mopidy/mopidy/core/playback.py
2014-09-23 01:10:51 +02:00

372 lines
12 KiB
Python

from __future__ import unicode_literals
import logging
import urlparse
from mopidy.audio import PlaybackState
from mopidy.core import listener
logger = logging.getLogger(__name__)
# TODO: split mixing out from playback?
class PlaybackController(object):
pykka_traversable = True
def __init__(self, mixer, backends, core):
self.mixer = mixer
self.backends = backends
self.core = core
self._state = PlaybackState.STOPPED
self._volume = None
self._mute = False
def _get_backend(self):
# TODO: take in track instead
if self.current_tl_track is None:
return None
uri = self.current_tl_track.track.uri
uri_scheme = urlparse.urlparse(uri).scheme
return self.backends.with_playback.get(uri_scheme, None)
# Properties
def get_current_tl_track(self):
return self.current_tl_track
current_tl_track = None
"""
The currently playing or selected :class:`mopidy.models.TlTrack`, or
:class:`None`.
"""
def get_current_track(self):
return self.current_tl_track and self.current_tl_track.track
current_track = property(get_current_track)
"""
The currently playing or selected :class:`mopidy.models.Track`.
Read-only. Extracted from :attr:`current_tl_track` for convenience.
"""
def get_state(self):
return self._state
def set_state(self, new_state):
(old_state, self._state) = (self.state, new_state)
logger.debug('Changing state: %s -> %s', old_state, new_state)
self._trigger_playback_state_changed(old_state, new_state)
state = property(get_state, set_state)
"""
The playback state. Must be :attr:`PLAYING`, :attr:`PAUSED`, or
:attr:`STOPPED`.
Possible states and transitions:
.. digraph:: state_transitions
"STOPPED" -> "PLAYING" [ label="play" ]
"STOPPED" -> "PAUSED" [ label="pause" ]
"PLAYING" -> "STOPPED" [ label="stop" ]
"PLAYING" -> "PAUSED" [ label="pause" ]
"PLAYING" -> "PLAYING" [ label="play" ]
"PAUSED" -> "PLAYING" [ label="resume" ]
"PAUSED" -> "STOPPED" [ label="stop" ]
"""
def get_time_position(self):
backend = self._get_backend()
if backend:
return backend.playback.get_time_position().get()
else:
return 0
time_position = property(get_time_position)
"""Time position in milliseconds."""
def get_volume(self):
if self.mixer:
return self.mixer.get_volume().get()
else:
# For testing
return self._volume
def set_volume(self, volume):
if self.mixer:
self.mixer.set_volume(volume)
else:
# For testing
self._volume = volume
volume = property(get_volume, set_volume)
"""Volume as int in range [0..100] or :class:`None` if unknown. The volume
scale is linear.
"""
def get_mute(self):
if self.mixer:
return self.mixer.get_mute().get()
else:
# For testing
return self._mute
def set_mute(self, value):
value = bool(value)
if self.mixer:
self.mixer.set_mute(value)
else:
# For testing
self._mute = value
mute = property(get_mute, set_mute)
"""Mute state as a :class:`True` if muted, :class:`False` otherwise"""
# Methods
# TODO: remove this.
def change_track(self, tl_track, on_error_step=1):
"""
Change to the given track, keeping the current playback state.
:param tl_track: track to change to
:type tl_track: :class:`mopidy.models.TlTrack` or :class:`None`
:param on_error_step: direction to step at play error, 1 for next
track (default), -1 for previous track
:type on_error_step: int, -1 or 1
"""
old_state = self.state
self.stop()
self.current_tl_track = tl_track
if old_state == PlaybackState.PLAYING:
self.play(on_error_step=on_error_step)
elif old_state == PlaybackState.PAUSED:
self.pause()
# TODO: this is not really end of track, this is on_need_next_track
def on_end_of_track(self):
"""
Tell the playback controller that end of track is reached.
Used by event handler in :class:`mopidy.core.Core`.
"""
if self.state == PlaybackState.STOPPED:
return
original_tl_track = self.current_tl_track
next_tl_track = self.core.tracklist.eot_track(original_tl_track)
if next_tl_track:
self.change_track(next_tl_track)
else:
self.stop()
self.current_tl_track = None
self.core.tracklist.mark_played(original_tl_track)
def on_tracklist_change(self):
"""
Tell the playback controller that the current playlist has changed.
Used by :class:`mopidy.core.TracklistController`.
"""
if self.current_tl_track not in self.core.tracklist.tl_tracks:
self.stop()
self.current_tl_track = None
def next(self):
"""
Change to the next track.
The current playback state will be kept. If it was playing, playing
will continue. If it was paused, it will still be paused, etc.
