if (!name)
       return;
 
     name = folder + file_api.env.directory_separator + name;
 
     if (name != file)
       file_api.file_rename(file, name);
 
     kolab_dialog_close(this);
   };
   buttons[rcmail.gettext('kolab_files.cancel')] = function() {
     kolab_dialog_close(this);
   };
 
   // Fix submitting form with Enter
   $('form', dialog).submit(kolab_dialog_submit_handler);
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.renamefile'),
     buttons: buttons,
     button_classes: ['mainaction'],
     minHeight: 100,
     height: 200
   });
 };
 
 // file creation (or cloning) dialog
 function kolab_files_file_create_dialog(file)
 {
   var buttons = {}, action = file ? 'copy' : 'create',
     dialog = $('#files-file-create-dialog'),
     type_select = $('select[name="type"]', dialog),
     select = $('select[name="parent"]', dialog).html(''),
     input = $('input[name="name"]', dialog).val(''),
     create_func = function(dialog, editaction) {
       var sel, folder = select.val(), type = type_select.val(), name = input.val();
 
       if (!name || !folder)
         return;
 
       if (!/\.[a-z0-9]{1,5}$/.test(name)) {
         name += '.' + rcmail.env.file_extensions[type];
       }
 
       name = folder + file_api.env.directory_separator + name;
 
       // get type of cloned file
       if (file) {
         if (rcmail.env.file_data)
           type = rcmail.env.file_data.type;
         else {
           sel = rcmail.fileslist.get_selection();
           type = $('#rcmrow' + sel[0]).data('type');
         }
       }
 
       file_api.file_create(name, type, editaction, file);
       kolab_dialog_close(dialog);
   };
 
   buttons[rcmail.gettext('kolab_files.' + action + 'andedit')] = function() {
     create_func(this, true);
   };
 
   if (action == 'create') {
     buttons[rcmail.gettext('kolab_files.create')] = function() {
       create_func(this);
     };
     type_select.parent('tr').show();
   }
   else {
     input.val(file_api.file_name(file));
     type_select.parent('tr').hide();
   }
 
   buttons[rcmail.gettext('kolab_files.cancel')] = function() {
     kolab_dialog_close(this);
   };
 
   // Fix submitting form with Enter
   $('form', dialog).submit(kolab_dialog_submit_handler);
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.' + action + 'file'),
     buttons: buttons,
     button_classes: ['mainaction'],
     minHeight: 150,
     height: 250
   });
 
   // build folder selector
   file_api.folder_select_element(select, {writable: true});
 };
 
 // file session dialog
 function kolab_files_session_dialog(session)
 {
   var buttons = {},
     dialog = $('#files-session-dialog'),
     filename = file_api.file_name(session.file),
     owner = session.owner_name || session.owner,
     title = rcmail.gettext('kolab_files.sessiondialog'),
     content = rcmail.gettext('kolab_files.sessiondialogcontent'),
     button_classes = ['mainaction'],
     join_session = function(id) {
       var viewer = file_api.file_type_supported('application/vnd.oasis.opendocument.text', rcmail.env.files_caps);
         params = {action: 'edit', session: id};
 
       file_api.file_open('', viewer, params);
     };
 
   content = content.replace('$file', filename).replace('$owner', owner);
   $('div', dialog).text(content);
 
   if (session.is_owner) {
     buttons[rcmail.gettext('kolab_files.open')] = function() {
       kolab_dialog_close(this);
       join_session(session.id);
     };
     buttons[rcmail.gettext('kolab_files.close')] = function() {
       kolab_dialog_close(this);
       file_api.document_delete(session.id);
     };
     button_classes.push('delete');
   }
   else if (session.is_invited) {
     // @TODO: check if not-accepted and provide "Decline invitation" button
     // @TODO: Add "Accept button", add comment field to the dialog
     buttons[rcmail.gettext('kolab_files.join')] = function() {
       kolab_dialog_close(this);
       join_session(session.id);
     };
   }
   else {
     buttons[rcmail.gettext('kolab_files.request')] = function() {
       kolab_dialog_close(this);
       // @TODO: Add comment field to the dialog
       document_editor.invitation_request({session_id: session.id});
     };
   }
 
   buttons[rcmail.gettext('kolab_files.cancel')] = function() {
     kolab_dialog_close(this);
   };
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: title,
     buttons: buttons,
     button_classes: button_classes,
     minHeight: 100,
     height: 150
   });
 };
 
 function kolab_dialog_show(content, params, onopen)
 {
   params = $.extend({
     modal: true,
     resizable: true,
     minWidth: 400,
     minHeight: 300,
     width: 500,
     height: 400
   }, params || {});
 
   // dialog close handler
   params.close = function(e, ui) {
     var elem, stack = rcmail.dialog_stack;
 
     content.appendTo(document.body).hide();
     $(this).parent().remove(); // remove dialog
 
     // focus previously focused element (guessed)
     stack.pop();
     if (stack.length) {
       elem = stack[stack.length-1].find('input[type!="hidden"]:not(:hidden):first');
       if (!elem.length)
         elem = stack[stack.length-1].parent().find('a[role="button"], .ui-dialog-buttonpane button').first();
     }
 
     (elem && elem.length ? elem : window).focus();
 
     rcmail.ksearch_blur();
   };
 
   // display it as popup
   var dialog = rcmail.show_popup_dialog('', params.title, params.buttons, params);
 
   content.appendTo(dialog).show().find('input[type!="hidden"]:not(:hidden):first').focus();
 
   if (onopen) onopen(content);
 
   // save dialog reference, to handle focus when closing one of opened dialogs
   if (!rcmail.dialog_stack)
     rcmail.dialog_stack = [];
 
   rcmail.dialog_stack.push(dialog);
 };
 
 // Handle form submit with Enter key, click first dialog button instead
 function kolab_dialog_submit_handler()
 {
   $(this).parents('.ui-dialog').find('.ui-button').first().click();
   return false;
 };
 
 // Hides dialog
 function kolab_dialog_close(dialog)
 {
   (rcmail.is_framed() ? window.parent : window).$(dialog).dialog('close');
 };
 
 // smart upload button
 function kolab_files_upload_input(button)
 {
   var link = $(button),
     file = $('<input>'),
     offset = link.offset();
 
   function move_file_input(e) {
     file.css({top: (e.pageY - offset.top - 10) + 'px', left: (e.pageX - offset.left - 10) + 'px'});
   }
 
   file.attr({name: 'file[]', type: 'file', multiple: 'multiple', size: 5, title: link.attr('title'), tabindex: "-1"})
     .change(function() { rcmail.files_upload('#filesuploadform'); })
     .click(function() { setTimeout(function() { link.mouseleave(); }, 20); })
     // opacity:0 does the trick, display/visibility doesn't work
     .css({opacity: 0, cursor: 'pointer', outline: 'none', position: 'absolute'});
 
   // In FF and IE we need to move the browser file-input's button under the cursor
   // Thanks to the size attribute above we know the length of the input field
   if (bw.mz || bw.ie)
     file.css({marginLeft: '-80px'});
 
   // Note: now, I observe problem with cursor style on FF < 4 only
   // Need position: relative (Bug #2615)
   link.css({overflow: 'hidden', cursor: 'pointer', position: 'relative'})
     .mouseenter(function() { this.__active = true; })
     // place button under the cursor
     .mousemove(function(e) {
       if (rcmail.commands['files-upload'] && this.__active)
         move_file_input(e);
       // move the input away if button is disabled
       else
         $(this).mouseleave();
     })
     .mouseleave(function() {
       file.css({top: '-10000px', left: '-10000px'});
       this.__active = false;
     })
     .attr('onclick', '') // remove default button action
     .click(function(e) {
       // forward click if mouse-enter event was missed
       if (rcmail.commands['files-upload'] && !this.__active) {
         this.__active = true;
         move_file_input(e);
         file.trigger(e);
       }
     })
     .mouseleave() // initially disable/hide input
     .append(file);
 };
 
 
 /***********************************************************/
 /**********          Main functionality           **********/
 /***********************************************************/
 
 // for reordering column array (Konqueror workaround)
 // and for setting some files/sessions list global variables
 function kolab_files_list_coltypes(type)
 {
   if (!type) type = 'files';
 
   var n, list = rcmail[type + 'list'];
 
   rcmail.env.subject_col = null;
 
   if ((n = $.inArray('name', rcmail.env[type + '_coltypes'])) >= 0) {
     rcmail.env.subject_col = n;
     list.subject_col = n;
   }
 
   list.init_header();
 };
 
 function kolab_files_set_list_options(cols, sort_col, sort_order, type)
 {
   var update = 0, i, idx, name, newcols = [], oldcols = rcmail.env[type + '_coltypes'];
 
   if (sort_col === undefined)
     sort_col = rcmail.env[type + '_sort_col'];
   if (!sort_order)
     sort_order = rcmail.env[type + '_sort_order'];
 
   if (rcmail.env[type + '_sort_col'] != sort_col || rcmail.env[type + '_sort_order'] != sort_order) {
     update = 1;
     // set table header class
     kolab_files_set_list_sorting(sort_col, sort_order, type);
   }
 
   if (cols && cols.length) {
     // make sure new columns are added at the end of the list
     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 += 2;
       oldcols = newcols;
     }
   }
 
   if (update == 1)
     rcmail.command(type + '-list', {sort: sort_col, reverse: sort_order == 'DESC'});
   else if (update) {
     rcmail.http_post('files/prefs', {
       type: type,
       kolab_files_list_cols: oldcols,
       kolab_files_sort_col: sort_col,
       kolab_files_sort_order: sort_order
       }, rcmail.set_busy(true, 'loading'));
   }
 };
 
 function kolab_files_set_list_sorting(sort_col, sort_order, type)
 {
   // set table header class
   var old_col = rcmail.env[type + '_sort_col'],
     old_sort = rcmail.env[type + '_sort_order'];
 
   $('#rcm' + old_col).removeClass('sortedASC sortedDESC');
   $('#rcm' + sort_col).addClass('sorted' + sort_order);
 
   rcmail.env[type + '_sort_col'] = sort_col;
   rcmail.env[type + '_sort_order'] = sort_order;
 };
 
 function kolab_files_set_coltypes(list, type)
 {
   var i, found, name, cols = list.list.tHead.rows[0].cells;
 
   rcmail.env[type + '_coltypes'] = [];
 
   for (i=0; i<cols.length; i++)
     if (cols[i].id && cols[i].id.match(/^rcm/)) {
       name = cols[i].id.replace(/^rcm/, '');
       rcmail.env[type + '_coltypes'].push(name);
     }
 
 //  if ((found = $.inArray('name', rcmail.env.files_coltypes)) >= 0)
 //    rcmail.env.subject_col = found;
   rcmail.env.subject_col = list.subject_col;
 
   rcmail.http_post('files/prefs', {kolab_files_list_cols: rcmail.env[type + '_coltypes'], type: type});
 };
 
 function kolab_files_sessions_list_dblclick(list)
 {
   rcmail.command('sessions-open');
 };
 
 function kolab_files_sessions_list_select(list)
 {
   var selected = list.selection.length;
 
   rcmail.enable_command('sessions-open', selected == 1);
 };
 
 function kolab_files_sessions_list_keypress(list)
 {
   if (list.modkey == CONTROL_KEY)
     return;
 
   if (list.key_pressed == list.ENTER_KEY) {
     // use setTimeout(), otherwise the opened dialog will be immediately closed
     setTimeout(function() { rcmail.command('sessions-open'); }, 50);
   }
 //  else if (list.key_pressed == list.DELETE_KEY || list.key_pressed == list.BACKSPACE_KEY)
 //    rcmail.command('sessions-delete');
 };
 
 function kolab_files_list_dblclick(list)
 {
   rcmail.command('files-open');
 };
 
 function kolab_files_list_select(list)
 {
   var selected = list.selection.length;
 
   rcmail.enable_command(rcmail.env.file_commands_all, selected);
   rcmail.enable_command(rcmail.env.file_commands, selected == 1);
 
