class CoverArtBrowserSource(RB.Source):
    '''
    Source utilized by the plugin to show all it's ui.
    '''
    rating_threshold = GObject.property(type=float, default=0)
    artist_paned_pos = GObject.property(type=str)
    min_paned_pos = 40
    
    # unique instance of the source
    instance = None

    def __init__(self, **kargs):
        '''
        Initializes the source.
        '''
        super(CoverArtBrowserSource, self).__init__(**kargs)

        # create source_source_settings and connect the source's properties
        self.gs = GSetting()

        self._connect_properties()

        self.hasActivated = False
        self.last_width = 0
        self.last_selected_album = None
        self.click_count = 0
        self.favourites = False
        self.task_progress = None
        
    def _connect_properties(self):
        '''
        Connects the source properties to the saved preferences.
        '''
        print("CoverArtBrowser DEBUG - _connect_properties")
        setting = self.gs.get_setting(self.gs.Path.PLUGIN)

        setting.bind(
            self.gs.PluginKey.RATING,
            self,
            'rating_threshold',
            Gio.SettingsBindFlags.GET)

        print("CoverArtBrowser DEBUG - end _connect_properties")

    def do_get_status(self, *args):
        '''
        Method called by Rhythmbox to figure out what to show on this source
        statusbar.
        If the custom statusbar is disabled, the source will
        show the selected album info.
        Also, it makes sure to show the progress on the album loading
        '''
        
        try:
            # this will only work for RB3.0 and later
            if not self.task_progress:
                self.task_progress = RB.TaskProgressSimple.new()
        except:
            pass
            
        try:
            progress = self.album_manager.progress
            progress_text = _('Loading...') if progress < 1 else ''
            try:
                # this will only work for RB3.0 and later
                if progress < 1:
                    if self.props.shell.props.task_list.get_model().n_items() == 0:
                        self.props.shell.props.task_list.add_task(self.task_progress)
            
                    self.task_progress.props.task_progress = progress
                    self.task_progress.props.task_label=progress_text
                else:
                    self.task_progress.props.task_outcome = RB.TaskOutcome.COMPLETE
            except:
                pass
        except:
            progress = 1
            progress_text = ''
            try:
                # this will only work for RB3.0 and later
                self.task_progress.props.task_outcome = RB.TaskOutcome.COMPLETE
            except:
                pass

        return (self.status, progress_text, progress)

    def do_selected(self):
        '''
        Called by Rhythmbox when the source is selected. It makes sure to
        create the ui the first time the source is showed.
        '''
        print("CoverArtBrowser DEBUG - do_selected")

        # first time of activation -> add graphical stuff
        if not self.hasActivated:
            self.do_impl_activate()

            # indicate that the source was activated before
            self.hasActivated = True

        print("CoverArtBrowser DEBUG - end do_selected")

    def do_impl_activate(self):
        '''
        Called by do_selected the first time the source is activated.
        It creates all the source ui and connects the necesary signals for it
        correct behavior.
        '''
        print("CoverArtBrowser DEBUG - do_impl_activate")

        # initialise some variables
        self.plugin = self.props.plugin
        self.shell = self.props.shell
        self.status = ''
        self.search_text = ''
        self.actiongroup = ActionGroup(self.shell, 'coverplaylist_submenu')
        self._browser_preferences = None
        self._search_preferences = None
        
        # indicate that the source was activated before
        self.hasActivated = True

        self._create_ui()
        self._setup_source()
        self._apply_settings()

        print("CoverArtBrowser DEBUG - end do_impl_activate")

    def _create_ui(self):
        '''
        Creates the ui for the source and saves the important widgets onto
        properties.
        '''
        print("CoverArtBrowser DEBUG - _create_ui")

        # dialog has not been created so lets do so.
        cl = CoverLocale()
        ui = Gtk.Builder()
        ui.set_translation_domain(cl.Locale.LOCALE_DOMAIN)
        ui.add_from_file(rb.find_plugin_file(self.plugin,
            'ui/coverart_browser.ui'))
        ui.connect_signals(self)

        # load the page and put it in the source
        self.page = ui.get_object('main_box')
        self.pack_start(self.page, True, True, 0)

        # get widgets for main icon-view
        self.status_label = ui.get_object('status_label')
        window = ui.get_object('scrolled_window')
        
        self.viewmgr = ViewManager(self, window)
                
        # get widgets for the artist paned
        self.artist_paned = ui.get_object('vertical_paned')
        Gdk.threads_add_timeout(GLib.PRIORITY_DEFAULT_IDLE, 50, self._change_artist_paned_pos, self.viewmgr.view_name)
        self.viewmgr.connect('new-view', self.on_view_changed)
        self.artist_treeview = ui.get_object('artist_treeview')
        self.artist_scrolledwindow = ui.get_object('artist_scrolledwindow')

        # define menu's
        self.popup_menu = Menu(self.plugin, self.shell)
        self.popup_menu.load_from_file('ui/coverart_browser_pop_rb2.ui',
            'ui/coverart_browser_pop_rb3.ui')
        self._external_plugins = None
        
        signals = \
            { 'play_album_menu_item': self.play_album_menu_item_callback,
              'queue_album_menu_item': self.queue_album_menu_item_callback,
              'new_playlist': self.add_playlist_menu_item_callback,
              'cover_search_menu_item': self.cover_search_menu_item_callback,
              'export_embed_menu_item': self.export_embed_menu_item_callback,
              'show_properties_menu_item': self.show_properties_menu_item_callback,
              'play_similar_artist_menu_item': self.play_similar_artist_menu_item_callback}
              
        self.popup_menu.connect_signals(signals)
        self.popup_menu.connect('pre-popup', self.add_external_menu)
        
        self.status_label = ui.get_object('status_label')
        self.request_status_box = ui.get_object('request_status_box')
        self.request_spinner = ui.get_object('request_spinner')
        self.request_statusbar = ui.get_object('request_statusbar')
        self.request_cancel_button = ui.get_object('request_cancel_button')
        self.paned = ui.get_object('paned')
        self.notebook = ui.get_object('bottom_notebook')
        
        #---- set up info pane -----#
        info_scrolled_window = ui.get_object('info_scrolled_window')
        info_button_box = ui.get_object('info_button_box')
        artist_info_paned = ui.get_object('vertical_info_paned')
        
        self.artist_info = ArtistInfoPane(info_button_box,
            info_scrolled_window,
            artist_info_paned,
            self)

        # quick search
        self.quick_search = ui.get_object('quick_search_entry')

        print("CoverArtBrowser DEBUG - end _create_ui")

    def _setup_source(self):
        '''
        Setups the differents parts of the source so they are ready to be used
        by the user. It also creates and configure some custom widgets.
        '''
        print("CoverArtBrowser DEBUG - _setup_source")
        
        cl = CoverLocale()
        cl.switch_locale(cl.Locale.LOCALE_DOMAIN)
 
        # setup iconview popup
        self.viewmgr.current_view.set_popup_menu(self.popup_menu)
        
        # setup entry-view objects and widgets
        setting = self.gs.get_setting(self.gs.Path.PLUGIN)
        setting.bind(self.gs.PluginKey.PANED_POSITION,
            self.paned, 'collapsible-y', Gio.SettingsBindFlags.DEFAULT)
        setting.bind(self.gs.PluginKey.DISPLAY_BOTTOM,
            self.paned.get_child2(), 'visible', Gio.SettingsBindFlags.DEFAULT)

        # create entry view. Don't allow to reorder until the load is finished
        self.entry_view = EV(self.shell, self)
        self.entry_view.set_columns_clickable(False)
        self.shell.props.library_source.get_entry_view().set_columns_clickable(
            False)

        self.stars = ReactiveStar()
        self.stars.set_rating(0)
        a = Gtk.Alignment.new(0.5, 0.5, 0, 0)
        a.add(self.stars)

        self.stars.connect('changed', self.rating_changed_callback)

        vbox = Gtk.Box()
        vbox.set_orientation(Gtk.Orientation.VERTICAL)
        vbox.pack_start(self.entry_view, True, True, 0)
        vbox.pack_start(a, False, False, 1)
        vbox.show_all()
        self.notebook.append_page(vbox, Gtk.Label.new_with_mnemonic(_("Tracks")))

