Implement filtering in playlist editor

[ncmpcpp.git] / src / actions.cpp

/***************************************************************************
 *   Copyright (C) 2008-2014 by Andrzej Rybczak                            *
 *   electricityispower@gmail.com                                          *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.              *
 ***************************************************************************/

#include <cassert>
#include <cerrno>
#include <cstring>
#include <boost/array.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/locale/conversion.hpp>
#include <boost/lexical_cast.hpp>
#include <algorithm>
#include <iostream>

#include "actions.h"
#include "charset.h"
#include "config.h"
#include "display.h"
#include "global.h"
#include "mpdpp.h"
#include "helpers.h"
#include "statusbar.h"
#include "utility/comparators.h"
#include "utility/conversion.h"

#include "bindings.h"
#include "browser.h"
#include "clock.h"
#include "help.h"
#include "media_library.h"
#include "menu_impl.h"
#include "lastfm.h"
#include "lyrics.h"
#include "playlist.h"
#include "playlist_editor.h"
#include "sort_playlist.h"
#include "search_engine.h"
#include "sel_items_adder.h"
#include "server_info.h"
#include "song_info.h"
#include "outputs.h"
#include "utility/readline.h"
#include "utility/string.h"
#include "utility/type_conversions.h"
#include "tag_editor.h"
#include "tiny_tag_editor.h"
#include "visualizer.h"
#include "title.h"
#include "tags.h"

#ifdef HAVE_TAGLIB_H
# include "fileref.h"
# include "tag.h"
#endif // HAVE_TAGLIB_H

using Global::myScreen;

namespace ph = std::placeholders;

namespace {

boost::array<
        Actions::BaseAction *, static_cast<size_t>(Actions::Type::_numberOfActions)
> AvailableActions;

void populateActions();

bool scrollTagCanBeRun(NC::List *&list, SongList *&songs);
void scrollTagUpRun(NC::List *list, SongList *songs, MPD::Song::GetFunction get);
void scrollTagDownRun(NC::List *list, SongList *songs, MPD::Song::GetFunction get);

void seek();
void findItem(const SearchDirection direction);
void listsChangeFinisher();

template <typename Iterator>
bool findSelectedRangeAndPrintInfoIfNot(Iterator &first, Iterator &last)
{
        bool success = findSelectedRange(first, last);
        if (!success)
                Statusbar::print("No range selected");
        return success;
}

}

namespace Actions {

bool OriginalStatusbarVisibility;
bool ExitMainLoop = false;

size_t HeaderHeight;
size_t FooterHeight;
size_t FooterStartY;

void validateScreenSize()
{
        using Global::MainHeight;
        
        if (COLS < 30 || MainHeight < 5)
        {
                NC::destroyScreen();
                std::cout << "Screen is too small to handle ncmpcpp correctly\n";
                exit(1);
        }
}

void initializeScreens()
{
        myHelp = new Help;
        myPlaylist = new Playlist;
        myBrowser = new Browser;
        mySearcher = new SearchEngine;
        myLibrary = new MediaLibrary;
        myPlaylistEditor = new PlaylistEditor;
        myLyrics = new Lyrics;
        mySelectedItemsAdder = new SelectedItemsAdder;
        mySongInfo = new SongInfo;
        myServerInfo = new ServerInfo;
        mySortPlaylistDialog = new SortPlaylistDialog;
        
#       ifdef HAVE_CURL_CURL_H
        myLastfm = new Lastfm;
#       endif // HAVE_CURL_CURL_H
        
#       ifdef HAVE_TAGLIB_H
        myTinyTagEditor = new TinyTagEditor;
        myTagEditor = new TagEditor;
#       endif // HAVE_TAGLIB_H
        
#       ifdef ENABLE_VISUALIZER
        myVisualizer = new Visualizer;
#       endif // ENABLE_VISUALIZER
        
#       ifdef ENABLE_OUTPUTS
        myOutputs = new Outputs;
#       endif // ENABLE_OUTPUTS
        
#       ifdef ENABLE_CLOCK
        myClock = new Clock;
#       endif // ENABLE_CLOCK
        
}

void setResizeFlags()
{
        myHelp->hasToBeResized = 1;
        myPlaylist->hasToBeResized = 1;
        myBrowser->hasToBeResized = 1;
        mySearcher->hasToBeResized = 1;
        myLibrary->hasToBeResized = 1;
        myPlaylistEditor->hasToBeResized = 1;
        myLyrics->hasToBeResized = 1;
        mySelectedItemsAdder->hasToBeResized = 1;
        mySongInfo->hasToBeResized = 1;
        myServerInfo->hasToBeResized = 1;
        mySortPlaylistDialog->hasToBeResized = 1;
        
#       ifdef HAVE_CURL_CURL_H
        myLastfm->hasToBeResized = 1;
#       endif // HAVE_CURL_CURL_H
        
#       ifdef HAVE_TAGLIB_H
        myTinyTagEditor->hasToBeResized = 1;
        myTagEditor->hasToBeResized = 1;
#       endif // HAVE_TAGLIB_H
        
#       ifdef ENABLE_VISUALIZER
        myVisualizer->hasToBeResized = 1;
#       endif // ENABLE_VISUALIZER
        
#       ifdef ENABLE_OUTPUTS
        myOutputs->hasToBeResized = 1;
#       endif // ENABLE_OUTPUTS
        
#       ifdef ENABLE_CLOCK
        myClock->hasToBeResized = 1;
#       endif // ENABLE_CLOCK
}

void resizeScreen(bool reload_main_window)
{
        using Global::MainHeight;
        using Global::wHeader;
        using Global::wFooter;

        // update internal screen dimensions
        if (reload_main_window)
        {
                rl_resize_terminal();
                endwin();
                refresh();
        }

        MainHeight = LINES-(Config.design == Design::Alternative ? 7 : 4);

        validateScreenSize();

        if (!Config.header_visibility)
                MainHeight += 2;
        if (!Config.statusbar_visibility)
                ++MainHeight;

        setResizeFlags();

        applyToVisibleWindows(&BaseScreen::resize);

        if (Config.header_visibility || Config.design == Design::Alternative)
                wHeader->resize(COLS, HeaderHeight);

        FooterStartY = LINES-(Config.statusbar_visibility ? 2 : 1);
        wFooter->moveTo(0, FooterStartY);
        wFooter->resize(COLS, Config.statusbar_visibility ? 2 : 1);

        applyToVisibleWindows(&BaseScreen::refresh);

        Status::Changes::elapsedTime(false);
        Status::Changes::playerState();
        // Note: routines for drawing separator if alternative user
        // interface is active and header is hidden are placed in
        // NcmpcppStatusChanges.StatusFlags
        Status::Changes::flags();
        drawHeader();
        wFooter->refresh();
        refresh();
}

void setWindowsDimensions()
{
        using Global::MainStartY;
        using Global::MainHeight;
        
        MainStartY = Config.design == Design::Alternative ? 5 : 2;
        MainHeight = LINES-(Config.design == Design::Alternative ? 7 : 4);
        
        if (!Config.header_visibility)
        {
                MainStartY -= 2;
                MainHeight += 2;
        }
        if (!Config.statusbar_visibility)
                ++MainHeight;
        
        HeaderHeight = Config.design == Design::Alternative ? (Config.header_visibility ? 5 : 3) : 2;
        FooterStartY = LINES-(Config.statusbar_visibility ? 2 : 1);
        FooterHeight = Config.statusbar_visibility ? 2 : 1;
}

void confirmAction(const boost::format &description)
{
        Statusbar::ScopedLock slock;
        Statusbar::put() << description.str()
        << " [" << NC::Format::Bold << 'y' << NC::Format::NoBold
        << '/' << NC::Format::Bold << 'n' << NC::Format::NoBold
        << "] ";
        auto answer = Statusbar::Helpers::promptReturnOneOf({"y", "n"});
        if (answer == "n")
                throw NC::PromptAborted(std::move(answer));
}

bool isMPDMusicDirSet()
{
        if (Config.mpd_music_dir.empty())
        {
                Statusbar::print("Proper mpd_music_dir variable has to be set in configuration file");
                return false;
        }
        return true;
}

BaseAction &get(Actions::Type at)
{
        if (AvailableActions[1] == nullptr)
                populateActions();
        BaseAction *action = AvailableActions[static_cast<size_t>(at)];
        // action should be always present if action type in queried
        assert(action != nullptr);
        return *action;
}

BaseAction *get(const std::string &name)
{
        BaseAction *result = 0;
        if (AvailableActions[1] == nullptr)
                populateActions();
        for (auto it = AvailableActions.begin(); it != AvailableActions.end(); ++it)
        {
                if (*it != nullptr && (*it)->name() == name)
                {
                        result = *it;
                        break;
                }
        }
        return result;
}

UpdateEnvironment::UpdateEnvironment()
: BaseAction(Type::UpdateEnvironment, "update_environment")
, m_past(boost::posix_time::from_time_t(0))
{ }

void UpdateEnvironment::run(bool update_timer, bool refresh_window)
{
        using Global::Timer;

        // update timer, status if necessary etc.
        Status::trace(update_timer, true);

        // header stuff
        if ((myScreen == myPlaylist || myScreen == myBrowser || myScreen == myLyrics)
        &&  (Timer - m_past > boost::posix_time::milliseconds(500))
        )
        {
                drawHeader();
                m_past = Timer;
        }

        if (refresh_window)
                myScreen->refreshWindow();
}

void UpdateEnvironment::run()
{
        run(true, true);
}

bool MouseEvent::canBeRun()
{
        return Config.mouse_support;
}

void MouseEvent::run()
{
        using Global::VolumeState;
        using Global::wFooter;

        m_old_mouse_event = m_mouse_event;
        m_mouse_event = wFooter->getMouseEvent();

        //Statusbar::printf("(%1%, %2%, %3%)", m_mouse_event.bstate, m_mouse_event.x, m_mouse_event.y);

        if (m_mouse_event.bstate & BUTTON1_PRESSED
        &&  m_mouse_event.y == LINES-(Config.statusbar_visibility ? 2 : 1)
           ) // progressbar
        {
                if (Status::State::player() == MPD::psStop)
                        return;
                Mpd.Seek(Status::State::currentSongPosition(),
                        Status::State::totalTime()*m_mouse_event.x/double(COLS));
        }
        else if (m_mouse_event.bstate & BUTTON1_PRESSED
             &&  (Config.statusbar_visibility || Config.design == Design::Alternative)
             &&  Status::State::player() != MPD::psStop
             &&  m_mouse_event.y == (Config.design == Design::Alternative ? 1 : LINES-1)
                         &&  m_mouse_event.x < 9
                ) // playing/paused
        {
                Mpd.Toggle();
        }
        else if ((m_mouse_event.bstate & BUTTON5_PRESSED || m_mouse_event.bstate & BUTTON4_PRESSED)
             &&  (Config.header_visibility || Config.design == Design::Alternative)
             &&  m_mouse_event.y == 0 && size_t(m_mouse_event.x) > COLS-VolumeState.length()
        ) // volume
        {
                if (m_mouse_event.bstate & BUTTON5_PRESSED)
                        get(Type::VolumeDown).execute();
                else
                        get(Type::VolumeUp).execute();
        }
        else if (m_mouse_event.bstate & (BUTTON1_PRESSED | BUTTON3_PRESSED | BUTTON4_PRESSED | BUTTON5_PRESSED))
                myScreen->mouseButtonPressed(m_mouse_event);
}

void ScrollUp::run()
{
        myScreen->scroll(NC::Scroll::Up);
        listsChangeFinisher();
}

