This change has us checking the return value of change_track when deciding if
the play call was a success or if the track is unplayable. Which ensures that
the following can no longer happen: 1) play stream 2) play stream that fails
change_track 3) stream 1) continues playing. Correct behavior being the next
stream playing instead.
While trying to remove traces of stop calls in core to get gapless working I
found we had no way to switch to switch tracks without triggering a play. This
change fixes this by changing the backends playback provider API.
- play() now _only_ starts playback and does not take any arguments.
- prepare_change() has been added, this could have been avoided with a kwarg to
change_track(track), but that would break more backends.
- core has been updated to call prepare_change+change_track+play as needed.
- tests have been updated to handle this change.
Longer term I hope to completely rework the playback API in backends, as 99% of
our backends only use change_track(track) to translate URIs. So we should make
simple case simple, and handle mopidy-spotify / appsrc in some other way.
Cherry picked from the WIP gapless branch.
This is done by checking for the presence of the organization tag typically set
by web streams. This might be a bit to strict and a bad heuristic, but it's
currently better than wrongly emitting stream titles for non streams IMO.
Seeks will now fail when the duration is None, this is an approximation to if
the track is seekable or not. This check is need as otherwise seeking a radio
stream will trigger the next track.
If the track truly isn't seekable despite having a duration we should still
fail as GStreamer will reject the seek.
The API I really want for this to support regular tracks, stream updates and
dynamic playlists is still unclear to me. As such I'm taking the KISS approach
and reducing this to just the stream title and nothing else.
If all goes as planed this will be replaced by playback_track_changed(tlid, ref)
style events and other improvements in a later version.
- Adds tests for new behaviors in core.
- Adds stream name to MPD format (fixes#944)
- Adds 'stream_changed' core event (needs a new name/event)
- Adds 'get_stream_reference' (which I'm also unsure about)
The bits I'm unsure about are mostly with respect to #270, but I'm going ahead
with this commit so we can discuss the details in PR with this code as an
example.