        # create an album manager
        self.album_manager = AlbumManager(self.plugin, self.viewmgr.current_view)
            
        self.viewmgr.current_view.initialise(self)
        # setup cover search pane
        colour = self.viewmgr.get_selection_colour()

        self.cover_search_pane = CoverSearchPane(self.plugin, colour)
        self.notebook.append_page(self.cover_search_pane, Gtk.Label.new_with_mnemonic(
            _("Covers")))

        # connect a signal to when the info of albums is ready
        self.load_fin_id = self.album_manager.loader.connect(
            'model-load-finished', self.load_finished_callback)

        # prompt the loader to load the albums
        self.album_manager.loader.load_albums(self.props.base_query_model)

        # initialise the variables of the quick search
        self.quick_search_controller = AlbumQuickSearchController(
            self.album_manager)
        self.quick_search_controller.connect_quick_search(self.quick_search)

        # set sensitivity of export menu item for iconview
        self.popup_menu.set_sensitive('export_embed_menu_item', 
            CoverArtExport(self.plugin,
                self.shell, self.album_manager).is_search_plugin_enabled())
        
        # setup the statusbar component
        self.statusbar = Statusbar(self)

        # initialise the toolbar manager
        self.toolbar_manager = ToolbarManager(self.plugin, self.page,
            self.viewmgr)
        self.viewmgr.current_view.emit('update-toolbar')

        cl.switch_locale(cl.Locale.RB)
        # setup the artist paned
        artist_pview = None
        for view in self.shell.props.library_source.get_property_views():
            print (view.props.title)
            print (_("Artist"))
            if view.props.title == _("Artist"):
                artist_pview = view
                break

        assert artist_pview, "cannot find artist property view"

        self.artist_treeview.set_model(artist_pview.get_model())
        setting.bind(self.gs.PluginKey.ARTIST_PANED_POSITION,
            self, 'artist-paned-pos', Gio.SettingsBindFlags.DEFAULT)

        self.artist_paned.connect('button-release-event', 
            self.artist_paned_button_release_callback)
            
        # intercept JumpToPlaying Song action so that we can scroll to the playing album
        
        appshell = rb3compat.ApplicationShell(self.shell)
        action = appshell.lookup_action("", "jump-to-playing", "win")
        action.action.connect("activate", self.jump_to_playing, None)
        
        self.echonest_similar_playlist = None
            
        print("CoverArtBrowser DEBUG - end _setup_source")
        
    def add_external_menu(self, *args):
        '''
        Callback when the popup menu is about to be displayed
        '''

        if not self._external_plugins:
            # initialise external plugin menu support
            self._external_plugins = \
            CreateExternalPluginMenu("ca_covers_view",
                7, self.popup_menu)
            self._external_plugins.create_menu('popup_menu', True)

        self.playlist_menu_item_callback()
        
    def jump_to_playing(self, *args):
        '''
        Callback when the JumpToPlaying action is invoked
        This will scroll the view to the playing song
        '''

        if not self.shell.props.selected_page.props.name == self.props.name:
            # if the source page that was played from is not the plugin then
            # nothing to do
            return
            
        album = None
        
        entry = self.shell.props.shell_player.get_playing_entry()
        
        if entry:
            album = self.album_manager.model.get_from_dbentry(entry)
        
        self.viewmgr.current_view.scroll_to_album(album)

    def artist_paned_button_release_callback(self, *args):
        '''
        Callback when the artist paned handle is released from its mouse click.
        '''
        child_width = self._get_child_width()
        
        paned_positions = eval(self.artist_paned_pos)
        
        found = None
        for viewpos in paned_positions:
            if self.viewmgr.view_name in viewpos:
                found = viewpos
                break
                
        if not found:
            return
            
        paned_positions.remove(found)
        if child_width <= self.min_paned_pos:
            child_width = 0
            self.artist_paned.set_position(child_width)
            
        paned_positions.append(self.viewmgr.view_name + ":" + str(child_width))
        
        self.artist_paned_pos = repr(paned_positions)
        
    def on_view_changed(self, widget, view_name):
        self._change_artist_paned_pos(view_name)
        
    def _change_artist_paned_pos(self, view_name):
        paned_positions = eval(self.artist_paned_pos)
        print (paned_positions)
        found = None
        for viewpos in paned_positions:
            if view_name in viewpos:
                found = viewpos
                break
        print (found)
        if not found:
            return
            
        child_width = int(found.split(":")[1])
        print (child_width)
        
        # odd case - if the pane is not visible but the position is zero
        # then the paned position on visible=true is some large arbitary value
        # hence - set it to be 1 px larger than the real value, then set it back
        # to its expected value
        self.artist_paned.set_position(child_width + 1)
        self.artist_paned.set_visible(True)
        self.artist_paned.set_position(child_width)
        
    def _get_child_width(self):
        child = self.artist_paned.get_child1()
        return child.get_allocated_width()
        
    def on_artist_treeview_selection_changed(self, view):
        model, artist_iter = view.get_selected()
        if artist_iter:
            artist = model[artist_iter][0]

            cl = CoverLocale()
            cl.switch_locale(cl.Locale.RB)
            #. TRANSLATORS - "All" is used in the context of "All artist names"
            if artist == _('All'):
                self.album_manager.model.remove_filter('quick_artist')
            else:
                self.album_manager.model.replace_filter('quick_artist', artist)

            cl.switch_locale(cl.Locale.LOCALE_DOMAIN)
            
    def _apply_settings(self):
        '''
        Applies all the settings related to the source and connects those that
        must be updated when the preferences dialog changes it's values. Also
        enables differents parts of the ui if the settings says so.
        '''
        print("CoverArtBrowser DEBUG - _apply_settings")

        # connect some signals to the loader to keep the source informed
        self.album_mod_id = self.album_manager.model.connect('album-updated',
            self.on_album_updated)
        
        self.notify_prog_id = self.album_manager.connect(
            'notify::progress', lambda *args: self.notify_status_changed())

        print("CoverArtBrowser DEBUG - end _apply_settings")

    def load_finished_callback(self, _):
        '''
        Callback called when the loader finishes loading albums into the
        covers view model.
        '''
        print("CoverArtBrowser DEBUG - load_finished_callback")

        #if not self.request_status_box.get_visible():
            # it should only be enabled if no cover request is going on
            #self.source_menu_search_all_item.set_sensitive(True)

        # enable sorting on the entryview
        self.entry_view.set_columns_clickable(True)
        self.shell.props.library_source.get_entry_view().set_columns_clickable(
            True)

        print("CoverArtBrowser DEBUG - end load_finished_callback")

    def get_entry_view(self):
        return self.entry_view

    def on_album_updated(self, model, path, tree_iter):
        '''
        Callback called by the album loader when one of the albums managed
        by him gets modified in some way.
        '''
        album = model.get_from_path(path)
        selected = self.viewmgr.current_view.get_selected_objects()

        if album in selected:
            # update the selection since it may have changed
            self.viewmgr.current_view.selectionchanged_callback()

            if album is selected[0] and \
                self.notebook.get_current_page() == \
                self.notebook.page_num(self.cover_search_pane):
                # also, if it's the first, update the cover search pane
                self.cover_search_pane.clear()
                self.cover_search_pane.do_search(album, 
                    self.album_manager.cover_man.update_cover)

    def play_similar_artist_menu_item_callback(self, *args):
        '''
        Callback called when the play similar artist option is selected from
        the cover view popup. It plays similar artists music.
        '''
    def play_similar_artist_menu_item_callback(self, *args):
        if not self.echonest_similar_playlist:
            self.echonest_similar_playlist = \
                EchoNestPlaylist(   self.shell,
                                    self.shell.props.queue_source)
                                    
        selected_albums = self.viewmgr.current_view.get_selected_objects()
        album = selected_albums[0]
        tracks = album.get_tracks()
        
        entry = tracks[0].entry
        self.echonest_similar_playlist.start(entry, reinitialise=True)
        
    def show_properties_menu_item_callback(self, *args):
        '''
        Callback called when the show album properties option is selected from
        the cover view popup. It shows a SongInfo dialog showing the selected
        albums' entries info, which can be modified.
        '''
        print("CoverArtBrowser DEBUG - show_properties_menu_item_callback")

        self.entry_view.select_all()

        info_dialog = RB.SongInfo(source=self, entry_view=self.entry_view)

        info_dialog.show_all()

        print("CoverArtBrowser DEBUG - end show_properties_menu_item_callback")

    def play_selected_album(self, favourites=False):
        '''
        Utilitary method that plays all entries from an album into the play
        queue.
        '''
        # callback when play an album
        print("CoverArtBrowser DEBUG - play_selected_album")