void ScrollDown::run()
{
        myScreen->scroll(NC::Scroll::Down);
        listsChangeFinisher();
}

bool ScrollUpArtist::canBeRun()
{
        return scrollTagCanBeRun(m_list, m_songs);
}

void ScrollUpArtist::run()
{
        scrollTagUpRun(m_list, m_songs, &MPD::Song::getArtist);
}

bool ScrollUpAlbum::canBeRun()
{
        return scrollTagCanBeRun(m_list, m_songs);
}

void ScrollUpAlbum::run()
{
        scrollTagUpRun(m_list, m_songs, &MPD::Song::getAlbum);
}

bool ScrollDownArtist::canBeRun()
{
        return scrollTagCanBeRun(m_list, m_songs);
}

void ScrollDownArtist::run()
{
        scrollTagDownRun(m_list, m_songs, &MPD::Song::getArtist);
}

bool ScrollDownAlbum::canBeRun()
{
        return scrollTagCanBeRun(m_list, m_songs);
}

void ScrollDownAlbum::run()
{
        scrollTagDownRun(m_list, m_songs, &MPD::Song::getAlbum);
}

void PageUp::run()
{
        myScreen->scroll(NC::Scroll::PageUp);
        listsChangeFinisher();
}

void PageDown::run()
{
        myScreen->scroll(NC::Scroll::PageDown);
        listsChangeFinisher();
}

void MoveHome::run()
{
        myScreen->scroll(NC::Scroll::Home);
        listsChangeFinisher();
}

void MoveEnd::run()
{
        myScreen->scroll(NC::Scroll::End);
        listsChangeFinisher();
}

void ToggleInterface::run()
{
        switch (Config.design)
        {
                case Design::Classic:
                        Config.design = Design::Alternative;
                        Config.statusbar_visibility = false;
                        break;
                case Design::Alternative:
                        Config.design = Design::Classic;
                        Config.statusbar_visibility = OriginalStatusbarVisibility;
                        break;
        }
        setWindowsDimensions();
        resizeScreen(false);
        // unlock progressbar
        Progressbar::ScopedLock();
        Status::Changes::mixer();
        Status::Changes::elapsedTime(false);
        Statusbar::printf("User interface: %1%", Config.design);
}

bool JumpToParentDirectory::canBeRun()
{
        return (myScreen == myBrowser)
#       ifdef HAVE_TAGLIB_H
            || (myScreen->activeWindow() == myTagEditor->Dirs)
#       endif // HAVE_TAGLIB_H
        ;
}

void JumpToParentDirectory::run()
{
        if (myScreen == myBrowser)
        {
                if (!myBrowser->inRootDirectory())
                {
                        myBrowser->main().reset();
                        myBrowser->enterDirectory();
                }
        }
#       ifdef HAVE_TAGLIB_H
        else if (myScreen == myTagEditor)
        {
                if (myTagEditor->CurrentDir() != "/")
                {
                        myTagEditor->Dirs->reset();
                        myTagEditor->enterDirectory();
                }
        }
#       endif // HAVE_TAGLIB_H
}

bool RunAction::canBeRun()
{
        m_ha = dynamic_cast<HasActions *>(myScreen);
        return m_ha != nullptr
                && m_ha->actionRunnable();
}

void RunAction::run()
{
        m_ha->runAction();
}

bool PreviousColumn::canBeRun()
{
        m_hc = dynamic_cast<HasColumns *>(myScreen);
        return m_hc != nullptr
                && m_hc->previousColumnAvailable();
}

void PreviousColumn::run()
{
        m_hc->previousColumn();
}

bool NextColumn::canBeRun()
{
        m_hc = dynamic_cast<HasColumns *>(myScreen);
        return m_hc != nullptr
                && m_hc->nextColumnAvailable();
}

void NextColumn::run()
{
        m_hc->nextColumn();
}

bool MasterScreen::canBeRun()
{
        using Global::myLockedScreen;
        using Global::myInactiveScreen;
        
        return myLockedScreen
            && myInactiveScreen
            && myLockedScreen != myScreen
            && myScreen->isMergable();
}

void MasterScreen::run()
{
        using Global::myInactiveScreen;
        using Global::myLockedScreen;
        
        myInactiveScreen = myScreen;
        myScreen = myLockedScreen;
        drawHeader();
}

bool SlaveScreen::canBeRun()
{
        using Global::myLockedScreen;
        using Global::myInactiveScreen;
        
        return myLockedScreen
            && myInactiveScreen
            && myLockedScreen == myScreen
            && myScreen->isMergable();
}

void SlaveScreen::run()
{
        using Global::myInactiveScreen;
        using Global::myLockedScreen;
        
        myScreen = myInactiveScreen;
        myInactiveScreen = myLockedScreen;
        drawHeader();
}

void VolumeUp::run()
{
        int volume = std::min(Status::State::volume()+Config.volume_change_step, 100u);
        Mpd.SetVolume(volume);
}

void VolumeDown::run()
{
        int volume = std::max(int(Status::State::volume()-Config.volume_change_step), 0);
        Mpd.SetVolume(volume);
}

bool AddItemToPlaylist::canBeRun()
{
        m_hs = dynamic_cast<HasSongs *>(myScreen);
        return m_hs != nullptr && m_hs->itemAvailable();
}

void AddItemToPlaylist::run()
{
        bool success = m_hs->addItemToPlaylist(false);
        if (success)
        {
                myScreen->scroll(NC::Scroll::Down);
                listsChangeFinisher();
        }
}

bool PlayItem::canBeRun()
{
        m_hs = dynamic_cast<HasSongs *>(myScreen);
        return m_hs != nullptr && m_hs->itemAvailable();
}

void PlayItem::run()
{
        bool success = m_hs->addItemToPlaylist(true);
        if (success)
                listsChangeFinisher();
}

bool DeletePlaylistItems::canBeRun()
{
        return (myScreen == myPlaylist && !myPlaylist->main().empty())
            || (myScreen->isActiveWindow(myPlaylistEditor->Content) && !myPlaylistEditor->Content.empty());
}

void DeletePlaylistItems::run()
{
        if (myScreen == myPlaylist)
        {
                Statusbar::print("Deleting items...");
                auto delete_fun = std::bind(&MPD::Connection::Delete, ph::_1, ph::_2);
                deleteSelectedSongs(myPlaylist->main(), delete_fun);
                Statusbar::print("Item(s) deleted");
        }
        else if (myScreen->isActiveWindow(myPlaylistEditor->Content))
        {
                std::string playlist = myPlaylistEditor->Playlists.current()->value().path();
                auto delete_fun = std::bind(&MPD::Connection::PlaylistDelete, ph::_1, playlist, ph::_2);
                Statusbar::print("Deleting items...");
                deleteSelectedSongs(myPlaylistEditor->Content, delete_fun);
                Statusbar::print("Item(s) deleted");
        }
}

bool DeleteBrowserItems::canBeRun()
{
        auto check_if_deletion_allowed = []() {
                if (Config.allow_for_physical_item_deletion)
                        return true;
                else
                {
                        Statusbar::print("Flag \"allow_for_physical_item_deletion\" needs to be enabled in configuration file");
                        return false;
                }
        };
        return myScreen == myBrowser
            && !myBrowser->main().empty()
            && isMPDMusicDirSet()
            && check_if_deletion_allowed();
}

void DeleteBrowserItems::run()
{
        auto get_name = [](const MPD::Item &item) -> std::string {
                std::string iname;
                switch (item.type())
                {
                        case MPD::Item::Type::Directory:
                                iname = getBasename(item.directory().path());
                                break;
                        case MPD::Item::Type::Song:
                                iname = item.song().getName();
                                break;
                        case MPD::Item::Type::Playlist:
                                iname = getBasename(item.playlist().path());
                                break;
                }
                return iname;
        };

        boost::format question;
        if (hasSelected(myBrowser->main().begin(), myBrowser->main().end()))
                question = boost::format("Delete selected items?");
        else
        {
                const auto &item = myBrowser->main().current()->value();
                // parent directories are not accepted (and they
                // can't be selected, so in other cases it's fine).
                if (myBrowser->isParentDirectory(item))
                        return;
                const char msg[] = "Delete \"%1%\"?";
                question = boost::format(msg) % wideShorten(
                        get_name(item), COLS-const_strlen(msg)-5
                );
        }
        confirmAction(question);

        auto items = getSelectedOrCurrent(
                myBrowser->main().begin(),
                myBrowser->main().end(),
                myBrowser->main().current()
        );
        for (const auto &item : items)
        {
                myBrowser->remove(item->value());
                const char msg[] = "Deleted %1% \"%2%\"";
                Statusbar::printf(msg,
                        itemTypeToString(item->value().type()),
                        wideShorten(get_name(item->value()), COLS-const_strlen(msg))
                );
        }

        if (!myBrowser->isLocal())
                Mpd.UpdateDirectory(myBrowser->currentDirectory());
        myBrowser->requestUpdate();
}

bool DeleteStoredPlaylist::canBeRun()
{
        return myScreen->isActiveWindow(myPlaylistEditor->Playlists);
}

void DeleteStoredPlaylist::run()
{
        if (myPlaylistEditor->Playlists.empty())
                return;
        boost::format question;
        if (hasSelected(myPlaylistEditor->Playlists.begin(), myPlaylistEditor->Playlists.end()))
                question = boost::format("Delete selected playlists?");
        else
                question = boost::format("Delete playlist \"%1%\"?")
                        % wideShorten(myPlaylistEditor->Playlists.current()->value().path(), COLS-question.size()-10);
        confirmAction(question);
        auto list = getSelectedOrCurrent(
                myPlaylistEditor->Playlists.begin(),
                myPlaylistEditor->Playlists.end(),
                myPlaylistEditor->Playlists.current()
        );
        for (const auto &item : list)
                Mpd.DeletePlaylist(item->value().path());
        Statusbar::printf("%1% deleted", list.size() == 1 ? "Playlist" : "Playlists");
        // force playlists update. this happens automatically, but only after call
        // to Key::read, therefore when we call PlaylistEditor::Update, it won't
        // yet see it, so let's point that it needs to update it.
        myPlaylistEditor->requestPlaylistsUpdate();
}

void ReplaySong::run()
{
        if (Status::State::player() != MPD::psStop)
                Mpd.Seek(Status::State::currentSongPosition(), 0);
}

void PreviousSong::run()
{
        Mpd.Prev();
}

void NextSong::run()
{
        Mpd.Next();
}

void Pause::run()
{
        Mpd.Toggle();
}

void SavePlaylist::run()
{
        using Global::wFooter;
        
        std::string playlist_name;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Save playlist as: ";
                playlist_name = wFooter->prompt();
        }
        try
        {
                Mpd.SavePlaylist(playlist_name);
                Statusbar::printf("Playlist saved as \"%1%\"", playlist_name);
        }
        catch (MPD::ServerError &e)
        {
                if (e.code() == MPD_SERVER_ERROR_EXIST)
                {
                        confirmAction(
                                boost::format("Playlist \"%1%\" already exists, overwrite?") % playlist_name
                        );
                        Mpd.DeletePlaylist(playlist_name);
                        Mpd.SavePlaylist(playlist_name);
                        Statusbar::print("Playlist overwritten");
                }
                else
                        throw;
        }
}

void Stop::run()
{
        Mpd.Stop();
}

void ExecuteCommand::run()
{
        using Global::wFooter;