"""
tl_track = self.core.tracklist.next_track(self.current_tl_track)
if tl_track:
# TODO: switch to:
# backend.play(track)
# wait for state change?
self.change_track(tl_track)
else:
self.stop()
self.current_tl_track = None
def pause(self):
"""Pause playback."""
backend = self._get_backend()
if not backend or backend.playback.pause().get():
# TODO: switch to:
# backend.track(pause)
# wait for state change?
self.state = PlaybackState.PAUSED
self._trigger_track_playback_paused()
def play(self, tl_track=None, on_error_step=1):
"""
Play the given track, or if the given track is :class:`None`, play the
currently active track.
:param tl_track: track to play
:type tl_track: :class:`mopidy.models.TlTrack` or :class:`None`
:param on_error_step: direction to step at play error, 1 for next
track (default), -1 for previous track
:type on_error_step: int, -1 or 1
"""
assert on_error_step in (-1, 1)
if tl_track is None:
if self.state == PlaybackState.PAUSED:
return self.resume()
if self.current_tl_track is not None:
tl_track = self.current_tl_track
else:
if on_error_step == 1:
tl_track = self.core.tracklist.next_track(tl_track)
elif on_error_step == -1:
tl_track = self.core.tracklist.previous_track(tl_track)
if tl_track is None:
return
assert tl_track in self.core.tracklist.tl_tracks
# TODO: switch to:
# backend.play(track)
# wait for state change?
if self.state == PlaybackState.PLAYING:
self.stop()
self.current_tl_track = tl_track
self.state = PlaybackState.PLAYING
backend = self._get_backend()
success = backend and backend.playback.play(tl_track.track).get()
if success:
self.core.tracklist.mark_playing(tl_track)
# TODO: replace with stream-changed
self._trigger_track_playback_started()
else:
self.core.tracklist.mark_unplayable(tl_track)
if on_error_step == 1:
# TODO: can cause an endless loop for single track repeat.
self.next()
elif on_error_step == -1:
self.previous()
def previous(self):
"""
Change to the previous track.
The current playback state will be kept. If it was playing, playing
will continue. If it was paused, it will still be paused, etc.
"""
tl_track = self.current_tl_track
# TODO: switch to:
# self.play(....)
# wait for state change?
self.change_track(
self.core.tracklist.previous_track(tl_track), on_error_step=-1)
def resume(self):
"""If paused, resume playing the current track."""
if self.state != PlaybackState.PAUSED:
return
backend = self._get_backend()
if backend and backend.playback.resume().get():
self.state = PlaybackState.PLAYING
# TODO: trigger via gst messages
self._trigger_track_playback_resumed()
# TODO: switch to:
# backend.resume()
# wait for state change?
def seek(self, time_position):
"""
Seeks to time position given in milliseconds.
:param time_position: time position in milliseconds
:type time_position: int
:rtype: :class:`True` if successful, else :class:`False`
"""
if not self.core.tracklist.tracks:
return False
if self.state == PlaybackState.STOPPED:
self.play()
elif self.state == PlaybackState.PAUSED:
self.resume()
if time_position < 0:
time_position = 0
elif time_position > self.current_track.length:
self.next()
return True
backend = self._get_backend()
if not backend:
return False
success = backend.playback.seek(time_position).get()
if success:
self._trigger_seeked(time_position)
return success
def stop(self):
"""Stop playing."""
if self.state != PlaybackState.STOPPED:
backend = self._get_backend()
time_position_before_stop = self.time_position
if not backend or backend.playback.stop().get():
self.state = PlaybackState.STOPPED
self._trigger_track_playback_ended(time_position_before_stop)
def _trigger_track_playback_paused(self):
logger.debug('Triggering track playback paused event')
if self.current_track is None:
return
listener.CoreListener.send(
'track_playback_paused',
tl_track=self.current_tl_track, time_position=self.time_position)
def _trigger_track_playback_resumed(self):
logger.debug('Triggering track playback resumed event')
if self.current_track is None:
return
listener.CoreListener.send(
'track_playback_resumed',
tl_track=self.current_tl_track, time_position=self.time_position)
def _trigger_track_playback_started(self):
logger.debug('Triggering track playback started event')
if self.current_tl_track is None:
return
listener.CoreListener.send(
'track_playback_started',
tl_track=self.current_tl_track)
def _trigger_track_playback_ended(self, time_position_before_stop):
logger.debug('Triggering track playback ended event')
if self.current_tl_track is None:
return
listener.CoreListener.send(
'track_playback_ended',
tl_track=self.current_tl_track,
time_position=time_position_before_stop)
def _trigger_playback_state_changed(self, old_state, new_state):
logger.debug('Triggering playback state change event')
listener.CoreListener.send(
'playback_state_changed',
old_state=old_state, new_state=new_state)
def _trigger_seeked(self, time_position):
logger.debug('Triggering seeked event')
listener.CoreListener.send('seeked', time_position=time_position)