        query_model = RB.RhythmDBQueryModel.new_empty(self.shell.props.db)
        self.queue_selected_album(query_model, favourites)

        if len(query_model) > 0:
            self.props.query_model = query_model

            # Start the music
            player = self.shell.props.shell_player

            player.play_entry(query_model[0][0], self)

        print("CoverArtBrowser DEBUG - end play_selected_album")

    def queue_selected_album(self, source, favourites=False):
        '''
        Utilitary method that queues all entries from an album into the play
        queue.
        '''
        print("CoverArtBrowser DEBUG - queue_selected_album")

        selected_albums = self.viewmgr.current_view.get_selected_objects()
        threshold = self.rating_threshold if favourites else 0

        total = 0        
        for album in selected_albums:
            # Retrieve and sort the entries of the album
            tracks = album.get_tracks(threshold)
            total = total + len(tracks)
            # Add the songs to the play queue
            for track in tracks:
                source.add_entry(track.entry, -1)

        if total == 0 and threshold:
            dialog = Gtk.MessageDialog(None,
                Gtk.DialogFlags.MODAL,
                Gtk.MessageType.INFO,
                Gtk.ButtonsType.OK,
                _("No tracks have been added because no tracks meet the favourite rating threshold"))

            dialog.run()
            dialog.destroy()
        print("CoverArtBrowser DEBUG - end queue_select_album")

    def play_album_menu_item_callback(self, *args):
        '''
        Callback called when the play album item from the cover view popup is
        selected. It cleans the play queue and queues the selected album.
        '''
        print("CoverArtBrowser DEBUG - play_album_menu_item_callback")

        self.play_selected_album(self.favourites)

        print("CoverArtBrowser DEBUG - end play_album_menu_item_callback")

    def queue_album_menu_item_callback(self, *args):
        '''
        Callback called when the queue album item from the cover view popup is
        selected. It queues the selected album at the end of the play queue.
        '''
        print("CoverArtBrowser DEBUG - queue_album_menu_item_callback()")
        self.queue_selected_album(self.shell.props.queue_source, self.favourites)

        print("CoverArtBrowser DEBUG - end queue_album_menu_item_callback()")

    def playlist_menu_item_callback(self, *args):
        print("CoverArtBrowser DEBUG - playlist_menu_item_callback")

        self.playlist_fillmenu(self.popup_menu, 'playlist_submenu', 'playlist_section',
                               self.actiongroup,
                               self.add_to_static_playlist_menu_item_callback,
                               self.favourites)

    def playlist_fillmenu(self, popup_menu, menubar, section_name,
        actiongroup, func, favourite=False):
        print("CoverArtBrowser DEBUG - playlist_fillmenu")

        playlist_manager = self.shell.props.playlist_manager
        playlists_entries = playlist_manager.get_playlists()

        # tidy up old playlists menu items before recreating the list
        actiongroup.remove_actions()
        popup_menu.remove_menu_items(menubar, section_name)

        if playlists_entries:
            for playlist in playlists_entries:
                if playlist.props.is_local and \
                    isinstance(playlist, RB.StaticPlaylistSource):

                    args=(playlist, favourite)
                    
                    # take the name of the playlist, strip out non-english characters and reduce the string
                    # to just a-to-z characters i.e. this will make the action_name valid in RB3
                    
                    ascii_name = unicodedata.normalize('NFKD', \
                        rb3compat.unicodestr(playlist.props.name, 'utf-8')).encode('ascii','ignore')
                    ascii_name = ascii_name.decode(encoding='UTF-8')
                    ascii_name = re.sub(r'[^a-zA-Z]', '', ascii_name)
                    action = actiongroup.add_action(func=func,
                        action_name=ascii_name,
                        playlist=playlist,favourite=favourite,
                        label=playlist.props.name)
                        
                    popup_menu.add_menu_item( menubar, section_name,
                        action )

    def add_to_static_playlist_menu_item_callback(self, action, param, args):
        print('''CoverArtBrowser DEBUG -
            add_to_static_playlist_menu_item_callback''')
            
        playlist=args['playlist']
        favourite = args['favourite']
        
        self.queue_selected_album(playlist, favourite)

    def add_playlist_menu_item_callback(self, *args):
        print('''CoverArtBrowser DEBUG - add_playlist_menu_item_callback''')
        playlist_manager = self.shell.props.playlist_manager
        playlist = playlist_manager.new_playlist(_('New Playlist'), False)

        self.queue_selected_album(playlist, self.favourites)

    def play_random_album_menu_item_callback(self, favourites=False):
        print('''CoverArtBrowser DEBUG - play_random_album_menu_item_callback''')
        query_model = RB.RhythmDBQueryModel.new_empty(self.shell.props.db)

        num_albums = len(self.album_manager.model.store)

        #random_list = []
        selected_albums = []

        gs = GSetting()
        settings = gs.get_setting(gs.Path.PLUGIN)        
        to_queue = settings[gs.PluginKey.RANDOM]

        if num_albums <= to_queue:
            dialog = Gtk.MessageDialog(None,
                    Gtk.DialogFlags.MODAL,
                    Gtk.MessageType.INFO,
                    Gtk.ButtonsType.OK,
                    _("The number of albums to randomly play is less than that displayed."))

            dialog.run()
            dialog.destroy()
            return
            
        album_col = self.album_manager.model.columns['album']

        chosen = {}

        # now loop through finding unique random albums
        # i.e. ensure we dont queue the same album twice
        
        for loop in range(0, to_queue):
            while True:
                pos = random.randint(0, num_albums - 1)
                if pos not in chosen:
                    chosen[pos] = None
                    selected_albums.append(self.album_manager.model.store[pos][album_col])
                    break

        threshold = self.rating_threshold if favourites else 0

        total = 0
        for album in selected_albums:
            # Retrieve and sort the entries of the album
            tracks = album.get_tracks(threshold)
            total = total + len(tracks)
            # Add the songs to the play queue
            for track in tracks:
                query_model.add_entry(track.entry, -1)

        if total == 0 and threshold:
            dialog = Gtk.MessageDialog(None,
                Gtk.DialogFlags.MODAL,
                Gtk.MessageType.INFO,
                Gtk.ButtonsType.OK,
                _("No tracks have been added because no tracks meet the favourite rating threshold"))

            dialog.run()
            dialog.destroy()
            
        self.props.query_model = query_model

        # Start the music
        player = self.shell.props.shell_player

        player.play_entry(query_model[0][0], self)

        print("CoverArtBrowser DEBUG - end play_selected_album")

    def cover_search_menu_item_callback(self, *args):
        '''
        Callback called when the search cover option is selected from the
        cover view popup. It prompts the album loader to retrieve the selected
        album cover
        '''
        print("CoverArtBrowser DEBUG - cover_search_menu_item_callback()")
        selected_albums = self.viewmgr.current_view.get_selected_objects()

        self.request_status_box.show_all()

        self.album_manager.cover_man.search_covers(selected_albums,
            self.update_request_status_bar)

        print("CoverArtBrowser DEBUG - end cover_search_menu_item_callback()")

    def export_embed_menu_item_callback(self, *args):
        '''
        Callback called when the export and embed coverart option
        is selected from the cover view popup.
        It prompts the exporter to copy and embed art for the albums chosen
        '''
        print("CoverArtBrowser DEBUG - export_embed_menu_item_callback()")
        selected_albums = self.viewmgr.current_view.get_selected_objects()