        std::string cmd_name;
        {
                Statusbar::ScopedLock slock;
                NC::Window::ScopedPromptHook helper(*wFooter,
                        Statusbar::Helpers::TryExecuteImmediateCommand()
                );
                Statusbar::put() << NC::Format::Bold << ":" << NC::Format::NoBold;
                cmd_name = wFooter->prompt();
        }

        auto cmd = Bindings.findCommand(cmd_name);
        if (cmd)
        {
                Statusbar::printf(1, "Executing %1%...", cmd_name);
                bool res = cmd->binding().execute();
                Statusbar::printf("Execution of command \"%1%\" %2%.",
                        cmd_name, res ? "successful" : "unsuccessful"
                );
        }
        else
                Statusbar::printf("No command named \"%1%\"", cmd_name);
}

bool MoveSortOrderUp::canBeRun()
{
        return myScreen == mySortPlaylistDialog;
}

void MoveSortOrderUp::run()
{
        mySortPlaylistDialog->moveSortOrderUp();
}

bool MoveSortOrderDown::canBeRun()
{
        return myScreen == mySortPlaylistDialog;
}

void MoveSortOrderDown::run()
{
        mySortPlaylistDialog->moveSortOrderDown();
}

bool MoveSelectedItemsUp::canBeRun()
{
        return ((myScreen == myPlaylist
            &&  !myPlaylist->main().empty())
         ||    (myScreen->isActiveWindow(myPlaylistEditor->Content)
            &&  !myPlaylistEditor->Content.empty()));
}

void MoveSelectedItemsUp::run()
{
        const char *filteredMsg = "Moving items up is disabled in filtered playlist";
        if (myScreen == myPlaylist)
        {
                if (myPlaylist->main().isFiltered())
                        Statusbar::print(filteredMsg);
                else
                        moveSelectedItemsUp(
                                myPlaylist->main(),
                                std::bind(&MPD::Connection::Move, ph::_1, ph::_2, ph::_3));
        }
        else if (myScreen == myPlaylistEditor)
        {
                if (myPlaylistEditor->Content.isFiltered())
                        Statusbar::print(filteredMsg);
                else
                {
                        auto playlist = myPlaylistEditor->Playlists.current()->value().path();
                        moveSelectedItemsUp(
                                myPlaylistEditor->Content,
                                std::bind(&MPD::Connection::PlaylistMove, ph::_1, playlist, ph::_2, ph::_3));
                }
        }
}

bool MoveSelectedItemsDown::canBeRun()
{
        return ((myScreen == myPlaylist
            &&  !myPlaylist->main().empty())
         ||    (myScreen->isActiveWindow(myPlaylistEditor->Content)
            &&  !myPlaylistEditor->Content.empty()));
}

void MoveSelectedItemsDown::run()
{
        const char *filteredMsg = "Moving items down is disabled in filtered playlist";
        if (myScreen == myPlaylist)
        {
                if (myPlaylist->main().isFiltered())
                        Statusbar::print(filteredMsg);
                else
                        moveSelectedItemsDown(
                                myPlaylist->main(),
                                std::bind(&MPD::Connection::Move, ph::_1, ph::_2, ph::_3));
        }
        else if (myScreen == myPlaylistEditor)
        {
                if (myPlaylistEditor->Content.isFiltered())
                        Statusbar::print(filteredMsg);
                else
                {
                        auto playlist = myPlaylistEditor->Playlists.current()->value().path();
                        moveSelectedItemsDown(
                                myPlaylistEditor->Content,
                                std::bind(&MPD::Connection::PlaylistMove, ph::_1, playlist, ph::_2, ph::_3));
                }
        }
}

bool MoveSelectedItemsTo::canBeRun()
{
        return myScreen == myPlaylist
            || myScreen->isActiveWindow(myPlaylistEditor->Content);
}

void MoveSelectedItemsTo::run()
{
        if (myScreen == myPlaylist)
        {
                if (!myPlaylist->main().empty())
                        moveSelectedItemsTo(myPlaylist->main(), std::bind(&MPD::Connection::Move, ph::_1, ph::_2, ph::_3));
        }
        else
        {
                assert(!myPlaylistEditor->Playlists.empty());
                std::string playlist = myPlaylistEditor->Playlists.current()->value().path();
                auto move_fun = std::bind(&MPD::Connection::PlaylistMove, ph::_1, playlist, ph::_2, ph::_3);
                moveSelectedItemsTo(myPlaylistEditor->Content, move_fun);
        }
}

bool Add::canBeRun()
{
        return myScreen != myPlaylistEditor
           || !myPlaylistEditor->Playlists.empty();
}

void Add::run()
{
        using Global::wFooter;
        
        std::string path;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << (myScreen == myPlaylistEditor ? "Add to playlist: " : "Add: ");
                path = wFooter->prompt();
        }

        // confirm when one wants to add the whole database
        if (path.empty())
                confirmAction("Are you sure you want to add the whole database?");

        Statusbar::put() << "Adding...";
        wFooter->refresh();
        if (myScreen == myPlaylistEditor)
                Mpd.AddToPlaylist(myPlaylistEditor->Playlists.current()->value().path(), path);
        else
        {
                try
                {
                        Mpd.Add(path);
                }
                catch (MPD::ServerError &err)
                {
                        // If a path is not a file or directory, assume it is a playlist.
                        if (err.code() == MPD_SERVER_ERROR_NO_EXIST)
                                Mpd.LoadPlaylist(path);
                        else
                                throw;
                }
        }
}

bool SeekForward::canBeRun()
{
        return Status::State::player() != MPD::psStop && Status::State::totalTime() > 0;
}

void SeekForward::run()
{
        seek();
}

bool SeekBackward::canBeRun()
{
        return Status::State::player() != MPD::psStop && Status::State::totalTime() > 0;
}

void SeekBackward::run()
{
        seek();
}

bool ToggleDisplayMode::canBeRun()
{
        return myScreen == myPlaylist
            || myScreen == myBrowser
            || myScreen == mySearcher
            || myScreen->isActiveWindow(myPlaylistEditor->Content);
}

void ToggleDisplayMode::run()
{
        if (myScreen == myPlaylist)
        {
                switch (Config.playlist_display_mode)
                {
                        case DisplayMode::Classic:
                                Config.playlist_display_mode = DisplayMode::Columns;
                                myPlaylist->main().setItemDisplayer(std::bind(
                                        Display::SongsInColumns, ph::_1, std::cref(myPlaylist->main())
                                ));
                                if (Config.titles_visibility)
                                        myPlaylist->main().setTitle(Display::Columns(myPlaylist->main().getWidth()));
                                else
                                        myPlaylist->main().setTitle("");
                                break;
                        case DisplayMode::Columns:
                                Config.playlist_display_mode = DisplayMode::Classic;
                                myPlaylist->main().setItemDisplayer(std::bind(
                                        Display::Songs, ph::_1, std::cref(myPlaylist->main()), std::cref(Config.song_list_format)
                                ));
                                myPlaylist->main().setTitle("");
                }
                Statusbar::printf("Playlist display mode: %1%", Config.playlist_display_mode);
        }
        else if (myScreen == myBrowser)
        {
                switch (Config.browser_display_mode)
                {
                        case DisplayMode::Classic:
                                Config.browser_display_mode = DisplayMode::Columns;
                                if (Config.titles_visibility)
                                        myBrowser->main().setTitle(Display::Columns(myBrowser->main().getWidth()));
                                else
                                        myBrowser->main().setTitle("");
                                break;
                        case DisplayMode::Columns:
                                Config.browser_display_mode = DisplayMode::Classic;
                                myBrowser->main().setTitle("");
                                break;
                }
                Statusbar::printf("Browser display mode: %1%", Config.browser_display_mode);
        }
        else if (myScreen == mySearcher)
        {
                switch (Config.search_engine_display_mode)
                {
                        case DisplayMode::Classic:
                                Config.search_engine_display_mode = DisplayMode::Columns;
                                break;
                        case DisplayMode::Columns:
                                Config.search_engine_display_mode = DisplayMode::Classic;
                                break;
                }
                Statusbar::printf("Search engine display mode: %1%", Config.search_engine_display_mode);
                if (mySearcher->main().size() > SearchEngine::StaticOptions)
                        mySearcher->main().setTitle(
                                   Config.search_engine_display_mode == DisplayMode::Columns
                                && Config.titles_visibility
                                ? Display::Columns(mySearcher->main().getWidth())
                                : ""
                        );
        }
        else if (myScreen->isActiveWindow(myPlaylistEditor->Content))
        {
                switch (Config.playlist_editor_display_mode)
                {
                        case DisplayMode::Classic:
                                Config.playlist_editor_display_mode = DisplayMode::Columns;
                                myPlaylistEditor->Content.setItemDisplayer(std::bind(
                                        Display::SongsInColumns, ph::_1, std::cref(myPlaylistEditor->Content)
                                ));
                                break;
                        case DisplayMode::Columns:
                                Config.playlist_editor_display_mode = DisplayMode::Classic;
                                myPlaylistEditor->Content.setItemDisplayer(std::bind(
                                        Display::Songs, ph::_1, std::cref(myPlaylistEditor->Content), std::cref(Config.song_list_format)
                                ));
                                break;
                }
                Statusbar::printf("Playlist editor display mode: %1%", Config.playlist_editor_display_mode);
        }
}

bool ToggleSeparatorsBetweenAlbums::canBeRun()
{
        return true;
}

void ToggleSeparatorsBetweenAlbums::run()
{
        Config.playlist_separate_albums = !Config.playlist_separate_albums;
        Statusbar::printf("Separators between albums: %1%",
                Config.playlist_separate_albums ? "on" : "off"
        );
}

bool ToggleLyricsUpdateOnSongChange::canBeRun()
{
        return myScreen == myLyrics;
}

void ToggleLyricsUpdateOnSongChange::run()
{
        Config.now_playing_lyrics = !Config.now_playing_lyrics;
        Statusbar::printf("Update lyrics if song changes: %1%",
                Config.now_playing_lyrics ? "on" : "off"
        );
}

#ifndef HAVE_CURL_CURL_H
bool ToggleLyricsFetcher::canBeRun()
{
        return false;
}
#endif // NOT HAVE_CURL_CURL_H

void ToggleLyricsFetcher::run()
{
#       ifdef HAVE_CURL_CURL_H
        myLyrics->ToggleFetcher();
#       endif // HAVE_CURL_CURL_H
}