     // reset all-pages-selection
 //  if (list.selection.length && list.selection.length != list.rowcount)
 //    rcmail.select_all_mode = false;
 
   if (selected == 1) {
     // get file mimetype
     var elem = $('tr.selected', list.list),
       type = elem.data('type'),
       folder = file_api.file_path(elem.data('file'));
 
     rcmail.env.viewer = file_api.file_type_supported(type, rcmail.env.files_caps);
 
     if (!file_api.is_writable(folder))
       rcmail.enable_command('files-delete', 'files-rename', false);
   }
   else
     rcmail.env.viewer = 0;
 
   rcmail.enable_command('files-edit', (rcmail.env.viewer & 4) == 4);
   rcmail.enable_command('files-open', rcmail.env.viewer);
 };
 
 function kolab_files_list_keypress(list)
 {
   if (list.modkey == CONTROL_KEY)
     return;
 
   if (list.key_pressed == list.ENTER_KEY)
     rcmail.command('files-open');
   else if (list.key_pressed == list.DELETE_KEY || list.key_pressed == list.BACKSPACE_KEY)
     rcmail.command('files-delete');
 };
 
 function kolab_files_drag_start(e)
 {
   rcmail.env.drag_target = null;
 
   if (rcmail.folder_list)
     rcmail.folder_list.drag_start();
 };
 
 function kolab_files_drag_end(e)
 {
   if (rcmail.folder_list) {
     rcmail.folder_list.drag_end();
 
     if (rcmail.env.drag_target) {
       var modkey = rcube_event.get_modifier(e),
         menu = rcmail.gui_objects.file_dragmenu;
 
       rcmail.fileslist.draglayer.hide();
 
       if (menu && modkey == SHIFT_KEY && rcmail.commands['files-copy']) {
         var pos = rcube_event.get_mouse_pos(e);
         $(menu).css({top: (pos.y-10)+'px', left: (pos.x-10)+'px'}).show();
         return;
       }
 
       rcmail.command('files-move', rcmail.env.drag_target);
     }
   }
 };
 
 function kolab_files_drag_move(e)
 {
   if (rcmail.folder_list) {
     var mouse = rcube_event.get_mouse_pos(e);
 
     rcmail.env.drag_target = rcmail.folder_list.intersects(mouse, true);
   }
 };
 
 function kolab_files_drag_menu_action(command)
 {
   var menu = rcmail.gui_objects.file_dragmenu;
 
   if (menu)
     $(menu).hide();
 
   rcmail.command(command, rcmail.env.drag_target);
 };
 
 function kolab_files_selected()
 {
   var files = [];
   $.each(rcmail.fileslist.get_selection(), function(i, v) {
     var name, row = $('#rcmrow'+v);
 
     if (row.length == 1 && (name = row.data('file')))
       files.push(name);
   });
 
   return files;
 };
 
 function kolab_files_frame_load(frame)
 {
   var win = frame.contentWindow,
     info = rcmail.env.file_data;
 
   try {
     rcmail.file_editor = win.file_editor;
   }
   catch (e) {};
 
   // on edit page switch immediately to edit mode
   if (rcmail.file_editor && rcmail.file_editor.editable && rcmail.env.action == 'edit')
     rcmail.files_edit();
 
   rcmail.enable_command('files-edit', (rcmail.file_editor && rcmail.file_editor.editable)
     || rcmail.env.editor_type
     || (file_api.file_type_supported(rcmail.env.file_data.type, rcmail.env.files_caps) & 4));
 
   rcmail.enable_command('files-print', (rcmail.file_editor && rcmail.file_editor.printable)
     || (info && /^image\//i.test(info.type)));
 
   // detect Print button and check if it can be accessed
   try {
     if ($('#fileframe').contents().find('#print').length)
       rcmail.enable_command('files-print', true);
   }
   catch(e) {};
 };
 
 // activate html5 file drop feature (if browser supports it)
 function kolab_files_drag_drop_init(container)
 {
   if (!window.FormData && !(window.XMLHttpRequest && XMLHttpRequest.prototype && XMLHttpRequest.prototype.sendAsBinary)) {
     return;
   }
 
   if (!container.length)
     return;
 
   $(document.body).bind('dragover dragleave drop', function(e) {
     if (!file_api.is_writable())
       return;
 
     e.preventDefault();
     container[e.type == 'dragover' ? 'addClass' : 'removeClass']('active');
   });
 
   container.bind('dragover dragleave', function(e) {
     return kolab_files_drag_hover(e);
   })
   container.children('div').bind('dragover dragleave', function(e) {
     return kolab_files_drag_hover(e);
   })
   container.get(0).addEventListener('drop', function(e) {
       // abort event and reset UI
       kolab_files_drag_hover(e);
       return file_api.file_drop(e);
     }, false);
 };
 
 // handler for drag/drop on element
 function kolab_files_drag_hover(e)
 {
   if (!file_api.is_writable())
     return;
 
   e.preventDefault();
   e.stopPropagation();
 
   var elem = $(e.target);
 
   if (!elem.hasClass('droptarget'))
     elem = elem.parents('.droptarget');
 
   elem[e.type == 'dragover' ? 'addClass' : 'removeClass']('hover');
 };
 
 // returns localized file size
 function kolab_files_file_size(size)
 {
   var i, units = ['GB', 'MB', 'KB', 'B'];
 
   size = file_api.file_size(size);
 
   for (i = 0; i < units.length; i++)
     if (size.toUpperCase().indexOf(units[i]) > 0)
       return size.replace(units[i], rcmail.gettext(units[i]));
 
   return size;
 };
 
 function kolab_files_progress_str(param)
 {
   var current, total = file_api.file_size(param.total).toUpperCase();
 
   if (total.indexOf('GB') > 0)
     current = parseFloat(param.current/1073741824).toFixed(1);
   else if (total.indexOf('MB') > 0)
     current = parseFloat(param.current/1048576).toFixed(1);
   else if (total.indexOf('KB') > 0)
     current = parseInt(param.current/1024);
   else
     current = param.current;
 
   total = kolab_files_file_size(param.total);
 
   return rcmail.gettext('uploadprogress')
     .replace(/\$percent/, param.percent + '%')
     .replace(/\$current/, current)
     .replace(/\$total/, total);
 };
 
 
 /**********************************************************/
 /*********     document editor functionality     **********/
 /**********************************************************/
 
 // Initialize document toolbar functionality
 function document_editor_init()
 {
   var info = rcmail.env.file_data;
 
   rcmail.enable_command('document-export', 'document-print', true);
 
   if (info && info.session && info.session.is_owner)
     rcmail.enable_command('document-close', 'document-editors', true);
 };
 
 // executed on editing session termination
 function document_editor_close()
 {
   $('<div>').addClass('popupdialog').attr('role', 'alertdialog')
     .html($('<span>').text(rcmail.gettext('kolab_files.sessionterminated')))
     .dialog({
       resizable: false,
       closeOnEscape: true,
       dialogClass: 'error',
       title: rcmail.gettext('kolab_files.sessionterminatedtitle'),
       close: function() { window.close(); },
       width: 420,
       minHeight: 90
     }).show();
 
   return false; // skip Chwala's error message
 };
 
 rcube_webmail.prototype.document_save = function()
 {
   document_editor.save(function(data) {
     rcmail.enable_command('document-save', false);
   });
 };
 
 rcube_webmail.prototype.document_export = function(type)
 {
   document_editor.export(type || 'odt');
 };
 
 rcube_webmail.prototype.document_print = function()
 {
   document_editor.print();
 };
 
 rcube_webmail.prototype.document_editors = function()
 {
   kolab_files_editors_dialog();
 };
 
 // close editing session
 rcube_webmail.prototype.document_close = function()
 {
   // check document "unsaved changes" state and display a warning
   if (this.commands['document-save'] && !confirm(this.gettext('kolab_files.unsavedchanges')))
     return;
 
   file_api.document_delete(this.env.file_data.session.id);
 };
 
 // document editors management dialog
 function kolab_files_editors_dialog(session)
 {
   var items = [], buttons = {},
     info = rcmail.env.file_data,
     dialog = $('#document-editors-dialog'),
     comment = $('#invitation-comment');
 
   if (!info || !info.session || !info.session.is_owner)
     return;
 
   // always add the session organizer
   items.push(kolab_files_attendee_record(info.session.owner, 'organizer'));
 
   $.each(info.session.invitations || [], function(i, u) {
     var record = kolab_files_attendee_record(u.user, u.status, u.user_name);
     items.push(record);
     info.session.invitations[i].record = record;
   });
 
   $('table > tbody', dialog).html(items);
 
   buttons[rcmail.gettext('kolab_files.close')] = function() {
     kolab_dialog_close(this);
   };
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.manageeditors'),
     buttons: buttons,
     button_classes: ['mainaction']
   });
 
   if (!rcmail.env.editors_dialog) {
     rcmail.env.editors_dialog = dialog;
     rcmail.init_address_input_events($('#invitation-editor-name'), {action: 'files/autocomplete'});
 
     rcmail.addEventListener('autocomplete_insert', function(e) {
       var success = false;
       if (e.field.name == 'participant') {
         // e.data && e.data.type == 'group' ? 'GROUP' : 'INDIVIDUAL'
         success = kolab_files_add_attendees(e.insert, comment.val());
       }
       if (e.field && success) {
         e.field.value = '';
       }
     });
 
     $('#invitation-editor-add').click(function() {
       var input = $('#invitation-editor-name');
       rcmail.ksearch_blur();
       if (kolab_files_add_attendees(input.val(), comment.val())) {
         input.val('');
       }
     });
   }
 };
 
 // add the given list of participants
 function kolab_files_add_attendees(names, comment)
 {
   var i, item, success, email, name, attendees = {}, counter = 0;
 
   names = file_api.explode_quoted_string(names.replace(/,\s*$/, ''), ',');
 
   // parse name/email pairs
   for (i = 0; i < names.length; i++) {
     email = name = '';
     item = $.trim(names[i]);
 
     if (!item.length) {
       continue;
     } // address in brackets without name (do nothing)
     else if (item.match(/^<[^@]+@[^>]+>$/)) {
       email = item.replace(/[<>]/g, '');
     } // address without brackets and without name (add brackets)
     else if (rcube_check_email(item)) {
       email = item;
     } // address with name
     else if (item.match(/([^\s<@]+@[^>]+)>*$/)) {
       email = RegExp.$1;
       name = item.replace(email, '').replace(/^["\s<>]+/, '').replace(/["\s<>]+$/, '');
     }
 
     if (email) {
       attendees[email] = {user: email, name: name};
       counter++;
     }
     else {
       alert(rcmail.gettext('noemailwarning'));
     }
   }
 
   success = counter > 0;
 
