IMP_Ftree_IteratorFilter::add PHP Method

    public function add($mask)
    {
        foreach (is_array($mask) ? $mask : array($mask) as $val) {
            $this->_mask |= $val;
        }
    }

 /**
  * AJAX action: Login to a remote account.
  *
  * Variables used:
  *   - password: (string) Remote server password.
  *   - password_base64: (boolean) If true, password is base64 encoded.
  *   - password_save: (boolean) If true, password is saved (encrypted)
  *                    to config data.
  *   - remoteid: (string) Remote server ID (base64url encoded).
  *   - unsub: (boolean) If true, show unsubscribed mailboxes.
  *
  * @return boolean  An object with the following properties:
  *   - success: (boolean) True if login was successful.
  */
 public function remoteLogin()
 {
     global $injector, $notification, $prefs;
     $remote = $injector->getInstance('IMP_Remote');
     $remoteid = IMP_Mailbox::formFrom($this->vars->remoteid);
     $res = new stdClass();
     $res->success = false;
     if (!isset($remote[$remoteid])) {
         $notification->push(_("Could not find remote server configuration."), 'horde.error');
         return $res;
     }
     $password = $this->vars->password;
     if ($this->vars->password_base64) {
         $password = base64_decode($password);
     }
     $remote_ob = $remote[$remoteid];
     try {
         switch ($remote_ob->login($password, $this->vars->password_save)) {
             case $remote_ob::LOGIN_BAD_CHANGED:
                 $remote[$remoteid] = $remote_ob;
                 // Fall-through
             // Fall-through
             case $remote_ob::LOGIN_BAD:
                 throw new Exception();
             case $remote_ob::LOGIN_OK_CHANGED:
                 $remote[$remoteid] = $remote_ob;
                 break;
         }
         $res->success = true;
         $notification->push(sprintf(_("Successfully authenticated to %s."), $remote_ob->label), 'horde.success');
         $ftree = $injector->getInstance('IMP_Ftree');
         $ftree->delete($remote_ob);
         $ftree->insert($remote_ob);
         $ftree[$remote_ob]->open = true;
         $this->_base->queue->setMailboxOpt('expand', 1);
         $iterator = new IMP_Ftree_IteratorFilter(new IMP_Ftree_Iterator($ftree[$remote_ob]));
         if ($this->vars->unsub) {
             $ftree->loadUnsubscribed();
             $iterator->remove($iterator::UNSUB);
         }
         switch ($prefs->getValue('nav_expanded')) {
             case IMP_Ftree_Prefs_Expanded::NO:
                 $iterator->add($iterator::CHILDREN);
                 break;
             case IMP_Ftree_Prefs_Expanded::LAST:
                 $iterator->add($iterator::EXPANDED);
                 break;
         }
         array_map(array($ftree->eltdiff, 'add'), iterator_to_array($iterator, false));
     } catch (Exception $e) {
         $notification->push(sprintf(_("Could not authenticate to %s."), $remote_ob->label), 'horde.error');
     }
     return $res;
 }