Artist and library playlists are allocated manually, so there should be
generic functions that both can use to get a playlist pointer and free
it when we're done.
I also add a callback for telling the UI when new playlists have been
allocated. This isn't needed for Library playlists, but this is the
only way the UI can know about new Artists.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>
I think "lookup" is a better name for this function, since it's similar
to performing a dictionary lookup.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>
This pointer can be used immediately by testing code instead of simply
looking at the return status.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>
Putting this code in a new file helps make gui/playlist.c less complex,
and better matches the organization of files in core/
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>