   // remove already existing entries
   if (counter) {
     if (attendees[rcmail.env.file_data.session.owner]) {
       delete attendees[this.user];
       counter--;
     }
     $.each(rcmail.env.file_data.session.invitations || [], function() {
       if (this.user in attendees) {
         delete attendees[this.user];
         counter--;
       }
     });
   }
 
   if (counter)
     file_api.document_invite(rcmail.env.file_data.session.id, attendees, comment);
 
   return success;
 };
 
 function kolab_files_attendee_record(user, status, username)
 {
   var options = [], select,
     type = status ? status.replace(/-.*$/, '') : '',
     name = $('<td class="name">').text(user),
     buttons = $('<td class="options">'),
     state = $('<td class="status">').text(rcmail.gettext('kolab_files.status' + type));
 
   // @todo: accept/decline invitation request
   if (type == 'requested' || status == 'accepted-owner' || status == 'declined-owner') {
     select = $('<select>').change(function() {
         var val = $(this).val(), map = {accepted: 'invitation_accept', declined: 'invitation_decline'};
         if (map[val])
           document_editor[map[val]]({user: user, session_id: rcmail.env.file_data.session.id});
       });
 
     if (type == 'requested')
       options.push($('<option>').text(rcmail.gettext('kolab_files.statusrequested')).attr('value', 'requested'));
 
     options.push($('<option>').text(rcmail.gettext('kolab_files.statusaccepted')).attr('value', 'accepted'));
     options.push($('<option>').text(rcmail.gettext('kolab_files.statusdeclined')).attr('value', 'declined'));
 
     state.html(select.html(options).val(type));
   }
 
   // delete button
   if (status != 'organizer') {
     $('<a>').attr({'class': 'delete', href: '#', title: rcmail.gettext('kolab_files.removeparticipant')})
       .click(function() {
         file_api.document_cancel(rcmail.env.file_data.session.id, [user]);
       })
       .appendTo(buttons);
   }
 
   if (username && status != 'organizer')
     name.html($('<a>').attr({href: 'mailto:' + user, 'class': 'mailtolink'}).text(username))
       .click(function(e) { rcmail.command('compose', user, e.target, e); return false; });
 
   return $('<tr>').attr('class', 'invitation' + (type ? ' ' + type : ''))
       .append(name).append(state).append(buttons);
 };
 
 function document_editor_invitation_handler(invitation)
 {
   // make the "More" link clickable
   $('#' + invitation.id).parent('div').click(function() { kolab_files_invitation_dialog(invitation); });
 };
 
 function kolab_files_invitation_dialog(invitation)
 {
   var text, records = [], content = [], buttons = {},
     dialog = $('#document-invitation-dialog'),
     data_map = {status: 'status', 'changed': 'when', filename: 'file', comment: 'comment'},
     record_fn = function(type, label, value) {
         records.push($('<tr>').attr('class', type)
           .append($('<td class="label">').text(rcmail.gettext('kolab_files.'+ label)))
           .append($('<td>').text(value))
         );
       };
     join_session = function() {
         var viewer = file_api.file_type_supported('application/vnd.oasis.opendocument.text', rcmail.env.files_caps);
           params = {action: 'edit', session: invitation.session_id};
 
         file_api.file_open('', viewer, params);
       };
 
   if (!dialog.length)
     dialog = $('<div>').attr({id: 'document-invitation-dialog', role: 'dialog', 'aria-hidden': 'true'})
       .append($('<div>'))
       .appendTo(document.body);
 
   if (!invitation.is_session_owner) {
     if (invitation.status == 'invited') {
       text = document_editor.invitation_msg(invitation);
 
       buttons[rcmail.gettext('kolab_files.join')] = function() {
         join_session();
         kolab_dialog_close(this);
       };
       buttons[rcmail.gettext('kolab_files.accept')] = function() {
         document_editor.invitation_accept(invitation);
         kolab_dialog_close(this);
       };
       buttons[rcmail.gettext('kolab_files.decline')] = function() {
         document_editor.invitation_decline(invitation);
         kolab_dialog_close(this);
       };
     }
     else if (invitation.status == 'declined-owner') {
       // @todo: add option to request for an invitation again?
       text = document_editor.invitation_msg(invitation);
     }
     else if (invitation.status == 'accepted-owner') {
       text = document_editor.invitation_msg(invitation);
 
       buttons[rcmail.gettext('kolab_files.join')] = function() {
         join_session();
         kolab_dialog_close(this);
       };
     }
   }
   else {
     if (invitation.status == 'accepted') {
       text = document_editor.invitation_msg(invitation);
     }
     else if (invitation.status == 'declined') {
       // @todo: add option to invite the user again?
       text = document_editor.invitation_msg(invitation);
     }
     else if (invitation.status == 'requested') {
       text = document_editor.invitation_msg(invitation);
 
       buttons[rcmail.gettext('kolab_files.accept')] = function() {
         document_editor.invitation_accept(invitation);
         kolab_dialog_close(this);
       };
       buttons[rcmail.gettext('kolab_files.decline')] = function() {
         document_editor.invitation_decline(invitation);
         kolab_dialog_close(this);
       };
     }
   }
 
   if (text) {
     $.each(data_map, function(i, label) {
       var value = invitation[i];
       if (value) {
         if (i == 'status')
           value = rcmail.gettext('kolab_files.status' + value.replace(/-.*$/, ''));
 
         record_fn(i, label, value);
       }
     });
 
     content.push($('<div>').text(text));
     content.push($('<table class="propform">').html(records));
   }
 
   buttons[rcmail.gettext('kolab_files.close')] = function() {
     kolab_dialog_close(this);
   };
 
   $('div', dialog).html(content);
 
   // show dialog window
   kolab_dialog_show(dialog, {
     title: rcmail.gettext('kolab_files.invitationtitle').replace('$file', invitation.filename),
     buttons: buttons
   });
 };
 
 /***********************************************************/
 /**********              Commands                 **********/
 /***********************************************************/
 
 rcube_webmail.prototype.files_sort = function(props)
 {
   this.files_sort_handler(props, 'files');
 };
 
 rcube_webmail.prototype.sessions_sort = function(props)
 {
   this.files_sort_handler(props, 'sessions');
 };
 
 rcube_webmail.prototype.files_sort_handler = function(col, type)
 {
   var params = {},
     c = type == 'files' ? '' : ('_' + type),
     sort_order = this.env[type + '_sort_order'],
     sort_col = !this.env['kolab_files' + c + '_disabled_sort_col'] ? col : this.env[type + '_sort_col'];
 
   if (!this.env['kolab_files' + c + '_disabled_sort_order'])
     sort_order = this.env[type + '_sort_col'] == sort_col && sort_order == 'ASC' ? 'DESC' : 'ASC';
 
   // set table header and update env
   kolab_files_set_list_sorting(sort_col, sort_order, type);
 
   this.http_post('files/prefs', {kolab_files_sort_col: sort_col, kolab_files_sort_order: sort_order, type: type});
 
   params.sort = sort_col;
   params.reverse = sort_order == 'DESC';
 
   this.command(type + '-list', params);
 };
 
 rcube_webmail.prototype.files_search = function()
 {
   var value = $(this.gui_objects.filesearchbox).val();
 
   if (value)
     file_api.file_search(value, $('#search_all_folders').is(':checked'));
   else
     file_api.file_search_reset();
 };
 
 rcube_webmail.prototype.files_search_reset = function()
 {
   $(this.gui_objects.filesearchbox).val('');
 
   file_api.file_search_reset();
 };
 
 rcube_webmail.prototype.files_folder_delete = function()
 {
   if (confirm(this.get_label('kolab_files.folderdeleteconfirm')))
     file_api.folder_delete(file_api.env.folder);
 };
 
 rcube_webmail.prototype.files_delete = function()
 {
   if (!confirm(this.get_label('kolab_files.filedeleteconfirm')))
     return;
 
   var files = this.env.file ? [this.env.file] : kolab_files_selected();
   file_api.file_delete(files);
 };
 
 rcube_webmail.prototype.files_move = function(folder)
 {
   var files = kolab_files_selected();
   file_api.file_move(files, folder);
 };
 
 rcube_webmail.prototype.files_copy = function(folder)
 {
   var files = kolab_files_selected();
   file_api.file_copy(files, folder);
 };
 
 rcube_webmail.prototype.files_upload = function(form)
 {
   if (form)
     file_api.file_upload(form);
 };
 
 rcube_webmail.prototype.files_list = function(param)
 {
   // just rcmail wrapper, to handle command busy states
   file_api.file_list(param);
 }
 
 rcube_webmail.prototype.files_list_update = function(head)
 {
   var list = this.fileslist;
 
   $('thead', list.fixed_header ? list.fixed_header : list.list).html(head);
   kolab_files_list_coltypes();
   file_api.file_list();
 };
 
 rcube_webmail.prototype.sessions_list = function(param)
 {
   // just rcmail wrapper, to handle command busy states
   file_api.session_list(param);
 }
 
 rcube_webmail.prototype.sessions_list_update = function(head)
 {
   var list = this.sessionslist;
 
   $('thead', list.fixed_header ? list.fixed_header : list.list).html(head);
   kolab_files_list_coltypes('sessions');
   file_api.sessions_list();
 };
 
 rcube_webmail.prototype.files_get = function()
 {
   var files = this.env.file ? [this.env.file] : kolab_files_selected();
 
   if (files.length == 1)
     file_api.file_get(files[0], {'force-download': true});
 };
 
 rcube_webmail.prototype.files_open = function()
 {
   var files = kolab_files_selected();
 
   if (files.length == 1)
     file_api.file_open(files[0], rcmail.env.viewer);
 };
 
 // enable file editor
 rcube_webmail.prototype.files_edit = function(session)
 {
   var files, readonly, sessions, file = this.env.file,
     params = {action: 'edit'};
 
   if (!file && !this.env.action) {
     files = kolab_files_selected();
     if (files.length == 1)
       file = files[0];
     readonly = !file_api.is_writable(file_api.file_path(file));
   }
   else {
     readonly = !this.env.file_data.writable;
   }
 
   // check if the folder is read-only or there are ongoing sessions
   // in such cases display dialog for the user to decide what to do
   if (!session) {
     sessions = file_api.file_sessions(file);
     if (sessions.length || readonly) {
       kolab_files_file_edit_dialog(file, sessions, readonly);
       return;
     }
   }
   else if (session !== true)
     params.session = session;
 
   if (this.file_editor && this.file_editor.editable && !session) {
     this.file_editor.enable();
     this.enable_command('files-save', true);
   }
   else if (this.env.file) {
     var viewer = file_api.file_type_supported(this.env.file_data.type, this.env.files_caps);
     params.local = true;
     file_api.file_open(file, viewer, params);
   }
   else if (file) {
     file_api.file_open(file, this.env.viewer, params);
   }
 };
 
 // save changes to the file
 rcube_webmail.prototype.files_save = function()
 {
   if (!this.file_editor)
     return;
 