#ifndef HAVE_CURL_CURL_H
bool ToggleFetchingLyricsInBackground::canBeRun()
{
        return false;
}
#endif // NOT HAVE_CURL_CURL_H

void ToggleFetchingLyricsInBackground::run()
{
#       ifdef HAVE_CURL_CURL_H
        Config.fetch_lyrics_in_background = !Config.fetch_lyrics_in_background;
        Statusbar::printf("Fetching lyrics for playing songs in background: %1%",
                Config.fetch_lyrics_in_background ? "on" : "off"
        );
#       endif // HAVE_CURL_CURL_H
}

void TogglePlayingSongCentering::run()
{
        Config.autocenter_mode = !Config.autocenter_mode;
        Statusbar::printf("Centering playing song: %1%",
                Config.autocenter_mode ? "on" : "off"
        );
        if (Config.autocenter_mode)
        {
                auto s = myPlaylist->nowPlayingSong();
                if (!s.empty())
                        myPlaylist->locateSong(s);
        }
}

void UpdateDatabase::run()
{
        if (myScreen == myBrowser)
                Mpd.UpdateDirectory(myBrowser->currentDirectory());
#       ifdef HAVE_TAGLIB_H
        else if (myScreen == myTagEditor)
                Mpd.UpdateDirectory(myTagEditor->CurrentDir());
#       endif // HAVE_TAGLIB_H
        else
                Mpd.UpdateDirectory("/");
}

bool JumpToPlayingSong::canBeRun()
{
        return myScreen == myPlaylist
            || myScreen == myBrowser
            || myScreen == myLibrary;
}

void JumpToPlayingSong::run()
{
        auto s = myPlaylist->nowPlayingSong();
        if (s.empty())
                return;
        if (myScreen == myPlaylist)
        {
                myPlaylist->locateSong(s);
        }
        else if (myScreen == myBrowser)
        {
                myBrowser->locateSong(s);
        }
        else if (myScreen == myLibrary)
        {
                myLibrary->locateSong(s);
        }
}

void ToggleRepeat::run()
{
        Mpd.SetRepeat(!Status::State::repeat());
}

bool Shuffle::canBeRun()
{
        if (myScreen != myPlaylist)
                return false;
        m_begin = myPlaylist->main().begin();
        m_end = myPlaylist->main().end();
        return findSelectedRangeAndPrintInfoIfNot(m_begin, m_end);
}

void Shuffle::run()
{
        if (Config.ask_before_shuffling_playlists)
                confirmAction("Do you really want to shuffle selected range?");
        auto begin = myPlaylist->main().begin();
        Mpd.ShuffleRange(m_begin-begin, m_end-begin);
        Statusbar::print("Range shuffled");
}

void ToggleRandom::run()
{
        Mpd.SetRandom(!Status::State::random());
}

bool StartSearching::canBeRun()
{
        return myScreen == mySearcher && !mySearcher->main()[0].isInactive();
}

void StartSearching::run()
{
        mySearcher->main().highlight(SearchEngine::SearchButton);
        mySearcher->main().setHighlighting(0);
        mySearcher->main().refresh();
        mySearcher->main().setHighlighting(1);
        mySearcher->runAction();
}

bool SaveTagChanges::canBeRun()
{
#       ifdef HAVE_TAGLIB_H
        return myScreen == myTinyTagEditor
            || myScreen->activeWindow() == myTagEditor->TagTypes;
#       else
        return false;
#       endif // HAVE_TAGLIB_H
}

void SaveTagChanges::run()
{
#       ifdef HAVE_TAGLIB_H
        if (myScreen == myTinyTagEditor)
        {
                myTinyTagEditor->main().highlight(myTinyTagEditor->main().size()-2); // Save
                myTinyTagEditor->runAction();
        }
        else if (myScreen->activeWindow() == myTagEditor->TagTypes)
        {
                myTagEditor->TagTypes->highlight(myTagEditor->TagTypes->size()-1); // Save
                myTagEditor->runAction();
        }
#       endif // HAVE_TAGLIB_H
}

void ToggleSingle::run()
{
        Mpd.SetSingle(!Status::State::single());
}

void ToggleConsume::run()
{
        Mpd.SetConsume(!Status::State::consume());
}

void ToggleCrossfade::run()
{
        Mpd.SetCrossfade(Status::State::crossfade() ? 0 : Config.crossfade_time);
}

void SetCrossfade::run()
{
        using Global::wFooter;
        
        Statusbar::ScopedLock slock;
        Statusbar::put() << "Set crossfade to: ";
        auto crossfade = fromString<unsigned>(wFooter->prompt());
        lowerBoundCheck(crossfade, 0u);
        Config.crossfade_time = crossfade;
        Mpd.SetCrossfade(crossfade);
}

void SetVolume::run()
{
        using Global::wFooter;
        
        unsigned volume;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Set volume to: ";
                volume = fromString<unsigned>(wFooter->prompt());
                boundsCheck(volume, 0u, 100u);
                Mpd.SetVolume(volume);
        }
        Statusbar::printf("Volume set to %1%%%", volume);
}

bool EnterDirectory::canBeRun()
{
        bool result = false;
        if (myScreen == myBrowser && !myBrowser->main().empty())
        {
                result = myBrowser->main().current()->value().type()
                        == MPD::Item::Type::Directory;
        }
#ifdef HAVE_TAGLIB_H
        else if (myScreen->activeWindow() == myTagEditor->Dirs)
                result = true;
#endif // HAVE_TAGLIB_H
        return result;
}

void EnterDirectory::run()
{
        if (myScreen == myBrowser)
                myBrowser->enterDirectory();
#ifdef HAVE_TAGLIB_H
        else if (myScreen->activeWindow() == myTagEditor->Dirs)
        {
                if (!myTagEditor->enterDirectory())
                        Statusbar::print("No subdirectories found");
        }
#endif // HAVE_TAGLIB_H
}

bool EditSong::canBeRun()
{
#       ifdef HAVE_TAGLIB_H
        m_song = currentSong(myScreen);
        return m_song != nullptr && isMPDMusicDirSet();
#       else
        return false;
#       endif // HAVE_TAGLIB_H
}

void EditSong::run()
{
#       ifdef HAVE_TAGLIB_H
        myTinyTagEditor->SetEdited(*m_song);
        myTinyTagEditor->switchTo();
#       endif // HAVE_TAGLIB_H
}

bool EditLibraryTag::canBeRun()
{
#       ifdef HAVE_TAGLIB_H
        return myScreen->isActiveWindow(myLibrary->Tags)
            && !myLibrary->Tags.empty()
            && isMPDMusicDirSet();
#       else
        return false;
#       endif // HAVE_TAGLIB_H
}

void EditLibraryTag::run()
{
#       ifdef HAVE_TAGLIB_H
        using Global::wFooter;

        std::string new_tag;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << NC::Format::Bold << tagTypeToString(Config.media_lib_primary_tag) << NC::Format::NoBold << ": ";
                new_tag = wFooter->prompt(myLibrary->Tags.current()->value().tag());
        }
        if (!new_tag.empty() && new_tag != myLibrary->Tags.current()->value().tag())
        {
                Statusbar::print("Updating tags...");
                Mpd.StartSearch(true);
                Mpd.AddSearch(Config.media_lib_primary_tag, myLibrary->Tags.current()->value().tag());
                MPD::MutableSong::SetFunction set = tagTypeToSetFunction(Config.media_lib_primary_tag);
                assert(set);
                bool success = true;
                std::string dir_to_update;
                for (MPD::SongIterator s = Mpd.CommitSearchSongs(), end; s != end; ++s)
                {
                        MPD::MutableSong ms = std::move(*s);
                        ms.setTags(set, new_tag);
                        Statusbar::printf("Updating tags in \"%1%\"...", ms.getName());
                        std::string path = Config.mpd_music_dir + ms.getURI();
                        if (!Tags::write(ms))
                        {
                                success = false;
                                const char msg[] = "Error while updating tags in \"%1%\"";
                                Statusbar::printf(msg, wideShorten(ms.getURI(), COLS-const_strlen(msg)));
                                s.finish();
                                break;
                        }
                        if (dir_to_update.empty())
                                dir_to_update = ms.getURI();
                        else
                                dir_to_update = getSharedDirectory(dir_to_update, ms.getURI());
                };
                if (success)
                {
                        Mpd.UpdateDirectory(dir_to_update);
                        Statusbar::print("Tags updated successfully");
                }
        }
#       endif // HAVE_TAGLIB_H
}

bool EditLibraryAlbum::canBeRun()
{
#       ifdef HAVE_TAGLIB_H
        return myScreen->isActiveWindow(myLibrary->Albums)
            && !myLibrary->Albums.empty()
                && isMPDMusicDirSet();
#       else
        return false;
#       endif // HAVE_TAGLIB_H
}

void EditLibraryAlbum::run()
{
#       ifdef HAVE_TAGLIB_H
        using Global::wFooter;
        // FIXME: merge this and EditLibraryTag. also, prompt on failure if user wants to continue
        std::string new_album;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << NC::Format::Bold << "Album: " << NC::Format::NoBold;
                new_album = wFooter->prompt(myLibrary->Albums.current()->value().entry().album());
        }
        if (!new_album.empty() && new_album != myLibrary->Albums.current()->value().entry().album())
        {
                bool success = 1;
                Statusbar::print("Updating tags...");
                for (size_t i = 0;  i < myLibrary->Songs.size(); ++i)
                {
                        Statusbar::printf("Updating tags in \"%1%\"...", myLibrary->Songs[i].value().getName());
                        std::string path = Config.mpd_music_dir + myLibrary->Songs[i].value().getURI();
                        TagLib::FileRef f(path.c_str());
                        if (f.isNull())
                        {
                                const char msg[] = "Error while opening file \"%1%\"";
                                Statusbar::printf(msg, wideShorten(myLibrary->Songs[i].value().getURI(), COLS-const_strlen(msg)));
                                success = 0;
                                break;
                        }
                        f.tag()->setAlbum(ToWString(new_album));
                        if (!f.save())
                        {
                                const char msg[] = "Error while writing tags in \"%1%\"";
                                Statusbar::printf(msg, wideShorten(myLibrary->Songs[i].value().getURI(), COLS-const_strlen(msg)));
                                success = 0;
                                break;
                        }
                }
                if (success)
                {
                        Mpd.UpdateDirectory(getSharedDirectory(myLibrary->Songs.beginV(), myLibrary->Songs.endV()));
                        Statusbar::print("Tags updated successfully");
                }
        }
#       endif // HAVE_TAGLIB_H
}

bool EditDirectoryName::canBeRun()
{
        return  ((myScreen == myBrowser
              && !myBrowser->main().empty()
              && myBrowser->main().current()->value().type() == MPD::Item::Type::Directory)
#       ifdef HAVE_TAGLIB_H
            ||   (myScreen->activeWindow() == myTagEditor->Dirs
              && !myTagEditor->Dirs->empty()
              && myTagEditor->Dirs->choice() > 0)
#       endif // HAVE_TAGLIB_H
        ) &&     isMPDMusicDirSet();
}

void EditDirectoryName::run()
{
        using Global::wFooter;
        if (myScreen == myBrowser)
        {
                std::string old_dir = myBrowser->main().current()->value().directory().path();
                std::string new_dir;
                {
                        Statusbar::ScopedLock slock;
                        Statusbar::put() << NC::Format::Bold << "Directory: " << NC::Format::NoBold;
                        new_dir = wFooter->prompt(old_dir);
                }
                if (!new_dir.empty() && new_dir != old_dir)
                {
                        std::string full_old_dir;
                        if (!myBrowser->isLocal())
                                full_old_dir += Config.mpd_music_dir;
                        full_old_dir += old_dir;
                        std::string full_new_dir;
                        if (!myBrowser->isLocal())
                                full_new_dir += Config.mpd_music_dir;
                        full_new_dir += new_dir;
                        boost::filesystem::rename(full_old_dir, full_new_dir);
                        const char msg[] = "Directory renamed to \"%1%\"";
                        Statusbar::printf(msg, wideShorten(new_dir, COLS-const_strlen(msg)));
                        if (!myBrowser->isLocal())
                                Mpd.UpdateDirectory(getSharedDirectory(old_dir, new_dir));
                        myBrowser->requestUpdate();
                }
        }
#       ifdef HAVE_TAGLIB_H
        else if (myScreen->activeWindow() == myTagEditor->Dirs)
        {
                std::string old_dir = myTagEditor->Dirs->current()->value().first, new_dir;
                {
                        Statusbar::ScopedLock slock;
                        Statusbar::put() << NC::Format::Bold << "Directory: " << NC::Format::NoBold;
                        new_dir = wFooter->prompt(old_dir);
                }
                if (!new_dir.empty() && new_dir != old_dir)
                {
                        std::string full_old_dir = Config.mpd_music_dir + myTagEditor->CurrentDir() + "/" + old_dir;
                        std::string full_new_dir = Config.mpd_music_dir + myTagEditor->CurrentDir() + "/" + new_dir;
                        if (rename(full_old_dir.c_str(), full_new_dir.c_str()) == 0)
                        {
                                const char msg[] = "Directory renamed to \"%1%\"";
                                Statusbar::printf(msg, wideShorten(new_dir, COLS-const_strlen(msg)));
                                Mpd.UpdateDirectory(myTagEditor->CurrentDir());
                        }
                        else
                        {
                                const char msg[] = "Couldn't rename \"%1%\": %2%";
                                Statusbar::printf(msg, wideShorten(old_dir, COLS-const_strlen(msg)-25), strerror(errno));
                        }
                }
        }
#       endif // HAVE_TAGLIB_H
}