        CoverArtExport(self.plugin,
            self.shell, self.album_manager).embed_albums(selected_albums)

        print("CoverArtBrowser DEBUG - export_embed_menu_item_callback()")

    def update_request_status_bar(self, coverobject):
        '''
        Callback called by the album loader starts performing a new cover
        request. It prompts the source to change the content of the request
        statusbar.
        '''
        print("CoverArtBrowser DEBUG - update_request_status_bar")

        if coverobject:
            # for example "Requesting the picture cover for the music artist Michael Jackson"
            tranlation_string = _('Requesting cover for %s...')
            self.request_statusbar.set_text(
                rb3compat.unicodedecode(_('Requesting cover for %s...') % (coverobject.name), 'UTF-8'))
        else:
            self.request_status_box.hide()
            self.popup_menu.set_sensitive('cover_search_menu_item', True)
            self.request_cancel_button.set_sensitive(True)
        print("CoverArtBrowser DEBUG - end update_request_status_bar")

    def cancel_request_callback(self, _):
        '''
        Callback connected to the cancel button on the request statusbar.
        When called, it prompts the album loader to cancel the full cover
        search after the current cover.
        '''
        print("CoverArtBrowser DEBUG - cancel_request_callback")

        self.request_cancel_button.set_sensitive(False)
        self._cover_search_manager.cover_man.cancel_cover_request()

        print("CoverArtBrowser DEBUG - end cancel_request_callback")

    def notebook_switch_page_callback(self, notebook, page, page_num):
        '''
        Callback called when the notebook page gets switched. It initiates
        the cover search when the cover search pane's page is selected.
        '''
        print("CoverArtBrowser DEBUG - notebook_switch_page_callback")

        if page_num == 1:
            self.viewmgr.current_view.switch_to_coverpane(self.cover_search_pane)
            
        print("CoverArtBrowser DEBUG - end notebook_switch_page_callback")

    def rating_changed_callback(self, widget):
        '''
        Callback called when the Rating stars is changed
        '''
        print("CoverArtBrowser DEBUG - rating_changed_callback")

        rating = widget.get_rating()

        for album in self.viewmgr.current_view.get_selected_objects():
            album.rating = rating

        print("CoverArtBrowser DEBUG - end rating_changed_callback")

    def show_hide_pane(self, params):
        '''
        helper function - if the entry is manually expanded
        then if necessary scroll the view to the last selected album
        params is "album" or a tuple of "album" and "force_expand" boolean
        '''
        
        if isinstance(params, tuple):
            album, force = params
        else:
            album = params
            force = PanedCollapsible.Paned.DEFAULT
        
        if (album and self.click_count == 1 \
            and self.last_selected_album is album) or force != PanedCollapsible.Paned.DEFAULT:
            # check if it's a second or third click on the album and expand
            # or collapse the entry view accordingly
            self.paned.expand(force)

        # update the selected album
        selected = self.viewmgr.current_view.get_selected_objects()
        self.last_selected_album = selected[0] if len(selected) == 1 else None

        # clear the click count
        self.click_count = 0

    def update_with_selection(self):
        '''
        Update the source view when an item gets selected.
        '''
        selected = self.viewmgr.current_view.get_selected_objects()

        # clear the entry view
        self.entry_view.clear()

        cover_search_pane_visible = self.notebook.get_current_page() == \
            self.notebook.page_num(self.cover_search_pane)

        if not selected:
            # clean cover tab if selected
            if cover_search_pane_visible:
                self.cover_search_pane.clear()

            return
        elif len(selected) == 1:
            self.stars.set_rating(selected[0].rating)

            if selected[0] is not self.last_selected_album:
                # when the selection changes we've to take into account two
                # things
                if not self.click_count:
                    # we may be using the arrows, so if there is no mouse
                    # involved, we should change the last selected
                    self.last_selected_album = selected[0]
                else:
                    # we may've doing a fast change after a valid second click,
                    # so it shouldn't be considered a double click
                    self.click_count -= 1
        else:
            self.stars.set_rating(0)

        if len(selected) == 1:
            self.artist_info.emit('selected', selected[0].artist, selected[0].name)
            
        for album in selected:
            # add the album to the entry_view
            self.entry_view.add_album(album)

        # update the cover search pane with the first selected album
        if cover_search_pane_visible:
            self.cover_search_pane.do_search(selected[0],
                self.album_manager.cover_man.update_cover)

        self.statusbar.emit('display-status', self.viewmgr.current_view)

    def propertiesbutton_callback(self, choice):
        
        if choice == 'download':
            self.request_status_box.show_all()
            self._cover_search_manager = self.viewmgr.current_view.get_default_manager()
            self._cover_search_manager.cover_man.search_covers(
                callback=self.update_request_status_bar)
        elif choice == 'random':
            self.play_random_album_menu_item_callback()
        elif choice == 'random favourite':
            self.play_random_album_menu_item_callback(True)
        elif choice == 'favourite':
            self.favourites = not self.favourites
            self.viewmgr.current_view.set_popup_menu(self.popup_menu)
        elif choice == 'browser prefs':
            if not self._browser_preferences:
                self._browser_preferences = Preferences()
                
            self._browser_preferences.display_preferences_dialog(self.plugin)
        elif choice == 'search prefs':
            try:
                if not self._search_preferences:                
                    from gi.repository import Peas
                    peas = Peas.Engine.get_default()
                    plugin_info = peas.get_plugin_info('coverart_search_providers')
                    module_name = plugin_info.get_module_name()
                    mod = __import__(module_name)
                    sp = getattr(mod, "SearchPreferences")
                    self._search_preferences = sp()
                    self._search_preferences.plugin_info = plugin_info

                self._search_preferences.display_preferences_dialog(self._search_preferences)
            except:
                dialog = Gtk.MessageDialog(None,
                    Gtk.DialogFlags.MODAL,
                    Gtk.MessageType.INFO,
                    Gtk.ButtonsType.OK,
                    _("Please install and activate the latest version of the Coverart Search Providers plugin"))

                dialog.run()
                dialog.destroy()
        else:
            assert 1==2, ("unknown choice %s", choice)

    @classmethod
    def get_instance(cls, **kwargs):
        '''
        Returns the unique instance of the manager.
        '''
        if not cls.instance:
            cls.instance = CoverArtBrowserSource(**kwargs)

        return cls.instance
class CoverArtBrowserSource(RB.Source):
    '''
    Source utilized by the plugin to show all it's ui.
    '''
    rating_threshold = GObject.property(type=float, default=0)
    artist_paned_pos = GObject.property(type=str)
    min_paned_pos = 40

    # unique instance of the source
    instance = None

    def __init__(self, **kargs):
        '''
        Initializes the source.
        '''
        super(CoverArtBrowserSource, self).__init__(**kargs)

        # create source_source_settings and connect the source's properties
        self.gs = GSetting()

        self._connect_properties()

        self.hasActivated = False
        self.last_width = 0
        self.last_selected_album = None
        self.click_count = 0
        self.favourites = False
        self.task_progress = None

    def _connect_properties(self):
        '''
        Connects the source properties to the saved preferences.
        '''
        print("CoverArtBrowser DEBUG - _connect_properties")
        setting = self.gs.get_setting(self.gs.Path.PLUGIN)

        setting.bind(self.gs.PluginKey.RATING, self, 'rating_threshold',
                     Gio.SettingsBindFlags.GET)

        print("CoverArtBrowser DEBUG - end _connect_properties")

    def do_get_status(self, *args):
        '''
        Method called by Rhythmbox to figure out what to show on this source
        statusbar.
        If the custom statusbar is disabled, the source will
        show the selected album info.
        Also, it makes sure to show the progress on the album loading
        '''

        try:
            # this will only work for RB3.0 and later
            if not self.task_progress:
                self.task_progress = RB.TaskProgressSimple.new()
        except:
            pass

        try:
            progress = self.album_manager.progress
            progress_text = _('Loading...') if progress < 1 else ''
            try:
                # this will only work for RB3.0 and later
                if progress < 1:
                    if self.props.shell.props.task_list.get_model().n_items(
                    ) == 0:
                        self.props.shell.props.task_list.add_task(
                            self.task_progress)

                    self.task_progress.props.task_progress = progress
                    self.task_progress.props.task_label = progress_text
                else:
                    self.task_progress.props.task_outcome = RB.TaskOutcome.COMPLETE
            except:
                pass
        except:
            progress = 1
            progress_text = ''
            try:
                # this will only work for RB3.0 and later
                self.task_progress.props.task_outcome = RB.TaskOutcome.COMPLETE
            except:
                pass

        return (self.status, progress_text, progress)

    def do_selected(self):
        '''
        Called by Rhythmbox when the source is selected. It makes sure to
        create the ui the first time the source is showed.
        '''
        print("CoverArtBrowser DEBUG - do_selected")

        # first time of activation -> add graphical stuff
        if not self.hasActivated:
            self.do_impl_activate()

            # indicate that the source was activated before
            self.hasActivated = True

        print("CoverArtBrowser DEBUG - end do_selected")

    def do_impl_activate(self):
        '''
        Called by do_selected the first time the source is activated.
        It creates all the source ui and connects the necesary signals for it
        correct behavior.
        '''
        print("CoverArtBrowser DEBUG - do_impl_activate")