   // binary files like ODF need to be updated using FormData
   if (this.file_editor.getContentCallback) {
     if (!file_api.file_uploader_support())
       return;
 
     file_api.req = file_api.set_busy(true, 'saving');
 //    this.file_editor.disable();
     this.file_editor.getContentCallback(function(content, filename) {
       file_api.file_uploader([content], {
         action: 'file_update',
         params: {file: rcmail.env.file, info: 1, token: file_api.env.token},
         response_handler: 'file_save_response',
         fieldname: 'content',
         single: true
       });
     });
 
     return;
   }
 
   var content = this.file_editor.getContent();
 
   file_api.file_save(this.env.file, content);
 };
 
 rcube_webmail.prototype.files_print = function()
 {
   if (this.file_editor && this.file_editor.printable)
     this.file_editor.print();
   else if (/^image\//i.test(this.env.file_data.type)) {
     var frame = $('#fileframe').get(0),
       win = frame ? frame.contentWindow : null;
 
     if (win) {
       win.focus();
       win.print();
     }
   }
   else {
     // e.g. Print button in PDF viewer
     try {
       $('#fileframe').contents().find('#print').click();
     }
     catch(e) {};
   }
 };
 
 rcube_webmail.prototype.files_set_quota = function(p)
 {
   if (p.total && window.file_api) {
     p.used *= 1024;
     p.total *= 1024;
     p.title = file_api.file_size(p.used) + ' / ' + file_api.file_size(p.total)
         + ' (' + p.percent + '%)';
   }
 
   p.type = this.env.quota_type;
 
   this.set_quota(p);
 };
 
 rcube_webmail.prototype.files_create = function()
 {
   kolab_files_file_create_dialog();
 };
 
 rcube_webmail.prototype.files_rename = function()
 {
   var files = kolab_files_selected();
   kolab_files_file_rename_dialog(files[0]);
 };
 
 rcube_webmail.prototype.folder_create = function()
 {
   kolab_files_folder_create_dialog();
 };
 
 rcube_webmail.prototype.folder_rename = function()
 {
   kolab_files_folder_edit_dialog();
 };
 
 rcube_webmail.prototype.folder_mount = function()
 {
   kolab_files_folder_mount_dialog();
 };
 
 // open a session dialog
 rcube_webmail.prototype.sessions_open = function()
 {
   var id = this.sessionslist.get_selection(),
     session = id ? file_api.env.sessions_list[id] : null;
 
   if (session)
     kolab_files_session_dialog(session);
 };
 
 
 /**********************************************************/
 /*********          Files API handler            **********/
 /**********************************************************/
 
 function kolab_files_ui()
 {
   this.requests = {};
   this.uploads = [];
   this.workers = {};
 
 /*
   // Called on "session expired" session
   this.logout = function(response) {};
 
   // called when a request timed out
   this.request_timed_out = function() {};
 
   // called on start of the request
   this.set_request_time = function() {};
 
   // called on request response
   this.update_request_time = function() {};
 */
   // set state
   this.set_busy = function(a, message)
   {
     if (this.req)
       rcmail.hide_message(this.req);
 
     return rcmail.set_busy(a, message);
   };
 
   // displays error message
   this.display_message = function(label, type)
   {
     return rcmail.display_message(this.t(label), type);
   };
 
   this.http_error = function(request, status, err, data)
   {
     rcmail.http_error(request, status, err, data ? data.req_id : null);
   };
 
   // check if specified/current folder/view is writable
   this.is_writable = function(folder)
   {
     if (!folder)
       folder = this.env.folder;
 
     if (!folder)
       return false;
 
     var all_folders = $.extend({}, this.env.folders, this.search_results);
 
     if (!all_folders[folder] || all_folders[folder].readonly || all_folders[folder].virtual)
       return false;
 
     return true;
   };
 
   // folders list request
   this.folder_list = function(params)
   {
     if (!params)
       params = {}
 
     params.permissions = 1;
     params.req = this.set_busy(true, 'loading');
 
     this.request('folder_list', this.list_params = params, 'folder_list_response');
   };
 
   // folder list response handler
   this.folder_list_response = function(response)
   {
     rcmail.hide_message(this.list_params.req);
 
     if (!this.response(response))
       return;
 
     var first, body, rows = [],
       list_selector = rcmail.env.folder_list_selector || '#files-folder-list',
       search_selector = rcmail.env.folder_search_selector || '#foldersearch',
       elem = $(list_selector),
       searchbox = $(search_selector),
       list = $('<ul class="treelist listing folderlist"></ul>'),
       collections = ['audio', 'video', 'image', 'document'];
 
     // try parent window if the list element does not exist
     // i.e. called from dialog in parent window
     if (!elem.length && window.parent && parent.rcmail) {
       body = window.parent.document.body;
       elem = $(list_selector, body);
       searchbox = $(search_selector, body);
     }
 
     if (elem.data('no-collections') == true)
       collections = [];
 
     elem.html('');
 
     this.env.folders = this.folder_list_parse(response.result && response.result.list ? response.result.list : response.result);
 
     $.each(this.env.folders, function(i, f) {
       var row;
       if (row = file_api.folder_list_row(i, f)) {
         if (!first)
           first = i;
         rows.push(row);
       }
     });
 
     // add virtual collections
     $.each(collections, function(i, n) {
       var row = $('<li class="mailbox collection ' + n + '"></li>');
 
       row.attr('id', 'rcmli' + rcmail.html_identifier_encode('folder-collection-' + n))
         .append($('<a class="name"></a>').text(rcmail.gettext('kolab_files.collection_' + n)))
 
       rows.push(row);
     });
 
     // add Sessions entry
     if (rcmail.task == 'files' && !rcmail.env.action && rcmail.env.files_caps && rcmail.env.files_caps.DOCEDIT) {
       rows.push($('<li class="mailbox collection sessions"></li>')
         .attr('id', 'rcmli' + rcmail.html_identifier_encode('folder-collection-sessions'))
         .append($('<a class="name"></a>').text(rcmail.gettext('kolab_files.sessions')))
       );
     }
 
     list.append(rows).appendTo(elem)
       .on('click', 'a.subscription', function(e) {
         return file_api.folder_list_subscription_button_click(this);
       });
 
     if (rcmail.folder_list) {
       rcmail.folder_list.reset();
       this.search_results_widget = null;
     }
 
     // init treelist widget
     rcmail.folder_list = new rcube_treelist_widget(list, {
         selectable: true,
         id_prefix: 'rcmli',
         parent_focus: true,
         searchbox: searchbox,
         id_encode: rcmail.html_identifier_encode,
         id_decode: rcmail.html_identifier_decode,
         check_droptarget: function(node) {
           return !node.virtual
             && node.id != file_api.env.folder
             && $.inArray('readonly', node.classes) == -1
             && $.inArray('collection', node.classes) == -1;
         }
     });
 
     rcmail.folder_list
       .addEventListener('collapse', function(node) { file_api.folder_collapsed(node); })
       .addEventListener('expand', function(node) { file_api.folder_collapsed(node); })
       .addEventListener('beforeselect', function(node) { return !rcmail.busy; })
       .addEventListener('search', function(search) { file_api.folder_search(search); })
       .addEventListener('select', function(node) {
         if (file_api.search_results_widget)
           file_api.search_results_widget.select();
         file_api.folder_select(node.id);
       });
 
     // select first folder?
-    if (response.result.auth_errors && response.result.auth_errors.length) { }
+    if (response.result.auth_errors && response.result.auth_errors.length)
+      this.env.folder = this.env.collection = null;
     else if (this.env.folder)
       rcmail.folder_list.select(this.env.folder);
     else if (this.env.collection)
       rcmail.folder_list.select('folder-collection-' + this.env.collection);
     else if (first)
       rcmail.folder_list.select(first);
 
     rcmail.enable_command('files-create', true);
 
     // add tree icons
 //    this.folder_list_tree(this.env.folders);
 
     // handle authentication errors on external sources
     if (elem.length)
       this.folder_list_auth_errors(response.result);
   };
 
   this.folder_select = function(folder)
   {
     if (rcmail.busy)
       return;
 
     var is_collection = folder.match(/^folder-collection-(.*)$/),
       collection = RegExp.$1 || null;
 
     if (rcmail.task == 'files' && !rcmail.env.action)
       rcmail.update_state(is_collection ? {collection: collection} : {folder: folder});
 
     if (collection == 'sessions') {
       rcmail.enable_command('files-list', 'files-folder-delete', 'folder-rename', 'files-upload', false);
       this.sessions_list();
       return;
     }
 
     if (is_collection)
       folder = null;
 
     // search-reset can re-select the same folder, skip
     if (this.env.folder == folder && this.env.collection == collection)
       return;
 
     this.env.folder = folder;
     this.env.collection = collection;
 
     rcmail.enable_command('files-list', true);
     rcmail.enable_command('files-folder-delete', 'folder-rename', !is_collection);
     rcmail.enable_command('files-upload', !is_collection && this.is_writable());
     rcmail.command('files-list', is_collection ? {collection: collection} : {folder: folder});
 
     this.quota();
   };
 
   this.folder_unselect = function()
   {
     rcmail.folder_list.select();
     this.env.folder = null;
     this.env.collection = null;
     rcmail.enable_command('files-folder-delete', 'files-upload', false);
   };
 
   this.folder_collapsed = function(node)
   {
     var prefname = 'kolab_files_collapsed_folders',
       old = rcmail.env[prefname],
       entry = '&' + urlencode(node.id) + '&';
 
     if (node.collapsed) {
       rcmail.env[prefname] = rcmail.env[prefname] + entry;
 
       // select the folder if one of its childs is currently selected
       // don't select if it's virtual (#1488346)
       if (!node.virtual && this.env.folder && this.env.folder.startsWith(node.id + '/')) {
         rcmail.folder_list.select(node.id);
       }
     }
     else {
       rcmail.env[prefname] = rcmail.env[prefname].replace(entry, '');
     }
 
     if (old !== rcmail.env[prefname] && (!rcmail.fileslist || !rcmail.fileslist.drag_active))
       rcmail.command('save-pref', {name: prefname, value: rcmail.env[prefname]});
   };
 
   this.folder_list_row = function(i, folder, parent)
   {
     var toggle, sublist, collapsed, parent, parent_name, classes = ['mailbox'],
       row = $('<li>'),
       id = 'rcmli' + rcmail.html_identifier_encode(i);
 
     row.attr('id', id).append($('<a class="name">').text(folder.name));
 
     if (folder.virtual)
       classes.push('virtual');
     else {
       if (folder.subscribed !== undefined)
         row.append(this.folder_list_subscription_button(folder.subscribed));
 
       if (folder.readonly)
         classes.push('readonly');
     }
 
     row.addClass(classes.join(' '));
 
     folder.ref = row;
 
     if (folder.depth) {
       // find parent folder
       parent_name = i.replace(/\/[^/]+$/, '');
       if (!parent)
         parent = $(this.env.folders[parent_name].ref);
 
       toggle = $('div.treetoggle', parent);
       sublist = $('> ul', parent);
 
       if (!toggle.length) {
         collapsed = rcmail.env.kolab_files_collapsed_folders.indexOf('&' + urlencode(parent_name) + '&') > -1;
 
         toggle = $('<div>').attr('class', 'treetoggle' + (collapsed ? ' collapsed' : ' expanded'))
           .html('&nbsp;').appendTo(parent);
 
         sublist = $('<ul>').attr({role: 'group'}).appendTo(parent);
         if (collapsed)
           sublist.hide();
       }
 
       sublist.append(row);
     }
     else {
       return row;
     }
   };
 