bool EditPlaylistName::canBeRun()
{
        return   (myScreen->isActiveWindow(myPlaylistEditor->Playlists)
              && !myPlaylistEditor->Playlists.empty())
            ||   (myScreen == myBrowser
              && !myBrowser->main().empty()
                  && myBrowser->main().current()->value().type() == MPD::Item::Type::Playlist);
}

void EditPlaylistName::run()
{
        using Global::wFooter;
        std::string old_name, new_name;
        if (myScreen->isActiveWindow(myPlaylistEditor->Playlists))
                old_name = myPlaylistEditor->Playlists.current()->value().path();
        else
                old_name = myBrowser->main().current()->value().playlist().path();
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << NC::Format::Bold << "Playlist: " << NC::Format::NoBold;
                new_name = wFooter->prompt(old_name);
        }
        if (!new_name.empty() && new_name != old_name)
        {
                Mpd.Rename(old_name, new_name);
                const char msg[] = "Playlist renamed to \"%1%\"";
                Statusbar::printf(msg, wideShorten(new_name, COLS-const_strlen(msg)));
        }
}

bool EditLyrics::canBeRun()
{
        return myScreen == myLyrics;
}

void EditLyrics::run()
{
        myLyrics->Edit();
}

bool JumpToBrowser::canBeRun()
{
        m_song = currentSong(myScreen);
        return m_song != nullptr;
}

void JumpToBrowser::run()
{
        myBrowser->locateSong(*m_song);
}

bool JumpToMediaLibrary::canBeRun()
{
        m_song = currentSong(myScreen);
        return m_song != nullptr;
}

void JumpToMediaLibrary::run()
{
        myLibrary->locateSong(*m_song);
}

bool JumpToPlaylistEditor::canBeRun()
{
        return myScreen == myBrowser
            && myBrowser->main().current()->value().type() == MPD::Item::Type::Playlist;
}

void JumpToPlaylistEditor::run()
{
        myPlaylistEditor->locatePlaylist(myBrowser->main().current()->value().playlist());
}

void ToggleScreenLock::run()
{
        using Global::wFooter;
        using Global::myLockedScreen;
        const char *msg_unlockable_screen = "Current screen can't be locked";
        if (myLockedScreen != nullptr)
        {
                BaseScreen::unlock();
                Actions::setResizeFlags();
                myScreen->resize();
                Statusbar::print("Screen unlocked");
        }
        else if (!myScreen->isLockable())
        {
                Statusbar::print(msg_unlockable_screen);
        }
        else
        {
                unsigned part = Config.locked_screen_width_part*100;
                if (Config.ask_for_locked_screen_width_part)
                {
                        Statusbar::ScopedLock slock;
                        Statusbar::put() << "% of the locked screen's width to be reserved (20-80): ";
                        part = fromString<unsigned>(wFooter->prompt(boost::lexical_cast<std::string>(part)));
                }
                boundsCheck(part, 20u, 80u);
                Config.locked_screen_width_part = part/100.0;
                if (myScreen->lock())
                        Statusbar::printf("Screen locked (with %1%%% width)", part);
                else
                        Statusbar::print(msg_unlockable_screen);
        }
}

bool JumpToTagEditor::canBeRun()
{
#       ifdef HAVE_TAGLIB_H
        m_song = currentSong(myScreen);
        return m_song != nullptr && isMPDMusicDirSet();
#       else
        return false;
#       endif // HAVE_TAGLIB_H
}

void JumpToTagEditor::run()
{
#       ifdef HAVE_TAGLIB_H
        myTagEditor->LocateSong(*m_song);
#       endif // HAVE_TAGLIB_H
}

bool JumpToPositionInSong::canBeRun()
{
        return Status::State::player() != MPD::psStop && Status::State::totalTime() > 0;
}

void JumpToPositionInSong::run()
{
        using Global::wFooter;
        
        const MPD::Song s = myPlaylist->nowPlayingSong();
        
        std::string spos;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Position to go (in %/m:ss/seconds(s)): ";
                spos = wFooter->prompt();
        }
        
        boost::regex rx;
        boost::smatch what;
        if (boost::regex_match(spos, what, rx.assign("([0-9]+):([0-9]{2})"))) // mm:ss
        {
                auto mins = fromString<unsigned>(what[1]);
                auto secs = fromString<unsigned>(what[2]);
                boundsCheck(secs, 0u, 60u);
                Mpd.Seek(s.getPosition(), mins * 60 + secs);
        }
        else if (boost::regex_match(spos, what, rx.assign("([0-9]+)s"))) // position in seconds
        {
                auto secs = fromString<unsigned>(what[1]);
                Mpd.Seek(s.getPosition(), secs);
        }
        else if (boost::regex_match(spos, what, rx.assign("([0-9]+)[%]{0,1}"))) // position in %
        {
                auto percent = fromString<unsigned>(what[1]);
                boundsCheck(percent, 0u, 100u);
                int secs = (percent * s.getDuration()) / 100.0;
                Mpd.Seek(s.getPosition(), secs);
        }
        else
                Statusbar::print("Invalid format ([m]:[ss], [s]s, [%]%, [%] accepted)");
}

bool SelectItem::canBeRun()
{
        m_list = dynamic_cast<NC::List *>(myScreen->activeWindow());
        return m_list != nullptr
            && !m_list->empty()
            && m_list->currentP()->isSelectable();
}

void SelectItem::run()
{
        auto current = m_list->currentP();
        current->setSelected(!current->isSelected());
}

bool SelectRange::canBeRun()
{
        m_list = dynamic_cast<NC::List *>(myScreen->activeWindow());
        if (m_list == nullptr)
                return false;
        m_begin = m_list->beginP();
        m_end = m_list->endP();
        return findRange(m_begin, m_end);
}

void SelectRange::run()
{
        for (; m_begin != m_end; ++m_begin)
                m_begin->setSelected(true);
        Statusbar::print("Range selected");
}

bool ReverseSelection::canBeRun()
{
        m_list = dynamic_cast<NC::List *>(myScreen->activeWindow());
        return m_list != nullptr;
}

void ReverseSelection::run()
{
        for (auto &p : *m_list)
                p.setSelected(!p.isSelected());
        Statusbar::print("Selection reversed");
}

bool RemoveSelection::canBeRun()
{
        m_list = dynamic_cast<NC::List *>(myScreen->activeWindow());
        return m_list != nullptr;
}

void RemoveSelection::run()
{
        for (auto &p : *m_list)
                p.setSelected(false);
        Statusbar::print("Selection removed");
}

bool SelectAlbum::canBeRun()
{
        auto *w = myScreen->activeWindow();
        if (m_list != static_cast<void *>(w))
                m_list = dynamic_cast<NC::List *>(w);
        if (m_songs != static_cast<void *>(w))
                m_songs = dynamic_cast<SongList *>(w);
        return m_list != nullptr && !m_list->empty()
            && m_songs != nullptr;
}

void SelectAlbum::run()
{
        const auto front = m_songs->beginS(), current = m_songs->currentS(), end = m_songs->endS();
        auto *s = current->get<Bit::Song>();
        if (s == nullptr)
                return;
        auto get = &MPD::Song::getAlbum;
        const std::string tag = s->getTags(get);
        // go up
        for (auto it = current; it != front;)
        {
                --it;
                s = it->get<Bit::Song>();
                if (s == nullptr || s->getTags(get) != tag)
                        break;
                it->get<Bit::Properties>().setSelected(true);
        }
        // go down
        for (auto it = current;;)
        {
                it->get<Bit::Properties>().setSelected(true);
                if (++it == end)
                        break;
                s = it->get<Bit::Song>();
                if (s == nullptr || s->getTags(get) != tag)
                        break;
        }
        Statusbar::print("Album around cursor position selected");
}

bool SelectFoundItems::canBeRun()
{
        m_list = dynamic_cast<NC::List *>(myScreen->activeWindow());
        if (m_list == nullptr || m_list->empty())
                return false;
        m_searchable = dynamic_cast<Searchable *>(myScreen);
        return m_searchable != nullptr && m_searchable->allowsSearching();
}

void SelectFoundItems::run()
{
        auto current_pos = m_list->choice();
        myScreen->activeWindow()->scroll(NC::Scroll::Home);
        bool found = m_searchable->search(SearchDirection::Forward, false, false);
        if (found)
        {
                Statusbar::print("Searching for items...");
                m_list->currentP()->setSelected(true);
                while (m_searchable->search(SearchDirection::Forward, false, true))
                        m_list->currentP()->setSelected(true);
                Statusbar::print("Found items selected");
        }
        m_list->highlight(current_pos);
}

bool AddSelectedItems::canBeRun()
{
        return myScreen != mySelectedItemsAdder;
}

void AddSelectedItems::run()
{
        mySelectedItemsAdder->switchTo();
}

void CropMainPlaylist::run()
{
        auto &w = myPlaylist->main();
        // cropping doesn't make sense in this case
        if (w.size() <= 1)
                return;
        if (Config.ask_before_clearing_playlists)
                confirmAction("Do you really want to crop main playlist?");
        Statusbar::print("Cropping playlist...");
        selectCurrentIfNoneSelected(w);
        cropPlaylist(w, std::bind(&MPD::Connection::Delete, ph::_1, ph::_2));
        Statusbar::print("Playlist cropped");
}

bool CropPlaylist::canBeRun()
{
        return myScreen == myPlaylistEditor;
}

void CropPlaylist::run()
{
        auto &w = myPlaylistEditor->Content;
        // cropping doesn't make sense in this case
        if (w.size() <= 1)
                return;
        assert(!myPlaylistEditor->Playlists.empty());
        std::string playlist = myPlaylistEditor->Playlists.current()->value().path();
        if (Config.ask_before_clearing_playlists)
                confirmAction(boost::format("Do you really want to crop playlist \"%1%\"?") % playlist);
        selectCurrentIfNoneSelected(w);
        Statusbar::printf("Cropping playlist \"%1%\"...", playlist);
        cropPlaylist(w, std::bind(&MPD::Connection::PlaylistDelete, ph::_1, playlist, ph::_2));
        Statusbar::printf("Playlist \"%1%\" cropped", playlist);
}

void ClearMainPlaylist::run()
{
        if (!myPlaylist->main().empty() && Config.ask_before_clearing_playlists)
                confirmAction("Do you really want to clear main playlist?");
        Mpd.ClearMainPlaylist();
        Statusbar::print("Playlist cleared");
        myPlaylist->main().reset();
}