        # initialise some variables
        self.plugin = self.props.plugin
        self.shell = self.props.shell
        self.status = ''
        self.search_text = ''
        self.actiongroup = ActionGroup(self.shell, 'coverplaylist_submenu')
        self._browser_preferences = None
        self._search_preferences = None

        # indicate that the source was activated before
        self.hasActivated = True

        self._create_ui()
        self._setup_source()
        self._apply_settings()

        print("CoverArtBrowser DEBUG - end do_impl_activate")

    def _create_ui(self):
        '''
        Creates the ui for the source and saves the important widgets onto
        properties.
        '''
        print("CoverArtBrowser DEBUG - _create_ui")

        # dialog has not been created so lets do so.
        cl = CoverLocale()
        ui = Gtk.Builder()
        ui.set_translation_domain(cl.Locale.LOCALE_DOMAIN)
        ui.add_from_file(
            rb.find_plugin_file(self.plugin, 'ui/coverart_browser.ui'))
        ui.connect_signals(self)

        # load the page and put it in the source
        self.page = ui.get_object('main_box')
        self.pack_start(self.page, True, True, 0)

        # get widgets for main icon-view
        self.status_label = ui.get_object('status_label')
        window = ui.get_object('scrolled_window')

        self.viewmgr = ViewManager(self, window)

        # get widgets for the artist paned
        self.artist_paned = ui.get_object('vertical_paned')
        Gdk.threads_add_timeout(GLib.PRIORITY_DEFAULT_IDLE, 50,
                                self._change_artist_paned_pos,
                                self.viewmgr.view_name)
        self.viewmgr.connect('new-view', self.on_view_changed)
        self.artist_treeview = ui.get_object('artist_treeview')
        self.artist_scrolledwindow = ui.get_object('artist_scrolledwindow')

        # define menu's
        self.popup_menu = Menu(self.plugin, self.shell)
        self.popup_menu.load_from_file('ui/coverart_browser_pop_rb2.ui',
                                       'ui/coverart_browser_pop_rb3.ui')
        self._external_plugins = None

        signals = \
            { 'play_album_menu_item': self.play_album_menu_item_callback,
              'queue_album_menu_item': self.queue_album_menu_item_callback,
              'new_playlist': self.add_playlist_menu_item_callback,
              'cover_search_menu_item': self.cover_search_menu_item_callback,
              'export_embed_menu_item': self.export_embed_menu_item_callback,
              'show_properties_menu_item': self.show_properties_menu_item_callback,
              'play_similar_artist_menu_item': self.play_similar_artist_menu_item_callback}

        self.popup_menu.connect_signals(signals)
        self.popup_menu.connect('pre-popup', self.add_external_menu)

        self.status_label = ui.get_object('status_label')
        self.request_status_box = ui.get_object('request_status_box')
        self.request_spinner = ui.get_object('request_spinner')
        self.request_statusbar = ui.get_object('request_statusbar')
        self.request_cancel_button = ui.get_object('request_cancel_button')
        self.paned = ui.get_object('paned')
        self.notebook = ui.get_object('bottom_notebook')

        #---- set up info pane -----#
        info_scrolled_window = ui.get_object('info_scrolled_window')
        info_button_box = ui.get_object('info_button_box')
        artist_info_paned = ui.get_object('vertical_info_paned')

        self.artist_info = ArtistInfoPane(info_button_box,
                                          info_scrolled_window,
                                          artist_info_paned, self)

        # quick search
        self.quick_search = ui.get_object('quick_search_entry')

        print("CoverArtBrowser DEBUG - end _create_ui")

    def _setup_source(self):
        '''
        Setups the differents parts of the source so they are ready to be used
        by the user. It also creates and configure some custom widgets.
        '''
        print("CoverArtBrowser DEBUG - _setup_source")

        cl = CoverLocale()
        cl.switch_locale(cl.Locale.LOCALE_DOMAIN)

        # setup iconview popup
        self.viewmgr.current_view.set_popup_menu(self.popup_menu)

        # setup entry-view objects and widgets
        setting = self.gs.get_setting(self.gs.Path.PLUGIN)
        setting.bind(self.gs.PluginKey.PANED_POSITION, self.paned,
                     'collapsible-y', Gio.SettingsBindFlags.DEFAULT)
        setting.bind(self.gs.PluginKey.DISPLAY_BOTTOM, self.paned.get_child2(),
                     'visible', Gio.SettingsBindFlags.DEFAULT)

        # create entry view. Don't allow to reorder until the load is finished
        self.entry_view = EV(self.shell, self)
        self.entry_view.set_columns_clickable(False)
        self.shell.props.library_source.get_entry_view().set_columns_clickable(
            False)

        self.stars = ReactiveStar()
        self.stars.set_rating(0)
        a = Gtk.Alignment.new(0.5, 0.5, 0, 0)
        a.add(self.stars)

        self.stars.connect('changed', self.rating_changed_callback)

        vbox = Gtk.Box()
        vbox.set_orientation(Gtk.Orientation.VERTICAL)
        vbox.pack_start(self.entry_view, True, True, 0)
        vbox.pack_start(a, False, False, 1)
        vbox.show_all()
        self.notebook.append_page(vbox,
                                  Gtk.Label.new_with_mnemonic(_("Tracks")))

        # create an album manager
        self.album_manager = AlbumManager(self.plugin,
                                          self.viewmgr.current_view)

        self.viewmgr.current_view.initialise(self)
        # setup cover search pane
        colour = self.viewmgr.get_selection_colour()

        self.cover_search_pane = CoverSearchPane(self.plugin, colour)
        self.notebook.append_page(self.cover_search_pane,
                                  Gtk.Label.new_with_mnemonic(_("Covers")))

        # connect a signal to when the info of albums is ready
        self.load_fin_id = self.album_manager.loader.connect(
            'model-load-finished', self.load_finished_callback)

        # prompt the loader to load the albums
        self.album_manager.loader.load_albums(self.props.base_query_model)

        # initialise the variables of the quick search
        self.quick_search_controller = AlbumQuickSearchController(
            self.album_manager)
        self.quick_search_controller.connect_quick_search(self.quick_search)

        # set sensitivity of export menu item for iconview
        self.popup_menu.set_sensitive(
            'export_embed_menu_item',
            CoverArtExport(self.plugin, self.shell,
                           self.album_manager).is_search_plugin_enabled())

        # setup the statusbar component
        self.statusbar = Statusbar(self)

        # initialise the toolbar manager
        self.toolbar_manager = ToolbarManager(self.plugin, self.page,
                                              self.viewmgr)
        self.viewmgr.current_view.emit('update-toolbar')

        cl.switch_locale(cl.Locale.RB)
        # setup the artist paned
        artist_pview = None
        for view in self.shell.props.library_source.get_property_views():
            print(view.props.title)
            print(_("Artist"))
            if view.props.title == _("Artist"):
                artist_pview = view
                break

        assert artist_pview, "cannot find artist property view"

        self.artist_treeview.set_model(artist_pview.get_model())
        setting.bind(self.gs.PluginKey.ARTIST_PANED_POSITION, self,
                     'artist-paned-pos', Gio.SettingsBindFlags.DEFAULT)

        self.artist_paned.connect('button-release-event',
                                  self.artist_paned_button_release_callback)

        # intercept JumpToPlaying Song action so that we can scroll to the playing album

        appshell = rb3compat.ApplicationShell(self.shell)
        action = appshell.lookup_action("", "jump-to-playing", "win")
        action.action.connect("activate", self.jump_to_playing, None)

        self.echonest_similar_playlist = None

        print("CoverArtBrowser DEBUG - end _setup_source")

    def add_external_menu(self, *args):
        '''
        Callback when the popup menu is about to be displayed
        '''

        if not self._external_plugins:
            # initialise external plugin menu support
            self._external_plugins = \
            CreateExternalPluginMenu("ca_covers_view",
                7, self.popup_menu)
            self._external_plugins.create_menu('popup_menu', True)

        self.playlist_menu_item_callback()

    def jump_to_playing(self, *args):
        '''
        Callback when the JumpToPlaying action is invoked
        This will scroll the view to the playing song
        '''

        if not self.shell.props.selected_page.props.name == self.props.name:
            # if the source page that was played from is not the plugin then
            # nothing to do
            return

        album = None

        entry = self.shell.props.shell_player.get_playing_entry()

        if entry:
            album = self.album_manager.model.get_from_dbentry(entry)

        self.viewmgr.current_view.scroll_to_album(album)

    def artist_paned_button_release_callback(self, *args):
        '''
        Callback when the artist paned handle is released from its mouse click.
        '''
        child_width = self._get_child_width()

        paned_positions = eval(self.artist_paned_pos)

        found = None
        for viewpos in paned_positions:
            if self.viewmgr.view_name in viewpos:
                found = viewpos
                break

        if not found:
            return

        paned_positions.remove(found)
        if child_width <= self.min_paned_pos:
            child_width = 0
            self.artist_paned.set_position(child_width)

        paned_positions.append(self.viewmgr.view_name + ":" + str(child_width))

        self.artist_paned_pos = repr(paned_positions)

    def on_view_changed(self, widget, view_name):
        self._change_artist_paned_pos(view_name)

    def _change_artist_paned_pos(self, view_name):
        paned_positions = eval(self.artist_paned_pos)
        print(paned_positions)
        found = None
        for viewpos in paned_positions:
            if view_name in viewpos:
                found = viewpos
                break
        print(found)
        if not found:
            return

        child_width = int(found.split(":")[1])
        print(child_width)