   // create subscription button element
   this.folder_list_subscription_button = function(subscribed)
   {
     return $('<a>').attr({
         title: rcmail.gettext('kolab_files.listpermanent'),
         'class': 'subscription' + (subscribed ? ' subscribed' : ''),
         'aria-checked': subscribed,
         role: 'checkbox'
     });
   };
 
   // subscription button handler
   this.folder_list_subscription_button_click = function(elem)
   {
     var folder = $(elem).parent('li').prop('id').replace(/^rcmli/, ''),
       selected = $(elem).hasClass('subscribed');
 
     folder = folder.replace(/--xsR$/, ''); // this might be a search result
     folder = rcmail.html_identifier_decode(folder);
     file_api['folder_' + (selected ? 'unsubscribe' : 'subscribe')](folder);
     return false;
   };
 
   // sets subscription button status
   this.folder_list_subscription_state = function(elem, status)
   {
     $(elem).children('a.subscription')
       .prop('aria-checked', status)[status ? 'addClass' : 'removeClass']('subscribed');
   };
 
   // Folder searching handler (for unsubscribed folders)
   this.folder_search = function(search)
   {
     // hide search results
     if (this.search_results_widget) {
       this.search_results_container.hide();
       this.search_results_widget.reset();
     }
     this.search_results = {};
 
     // send search request to the server
     if (search.query && search.execute) {
       // cancel previous search request
       if (this.listsearch_request) {
         this.listsearch_request.abort();
         this.listsearch_request = null;
       }
 
       var params = $.extend({search: search.query, unsubscribed: 1}, this.list_params);
 
       this.req = this.set_busy(true, rcmail.gettext('searching'));
       this.listsearch_request = this.request('folder_list', params, 'folder_search_response');
     }
     else if (!search.query) {
       if (this.listsearch_request) {
         this.listsearch_request.abort();
         this.listsearch_request = null;
       }
 
       // any subscription changed, make sure the newly added records
       // are listed before collections not after
       if (this.folder_subscribe) {
         var r, last, move = [], rows = $(rcmail.folder_list.container).children('li');
 
         if (rows.length && !$(rows[rows.length-1]).hasClass('collection')) {
           // collect all folders to move
           while (rows.length--) {
             r = $(rows[rows.length]);
             if (r.hasClass('collection'))
               last = r;
             else if (last)
               break;
             else
               move.push(r);
           }
 
           if (last)
             $.each(move, function() {
               this.remove();
               last.before(this);
             });
         }
       }
     }
   };
 
   // folder search response handler
   this.folder_search_response = function(response)
   {
     if (!this.response(response))
       return;
 
     var folders = response.result && response.result.list ? response.result.list : response.result;
 
     if (!folders.length)
       return;
 
     folders = this.folder_list_parse(folders, 10000, false);
 
     if (!this.search_results_widget) {
       var list = rcmail.folder_list.container,
         title = rcmail.gettext('kolab_files.additionalfolders'),
         list_id = list.attr('id') || '0';
 
       this.search_results_container = $('<div class="searchresults"></div>')
           .append($('<h2 class="boxtitle" id="st:' + list_id + '"></h2>').text(title))
           .insertAfter(list);
 
       this.search_results_widget = new rcube_treelist_widget('<ul>', {
           id_prefix: 'rcmli',
           id_encode: rcmail.html_identifier_encode,
           id_decode: rcmail.html_identifier_decode,
           selectable: true
       });
 
       this.search_results_widget
         .addEventListener('beforeselect', function(node) { return !rcmail.busy; })
         .addEventListener('select', function(node) {
           rcmail.folder_list.select();
           file_api.folder_select(node.id);
         });
 
       this.search_results_widget.container
         // copy classes from main list
         .addClass(list.attr('class')).attr('aria-labelledby', 'st:' + list_id)
         .appendTo(this.search_results_container)
         .on('click', 'a.subscription', function(e) {
           return file_api.folder_list_subscription_button_click(this);
         });
     }
 
     // add results to the list
     $.each(folders, function(i, folder) {
       var node, separator = file_api.env.directory_separator,
         path = i.split(separator),
         classes = ['mailbox'],
         html = [$('<a>').text(folder.name)];
 
       if (!folder.virtual) {
         // add subscription button
         html.push(file_api.folder_list_subscription_button(false));
 
         if (folder.readonly)
           classes.push('readonly');
       }
 
       path.pop();
 
       file_api.search_results_widget.insert({
           id: i,
           classes: classes,
           text: folder.name,
           html: html,
           collapsed: false,
           virtual: folder.virtual
         }, path.length ? path.join(separator) : null);
     });
 
     this.search_results = folders;
     this.search_results_container.show();
   };
 
   // folder subscribe request
   this.folder_subscribe = function(folder)
   {
     this.env.folder_subscribe = folder;
     this.req = this.set_busy(true, 'foldersubscribing');
     this.request('folder_subscribe', {folder: folder}, 'folder_subscribe_response');
   }
 
   // folder subscribe response handler
   this.folder_subscribe_response = function(response)
   {
     if (!this.response(response))
       return;
 
     this.display_message('foldersubscribed', 'confirmation');
 
     var item, node = rcmail.folder_list.get_item(this.env.folder_subscribe);
 
     if (this.search_results && this.search_results[this.env.folder_subscribe]) {
       item = this.search_results_widget.get_item(this.env.folder_subscribe);
       this.folder_list_subscription_state(item, true);
       if (item = $(item).attr('id'))
         this.folder_list_subscription_state($('#' + item.replace(/--xsR$/, '')), true);
     }
 
     // search result, move from search to main list widget
     if (!node && this.search_results && this.search_results[this.env.folder_subscribe]) {
       var i, html, dir, folder, separator = this.env.directory_separator,
         path = this.env.folder_subscribe.split(separator);
 
       // add all folders in a path to the main list if needed
       // including the subscribed folder
       for (i=0; i<path.length; i++) {
         dir = path.slice(0, i + 1).join(separator);
         node = rcmail.folder_list.get_node(dir);
 
         if (!node) {
           node = this.search_results_widget.get_node(dir);
           if (!node) {
             // sanity check
             return;
           }
 
           if (i == path.length - 1) {
             item = this.search_results_widget.get_item(dir);
             this.folder_list_subscription_state(item, true);
           }
 
           folder = this.search_results[dir];
           html = [$('<a>').text(folder.name)];
           if (!folder.virtual)
             html.push(this.folder_list_subscription_button(true));
 
           node.html = html;
           delete node.children;
 
           rcmail.folder_list.insert(node, i > 0 ? path.slice(0, i).join(separator) : null);
           // we're in search result, so there will be two records,
           // add subscription button to the visible one, it was not cloned
           if (!folder.virtual) {
             node = rcmail.folder_list.get_item(dir);
             $(node).append(file_api.folder_list_subscription_button(true));
           }
 
           this.env.folders[dir] = folder;
         }
       }
 
       // now remove them from the search widget
       while (path.length) {
         dir = path.join(separator);
         node = this.search_results_widget.get_item(dir);
 
         if ($('ul[role="group"] > li', node).length)
           break;
 
         this.search_results_widget.remove(dir);
 
         path.pop();
       }
 
       node = null;
     }
 
     if (node)
       this.folder_list_subscription_state(node, true);
 
     this.env.folders[this.env.folder_subscribe].subscribed = true;
   };
 
   // folder unsubscribe request
   this.folder_unsubscribe = function(folder)
   {
     this.env.folder_subscribe = folder;
     this.req = this.set_busy(true, 'folderunsubscribing');
     this.request('folder_unsubscribe', {folder: folder}, 'folder_unsubscribe_response');
   }
 
   // folder unsubscribe response handler
   this.folder_unsubscribe_response = function(response)
   {
     if (!this.response(response))
       return;
 
     this.display_message('folderunsubscribed', 'confirmation');
 
     var folder = this.env.folders[this.env.folder_subscribe],
       node = rcmail.folder_list.get_item(this.env.folder_subscribe);
 
     if (this.search_results && this.search_results[this.env.folder_subscribe]) {
       item = this.search_results_widget.get_item(this.env.folder_subscribe);
 
       if (item) {
         this.folder_list_subscription_state(item, false);
         item = $('#' + $(item).attr('id').replace(/--xsR$/, ''));
       }
       else
         item = $('#rcmli' + rcmail.html_identifier_encode(this.env.folder_subscribe), rcmail.folder_list.container);
 
       this.folder_list_subscription_state(item, false);
     }
 
     this.folder_list_subscription_state(node, false);
 
     folder.subscribed = false;
   };
 
   // folder create request
   this.folder_create = function(folder)
   {
     this.req = this.set_busy(true, 'kolab_files.foldercreating');
     this.request('folder_create', {folder: folder}, 'folder_create_response');
   };
 
   // folder create response handler
   this.folder_create_response = function(response)
   {
     if (!this.response(response))
       return;
 
     this.display_message('kolab_files.foldercreatenotice', 'confirmation');
 
     // refresh folders list
     this.folder_list();
   };
 
   // folder rename request
   this.folder_rename = function(folder, new_name)
   {
     if (folder == new_name)
       return;
 
     this.env.folder_rename = new_name;
     this.req = this.set_busy(true, 'kolab_files.folderupdating');
     this.request('folder_move', {folder: folder, 'new': new_name}, 'folder_rename_response');
   };
 
   // folder create response handler
   this.folder_rename_response = function(response)
   {
     if (!this.response(response))
       return;
 
     this.display_message('kolab_files.folderupdatenotice', 'confirmation');
 
     // refresh folders and files list
     this.env.folder = this.env.folder_rename;
     this.folder_list();
   };
 
   // folder mount (external storage) request
   this.folder_mount = function(data)
   {
     this.req = this.set_busy(true, 'kolab_files.foldermounting');
     this.request('folder_create', data, 'folder_mount_response');
   };
 
   // folder create response handler
   this.folder_mount_response = function(response)
   {
     if (!this.response(response))
       return;
 
     this.display_message('kolab_files.foldermountnotice', 'confirmation');
 
     // refresh folders list
     this.folder_list();
   };
 
   // folder delete request
   this.folder_delete = function(folder)
   {
     this.req = this.set_busy(true, 'kolab_files.folderdeleting');
     this.request('folder_delete', {folder: folder}, 'folder_delete_response');
   };
 
   // folder delete response handler
   this.folder_delete_response = function(response)
   {
     if (!this.response(response))
       return;
 
     this.env.folder = null;
     rcmail.enable_command('files-folder-delete', 'folder-rename', 'files-list', false);
     this.display_message('kolab_files.folderdeletenotice', 'confirmation');
 
     // refresh folders list
     this.folder_list();
     this.quota();
   };
 
   // quota request
   this.quota = function()
   {
     if (rcmail.env.files_quota)
       this.request('quota', {folder: this.env.folder}, 'quota_response');
   };
 
   // quota response handler
   this.quota_response = function(response)
   {
     if (!this.response(response))
       return;
 
     rcmail.files_set_quota(response.result);
   };
 
   // List of sessions
   this.sessions_list = function(params)
   {
     if (!rcmail.gui_objects.sessionslist)
       return;
 
     if (!params)
       params = {};
 
     if (rcmail.gui_objects.fileslist) {
       $(rcmail.gui_objects.fileslist).parent().hide();
       $(rcmail.gui_objects.sessionslist).parent().show();
       rcmail.fileslist.clear();
     }
 
     this.env.folder = null;
     this.env.collection = null;
 