bool ClearPlaylist::canBeRun()
{
        return myScreen == myPlaylistEditor;
}

void ClearPlaylist::run()
{
        if (myPlaylistEditor->Playlists.empty())
                return;
        std::string playlist = myPlaylistEditor->Playlists.current()->value().path();
        if (Config.ask_before_clearing_playlists)
                confirmAction(boost::format("Do you really want to clear playlist \"%1%\"?") % playlist);
        Mpd.ClearPlaylist(playlist);
        Statusbar::printf("Playlist \"%1%\" cleared", playlist);
}

bool SortPlaylist::canBeRun()
{
        if (myScreen != myPlaylist)
                return false;
        auto first = myPlaylist->main().begin(), last = myPlaylist->main().end();
        return findSelectedRangeAndPrintInfoIfNot(first, last);
}

void SortPlaylist::run()
{
        mySortPlaylistDialog->switchTo();
}

bool ReversePlaylist::canBeRun()
{
        if (myScreen != myPlaylist)
                return false;
        m_begin = myPlaylist->main().begin();
        m_end = myPlaylist->main().end();
        return findSelectedRangeAndPrintInfoIfNot(m_begin, m_end);
}

void ReversePlaylist::run()
{
        Statusbar::print("Reversing range...");
        Mpd.StartCommandsList();
        for (--m_end; m_begin < m_end; ++m_begin, --m_end)
                Mpd.Swap(m_begin->value().getPosition(), m_end->value().getPosition());
        Mpd.CommitCommandsList();
        Statusbar::print("Range reversed");
}

bool ApplyFilter::canBeRun()
{
        m_searchable = dynamic_cast<Searchable *>(myScreen);
        return m_searchable != nullptr;
}

void ApplyFilter::run()
{
        using Global::wFooter;

        std::string filter = m_searchable->currentFilter();
        if (!filter.empty())
        {
                m_searchable->applyFilter(filter);
                myScreen->refreshWindow();
        }

        try
        {
                Statusbar::ScopedLock slock;
                NC::Window::ScopedPromptHook helper(
                        *wFooter,
                        Statusbar::Helpers::ApplyFilterImmediately(m_searchable));
                Statusbar::put() << "Apply filter: ";
                filter = wFooter->prompt(filter);
        }
        catch (NC::PromptAborted &)
        {
                m_searchable->applyFilter(filter);
                throw;
        }

        if (filter.empty())
                Statusbar::printf("Filtering disabled");
        else
                Statusbar::printf("Using filter \"%1%\"", filter);

        if (myScreen == myPlaylist)
                myPlaylist->reloadTotalLength();

        listsChangeFinisher();
}

bool Find::canBeRun()
{
        return myScreen == myHelp
            || myScreen == myLyrics
#       ifdef HAVE_CURL_CURL_H
            || myScreen == myLastfm
#       endif // HAVE_CURL_CURL_H
        ;
}

void Find::run()
{
        using Global::wFooter;
        
        std::string token;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Find: ";
                token = wFooter->prompt();
        }
        
        Statusbar::print("Searching...");
        auto s = static_cast<Screen<NC::Scrollpad> *>(myScreen);
        s->main().removeProperties();
        if (token.empty() || s->main().setProperties(NC::Format::Reverse, token, NC::Format::NoReverse, Config.regex_type))
                Statusbar::print("Done");
        else
                Statusbar::print("No matching patterns found");
        s->main().flush();
}

bool FindItemBackward::canBeRun()
{
        auto w = dynamic_cast<Searchable *>(myScreen);
        return w && w->allowsSearching();
}

void FindItemForward::run()
{
        findItem(SearchDirection::Forward);
        listsChangeFinisher();
}

bool FindItemForward::canBeRun()
{
        auto w = dynamic_cast<Searchable *>(myScreen);
        return w && w->allowsSearching();
}

void FindItemBackward::run()
{
        findItem(SearchDirection::Backward);
        listsChangeFinisher();
}

bool NextFoundItem::canBeRun()
{
        return dynamic_cast<Searchable *>(myScreen);
}

void NextFoundItem::run()
{
        Searchable *w = dynamic_cast<Searchable *>(myScreen);
        assert(w != nullptr);
        w->search(SearchDirection::Forward, Config.wrapped_search, true);
        listsChangeFinisher();
}

bool PreviousFoundItem::canBeRun()
{
        return dynamic_cast<Searchable *>(myScreen);
}

void PreviousFoundItem::run()
{
        Searchable *w = dynamic_cast<Searchable *>(myScreen);
        assert(w != nullptr);
        w->search(SearchDirection::Backward, Config.wrapped_search, true);
        listsChangeFinisher();
}

void ToggleFindMode::run()
{
        Config.wrapped_search = !Config.wrapped_search;
        Statusbar::printf("Search mode: %1%",
                Config.wrapped_search ? "Wrapped" : "Normal"
        );
}

void ToggleReplayGainMode::run()
{
        using Global::wFooter;
        
        char rgm = 0;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Replay gain mode? "
                << "[" << NC::Format::Bold << 'o' << NC::Format::NoBold << "ff"
                << "/" << NC::Format::Bold << 't' << NC::Format::NoBold << "rack"
                << "/" << NC::Format::Bold << 'a' << NC::Format::NoBold << "lbum"
                << "] ";
                rgm = Statusbar::Helpers::promptReturnOneOf({"t", "a", "o"})[0];
        }
        switch (rgm)
        {
                case 't':
                        Mpd.SetReplayGainMode(MPD::rgmTrack);
                        break;
                case 'a':
                        Mpd.SetReplayGainMode(MPD::rgmAlbum);
                        break;
                case 'o':
                        Mpd.SetReplayGainMode(MPD::rgmOff);
                        break;
                default: // impossible
                        throw std::runtime_error(
                                (boost::format("ToggleReplayGainMode: impossible case reached: %1%") % rgm).str()
                        );
        }
        Statusbar::printf("Replay gain mode: %1%", Mpd.GetReplayGainMode());
}

void ToggleAddMode::run()
{
        std::string mode_desc;
        switch (Config.space_add_mode)
        {
                case SpaceAddMode::AddRemove:
                        Config.space_add_mode = SpaceAddMode::AlwaysAdd;
                        mode_desc = "always add an item to playlist";
                        break;
                case SpaceAddMode::AlwaysAdd:
                        Config.space_add_mode = SpaceAddMode::AddRemove;
                        mode_desc = "add an item to playlist or remove if already added";
                        break;
        }
        Statusbar::printf("Add mode: %1%", mode_desc);
}

void ToggleMouse::run()
{
        Config.mouse_support = !Config.mouse_support;
        if (Config.mouse_support)
                NC::Mouse::enable();
        else
                NC::Mouse::disable();
        Statusbar::printf("Mouse support %1%",
                Config.mouse_support ? "enabled" : "disabled"
        );
}

void ToggleBitrateVisibility::run()
{
        Config.display_bitrate = !Config.display_bitrate;
        Statusbar::printf("Bitrate visibility %1%",
                Config.display_bitrate ? "enabled" : "disabled"
        );
}

void AddRandomItems::run()
{
        using Global::wFooter;
        char rnd_type = 0;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Add random? "
                << "[" << NC::Format::Bold << 's' << NC::Format::NoBold << "ongs"
                << "/" << NC::Format::Bold << 'a' << NC::Format::NoBold << "rtists"
                << "/" << "album" << NC::Format::Bold << 'A' << NC::Format::NoBold << "rtists"
                << "/" << "al" << NC::Format::Bold << 'b' << NC::Format::NoBold << "ums"
                << "] ";
                rnd_type = Statusbar::Helpers::promptReturnOneOf({"s", "a", "A", "b"})[0];
        }

        mpd_tag_type tag_type = MPD_TAG_ARTIST;
        std::string tag_type_str ;
        if (rnd_type != 's')
        {
                tag_type = charToTagType(rnd_type);
                tag_type_str = boost::locale::to_lower(tagTypeToString(tag_type));
        }
        else
                tag_type_str = "song";
        
        unsigned number;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Number of random " << tag_type_str << "s: ";
                number = fromString<unsigned>(wFooter->prompt());
        }
        if (number > 0)
        {
                bool success;
                if (rnd_type == 's')
                        success = Mpd.AddRandomSongs(number, Global::RNG);
                else
                        success = Mpd.AddRandomTag(tag_type, number, Global::RNG);
                if (success)
                        Statusbar::printf("%1% random %2%%3% added to playlist", number, tag_type_str, number == 1 ? "" : "s");
        }
}

bool ToggleBrowserSortMode::canBeRun()
{
        return myScreen == myBrowser;
}

void ToggleBrowserSortMode::run()
{
        switch (Config.browser_sort_mode)
        {
                case SortMode::Name:
                        Config.browser_sort_mode = SortMode::ModificationTime;
                        Statusbar::print("Sort songs by: modification time");
                        break;
                case SortMode::ModificationTime:
                        Config.browser_sort_mode = SortMode::CustomFormat;
                        Statusbar::print("Sort songs by: custom format");
                        break;
                case SortMode::CustomFormat:
                        Config.browser_sort_mode = SortMode::NoOp;
                        Statusbar::print("Do not sort songs");
                        break;
                case SortMode::NoOp:
                        Config.browser_sort_mode = SortMode::Name;
                        Statusbar::print("Sort songs by: name");
        }
        if (Config.browser_sort_mode != SortMode::NoOp)
        {
                size_t sort_offset = myBrowser->inRootDirectory() ? 0 : 1;
                std::sort(myBrowser->main().begin()+sort_offset, myBrowser->main().end(),
                        LocaleBasedItemSorting(std::locale(), Config.ignore_leading_the, Config.browser_sort_mode)
                );
        }
}

bool ToggleLibraryTagType::canBeRun()
{
        return (myScreen->isActiveWindow(myLibrary->Tags))
            || (myLibrary->columns() == 2 && myScreen->isActiveWindow(myLibrary->Albums));
}

void ToggleLibraryTagType::run()
{
        using Global::wFooter;
        
        char tag_type = 0;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Tag type? "
                << "[" << NC::Format::Bold << 'a' << NC::Format::NoBold << "rtist"
                << "/" << "album" << NC::Format::Bold << 'A' << NC::Format::NoBold << "rtist"
                << "/" << NC::Format::Bold << 'y' << NC::Format::NoBold << "ear"
                << "/" << NC::Format::Bold << 'g' << NC::Format::NoBold << "enre"
                << "/" << NC::Format::Bold << 'c' << NC::Format::NoBold << "omposer"
                << "/" << NC::Format::Bold << 'p' << NC::Format::NoBold << "erformer"
                << "] ";
                tag_type = Statusbar::Helpers::promptReturnOneOf({"a", "A", "y", "g", "c", "p"})[0];
        }
        mpd_tag_type new_tagitem = charToTagType(tag_type);
        if (new_tagitem != Config.media_lib_primary_tag)
        {
                Config.media_lib_primary_tag = new_tagitem;
                std::string item_type = tagTypeToString(Config.media_lib_primary_tag);
                myLibrary->Tags.setTitle(Config.titles_visibility ? item_type + "s" : "");
                myLibrary->Tags.reset();
                item_type = boost::locale::to_lower(item_type);
                std::string and_mtime = Config.media_library_sort_by_mtime ?
                                        " and mtime" :
                                        "";
                if (myLibrary->columns() == 2)
                {
                        myLibrary->Songs.clear();
                        myLibrary->Albums.reset();
                        myLibrary->Albums.clear();
                        myLibrary->Albums.setTitle(Config.titles_visibility ? "Albums (sorted by " + item_type + and_mtime + ")" : "");
                        myLibrary->Albums.display();
                }
                else
                {
                        myLibrary->Tags.clear();
                        myLibrary->Tags.display();
                }
                Statusbar::printf("Switched to the list of %1%s", item_type);
        }
}