        # odd case - if the pane is not visible but the position is zero
        # then the paned position on visible=true is some large arbitary value
        # hence - set it to be 1 px larger than the real value, then set it back
        # to its expected value
        self.artist_paned.set_position(child_width + 1)
        self.artist_paned.set_visible(True)
        self.artist_paned.set_position(child_width)

    def _get_child_width(self):
        child = self.artist_paned.get_child1()
        return child.get_allocated_width()

    def on_artist_treeview_selection_changed(self, view):
        model, artist_iter = view.get_selected()
        if artist_iter:
            artist = model[artist_iter][0]

            cl = CoverLocale()
            cl.switch_locale(cl.Locale.RB)
            #. TRANSLATORS - "All" is used in the context of "All artist names"
            if artist == _('All'):
                self.album_manager.model.remove_filter('quick_artist')
            else:
                self.album_manager.model.replace_filter('quick_artist', artist)

            cl.switch_locale(cl.Locale.LOCALE_DOMAIN)

    def _apply_settings(self):
        '''
        Applies all the settings related to the source and connects those that
        must be updated when the preferences dialog changes it's values. Also
        enables differents parts of the ui if the settings says so.
        '''
        print("CoverArtBrowser DEBUG - _apply_settings")

        # connect some signals to the loader to keep the source informed
        self.album_mod_id = self.album_manager.model.connect(
            'album-updated', self.on_album_updated)

        self.notify_prog_id = self.album_manager.connect(
            'notify::progress', lambda *args: self.notify_status_changed())

        print("CoverArtBrowser DEBUG - end _apply_settings")

    def load_finished_callback(self, _):
        '''
        Callback called when the loader finishes loading albums into the
        covers view model.
        '''
        print("CoverArtBrowser DEBUG - load_finished_callback")

        #if not self.request_status_box.get_visible():
        # it should only be enabled if no cover request is going on
        #self.source_menu_search_all_item.set_sensitive(True)

        # enable sorting on the entryview
        self.entry_view.set_columns_clickable(True)
        self.shell.props.library_source.get_entry_view().set_columns_clickable(
            True)

        print("CoverArtBrowser DEBUG - end load_finished_callback")

    def get_entry_view(self):
        return self.entry_view

    def on_album_updated(self, model, path, tree_iter):
        '''
        Callback called by the album loader when one of the albums managed
        by him gets modified in some way.
        '''
        album = model.get_from_path(path)
        selected = self.viewmgr.current_view.get_selected_objects()

        if album in selected:
            # update the selection since it may have changed
            self.viewmgr.current_view.selectionchanged_callback()

            if album is selected[0] and \
                self.notebook.get_current_page() == \
                self.notebook.page_num(self.cover_search_pane):
                # also, if it's the first, update the cover search pane
                self.cover_search_pane.clear()
                self.cover_search_pane.do_search(
                    album, self.album_manager.cover_man.update_cover)

    def play_similar_artist_menu_item_callback(self, *args):
        '''
        Callback called when the play similar artist option is selected from
        the cover view popup. It plays similar artists music.
        '''

    def play_similar_artist_menu_item_callback(self, *args):
        if not self.echonest_similar_playlist:
            self.echonest_similar_playlist = \
                EchoNestPlaylist(   self.shell,
                                    self.shell.props.queue_source)

        selected_albums = self.viewmgr.current_view.get_selected_objects()
        album = selected_albums[0]
        tracks = album.get_tracks()

        entry = tracks[0].entry
        self.echonest_similar_playlist.start(entry, reinitialise=True)

    def show_properties_menu_item_callback(self, *args):
        '''
        Callback called when the show album properties option is selected from
        the cover view popup. It shows a SongInfo dialog showing the selected
        albums' entries info, which can be modified.
        '''
        print("CoverArtBrowser DEBUG - show_properties_menu_item_callback")

        self.entry_view.select_all()

        info_dialog = RB.SongInfo(source=self, entry_view=self.entry_view)

        info_dialog.show_all()

        print("CoverArtBrowser DEBUG - end show_properties_menu_item_callback")

    def play_selected_album(self, favourites=False):
        '''
        Utilitary method that plays all entries from an album into the play
        queue.
        '''
        # callback when play an album
        print("CoverArtBrowser DEBUG - play_selected_album")

        query_model = RB.RhythmDBQueryModel.new_empty(self.shell.props.db)
        self.queue_selected_album(query_model, favourites)

        if len(query_model) > 0:
            self.props.query_model = query_model

            # Start the music
            player = self.shell.props.shell_player

            player.play_entry(query_model[0][0], self)

        print("CoverArtBrowser DEBUG - end play_selected_album")

    def queue_selected_album(self, source, favourites=False):
        '''
        Utilitary method that queues all entries from an album into the play
        queue.
        '''
        print("CoverArtBrowser DEBUG - queue_selected_album")

        selected_albums = self.viewmgr.current_view.get_selected_objects()
        threshold = self.rating_threshold if favourites else 0

        total = 0
        for album in selected_albums:
            # Retrieve and sort the entries of the album
            tracks = album.get_tracks(threshold)
            total = total + len(tracks)
            # Add the songs to the play queue
            for track in tracks:
                source.add_entry(track.entry, -1)

        if total == 0 and threshold:
            dialog = Gtk.MessageDialog(
                None, Gtk.DialogFlags.MODAL, Gtk.MessageType.INFO,
                Gtk.ButtonsType.OK,
                _("No tracks have been added because no tracks meet the favourite rating threshold"
                  ))

            dialog.run()
            dialog.destroy()
        print("CoverArtBrowser DEBUG - end queue_select_album")

    def play_album_menu_item_callback(self, *args):
        '''
        Callback called when the play album item from the cover view popup is
        selected. It cleans the play queue and queues the selected album.
        '''
        print("CoverArtBrowser DEBUG - play_album_menu_item_callback")

        self.play_selected_album(self.favourites)

        print("CoverArtBrowser DEBUG - end play_album_menu_item_callback")

    def queue_album_menu_item_callback(self, *args):
        '''
        Callback called when the queue album item from the cover view popup is
        selected. It queues the selected album at the end of the play queue.
        '''
        print("CoverArtBrowser DEBUG - queue_album_menu_item_callback()")
        self.queue_selected_album(self.shell.props.queue_source,
                                  self.favourites)

        print("CoverArtBrowser DEBUG - end queue_album_menu_item_callback()")

    def playlist_menu_item_callback(self, *args):
        print("CoverArtBrowser DEBUG - playlist_menu_item_callback")

        self.playlist_fillmenu(self.popup_menu, 'playlist_submenu',
                               'playlist_section', self.actiongroup,
                               self.add_to_static_playlist_menu_item_callback,
                               self.favourites)

    def playlist_fillmenu(self,
                          popup_menu,
                          menubar,
                          section_name,
                          actiongroup,
                          func,
                          favourite=False):
        print("CoverArtBrowser DEBUG - playlist_fillmenu")

        playlist_manager = self.shell.props.playlist_manager
        playlists_entries = playlist_manager.get_playlists()

        # tidy up old playlists menu items before recreating the list
        actiongroup.remove_actions()
        popup_menu.remove_menu_items(menubar, section_name)

        if playlists_entries:
            for playlist in playlists_entries:
                if playlist.props.is_local and \
                    isinstance(playlist, RB.StaticPlaylistSource):

                    args = (playlist, favourite)

