playlist: Add a Playlist model

This model builds on the TrackidModel to make it more Playlist and Track
focused instead of trackid centric.

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

emmental/playlist/playlist.py

@@ -0,0 +1,44 @@
+# Copyright 2023 (c) Anna Schumaker.
+"""A TrackidModel with extra features."""
+from gi.repository import GObject
+from . import model
+from .. import db
+
+
+class Playlist(model.TrackidModel):
+    """A TrackidModel with extra Playlist features."""
+
+    def __init__(self, sql: db.Connection,
+                 playlist: db.playlist.Playlist = None):
+        """Initialize the Playlist instance."""
+        super().__init__(sql=sql)
+        self.__playlist = None
+
+        if playlist is not None:
+            self.playlist = playlist
+
+    def add_track(self, track: db.tracks.Track) -> None:
+        """Add a track to the playlist."""
+        if self.__playlist is not None:
+            self.__playlist.add_track(track)
+
+    def index(self, track: db.tracks.Track) -> int | None:
+        """Find the index of a track in the list."""
+        if track is not None:
+            return super().index(track.trackid)
+
+    def remove_track(self, track: db.tracks.Track) -> None:
+        """Remove a track from the playlist."""
+        if self.__playlist is not None:
+            self.__playlist.remove_track(track)
+
+    @GObject.Property(type=db.playlist.Playlist)
+    def playlist(self) -> db.playlist.Playlist | None:
+        """Get the current db playlist."""
+        return self.__playlist
+
+    @playlist.setter
+    def playlist(self, new: db.playlist.Playlist | None) -> None:
+        """Set a new db playlist to the playlist."""
+        self.__playlist = new
+        self.trackid_set = None if new is None else new.tracks

tests/playlist/test_playlist.py

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+# Copyright 2023 (c) Anna Schumaker.
+"""Tests our PlaylistModel."""
+import pathlib
+import tests.util
+import emmental.playlist.playlist
+
+
+class TestPlaylist(tests.util.TestCase):
+    """Tests the Playlist Gio.ListModel."""
+
+    def setUp(self):
+        """Set up common variables."""
+        super().setUp()
+        self.db_plist = self.sql.playlists.create("Test Playlist")
+        self.playlist = emmental.playlist.playlist.Playlist(self.sql)
+
+        self.library = self.sql.libraries.create(pathlib.Path("/a/b"))
+        self.album = self.sql.albums.create("Test Album", "Artist", "2023")
+        self.medium = self.sql.media.create(self.album, "", number=1)
+        self.year = self.sql.years.create(2023)
+
+        self.track1 = self.sql.tracks.create(self.library,
+                                             pathlib.Path("/a/b/1.ogg"),
+                                             self.medium, self.year, number=1)
+        self.track2 = self.sql.tracks.create(self.library,
+                                             pathlib.Path("/a/b/2.ogg"),
+                                             self.medium, self.year, number=2)
+
+    def test_init(self):
+        """Test that the Playlist was set up correctly."""
+        self.assertIsInstance(self.playlist,
+                              emmental.playlist.model.TrackidModel)
+        self.assertEqual(self.playlist.sql, self.sql)
+        self.assertIsNone(self.playlist._Playlist__playlist)
+
+        plist2 = emmental.playlist.playlist.Playlist(self.sql, self.db_plist)
+        self.assertEqual(plist2.playlist, self.db_plist)
+
+    def test_add_track(self):
+        """Test the playlist add_track() function."""
+        self.playlist.add_track(self.track1)
+
+        self.playlist.playlist = self.db_plist
+        self.playlist.add_track(self.track1)
+        self.assertListEqual(self.playlist.trackids, [self.track1.trackid])
+
+    def test_index(self):
+        """Test the playlist index() function."""
+        self.assertIsNone(self.playlist.index(self.track1))
+
+        self.playlist.playlist = self.db_plist
+        self.playlist.add_track(self.track1)
+
+        self.assertEqual(self.playlist.index(self.track1), 0)
+        self.assertIsNone(self.playlist.index(self.track2))
+        self.assertIsNone(self.playlist.index(None))
+
+    def test_remove_track(self):
+        """Test the playlist remove_track() function."""
+        self.playlist.remove_track(self.track1)
+
+        self.db_plist.add_track(self.track1)
+        self.playlist.playlist = self.db_plist
+        self.playlist.remove_track(self.track1)
+        self.assertListEqual(self.playlist.trackids, [])
+
+    def test_playlist(self):
+        """Test the playlist property."""
+        self.assertIsNone(self.playlist.playlist)
+
+        self.playlist.playlist = self.db_plist
+        self.assertEqual(self.playlist._Playlist__playlist, self.db_plist)
+        self.assertEqual(self.playlist.playlist, self.db_plist)
+        self.assertEqual(self.playlist.trackid_set, self.db_plist.tracks)
+
+        self.playlist.playlist = None
+        self.assertIsNone(self.playlist.playlist)
+        self.assertIsNone(self.playlist.trackid_set)