bool ToggleMediaLibrarySortMode::canBeRun()
{
        return myScreen == myLibrary;
}

void ToggleMediaLibrarySortMode::run()
{
        myLibrary->toggleSortMode();
}

bool RefetchLyrics::canBeRun()
{
#       ifdef HAVE_CURL_CURL_H
        return myScreen == myLyrics;
#       else
        return false;
#       endif // HAVE_CURL_CURL_H
}

void RefetchLyrics::run()
{
#       ifdef HAVE_CURL_CURL_H
        myLyrics->Refetch();
#       endif // HAVE_CURL_CURL_H
}

bool SetSelectedItemsPriority::canBeRun()
{
        if (Mpd.Version() < 17)
        {
                Statusbar::print("Priorities are supported in MPD >= 0.17.0");
                return false;
        }
        return myScreen == myPlaylist && !myPlaylist->main().empty();
}

void SetSelectedItemsPriority::run()
{
        using Global::wFooter;
        
        unsigned prio;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Set priority [0-255]: ";
                prio = fromString<unsigned>(wFooter->prompt());
                boundsCheck(prio, 0u, 255u);
        }
        myPlaylist->setSelectedItemsPriority(prio);
}

bool ToggleOutput::canBeRun()
{
#ifdef ENABLE_OUTPUTS
        return myScreen == myOutputs;
#else
        return false;
#endif // ENABLE_OUTPUTS
}

void ToggleOutput::run()
{
#ifdef ENABLE_OUTPUTS
        myOutputs->toggleOutput();
#endif // ENABLE_OUTPUTS
}

bool ToggleVisualizationType::canBeRun()
{
#       ifdef ENABLE_VISUALIZER
        return myScreen == myVisualizer;
#       else
        return false;
#       endif // ENABLE_VISUALIZER
}

void ToggleVisualizationType::run()
{
#       ifdef ENABLE_VISUALIZER
        myVisualizer->ToggleVisualizationType();
#       endif // ENABLE_VISUALIZER
}

bool SetVisualizerSampleMultiplier::canBeRun()
{
#       ifdef ENABLE_VISUALIZER
        return myScreen == myVisualizer;
#       else
        return false;
#       endif // ENABLE_VISUALIZER
}

void SetVisualizerSampleMultiplier::run()
{
#       ifdef ENABLE_VISUALIZER
        using Global::wFooter;

        double multiplier;
        {
                Statusbar::ScopedLock slock;
                Statusbar::put() << "Set visualizer sample multiplier: ";
                multiplier = fromString<double>(wFooter->prompt());
                lowerBoundCheck(multiplier, 0.0);
                Config.visualizer_sample_multiplier = multiplier;
        }
        Statusbar::printf("Visualizer sample multiplier set to %1%", multiplier);
#       endif // ENABLE_VISUALIZER
}

void ShowSongInfo::run()
{
        mySongInfo->switchTo();
}

bool ShowArtistInfo::canBeRun()
{
        #ifdef HAVE_CURL_CURL_H
        return myScreen == myLastfm
          ||   (myScreen->isActiveWindow(myLibrary->Tags)
            && !myLibrary->Tags.empty()
            && Config.media_lib_primary_tag == MPD_TAG_ARTIST)
          ||   currentSong(myScreen);
#       else
        return false;
#       endif // NOT HAVE_CURL_CURL_H
}

void ShowArtistInfo::run()
{
#       ifdef HAVE_CURL_CURL_H
        if (myScreen == myLastfm)
        {
                myLastfm->switchTo();
                return;
        }
        
        std::string artist;
        if (myScreen->isActiveWindow(myLibrary->Tags))
        {
                assert(!myLibrary->Tags.empty());
                assert(Config.media_lib_primary_tag == MPD_TAG_ARTIST);
                artist = myLibrary->Tags.current()->value().tag();
        }
        else
        {
                auto s = currentSong(myScreen);
                assert(s);
                artist = s->getArtist();
        }
        
        if (!artist.empty())
        {
                myLastfm->queueJob(new LastFm::ArtistInfo(artist, Config.lastfm_preferred_language));
                myLastfm->switchTo();
        }
#       endif // HAVE_CURL_CURL_H
}

void ShowLyrics::run()
{
        myLyrics->switchTo();
}

void Quit::run()
{
        ExitMainLoop = true;
}

void NextScreen::run()
{
        if (Config.screen_switcher_previous)
        {
                if (auto tababble = dynamic_cast<Tabbable *>(myScreen))
                        tababble->switchToPreviousScreen();
        }
        else if (!Config.screen_sequence.empty())
        {
                const auto &seq = Config.screen_sequence;
                auto screen_type = std::find(seq.begin(), seq.end(), myScreen->type());
                if (++screen_type == seq.end())
                        toScreen(seq.front())->switchTo();
                else
                        toScreen(*screen_type)->switchTo();
        }
}

void PreviousScreen::run()
{
        if (Config.screen_switcher_previous)
        {
                if (auto tababble = dynamic_cast<Tabbable *>(myScreen))
                        tababble->switchToPreviousScreen();
        }
        else if (!Config.screen_sequence.empty())
        {
                const auto &seq = Config.screen_sequence;
                auto screen_type = std::find(seq.begin(), seq.end(), myScreen->type());
                if (screen_type == seq.begin())
                        toScreen(seq.back())->switchTo();
                else
                        toScreen(*--screen_type)->switchTo();
        }
}

bool ShowHelp::canBeRun()
{
        return myScreen != myHelp
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
}

void ShowHelp::run()
{
        myHelp->switchTo();
}

bool ShowPlaylist::canBeRun()
{
        return myScreen != myPlaylist
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
}

void ShowPlaylist::run()
{
        myPlaylist->switchTo();
}

bool ShowBrowser::canBeRun()
{
        return myScreen != myBrowser
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
}

void ShowBrowser::run()
{
        myBrowser->switchTo();
}

bool ChangeBrowseMode::canBeRun()
{
        return myScreen == myBrowser;
}

void ChangeBrowseMode::run()
{
        myBrowser->changeBrowseMode();
}

bool ShowSearchEngine::canBeRun()
{
        return myScreen != mySearcher
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
}

void ShowSearchEngine::run()
{
        mySearcher->switchTo();
}

bool ResetSearchEngine::canBeRun()
{
        return myScreen == mySearcher;
}

void ResetSearchEngine::run()
{
        mySearcher->reset();
}

bool ShowMediaLibrary::canBeRun()
{
        return myScreen != myLibrary
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
}

void ShowMediaLibrary::run()
{
        myLibrary->switchTo();
}

bool ToggleMediaLibraryColumnsMode::canBeRun()
{
        return myScreen == myLibrary;
}

void ToggleMediaLibraryColumnsMode::run()
{
        myLibrary->toggleColumnsMode();
        myLibrary->refresh();
}

bool ShowPlaylistEditor::canBeRun()
{
        return myScreen != myPlaylistEditor
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
}

void ShowPlaylistEditor::run()
{
        myPlaylistEditor->switchTo();
}

bool ShowTagEditor::canBeRun()
{
#       ifdef HAVE_TAGLIB_H
        return myScreen != myTagEditor
            && myScreen != myTinyTagEditor;
#       else
        return false;
#       endif // HAVE_TAGLIB_H
}

void ShowTagEditor::run()
{
#       ifdef HAVE_TAGLIB_H
        if (isMPDMusicDirSet())
                myTagEditor->switchTo();
#       endif // HAVE_TAGLIB_H
}

bool ShowOutputs::canBeRun()
{
#       ifdef ENABLE_OUTPUTS
        return myScreen != myOutputs
#       ifdef HAVE_TAGLIB_H     
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
#       else
        return false;
#       endif // ENABLE_OUTPUTS
}

void ShowOutputs::run()
{
#       ifdef ENABLE_OUTPUTS
        myOutputs->switchTo();
#       endif // ENABLE_OUTPUTS
}

bool ShowVisualizer::canBeRun()
{
#       ifdef ENABLE_VISUALIZER
        return myScreen != myVisualizer
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
#       else
        return false;
#       endif // ENABLE_VISUALIZER
}

void ShowVisualizer::run()
{
#       ifdef ENABLE_VISUALIZER
        myVisualizer->switchTo();
#       endif // ENABLE_VISUALIZER
}

bool ShowClock::canBeRun()
{
#       ifdef ENABLE_CLOCK
        return myScreen != myClock
#       ifdef HAVE_TAGLIB_H
            && myScreen != myTinyTagEditor
#       endif // HAVE_TAGLIB_H
        ;
#       else
        return false;
#       endif // ENABLE_CLOCK
}

void ShowClock::run()
{
#       ifdef ENABLE_CLOCK
        myClock->switchTo();
#       endif // ENABLE_CLOCK
}

#ifdef HAVE_TAGLIB_H
bool ShowServerInfo::canBeRun()
{
        return myScreen != myTinyTagEditor;
}
#endif // HAVE_TAGLIB_H