                    # take the name of the playlist, strip out non-english characters and reduce the string
                    # to just a-to-z characters i.e. this will make the action_name valid in RB3

                    ascii_name = unicodedata.normalize('NFKD', \
                        rb3compat.unicodestr(playlist.props.name, 'utf-8')).encode('ascii','ignore')
                    ascii_name = ascii_name.decode(encoding='UTF-8')
                    ascii_name = re.sub(r'[^a-zA-Z]', '', ascii_name)
                    action = actiongroup.add_action(func=func,
                                                    action_name=ascii_name,
                                                    playlist=playlist,
                                                    favourite=favourite,
                                                    label=playlist.props.name)

                    popup_menu.add_menu_item(menubar, section_name, action)

    def add_to_static_playlist_menu_item_callback(self, action, param, args):
        print('''CoverArtBrowser DEBUG -
            add_to_static_playlist_menu_item_callback''')

        playlist = args['playlist']
        favourite = args['favourite']

        self.queue_selected_album(playlist, favourite)

    def add_playlist_menu_item_callback(self, *args):
        print('''CoverArtBrowser DEBUG - add_playlist_menu_item_callback''')
        playlist_manager = self.shell.props.playlist_manager
        playlist = playlist_manager.new_playlist(_('New Playlist'), False)

        self.queue_selected_album(playlist, self.favourites)

    def play_random_album_menu_item_callback(self, favourites=False):
        print(
            '''CoverArtBrowser DEBUG - play_random_album_menu_item_callback''')
        query_model = RB.RhythmDBQueryModel.new_empty(self.shell.props.db)

        num_albums = len(self.album_manager.model.store)

        #random_list = []
        selected_albums = []

        gs = GSetting()
        settings = gs.get_setting(gs.Path.PLUGIN)
        to_queue = settings[gs.PluginKey.RANDOM]

        if num_albums <= to_queue:
            dialog = Gtk.MessageDialog(
                None, Gtk.DialogFlags.MODAL, Gtk.MessageType.INFO,
                Gtk.ButtonsType.OK,
                _("The number of albums to randomly play is less than that displayed."
                  ))

            dialog.run()
            dialog.destroy()
            return

        album_col = self.album_manager.model.columns['album']

        chosen = {}

        # now loop through finding unique random albums
        # i.e. ensure we dont queue the same album twice

        for loop in range(0, to_queue):
            while True:
                pos = random.randint(0, num_albums - 1)
                if pos not in chosen:
                    chosen[pos] = None
                    selected_albums.append(
                        self.album_manager.model.store[pos][album_col])
                    break

        threshold = self.rating_threshold if favourites else 0

        total = 0
        for album in selected_albums:
            # Retrieve and sort the entries of the album
            tracks = album.get_tracks(threshold)
            total = total + len(tracks)
            # Add the songs to the play queue
            for track in tracks:
                query_model.add_entry(track.entry, -1)

        if total == 0 and threshold:
            dialog = Gtk.MessageDialog(
                None, Gtk.DialogFlags.MODAL, Gtk.MessageType.INFO,
                Gtk.ButtonsType.OK,
                _("No tracks have been added because no tracks meet the favourite rating threshold"
                  ))

            dialog.run()
            dialog.destroy()

        self.props.query_model = query_model

        # Start the music
        player = self.shell.props.shell_player

        player.play_entry(query_model[0][0], self)

        print("CoverArtBrowser DEBUG - end play_selected_album")

    def cover_search_menu_item_callback(self, *args):
        '''
        Callback called when the search cover option is selected from the
        cover view popup. It prompts the album loader to retrieve the selected
        album cover
        '''
        print("CoverArtBrowser DEBUG - cover_search_menu_item_callback()")
        selected_albums = self.viewmgr.current_view.get_selected_objects()

        self.request_status_box.show_all()

        self.album_manager.cover_man.search_covers(
            selected_albums, self.update_request_status_bar)

        print("CoverArtBrowser DEBUG - end cover_search_menu_item_callback()")

    def export_embed_menu_item_callback(self, *args):
        '''
        Callback called when the export and embed coverart option
        is selected from the cover view popup.
        It prompts the exporter to copy and embed art for the albums chosen
        '''
        print("CoverArtBrowser DEBUG - export_embed_menu_item_callback()")
        selected_albums = self.viewmgr.current_view.get_selected_objects()

        CoverArtExport(self.plugin, self.shell,
                       self.album_manager).embed_albums(selected_albums)

        print("CoverArtBrowser DEBUG - export_embed_menu_item_callback()")

    def update_request_status_bar(self, coverobject):
        '''
        Callback called by the album loader starts performing a new cover
        request. It prompts the source to change the content of the request
        statusbar.
        '''
        print("CoverArtBrowser DEBUG - update_request_status_bar")

        if coverobject:
            # for example "Requesting the picture cover for the music artist Michael Jackson"
            tranlation_string = _('Requesting cover for %s...')
            self.request_statusbar.set_text(
                rb3compat.unicodedecode(
                    _('Requesting cover for %s...') % (coverobject.name),
                    'UTF-8'))
        else:
            self.request_status_box.hide()
            self.popup_menu.set_sensitive('cover_search_menu_item', True)
            self.request_cancel_button.set_sensitive(True)
        print("CoverArtBrowser DEBUG - end update_request_status_bar")

    def cancel_request_callback(self, _):
        '''
        Callback connected to the cancel button on the request statusbar.
        When called, it prompts the album loader to cancel the full cover
        search after the current cover.
        '''
        print("CoverArtBrowser DEBUG - cancel_request_callback")

        self.request_cancel_button.set_sensitive(False)
        self._cover_search_manager.cover_man.cancel_cover_request()

        print("CoverArtBrowser DEBUG - end cancel_request_callback")

    def notebook_switch_page_callback(self, notebook, page, page_num):
        '''
        Callback called when the notebook page gets switched. It initiates
        the cover search when the cover search pane's page is selected.
        '''
        print("CoverArtBrowser DEBUG - notebook_switch_page_callback")

        if page_num == 1:
            self.viewmgr.current_view.switch_to_coverpane(
                self.cover_search_pane)

        print("CoverArtBrowser DEBUG - end notebook_switch_page_callback")

    def rating_changed_callback(self, widget):
        '''
        Callback called when the Rating stars is changed
        '''
        print("CoverArtBrowser DEBUG - rating_changed_callback")

        rating = widget.get_rating()

        for album in self.viewmgr.current_view.get_selected_objects():
            album.rating = rating

        print("CoverArtBrowser DEBUG - end rating_changed_callback")

    def show_hide_pane(self, params):
        '''
        helper function - if the entry is manually expanded
        then if necessary scroll the view to the last selected album
        params is "album" or a tuple of "album" and "force_expand" boolean
        '''

        if isinstance(params, tuple):
            album, force = params
        else:
            album = params
            force = PanedCollapsible.Paned.DEFAULT

        if (album and self.click_count == 1 \
            and self.last_selected_album is album) or force != PanedCollapsible.Paned.DEFAULT:
            # check if it's a second or third click on the album and expand
            # or collapse the entry view accordingly
            self.paned.expand(force)

        # update the selected album
        selected = self.viewmgr.current_view.get_selected_objects()
        self.last_selected_album = selected[0] if len(selected) == 1 else None

        # clear the click count
        self.click_count = 0

    def update_with_selection(self):
        '''
        Update the source view when an item gets selected.
        '''
        selected = self.viewmgr.current_view.get_selected_objects()

        # clear the entry view
        self.entry_view.clear()

        cover_search_pane_visible = self.notebook.get_current_page() == \
            self.notebook.page_num(self.cover_search_pane)

        if not selected:
            # clean cover tab if selected
            if cover_search_pane_visible:
                self.cover_search_pane.clear()

            return
        elif len(selected) == 1:
            self.stars.set_rating(selected[0].rating)

            if selected[0] is not self.last_selected_album:
                # when the selection changes we've to take into account two
                # things
                if not self.click_count:
                    # we may be using the arrows, so if there is no mouse
                    # involved, we should change the last selected
                    self.last_selected_album = selected[0]
                else:
                    # we may've doing a fast change after a valid second click,
                    # so it shouldn't be considered a double click
                    self.click_count -= 1
        else:
            self.stars.set_rating(0)

        if len(selected) == 1:
            self.artist_info.emit('selected', selected[0].artist,
                                  selected[0].name)

        for album in selected:
            # add the album to the entry_view
            self.entry_view.add_album(album)