     // empty the list
     this.env.sessions_list = {};
     rcmail.sessionslist.clear(true);
 
     rcmail.enable_command(rcmail.env.file_commands, false);
     rcmail.enable_command(rcmail.env.file_commands_all, false);
 
     params.req_id = this.set_busy(true, 'loading');
     this.requests[params.req_id] = this.request('sessions', params, 'sessions_list_response');
   };
 
   // file list response handler
   this.sessions_list_response = function(response)
   {
     if (response.req_id)
       rcmail.hide_message(response.req_id);
 
     if (!this.response(response))
       return;
 
     $.each(response.result, function(sess_id, data) {
       var row = file_api.session_list_row(sess_id, data);
       rcmail.sessionslist.insert_row(row);
       response.result[sess_id].row = row;
     });
 
     this.env.sessions_list = response.result;
     rcmail.sessionslist.resize();
   };
 
   // Files list
   this.file_list = function(params)
   {
     if (!rcmail.gui_objects.fileslist)
       return;
 
     if (!params)
       params = {};
 
     // reset all pending list requests
     $.each(this.requests, function(i, v) {
       v.abort();
       rcmail.hide_message(i);
     });
 
     // reset folder_info workers
     $.each(this.workers, function(i, v) {
       clearTimeout(v);
     });
 
     this.workers = {};
     this.requests = {};
 
     if (params.all_folders) {
       params.collection = null;
       params.folder = null;
       this.folder_unselect();
     }
 
     if (params.collection == undefined)
       params.collection = this.env.collection;
     if (params.folder == undefined)
       params.folder = this.env.folder;
     if (params.sort == undefined)
       params.sort = this.env.files_sort_col;
     if (params.reverse == undefined)
       params.reverse = this.env.files_sort_reverse;
     if (params.search == undefined)
       params.search = this.env.search;
 
     this.env.folder = params.folder;
     this.env.collection = params.collection;
     this.env.files_sort_col = params.sort;
     this.env.files_sort_reverse = params.reverse;
 
     rcmail.enable_command(rcmail.env.file_commands, false);
     rcmail.enable_command(rcmail.env.file_commands_all, false);
 
     if (rcmail.gui_objects.sessionslist) {
       $(rcmail.gui_objects.sessionslist).parent().hide();
       $(rcmail.gui_objects.fileslist).parent().show();
       rcmail.sessionslist.clear(true)
     }
 
     // empty the list
     this.env.file_list = [];
     rcmail.fileslist.clear(true);
 
     // request
     if (params.collection || params.all_folders)
       this.file_list_loop(params);
     else if (this.env.folder) {
       params.req_id = this.set_busy(true, 'loading');
       this.requests[params.req_id] = this.request('file_list', params, 'file_list_response');
     }
   };
 
   // file list response handler
   this.file_list_response = function(response)
   {
     if (response.req_id)
       rcmail.hide_message(response.req_id);
 
     if (!this.response(response))
       return;
 
     var i = 0, list = [];
 
     $.each(response.result, function(key, data) {
       var row = file_api.file_list_row(key, data, ++i);
       rcmail.fileslist.insert_row(row);
       data.row = row;
       data.filename = key;
       list.push(data);
     });
 
     this.env.file_list = list;
     rcmail.fileslist.resize();
 
     // update document sessions info of this folder
     if (list && list.length)
       this.request('folder_info', {folder: this.file_path(list[0].filename), sessions: 1}, 'folder_info_response');
   };
 
   // call file_list request for every folder (used for search and virt. collections)
   this.file_list_loop = function(params)
   {
     var i, folders = [], limit = Math.max(this.env.search_threads || 1, 1);
 
     if (params.collection) {
       if (!params.search)
         params.search = {};
       params.search['class'] = params.collection;
       delete params['collection'];
     }
 
     delete params['all_folders'];
 
     $.each(this.env.folders, function(i, f) {
       if (!f.virtual)
         folders.push(i);
     });
 
     this.env.folders_loop = folders;
     this.env.folders_loop_params = params;
     this.env.folders_loop_lock = false;
 
     for (i=0; i<folders.length && i<limit; i++) {
       params.req_id = this.set_busy(true, 'loading');
       params.folder = folders.shift();
       this.requests[params.req_id] = this.request('file_list', params, 'file_list_loop_response');
     }
   };
 
   // file list response handler for loop'ed request
   this.file_list_loop_response = function(response)
   {
     var i, folders = this.env.folders_loop,
       params = this.env.folders_loop_params,
       limit = Math.max(this.env.search_threads || 1, 1),
       valid = this.response(response);
 
     if (response.req_id)
       rcmail.hide_message(response.req_id);
 
     for (i=0; i<folders.length && i<limit; i++) {
       params.req_id = this.set_busy(true, 'loading');
       params.folder = folders.shift();
       this.requests[params.req_id] = this.request('file_list', params, 'file_list_loop_response');
     }
 
     rcmail.fileslist.resize();
 
     if (!valid)
       return;
 
     this.file_list_loop_result_add(response.result);
   };
 
   // add files from list request to the table (with sorting)
   this.file_list_loop_result_add = function(result)
   {
     // chack if result (hash-array) is empty
     if (!object_is_empty(result))
       return;
 
     if (this.env.folders_loop_lock) {
       setTimeout(function() { file_api.file_list_loop_result_add(result); }, 100);
       return;
     }
 
     // lock table, other list responses will wait
     this.env.folders_loop_lock = true;
 
     var n, i, len, elem, row, folder, list = [],
       index = this.env.file_list.length,
       table = rcmail.fileslist;
 
     for (n=0, len=index; n<len; n++) {
       elem = this.env.file_list[n];
       for (i in result) {
         if (this.sort_compare(elem, result[i]) < 0)
           break;
 
         row = this.file_list_row(i, result[i], ++index);
         table.insert_row(row, elem.row);
         result[i].row = row;
         result[i].filename = i;
         list.push(result[i]);
 
         if (!folder)
           folder = this.file_path(i);
 
         delete result[i];
       }
 
       list.push(elem);
     }
 
     // add the rest of rows
     $.each(result, function(key, data) {
       var row = file_api.file_list_row(key, data, ++index);
       table.insert_row(row);
       result[key].row = row;
       result[key].filename = key;
       list.push(result[key]);
 
       if (!folder)
         folder = file_api.file_path(key);
     });
 
     this.env.file_list = list;
     this.env.folders_loop_lock = false;
 
     // update document sessions info of this folder
     if (folder)
       this.request('folder_info', {folder: folder, sessions: 1}, 'folder_info_response');
   };
 
   // sort files list (without API request)
   this.file_list_sort = function(col, reverse)
   {
     var n, len, list = this.env.file_list,
       table = $('#filelist'), tbody = $('<tbody>', table);
 
     this.env.sort_col = col;
     this.env.sort_reverse = reverse;
 
     if (!list || !list.length)
       return;
 
     // sort the list
     list.sort(function (a, b) {
       return file_api.sort_compare(a, b);
     });
 
     // add rows to the new body
     for (n=0, len=list.length; n<len; n++) {
       tbody.append(list[n].row);
     }
 
     // replace table bodies
     $('tbody', table).replaceWith(tbody);
   };
 
   // Files list record
   this.file_list_row = function(file, data, index)
   {
     var c, col, row = '';
 
     for (c in rcmail.env.files_coltypes) {
       c = rcmail.env.files_coltypes[c];
       if (c == 'name')
         col = '<td class="name filename ' + this.file_type_class(data.type) + '">'
           + '<span>' + escapeHTML(data.name) + '</span></td>';
       else if (c == 'mtime')
         col = '<td class="mtime">' + data.mtime + '</td>';
       else if (c == 'size')
         col = '<td class="size">' + this.file_size(data.size) + '</td>';
       else if (c == 'options')
         col = '<td class="options"><span></span></td>';
       else
         col = '<td class="' + c + '"></td>';
 
       row += col;
     }
 
     row = $('<tr>')
       .html(row)
       .attr({id: 'rcmrow' + index, 'data-file': file, 'data-type': data.type});
 
     // collection (or search) lists files from all folders
     // display file name with full path as title
     if (!this.env.folder)
       $('td.name span', row).attr('title', file);
 
     return row.get(0);
   };
 
   // Sessions list record
   this.session_list_row = function(id, data)
   {
     var c, col, row = '', classes = ['session'];
 
     for (c in rcmail.env.sessions_coltypes) {
       c = rcmail.env.sessions_coltypes[c];
       if (c == 'name')
         col = '<td class="name filename ' + this.file_type_class(data.type) + '">'
           + '<span>' + escapeHTML(file_api.file_name(data.file)) + '</span></td>';
 /*
       else if (c == 'mtime')
         col = '<td class="mtime">' + data.mtime + '</td>';
       else if (c == 'size')
         col = '<td class="size">' + this.file_size(data.size) + '</td>';
 */
       else if (c == 'owner')
         col = '<td class="owner">' + escapeHTML(data.owner_name || data.owner) + '</td>';
       else if (c == 'options')
         col = '<td class="options"><span></span></td>';
 
       row += col;
     }
 
     if (data.is_owner)
       classes.push('owner');
     else if (data.is_invited)
       classes.push('invited');
 
     row = $('<tr>')
       .html(row)
       .attr({id: 'rcmrow' + id, 'class': classes.join(' ')});
 
     return row.get(0);
   };
 
   this.file_search = function(value, all_folders)
   {
     if (value) {
       this.env.search = {name: value};
       rcmail.command('files-list', {search: this.env.search, all_folders: all_folders});
     }
     else
       this.search_reset();
   };
 
   this.file_search_reset = function()
   {
     if (this.env.search) {
       this.env.search = null;
       rcmail.command('files-list');
     }
   };
 
   // handler for folder info response
   this.folder_info_response = function(response)
   {
     if (!this.response(response) || !response.result)
       return;
 
     var folder = response.result.folder,
       prefix = folder + file_api.env.directory_separator;
 
     if (response.result.sessions)
       this.sessions[folder] = response.result.sessions;
 
     // update files list with document session info
     $.each(file_api.env.file_list || [], function(i, file) {
       // skip files from a different folder (in multi-folder listing)
       if (file.filename.indexOf(prefix) !== 0)
         return;
 
       var classes = [];
 
       if ($(file.row).is('.selected'))
         classes.push('selected');
 
       $.each(response.result.sessions || [], function(session_id, session) {
         if (file.filename == session.file) {
           if ($.inArray('session', classes) < 0)
             classes.push('session');
 
           if (session.is_owner && $.inArray('owner', classes) < 0)
             classes.push('owner');
           else if (session.is_invited && $.inArray('invited', classes) < 0)
             classes.push('invited');
         }
       });
 
       $(file.row).attr('class', classes.join(' '));
     });
 
     // refresh sessions info in time intervals
     if (rcmail.env.files_caps && rcmail.env.files_caps.DOCEDIT && (rcmail.fileslist || rcmail.env.file))
       this.workers[folder] = setTimeout(function() {
         file_api.request('folder_info', {folder: folder, sessions: 1}, 'folder_info_response');
       }, (rcmail.env.files_interval || 60) * 1000);
   };
 
   this.file_get = function(file, params)
   {
     if (!params)
       params = {};
 
     params.token = this.env.token;
     params.file = file;
 
     rcmail.redirect(this.env.url + this.url('file_get', params));
   };
 
