void VideoListImp::buildDbList()
{
    metadata_list ml;
    VideoMetadataListManager::loadAllFromDatabase(ml);
    m_metadata.setList(ml);

    metadata_view_list mlist;
    mlist.reserve(m_metadata.getList().size());

    back_insert_iterator<metadata_view_list> mli(mlist);
    transform(m_metadata.getList().begin(), m_metadata.getList().end(),
              mli, to_metadata_ptr());

//    print_meta_list(mlist);

    metadata_path_sort mps(true);
    sort(mlist.begin(), mlist.end(), mps);

    // TODO: break out the prefix in the DB so this isn't needed
    typedef map<QString, meta_dir_node *> prefix_to_node_map;
    prefix_to_node_map ptnm;

    QStringList dirs = GetVideoDirs();

    if (dirs.isEmpty())
        return;

    QString test_prefix(dirs[0]);

    meta_dir_node *video_root = &m_metadata_tree;
    if (dirs.size() == 1)
    {
        video_root->setPathRoot();
        video_root->setPath(test_prefix);
        video_root->setName("videos");
        ptnm.insert(prefix_to_node_map::value_type(test_prefix, video_root));
    }

    for (metadata_view_list::iterator p = mlist.begin(); p != mlist.end(); ++p)
    {
        AddMetadataToDir(*p, video_root);
    }

//    print_dir_tree(m_metadata_tree); // AEW DEBUG
}

bool VideoMetadata::fillDataFromID(const VideoMetadataListManager &cache)
{
    if (m_imp->getID() == 0)
        return false;

    VideoMetadataListManager::VideoMetadataPtr mp = cache.byID(m_imp->getID());
    if (mp.get())
    {
        *this = *mp;
        return true;
    }

    return false;
}

bool VideoMetadata::FillDataFromFilename(const VideoMetadataListManager &cache)
{
    if (m_imp->getFilename().isEmpty())
        return false;

    VideoMetadataListManager::VideoMetadataPtr mp =
            cache.byFilename(m_imp->getFilename());
    if (mp)
    {
        *this = *mp;
        return true;
    }

    return false;
}

void VideoListImp::buildGroupList(metadata_list_type whence)
{
    metadata_list ml;
    VideoMetadataListManager::loadAllFromDatabase(ml);
    m_metadata.setList(ml);

    metadata_view_list mlist;
    mlist.reserve(m_metadata.getList().size());

    back_insert_iterator<metadata_view_list> mli(mlist);
    transform(m_metadata.getList().begin(), m_metadata.getList().end(),
              mli, to_metadata_ptr());

    metadata_path_sort mps(true);
    sort(mlist.begin(), mlist.end(), mps);

    typedef map<QString, meta_dir_node *> group_to_node_map;
    group_to_node_map gtnm;

    meta_dir_node *video_root = &m_metadata_tree;

    smart_dir_node sdn = video_root->addSubDir("All");
    meta_dir_node* all_group_node = sdn.get();

    for (metadata_view_list::iterator p = mlist.begin(); p != mlist.end(); ++p)
    {
        VideoMetadata *data = *p;

        all_group_node->addEntry(smart_meta_node(new meta_data_node(data)));

        vector<QString> groups;

        switch (whence)
        {
            case ltDBGenreGroup:
            {
                vector<pair <int, QString> > genres =
                    data->GetGenres();

                for (vector<pair <int, QString> >::iterator i =
                         genres.begin(); i != genres.end(); ++i)
                {
                    pair<int, QString> item = *i;
                    groups.push_back(item.second);
                }
                break;
            }
            case ltDBCategoryGroup:
            {
                groups.push_back(data->GetCategory());
                break;
            }
            case ltDBYearGroup:
            {
                groups.push_back(QString::number(data->GetYear()));
                break;
            }
            case ltDBDirectorGroup:
            {
                groups.push_back(data->GetDirector());
                break;
            }
            case ltDBStudioGroup:
            {
                groups.push_back(data->GetStudio());
                break;
            }
            case ltDBCastGroup:
            {
                vector<pair<int, QString> > cast = data->GetCast();

                for (vector<pair<int, QString> >::iterator i =
                         cast.begin(); i != cast.end(); ++i)
                {
                    pair<int, QString> item = *i;
                    groups.push_back(item.second);
                }
                break;
            }
            case ltDBUserRatingGroup:
            {
                int i = data->GetUserRating();
                groups.push_back(QString::number(i));
                break;
            }
            case ltDBInsertDateGroup:
            {
                QDate date = data->GetInsertdate();
                QString tmp = MythDate::toString(
                    date, MythDate::kDateFull | MythDate::kSimplify);
                groups.push_back(tmp);
                break;
            }
            default:
            {
                LOG(VB_GENERAL, LOG_ERR, "Invalid type of grouping");
                break;
            }
        }

//.........这里部分代码省略.........

void VideoListImp::fillMetadata(metadata_list_type whence)
{
    if (m_metadata_list_type != whence)
    {
        m_metadata_list_type = whence;
        // flush existing data
        metadata_list ml;
        m_metadata.setList(ml);
        m_metadata_tree.clear();

        switch (whence)
        {
            case ltFileSystem:
                buildFsysList();
                break;
            case ltDBMetadata:
                buildDbList();
                break;
            case ltTVMetadata:
                buildTVList();
                break;
            case ltDBGenreGroup:
            case ltDBCategoryGroup:
            case ltDBYearGroup:
            case ltDBDirectorGroup:
            case ltDBStudioGroup:
            case ltDBCastGroup:
            case ltDBUserRatingGroup:
            case ltDBInsertDateGroup:
                buildGroupList(whence);
                break;
            case ltNone:
                break;
        }
    }
}