        # update the cover search pane with the first selected album
        if cover_search_pane_visible:
            self.cover_search_pane.do_search(
                selected[0], self.album_manager.cover_man.update_cover)

        self.statusbar.emit('display-status', self.viewmgr.current_view)

    def propertiesbutton_callback(self, choice):

        if choice == 'download':
            self.request_status_box.show_all()
            self._cover_search_manager = self.viewmgr.current_view.get_default_manager(
            )
            self._cover_search_manager.cover_man.search_covers(
                callback=self.update_request_status_bar)
        elif choice == 'random':
            self.play_random_album_menu_item_callback()
        elif choice == 'random favourite':
            self.play_random_album_menu_item_callback(True)
        elif choice == 'favourite':
            self.favourites = not self.favourites
            self.viewmgr.current_view.set_popup_menu(self.popup_menu)
        elif choice == 'browser prefs':
            if not self._browser_preferences:
                self._browser_preferences = Preferences()

            self._browser_preferences.display_preferences_dialog(self.plugin)
        elif choice == 'search prefs':
            try:
                if not self._search_preferences:
                    from gi.repository import Peas
                    peas = Peas.Engine.get_default()
                    plugin_info = peas.get_plugin_info(
                        'coverart_search_providers')
                    module_name = plugin_info.get_module_name()
                    mod = __import__(module_name)
                    sp = getattr(mod, "SearchPreferences")
                    self._search_preferences = sp()
                    self._search_preferences.plugin_info = plugin_info

                self._search_preferences.display_preferences_dialog(
                    self._search_preferences)
            except:
                dialog = Gtk.MessageDialog(
                    None, Gtk.DialogFlags.MODAL, Gtk.MessageType.INFO,
                    Gtk.ButtonsType.OK,
                    _("Please install and activate the latest version of the Coverart Search Providers plugin"
                      ))

                dialog.run()
                dialog.destroy()
        else:
            assert 1 == 2, ("unknown choice %s", choice)

    @classmethod
    def get_instance(cls, **kwargs):
        '''
        Returns the unique instance of the manager.
        '''
        if not cls.instance:
            cls.instance = CoverArtBrowserSource(**kwargs)

        return cls.instance
    def _create_ui(self):
        '''
        Creates the ui for the source and saves the important widgets onto
        properties.
        '''
        print("CoverArtBrowser DEBUG - _create_ui")

        # dialog has not been created so lets do so.
        cl = CoverLocale()
        ui = Gtk.Builder()
        ui.set_translation_domain(cl.Locale.LOCALE_DOMAIN)
        ui.add_from_file(rb.find_plugin_file(self.plugin,
            'ui/coverart_browser.ui'))
        ui.connect_signals(self)

        # load the page and put it in the source
        self.page = ui.get_object('main_box')
        self.pack_start(self.page, True, True, 0)

        # get widgets for main icon-view
        self.status_label = ui.get_object('status_label')
        window = ui.get_object('scrolled_window')
        
        self.viewmgr = ViewManager(self, window)
                
        # get widgets for the artist paned
        self.artist_paned = ui.get_object('vertical_paned')
        Gdk.threads_add_timeout(GLib.PRIORITY_DEFAULT_IDLE, 50, self._change_artist_paned_pos, self.viewmgr.view_name)
        self.viewmgr.connect('new-view', self.on_view_changed)
        self.artist_treeview = ui.get_object('artist_treeview')
        self.artist_scrolledwindow = ui.get_object('artist_scrolledwindow')

        # define menu's
        self.popup_menu = Menu(self.plugin, self.shell)
        self.popup_menu.load_from_file('ui/coverart_browser_pop_rb2.ui',
            'ui/coverart_browser_pop_rb3.ui')
        self._external_plugins = None
        
        signals = \
            { 'play_album_menu_item': self.play_album_menu_item_callback,
              'queue_album_menu_item': self.queue_album_menu_item_callback,
              'new_playlist': self.add_playlist_menu_item_callback,
              'cover_search_menu_item': self.cover_search_menu_item_callback,
              'export_embed_menu_item': self.export_embed_menu_item_callback,
              'show_properties_menu_item': self.show_properties_menu_item_callback,
              'play_similar_artist_menu_item': self.play_similar_artist_menu_item_callback}
              
        self.popup_menu.connect_signals(signals)
        self.popup_menu.connect('pre-popup', self.add_external_menu)
        
        self.status_label = ui.get_object('status_label')
        self.request_status_box = ui.get_object('request_status_box')
        self.request_spinner = ui.get_object('request_spinner')
        self.request_statusbar = ui.get_object('request_statusbar')
        self.request_cancel_button = ui.get_object('request_cancel_button')
        self.paned = ui.get_object('paned')
        self.notebook = ui.get_object('bottom_notebook')
        
        #---- set up info pane -----#
        info_scrolled_window = ui.get_object('info_scrolled_window')
        info_button_box = ui.get_object('info_button_box')
        artist_info_paned = ui.get_object('vertical_info_paned')
        
        self.artist_info = ArtistInfoPane(info_button_box,
            info_scrolled_window,
            artist_info_paned,
            self)

        # quick search
        self.quick_search = ui.get_object('quick_search_entry')

        print("CoverArtBrowser DEBUG - end _create_ui")
    def _create_ui(self):
        '''
        Creates the ui for the source and saves the important widgets onto
        properties.
        '''
        print("CoverArtBrowser DEBUG - _create_ui")

        # dialog has not been created so lets do so.
        cl = CoverLocale()
        ui = Gtk.Builder()
        ui.set_translation_domain(cl.Locale.LOCALE_DOMAIN)
        ui.add_from_file(
            rb.find_plugin_file(self.plugin, 'ui/coverart_browser.ui'))
        ui.connect_signals(self)

        # load the page and put it in the source
        self.page = ui.get_object('main_box')
        self.pack_start(self.page, True, True, 0)

        # get widgets for main icon-view
        self.status_label = ui.get_object('status_label')
        window = ui.get_object('scrolled_window')

        self.viewmgr = ViewManager(self, window)

        # get widgets for the artist paned
        self.artist_paned = ui.get_object('vertical_paned')
        Gdk.threads_add_timeout(GLib.PRIORITY_DEFAULT_IDLE, 50,
                                self._change_artist_paned_pos,
                                self.viewmgr.view_name)
        self.viewmgr.connect('new-view', self.on_view_changed)
        self.artist_treeview = ui.get_object('artist_treeview')
        self.artist_scrolledwindow = ui.get_object('artist_scrolledwindow')

        # define menu's
        self.popup_menu = Menu(self.plugin, self.shell)
        self.popup_menu.load_from_file('ui/coverart_browser_pop_rb2.ui',
                                       'ui/coverart_browser_pop_rb3.ui')
        self._external_plugins = None

        signals = \
            { 'play_album_menu_item': self.play_album_menu_item_callback,
              'queue_album_menu_item': self.queue_album_menu_item_callback,
              'new_playlist': self.add_playlist_menu_item_callback,
              'cover_search_menu_item': self.cover_search_menu_item_callback,
              'export_embed_menu_item': self.export_embed_menu_item_callback,
              'show_properties_menu_item': self.show_properties_menu_item_callback,
              'play_similar_artist_menu_item': self.play_similar_artist_menu_item_callback}

        self.popup_menu.connect_signals(signals)
        self.popup_menu.connect('pre-popup', self.add_external_menu)

        self.status_label = ui.get_object('status_label')
        self.request_status_box = ui.get_object('request_status_box')
        self.request_spinner = ui.get_object('request_spinner')
        self.request_statusbar = ui.get_object('request_statusbar')
        self.request_cancel_button = ui.get_object('request_cancel_button')
        self.paned = ui.get_object('paned')
        self.notebook = ui.get_object('bottom_notebook')

        #---- set up info pane -----#
        info_scrolled_window = ui.get_object('info_scrolled_window')
        info_button_box = ui.get_object('info_button_box')
        artist_info_paned = ui.get_object('vertical_info_paned')

        self.artist_info = ArtistInfoPane(info_button_box,
                                          info_scrolled_window,
                                          artist_info_paned, self)

        # quick search
        self.quick_search = ui.get_object('quick_search_entry')

        print("CoverArtBrowser DEBUG - end _create_ui")