   // file(s) delete request
   this.file_delete = function(files)
   {
     this.req = this.set_busy(true, 'kolab_files.filedeleting');
     this.request('file_delete', {file: files}, 'file_delete_response');
   };
 
   // file(s) delete response handler
   this.file_delete_response = function(response)
   {
     if (!this.response(response))
       return;
 
     var rco, dir, self = this;
 
     this.display_message('kolab_files.filedeletenotice', 'confirmation');
 
     if (rcmail.env.file) {
       rco = rcmail.opener();
       dir = this.file_path(rcmail.env.file);
 
       // check if opener window contains files list, if not we can just close current window
       if (rco && rco.fileslist && (opener.file_api.env.folder == dir || !opener.file_api.env.folder))
         self = opener.file_api;
       else
         window.close();
     }
 
     // @TODO: consider list modification "in-place" instead of full reload
     self.file_list();
     self.quota();
 
     if (rcmail.env.file)
       window.close();
   };
 
   // file(s) move request
   this.file_move = function(files, folder)
   {
     if (!files || !files.length || !folder)
       return;
 
     var count = 0, list = {};
 
     $.each(files, function(i, v) {
       var name = folder + file_api.env.directory_separator + file_api.file_name(v);
 
       if (name != v) {
         list[v] = name;
         count++;
       }
     });
 
     if (!count)
       return;
 
     this.req = this.set_busy(true, 'kolab_files.filemoving');
     this.request('file_move', {file: list}, 'file_move_response');
   };
 
   // file(s) move response handler
   this.file_move_response = function(response)
   {
     if (!this.response(response))
       return;
 
     if (response.result && response.result.already_exist && response.result.already_exist.length)
       this.file_move_ask_user(response.result.already_exist, true);
     else {
       this.display_message('kolab_files.filemovenotice', 'confirmation');
       this.file_list();
     }
   };
 
   // file(s) copy request
   this.file_copy = function(files, folder)
   {
     if (!files || !files.length || !folder)
       return;
 
     var count = 0, list = {};
 
     $.each(files, function(i, v) {
       var name = folder + file_api.env.directory_separator + file_api.file_name(v);
 
       if (name != v) {
         list[v] = name;
         count++;
       }
     });
 
     if (!count)
       return;
 
     this.req = this.set_busy(true, 'kolab_files.filecopying');
     this.request('file_copy', {file: list}, 'file_copy_response');
   };
 
   // file(s) copy response handler
   this.file_copy_response = function(response)
   {
     if (!this.response(response))
       return;
 
     if (response.result && response.result.already_exist && response.result.already_exist.length)
       this.file_move_ask_user(response.result.already_exist);
     else {
       this.display_message('kolab_files.filecopynotice', 'confirmation');
       this.quota();
     }
   };
 
   // when file move/copy operation returns file-exists error
   // this displays a dialog where user can decide to skip
   // or overwrite destination file(s)
   this.file_move_ask_user = function(list, move)
   {
     var file = list[0], buttons = {},
       text = rcmail.gettext('kolab_files.filemoveconfirm').replace('$file', file.dst)
       dialog = $('<div></div>');
 
     buttons[rcmail.gettext('kolab_files.fileoverwrite')] = function() {
       var file = list.shift(), f = {},
         action = move ? 'file_move' : 'file_copy';
 
       f[file.src] = file.dst;
       file_api.file_move_ask_list = list;
       file_api.file_move_ask_mode = move;
       dialog.dialog('destroy').remove();
       file_api.req = file_api.set_busy(true, move ? 'kolab_files.filemoving' : 'kolab_files.filecopying');
       file_api.request(action, {file: f, overwrite: 1}, 'file_move_ask_user_response');
     };
 
     if (list.length > 1)
       buttons[rcmail.gettext('kolab_files.fileoverwriteall')] = function() {
         var f = {}, action = move ? 'file_move' : 'file_copy';
 
         $.each(list, function() { f[this.src] = this.dst; });
         dialog.dialog('destroy').remove();
         file_api.req = file_api.set_busy(true, move ? 'kolab_files.filemoving' : 'kolab_files.filecopying');
         file_api.request(action, {file: f, overwrite: 1}, action + '_response');
       };
 
     var skip_func = function() {
       list.shift();
       dialog.dialog('destroy').remove();
 
       if (list.length)
         file_api.file_move_ask_user(list, move);
       else if (move)
         file_api.file_list();
     };
 
     buttons[rcmail.gettext('kolab_files.fileskip')] = skip_func;
 
     if (list.length > 1)
       buttons[rcmail.gettext('kolab_files.fileskipall')] = function() {
       dialog.dialog('destroy').remove();
         if (move)
           file_api.file_list();
       };
 
     // open jquery UI dialog
     kolab_dialog_show(dialog.html(text), {
       close: skip_func,
       buttons: buttons,
       minWidth: 400,
       width: 400
     });
   };
 
   // file move (with overwrite) response handler
   this.file_move_ask_user_response = function(response)
   {
     var move = this.file_move_ask_mode, list = this.file_move_ask_list;
 
     this.response(response);
 
     if (list && list.length)
       this.file_move_ask_user(list, mode);
     else {
       this.display_message('kolab_files.file' + (move ? 'move' : 'copy') + 'notice', 'confirmation');
       if (move)
         this.file_list();
     }
   };
 
   // file(s) create (or clone) request
   this.file_create = function(file, type, edit, cloneof)
   {
     this.file_create_edit_file = edit ? file : null;
     this.file_create_edit_type = edit ? type : null;
     this.file_create_folder = this.file_path(file);
 
     if (cloneof) {
       this.req = this.set_busy(true, 'kolab_files.filecopying');
       this.request('file_copy', {file: cloneof, 'new': file}, 'file_create_response');
     }
     else {
       this.req = this.set_busy(true, 'kolab_files.filecreating');
       this.request('file_create', {file: file, 'content-type': type, content: ''}, 'file_create_response');
     }
   };
 
   // file(s) create response handler
   this.file_create_response = function(response)
   {
     if (!this.response(response))
       return;
 
     // @TODO: we could update metadata instead
     if (this.file_create_folder == this.env.folder)
       this.file_list();
 
     // open the file for editing if editable
     if (this.file_create_edit_file) {
       var viewer = this.file_type_supported(this.file_create_edit_type, rcmail.env.files_caps);
       this.file_open(this.file_create_edit_file, viewer, {action: 'edit'});
     }
   };
 
   // file(s) rename request
   this.file_rename = function(oldfile, newfile)
   {
     this.req = this.set_busy(true, 'kolab_files.fileupdating');
     this.request('file_move', {file: oldfile, 'new': newfile}, 'file_rename_response');
   };
 
   // file(s) move response handler
   this.file_rename_response = function(response)
   {
     if (!this.response(response))
       return;
 
     // @TODO: we could update metadata instead
     this.file_list();
   };
 
   // file upload request
   this.file_upload = function(form)
   {
     var form = $(form),
       field = $('input[type=file]', form).get(0),
       files = field.files ? field.files.length : field.value ? 1 : 0;
 
     if (!files || !this.file_upload_size_check(field.files))
       return;
 
     // submit form and read server response
     this.file_upload_form(form, 'file_upload', function(event) {
       var doc, response;
       try {
         doc = this.contentDocument ? this.contentDocument : this.contentWindow.document;
         response = doc.body.innerHTML;
         // response may be wrapped in <pre> tag
         if (response.slice(0, 5).toLowerCase() == '<pre>' && response.slice(-6).toLowerCase() == '</pre>') {
           response = doc.body.firstChild.firstChild.nodeValue;
         }
         response = eval('(' + response + ')');
       }
       catch (err) {
         response = {status: 'ERROR'};
       }
 
       file_api.file_upload_progress_stop(event.data.ts);
 
       // refresh the list on upload success
       file_api.file_upload_response(response);
     });
   };
 
   // refresh the list on upload success
   this.file_upload_response = function(response)
   {
     if (this.response_parse(response)) {
        this.file_list();
        this.quota();
     }
   };
 
   // check upload max size
   this.file_upload_size_check = function(files)
   {
     var i, size = 0, maxsize = rcmail.env.files_max_upload;
 
     if (maxsize && files) {
       for (i=0; i < files.length; i++)
         size += files[i].size || files[i].fileSize;
 
       if (size > maxsize) {
         alert(rcmail.get_label('kolab_files.uploadsizeerror').replace('$size', kolab_files_file_size(maxsize)));
         return false;
       }
     }
 
     return true;
   };
 
   // post the given form to a hidden iframe
   this.file_upload_form = function(form, action, onload)
   {
     var ts = new Date().getTime(),
       frame_name = 'fileupload' + ts;
 
     // upload progress support
     if (rcmail.env.files_progress_name) {
       var fname = rcmail.env.files_progress_name,
         field = $('input[name='+fname+']', form);
 
       if (!field.length) {
         field = $('<input>').attr({type: 'hidden', name: fname});
         field.prependTo(form);
       }
 
       field.val(ts);
       this.file_upload_progress(ts, true);
     }
 
     rcmail.display_progress({name: ts});
 
     // have to do it this way for IE
     // otherwise the form will be posted to a new window
     if (document.all) {
       var html = '<iframe id="'+frame_name+'" name="'+frame_name+'"'
         + ' src="' + rcmail.assets_path('program/resources/blank.gif') + '"'
         + ' style="width:0;height:0;visibility:hidden;"></iframe>';
       document.body.insertAdjacentHTML('BeforeEnd', html);
     }
     // for standards-compliant browsers
     else
       $('<iframe>')
         .attr({name: frame_name, id: frame_name})
         .css({border: 'none', width: 0, height: 0, visibility: 'hidden'})
         .appendTo(document.body);
 
     // handle upload errors, parsing iframe content in onload
     $('#'+frame_name).on('load', {ts:ts}, onload);
 
     $(form).attr({
       target: frame_name,
       action: this.env.url + this.url(action, {folder: this.env.folder, token: this.env.token}),
       method: 'POST'
     }).attr(form.encoding ? 'encoding' : 'enctype', 'multipart/form-data')
       .submit();
   };
 
   // handler when files are dropped to a designated area.
   // compose a multipart form data and submit it to the server
   this.file_drop = function(e)
   {
     var files = e.target.files || e.dataTransfer.files;
 
     if (!files || !files.length || !this.file_upload_size_check(files))
       return;
 
     // prepare multipart form data composition
     var ts = new Date().getTime(),
       formdata = window.FormData ? new FormData() : null,
       fieldname = 'file[]',
       boundary = '------multipartformboundary' + (new Date).getTime(),
       dashdash = '--', crlf = '\r\n',
       multipart = dashdash + boundary + crlf;
 
     // inline function to submit the files to the server
     var submit_data = function() {
       var multiple = files.length > 1;
 
       rcmail.display_progress({name: ts});
       if (rcmail.env.files_progress_name)
         file_api.file_upload_progress(ts, true);
 
       // complete multipart content and post request
       multipart += dashdash + boundary + dashdash + crlf;
 