void ShowServerInfo::run()
{
        myServerInfo->switchTo();
}

}

namespace {

void populateActions()
{
        auto insert_action = [](Actions::BaseAction *a) {
                AvailableActions[static_cast<size_t>(a->type())] = a;
        };
        insert_action(new Actions::Dummy());
        insert_action(new Actions::UpdateEnvironment());
        insert_action(new Actions::MouseEvent());
        insert_action(new Actions::ScrollUp());
        insert_action(new Actions::ScrollDown());
        insert_action(new Actions::ScrollUpArtist());
        insert_action(new Actions::ScrollUpAlbum());
        insert_action(new Actions::ScrollDownArtist());
        insert_action(new Actions::ScrollDownAlbum());
        insert_action(new Actions::PageUp());
        insert_action(new Actions::PageDown());
        insert_action(new Actions::MoveHome());
        insert_action(new Actions::MoveEnd());
        insert_action(new Actions::ToggleInterface());
        insert_action(new Actions::JumpToParentDirectory());
        insert_action(new Actions::RunAction());
        insert_action(new Actions::SelectItem());
        insert_action(new Actions::SelectRange());
        insert_action(new Actions::PreviousColumn());
        insert_action(new Actions::NextColumn());
        insert_action(new Actions::MasterScreen());
        insert_action(new Actions::SlaveScreen());
        insert_action(new Actions::VolumeUp());
        insert_action(new Actions::VolumeDown());
        insert_action(new Actions::AddItemToPlaylist());
        insert_action(new Actions::DeletePlaylistItems());
        insert_action(new Actions::DeleteStoredPlaylist());
        insert_action(new Actions::DeleteBrowserItems());
        insert_action(new Actions::ReplaySong());
        insert_action(new Actions::PreviousSong());
        insert_action(new Actions::NextSong());
        insert_action(new Actions::Pause());
        insert_action(new Actions::Stop());
        insert_action(new Actions::ExecuteCommand());
        insert_action(new Actions::SavePlaylist());
        insert_action(new Actions::MoveSortOrderUp());
        insert_action(new Actions::MoveSortOrderDown());
        insert_action(new Actions::MoveSelectedItemsUp());
        insert_action(new Actions::MoveSelectedItemsDown());
        insert_action(new Actions::MoveSelectedItemsTo());
        insert_action(new Actions::Add());
        insert_action(new Actions::PlayItem());
        insert_action(new Actions::SeekForward());
        insert_action(new Actions::SeekBackward());
        insert_action(new Actions::ToggleDisplayMode());
        insert_action(new Actions::ToggleSeparatorsBetweenAlbums());
        insert_action(new Actions::ToggleLyricsUpdateOnSongChange());
        insert_action(new Actions::ToggleLyricsFetcher());
        insert_action(new Actions::ToggleFetchingLyricsInBackground());
        insert_action(new Actions::TogglePlayingSongCentering());
        insert_action(new Actions::UpdateDatabase());
        insert_action(new Actions::JumpToPlayingSong());
        insert_action(new Actions::ToggleRepeat());
        insert_action(new Actions::Shuffle());
        insert_action(new Actions::ToggleRandom());
        insert_action(new Actions::StartSearching());
        insert_action(new Actions::SaveTagChanges());
        insert_action(new Actions::ToggleSingle());
        insert_action(new Actions::ToggleConsume());
        insert_action(new Actions::ToggleCrossfade());
        insert_action(new Actions::SetCrossfade());
        insert_action(new Actions::SetVolume());
        insert_action(new Actions::EnterDirectory());
        insert_action(new Actions::EditSong());
        insert_action(new Actions::EditLibraryTag());
        insert_action(new Actions::EditLibraryAlbum());
        insert_action(new Actions::EditDirectoryName());
        insert_action(new Actions::EditPlaylistName());
        insert_action(new Actions::EditLyrics());
        insert_action(new Actions::JumpToBrowser());
        insert_action(new Actions::JumpToMediaLibrary());
        insert_action(new Actions::JumpToPlaylistEditor());
        insert_action(new Actions::ToggleScreenLock());
        insert_action(new Actions::JumpToTagEditor());
        insert_action(new Actions::JumpToPositionInSong());
        insert_action(new Actions::ReverseSelection());
        insert_action(new Actions::RemoveSelection());
        insert_action(new Actions::SelectAlbum());
        insert_action(new Actions::SelectFoundItems());
        insert_action(new Actions::AddSelectedItems());
        insert_action(new Actions::CropMainPlaylist());
        insert_action(new Actions::CropPlaylist());
        insert_action(new Actions::ClearMainPlaylist());
        insert_action(new Actions::ClearPlaylist());
        insert_action(new Actions::SortPlaylist());
        insert_action(new Actions::ReversePlaylist());
        insert_action(new Actions::ApplyFilter());
        insert_action(new Actions::Find());
        insert_action(new Actions::FindItemForward());
        insert_action(new Actions::FindItemBackward());
        insert_action(new Actions::NextFoundItem());
        insert_action(new Actions::PreviousFoundItem());
        insert_action(new Actions::ToggleFindMode());
        insert_action(new Actions::ToggleReplayGainMode());
        insert_action(new Actions::ToggleAddMode());
        insert_action(new Actions::ToggleMouse());
        insert_action(new Actions::ToggleBitrateVisibility());
        insert_action(new Actions::AddRandomItems());
        insert_action(new Actions::ToggleBrowserSortMode());
        insert_action(new Actions::ToggleLibraryTagType());
        insert_action(new Actions::ToggleMediaLibrarySortMode());
        insert_action(new Actions::RefetchLyrics());
        insert_action(new Actions::SetSelectedItemsPriority());
        insert_action(new Actions::ToggleOutput());
        insert_action(new Actions::ToggleVisualizationType());
        insert_action(new Actions::SetVisualizerSampleMultiplier());
        insert_action(new Actions::ShowSongInfo());
        insert_action(new Actions::ShowArtistInfo());
        insert_action(new Actions::ShowLyrics());
        insert_action(new Actions::Quit());
        insert_action(new Actions::NextScreen());
        insert_action(new Actions::PreviousScreen());
        insert_action(new Actions::ShowHelp());
        insert_action(new Actions::ShowPlaylist());
        insert_action(new Actions::ShowBrowser());
        insert_action(new Actions::ChangeBrowseMode());
        insert_action(new Actions::ShowSearchEngine());
        insert_action(new Actions::ResetSearchEngine());
        insert_action(new Actions::ShowMediaLibrary());
        insert_action(new Actions::ToggleMediaLibraryColumnsMode());
        insert_action(new Actions::ShowPlaylistEditor());
        insert_action(new Actions::ShowTagEditor());
        insert_action(new Actions::ShowOutputs());
        insert_action(new Actions::ShowVisualizer());
        insert_action(new Actions::ShowClock());
        insert_action(new Actions::ShowServerInfo());
}

bool scrollTagCanBeRun(NC::List *&list, SongList *&songs)
{
        auto w = myScreen->activeWindow();
        if (list != static_cast<void *>(w))
                list = dynamic_cast<NC::List *>(w);
        if (songs != static_cast<void *>(w))
                songs = dynamic_cast<SongList *>(w);
        return list != nullptr && !list->empty()
            && songs != nullptr;
}

void scrollTagUpRun(NC::List *list, SongList *songs, MPD::Song::GetFunction get)
{
        const auto front = songs->beginS();
        auto it = songs->currentS();
        if (auto *s = it->get<Bit::Song>())
        {
                const std::string tag = s->getTags(get);
                while (it != front)
                {
                        --it;
                        s = it->get<Bit::Song>();
                        if (s == nullptr || s->getTags(get) != tag)
                                break;
                }
                list->highlight(it-front);
        }
}

void scrollTagDownRun(NC::List *list, SongList *songs, MPD::Song::GetFunction get)
{
        const auto front = songs->beginS(), back = --songs->endS();
        auto it = songs->currentS();
        if (auto *s = it->get<Bit::Song>())
        {
                const std::string tag = s->getTags(get);
                while (it != back)
                {
                        ++it;
                        s = it->get<Bit::Song>();
                        if (s == nullptr || s->getTags(get) != tag)
                                break;
                }
                list->highlight(it-front);
        }
}

void seek()
{
        using Global::wHeader;
        using Global::wFooter;
        using Global::Timer;
        using Global::SeekingInProgress;
        
        if (!Status::State::totalTime())
        {
                Statusbar::print("Unknown item length");
                return;
        }
        
        Progressbar::ScopedLock progressbar_lock;
        Statusbar::ScopedLock statusbar_lock;

        unsigned songpos = Status::State::elapsedTime();
        auto t = Timer;
        
        int old_timeout = wFooter->getTimeout();
        wFooter->setTimeout(BaseScreen::defaultWindowTimeout);
        
        // Accept single action of a given type or action chain for which all actions
        // can be run and one of them is of the given type. This will still not work
        // in some contrived cases, but allows for more flexibility than accepting
        // single actions only.
        auto hasRunnableAction = [](BindingsConfiguration::BindingIteratorPair &bindings, Actions::Type type) {
                bool success = false;
                for (auto binding = bindings.first; binding != bindings.second; ++binding)
                {
                        auto &actions = binding->actions();
                        for (const auto &action : actions)
                        {
                                if (action->canBeRun())
                                {
                                        if (action->type() == type)
                                                success = true;
                                }
                                else
                                {
                                        success = false;
                                        break;
                                }
                        }
                        if (success)
                                break;
                }
                return success;
        };

        SeekingInProgress = true;
        while (true)
        {
                Status::trace();
                
                unsigned howmuch = Config.incremental_seeking
                                 ? (Timer-t).total_seconds()/2+Config.seek_time
                                 : Config.seek_time;
                
                NC::Key::Type input = readKey(*wFooter);

                auto k = Bindings.get(input);
                if (hasRunnableAction(k, Actions::Type::SeekForward))
                {
                        if (songpos < Status::State::totalTime())
                                songpos = std::min(songpos + howmuch, Status::State::totalTime());
                }
                else if (hasRunnableAction(k, Actions::Type::SeekBackward))
                {
                        if (songpos > 0)
                        {
                                if (songpos < howmuch)
                                        songpos = 0;
                                else
                                        songpos -= howmuch;
                        }
                }
                else
                        break;
                
                *wFooter << NC::Format::Bold;
                std::string tracklength;
                // FIXME: merge this with the code in status.cpp
                switch (Config.design)
                {
                        case Design::Classic:
                                tracklength = " [";
                                if (Config.display_remaining_time)
                                {
                                        tracklength += "-";
                                        tracklength += MPD::Song::ShowTime(Status::State::totalTime()-songpos);
                                }
                                else
                                        tracklength += MPD::Song::ShowTime(songpos);
                                tracklength += "/";
                                tracklength += MPD::Song::ShowTime(Status::State::totalTime());
                                tracklength += "]";
                                *wFooter << NC::XY(wFooter->getWidth()-tracklength.length(), 1) << tracklength;
                                break;
                        case Design::Alternative:
                                if (Config.display_remaining_time)
                                {
                                        tracklength = "-";
                                        tracklength += MPD::Song::ShowTime(Status::State::totalTime()-songpos);
                                }
                                else
                                        tracklength = MPD::Song::ShowTime(songpos);
                                tracklength += "/";
                                tracklength += MPD::Song::ShowTime(Status::State::totalTime());
                                *wHeader << NC::XY(0, 0) << tracklength << " ";
                                wHeader->refresh();
                                break;
                }
                *wFooter << NC::Format::NoBold;
                Progressbar::draw(songpos, Status::State::totalTime());
                wFooter->refresh();
        }
        SeekingInProgress = false;
        Mpd.Seek(Status::State::currentSongPosition(), songpos);
        
        wFooter->setTimeout(old_timeout);
}

void findItem(const SearchDirection direction)
{
        using Global::wFooter;
        
        Searchable *w = dynamic_cast<Searchable *>(myScreen);
        assert(w != nullptr);
        assert(w->allowsSearching());
        
        std::string constraint = w->searchConstraint();
        try
        {
                Statusbar::ScopedLock slock;
                NC::Window::ScopedPromptHook prompt_hook(
                        *wFooter,
                        Statusbar::Helpers::FindImmediately(w, direction));
                Statusbar::put() << (boost::format("Find %1%: ") % direction).str();
                constraint = wFooter->prompt(constraint);
        }
        catch (NC::PromptAborted &)
        {
                w->setSearchConstraint(constraint);
                w->search(direction, Config.wrapped_search, false);
                throw;
        }

        if (constraint.empty())
        {
                Statusbar::printf("Constraint unset");
                w->clearSearchConstraint();
        }
        else
                Statusbar::printf("Using constraint \"%1%\"", constraint);
}

void listsChangeFinisher()
{
        if (myScreen == myLibrary
        ||  myScreen == myPlaylistEditor
#       ifdef HAVE_TAGLIB_H
        ||  myScreen == myTagEditor
#       endif // HAVE_TAGLIB_H
           )
        {
                if (myScreen->activeWindow() == &myLibrary->Tags)
                {
                        myLibrary->Albums.clear();
                        myLibrary->Albums.refresh();
                        myLibrary->Songs.clear();
                        myLibrary->Songs.refresh();
                        myLibrary->updateTimer();
                }
                else if (myScreen->activeWindow() == &myLibrary->Albums)
                {
                        myLibrary->Songs.clear();
                        myLibrary->Songs.refresh();
                        myLibrary->updateTimer();
                }
                else if (myScreen->isActiveWindow(myPlaylistEditor->Playlists))
                {
                        myPlaylistEditor->Content.clear();
                        myPlaylistEditor->Content.refresh();
                        myPlaylistEditor->updateTimer();
                }
#               ifdef HAVE_TAGLIB_H
                else if (myScreen->activeWindow() == myTagEditor->Dirs)
                {
                        myTagEditor->Tags->clear();
                }
#               endif // HAVE_TAGLIB_H
        }
}

}