text: from __future__ import absolute_import, unicode_literals
  
  from mopidy import listener
  
  
  class CoreListener(listener.Listener):
      """
      Marker interface for recipients of events sent by the core actor.
  
      Any Pykka actor that mixes in this class will receive calls to the methods
      defined here when the corresponding events happen in the core actor. This
      interface is used both for looking up what actors to notify of the events,
      and for providing default implementations for those listeners that are not
      interested in all events.
      """
  
      @staticmethod
      def send(event, **kwargs):
          """Helper to allow calling of core listener events"""
          listener.send_async(CoreListener, event, **kwargs)
  
      def on_event(self, event, **kwargs):
          """
          Called on all events.
  
          *MAY* be implemented by actor. By default, this method forwards the
          event to the specific event methods.
  
          :param event: the event name
          :type event: string
          :param kwargs: any other arguments to the specific event handlers
          """
          getattr(self, event)(**kwargs)
  
      def track_playback_paused(self, tl_track, time_position):
          """
          Called whenever track playback is paused.
  
          *MAY* be implemented by actor.
  
          :param tl_track: the track that was playing when playback paused
          :type tl_track: :class:`mopidy.models.TlTrack`
          :param time_position: the time position in milliseconds
          :type time_position: int
          """
          pass
  
      def track_playback_resumed(self, tl_track, time_position):
          """
          Called whenever track playback is resumed.
  
          *MAY* be implemented by actor.
  
          :param tl_track: the track that was playing when playback resumed
          :type tl_track: :class:`mopidy.models.TlTrack`
          :param time_position: the time position in milliseconds
          :type time_position: int
          """
          pass
  
      def track_playback_started(self, tl_track):
          """
          Called whenever a new track starts playing.
  
          *MAY* be implemented by actor.
  
          :param tl_track: the track that just started playing
          :type tl_track: :class:`mopidy.models.TlTrack`
          """
          pass
  
      def track_playback_ended(self, tl_track, time_position):
          """
          Called whenever playback of a track ends.
  
          *MAY* be implemented by actor.
  
          :param tl_track: the track that was played before playback stopped
          :type tl_track: :class:`mopidy.models.TlTrack`
          :param time_position: the time position in milliseconds
          :type time_position: int
          """
          pass
  
      def playback_state_changed(self, old_state, new_state):
          """
          Called whenever playback state is changed.
  
          *MAY* be implemented by actor.
  
          :param old_state: the state before the change
          :type old_state: string from :class:`mopidy.core.PlaybackState` field
          :param new_state: the state after the change
          :type new_state: string from :class:`mopidy.core.PlaybackState` field
          """
          pass
  
      def tracklist_changed(self):
          """
          Called whenever the tracklist is changed.
  
          *MAY* be implemented by actor.
          """
          pass
  
      def playlists_loaded(self):
          """
          Called when playlists are loaded or refreshed.
  
          *MAY* be implemented by actor.
          """
          pass
  
      def playlist_changed(self, playlist):
          """
          Called whenever a playlist is changed.
  
          *MAY* be implemented by actor.
  
          :param playlist: the changed playlist
          :type playlist: :class:`mopidy.models.Playlist`
          """
          pass
  
      def options_changed(self):
          """
          Called whenever an option is changed.
  
          *MAY* be implemented by actor.
          """
          pass
  
      def volume_changed(self, volume):
          """
          Called whenever the volume is changed.
  
          *MAY* be implemented by actor.
  
          :param volume: the new volume in the range [0..100]
          :type volume: int
          """
          pass
  
      def mute_changed(self, mute):
          """
          Called whenever the mute state is changed.
  
          *MAY* be implemented by actor.
  
          :param mute: the new mute state
          :type mute: boolean
          """
          pass
  
      def seeked(self, time_position):
          """
          Called whenever the time position changes by an unexpected amount, e.g.
          at seek to a new time position.
  
          *MAY* be implemented by actor.
  
          :param time_position: the position that was seeked to in milliseconds
          :type time_position: int
          """
          pass
  