       $.ajax({
         type: 'POST',
         dataType: 'json',
         url: file_api.env.url + file_api.url('file_upload', {folder: file_api.env.folder}),
         contentType: formdata ? false : 'multipart/form-data; boundary=' + boundary,
         processData: false,
         timeout: 0, // disable default timeout set in ajaxSetup()
         data: formdata || multipart,
         headers: {'X-Session-Token': file_api.env.token},
         success: function(data) {
           file_api.file_upload_progress_stop(ts);
           file_api.file_upload_response(data);
         },
         error: function(o, status, err) {
           file_api.file_upload_progress_stop(ts);
           rcmail.http_error(o, status, err);
         },
         xhr: function() {
           var xhr = jQuery.ajaxSettings.xhr();
           if (!formdata && xhr.sendAsBinary)
             xhr.send = xhr.sendAsBinary;
           return xhr;
         }
       });
     };
 
     // upload progress supported (and handler exists)
     // add progress ID to the request - need to be added before files
     if (rcmail.env.files_progress_name) {
       if (formdata)
         formdata.append(rcmail.env.files_progress_name, ts);
       else
         multipart += 'Content-Disposition: form-data; name="' + rcmail.env.files_progress_name + '"'
           + crlf + crlf + ts + crlf + dashdash + boundary + crlf;
     }
 
     // get contents of all dropped files
     var f, j, i = 0, last = files.length - 1;
     for (j = 0; j <= last && (f = files[i]); i++) {
       if (!f.name) f.name = f.fileName;
       if (!f.size) f.size = f.fileSize;
       if (!f.type) f.type = 'application/octet-stream';
 
       // file name contains non-ASCII characters, do UTF8-binary string conversion.
       if (!formdata && /[^\x20-\x7E]/.test(f.name))
         f.name_bin = unescape(encodeURIComponent(f.name));
 
       // do it the easy way with FormData (FF 4+, Chrome 5+, Safari 5+)
       if (formdata) {
         formdata.append(fieldname, f);
         if (j == last)
           return submit_data();
       }
       // use FileReader supporetd by Firefox 3.6
       else if (window.FileReader) {
         var reader = new FileReader();
 
         // closure to pass file properties to async callback function
         reader.onload = (function(file, j) {
           return function(e) {
             multipart += 'Content-Disposition: form-data; name="' + fieldname + '"';
             multipart += '; filename="' + (f.name_bin || file.name) + '"' + crlf;
             multipart += 'Content-Length: ' + file.size + crlf;
             multipart += 'Content-Type: ' + file.type + crlf + crlf;
             multipart += reader.result + crlf;
             multipart += dashdash + boundary + crlf;
 
             if (j == last)  // we're done, submit the data
               return submit_data();
           }
         })(f,j);
         reader.readAsBinaryString(f);
       }
 
       j++;
     }
   };
 
   // upload progress requests
   this.file_upload_progress = function(id, init)
   {
     if (init && id)
       this.uploads[id] = this.env.folder;
 
     setTimeout(function() {
       if (id && file_api.uploads[id])
         file_api.request('upload_progress', {id: id}, 'file_upload_progress_response');
     }, rcmail.env.files_progress_time * 1000);
   };
 
   // upload progress response
   this.file_upload_progress_response = function(response)
   {
     if (!this.response(response))
       return;
 
     var param = response.result;
 
     if (!param.id || !this.uploads[param.id])
       return;
 
     if (param.total) {
       param.name = param.id;
 
       if (!param.done)
         param.text = kolab_files_progress_str(param);
 
       rcmail.display_progress(param);
     }
 
     if (!param.done && param.total)
       this.file_upload_progress(param.id);
     else
       delete this.uploads[param.id];
   };
 
   this.file_upload_progress_stop = function(id)
   {
     if (id) {
       delete this.uploads[id];
       rcmail.display_progress({name: id});
     }
   };
 
   // open file in new window, using file API viewer
   this.file_open = function(file, viewer, params)
   {
     var args = {
       _task: 'files',
       _action: params && params.action ? params.action : 'open',
       _file: file,
       _viewer: viewer || 0
     };
 
     if (params && params.session)
       args._session = params.session;
 
     if (rcmail.env.extwin)
       args._extwin = 1;
 
     href = '?' + $.param(args);
 
     if (params && params.local)
       location.href = href;
     else
       rcmail.open_window(href, false, true);
   };
 
   // save file
   this.file_save = function(file, content)
   {
     rcmail.enable_command('files-save', false);
     // because we currently can edit only text files
     // and we do not expect them to be very big, we save
     // file in a very simple way, no upload progress, etc.
     this.req = this.set_busy(true, 'saving');
     this.request('file_update', {file: file, content: content, info: 1}, 'file_save_response');
   };
 
   // file save response handler
   this.file_save_response = function(response)
   {
     rcmail.enable_command('files-save', true);
 
     if (!this.response(response))
       return;
 
     // update file properties table
     var table = $('#fileinfobox table'), file = response.result;
 
     if (file) {
       $('td.filetype', table).text(file.type);
       $('td.filesize', table).text(this.file_size(file.size));
       $('td.filemtime', table).text(file.mtime);
     }
   };
 
   // document session delete request
   this.document_delete = function(id)
   {
     this.req = this.set_busy(true, 'kolab_files.sessionterminating');
     this.deleted_session = id;
     this.request('document_delete', {id: id}, 'document_delete_response');
   };
 
   // document session delete response handler
   this.document_delete_response = function(response)
   {
     if (!this.response(response))
       return;
 
     if (rcmail.task == 'files' && rcmail.env.action == 'edit') {
       if (document_editor && document_editor.terminate)
         document_editor.terminate();
       // use timeout to have a chance to properly propagate termination request
       setTimeout(function() { window.close(); }, 500);
     }
 
     // @todo: force sessions info update
 
     var win = window, list = rcmail.sessionslist;
 
     if (!list) {
       win = window.opener;
       if (win && win.rcmail && win.file_api)
         list = win.rcmail.sessionslist;
     }
 
     // remove session from the list (if sessions list exist)
     if (list)
       list.remove_row(this.deleted_session);
     if (win.file_api && win.file_api.env.sessions_list)
       delete win.file_api.env.sessions_list[this.deleted_session];
   };
 
   // Invite document session participants
   this.document_invite = function(id, attendees, comment)
   {
     var list = [];
 
     // expect attendees to be email => name hash
     $.each(attendees || {}, function() { list.push(this); });
 
     if (list.length) {
       this.req = this.set_busy(true, 'kolab_files.documentinviting');
       this.request('document_invite', {id: id, users: list, comment: comment || ''}, 'document_invite_response');
     }
   };
 
   // document invite response handler
   this.document_invite_response = function(response)
   {
     if (!this.response(response) || !response.result)
       return;
 
     var info = rcmail.env.file_data,
       table = $('#document-editors-dialog table > tbody');
 
     $.each(response.result.list || {}, function() {
       var record = kolab_files_attendee_record(this.user, this.status, this.user_name);
       table.append(record);
       if (info.session && info.session.invitations)
         info.session.invitations.push($.extend({status: 'invited', record: record}, this));
     });
   };
 
   // Cancel invitations to an editing session
   this.document_cancel = function(id, attendees)
   {
     if (attendees.length) {
       this.req = this.set_busy(true, 'kolab_files.documentcancelling');
       this.request('document_cancel', {id: id, users: attendees}, 'document_cancel_response');
     }
   };
 
   // document_cancel response handler
   this.document_cancel_response = function(response)
   {
     if (!this.response(response) || !response.result)
       return;
 
     var info = rcmail.env.file_data;
 
     $.each(response.result.list || {}, function(i, user) {
       var invitations = [];
       $.each(info.session.invitations, function(i, u) {
         if (u.user == user && u.record)
           u.record.remove();
         else
           invitations.push(u);
       });
       info.session.invitations = invitations;
     });
   };
 
   // handle auth errors on folder list
   this.folder_list_auth_errors = function(result)
   {
     if (result && result.auth_errors) {
       if (!this.auth_errors)
         this.auth_errors = {};
 
       $.extend(this.auth_errors, result.auth_errors);
     }
 
     // ask for password to the first storage on the list
     $.each(this.auth_errors || [], function(i, v) {
       file_api.folder_list_auth_dialog(i, v);
       return false;
     });
   };
 
   // create dialog for user credentials of external storage
   this.folder_list_auth_dialog = function(label, driver)
   {
     var args = {width: 400, height: 300, buttons: {}},
       dialog = $('#files-folder-auth-dialog'),
       content = this.folder_list_auth_form(driver);
 
     dialog.find('table.propform').remove();
     $('.auth-options', dialog).before(content);
 
     args.buttons[this.t('kolab_files.save')] = function() {
       var data = {folder: label, list: 1};
 
       $('input', dialog).each(function() {
         data[this.name] = this.type == 'checkbox' && !this.checked ? '' : this.value;
       });
 
       file_api.open_dialog = this;
       file_api.req = file_api.set_busy(true, 'kolab_files.authenticating');
       file_api.request('folder_auth', data, 'folder_auth_response');
     };
 
     args.buttons[this.t('kolab_files.cancel')] = function() {
       delete file_api.auth_errors[label];
       kolab_dialog_close(this);
       // go to the next one
       file_api.folder_list_auth_errors();
     };
 
     args.title = this.t('kolab_files.folderauthtitle').replace('$title', label);
 
     // show dialog window
     kolab_dialog_show(dialog, args, function() {
       // focus first empty input
       $('input', dialog).each(function() {
         if (!this.value) {
           this.focus();
           return false;
         }
       });
     });
   };
 
   // folder_auth handler
   this.folder_auth_response = function(response)
   {
     if (!this.response(response))
       return;
 
     var folders, found,
       folder = response.result.folder,
       id = 'rcmli' + rcmail.html_identifier_encode(folder),
       parent = $('#' + id);
 
     // try parent window if the folder element does not exist
     if (!parent.length && window.parent && window.parent.rcmail) {
       parent = $('#' + id, window.parent.document.body);
     }
 
     delete this.auth_errors[folder];
     kolab_dialog_close(this.open_dialog);
 
     // go to the next one
     this.folder_list_auth_errors();
 
     // parse result
     folders = this.folder_list_parse(response.result.list);
     delete folders[folder]; // remove root added in folder_list_parse()
 
     // add folders from the external source to the list
     $.each(folders, function(i, f) {
       file_api.folder_list_row(i, f, parent.get(0));
       found = true;
     });
 
     // reset folders list widget
     if (found)
       rcmail.folder_list.reset(true);
 
     // add tree icons
 //    this.folder_list_tree(folders);
 
     $.extend(this.env.folders, folders);
   };
 
   // returns content of the external storage authentication form
   this.folder_list_auth_form = function(driver)
   {
     var rows = [];
 
     $.each(driver.form, function(fi, fv) {
       var id = 'authinput' + fi,
         attrs = {type: fi.match(/pass/) ? 'password' : 'text', size: 25, name: fi, id: id},
         input = $('<input>').attr(attrs);
 
       if (driver.form_values && driver.form_values[fi])
         input.attr({value: driver.form_values[fi]});
 
       rows.push($('<tr>')
         .append($('<td class="title">').append($('<label>').attr('for', id).text(fv)))
         .append($('<td>').append(input))
       );
     });
 
     return $('<table class="propform">').append(rows);
   };
 };