playlist: Have the Factory create a previous Playlist

And add some special handling so a previous.Previous() playlist type is
created for the db_previous playlist.

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

emmental/playlist/__init__.py

@@ -2,6 +2,7 @@
 """An object for managing the visible and active playlists."""
 from gi.repository import GObject
 from . import playlist
+from . import previous
 from .. import db
 
 
@@ -15,6 +16,7 @@ class Factory(GObject.GObject):
     db_visible = GObject.Property(type=db.playlist.Playlist)
 
     active_playlist = GObject.Property(type=playlist.Playlist)
+    previous_playlist = GObject.Property(type=previous.Previous)
     visible_playlist = GObject.Property(type=playlist.Playlist)
 
     def __init__(self, sql: db.Connection):
@@ -24,7 +26,8 @@ class Factory(GObject.GObject):
         self.connect("notify", self.__notify_db_playlists)
 
     def __get_playlists(self) -> list[playlist.Playlist]:
-        plists = [self.active_playlist, self.visible_playlist]
+        plists = [self.active_playlist, self.previous_playlist,
+                  self.visible_playlist]
         return [p for p in plists if p is not None]
 
     def __search_playlists(self, db_plist: db.playlist.Playlist) \
@@ -33,6 +36,12 @@ class Factory(GObject.GObject):
             if plist.playlist == db_plist:
                 return plist
 
+    def __make_playlist(self,
+                        db_plist: db.playlist.Playlist) -> playlist.Playlist:
+        if db_plist == self.sql.playlists.previous:
+            return previous.Previous(self.sql, db_plist)
+        return playlist.Playlist(self.sql, db_plist)
+
     def __run_factory(self, label: str) -> None:
         db_plist = self.get_property(f"db-{label}")
         plist = self.get_property(f"{label}-playlist")
@@ -46,7 +55,7 @@ class Factory(GObject.GObject):
             new = None
         elif plist is None or self.__get_playlists().count(plist) > 1:
             if (new := self.__search_playlists(db_plist)) is None:
-                new = playlist.Playlist(self.sql, db_plist)
+                new = self.__make_playlist(db_plist)
         elif (new := self.__search_playlists(db_plist)) is None:
             plist.playlist = db_plist
             return
@@ -62,9 +71,7 @@ class Factory(GObject.GObject):
                 self.notify("active-loop")
                 self.notify("active-shuffle")
             case "db-previous":
-                plist = self.get_property(param.name)
-                name = "<None>" if plist is None else plist.name
-                print(f"factory: {param.name[3:]} playlist is:", name)
+                self.__run_factory("previous")
             case "db-visible":
                 self.__run_factory("visible")
 

tests/playlist/test_factory.py

@@ -145,6 +145,22 @@ class TestFactory(tests.util.TestCase):
         self.assertRegex(mock_stdout.getvalue(),
                          "factory: previous playlist is: <None>")
 
+    def test_previous_playlist(self, mock_stdout: io.StringIO):
+        """Test creating a Playlist when setting the db_previous property."""
+        self.assertIsNone(self.factory.previous_playlist)
+
+        self.factory.db_previous = self.sql.playlists.previous
+        self.assertIsInstance(self.factory.previous_playlist,
+                              emmental.playlist.previous.Previous)
+        self.assertEqual(self.factory.previous_playlist.sql, self.sql)
+        self.assertEqual(self.factory.previous_playlist.playlist,
+                         self.sql.playlists.previous)
+
+        previous = self.factory.previous_playlist
+        self.factory.db_previous = None
+        self.assertIsNone(self.factory.previous_playlist)
+        self.assertIsNone(previous.playlist)
+
     def test_visible(self, mock_stdout: io.StringIO):
         """Test the visible playlist property."""
         self.assertIsNone(self.factory.db_visible)
@@ -205,3 +221,14 @@ class TestFactory(tests.util.TestCase):
         self.factory.db_visible = None
         self.assertEqual(visible.playlist, self.user_plist)
         self.assertIsNone(self.factory.visible_playlist)
+
+    def test_visible_previous_playlist(self, mock_stdout: io.StringIO):
+        """Test setting the visible playlist to the previous playlist."""
+        self.factory.db_previous = self.sql.playlists.previous
+        self.factory.db_visible = self.sql.playlists.previous
+        self.assertEqual(id(self.factory.visible_playlist),
+                         id(self.factory.previous_playlist))
+
+        self.factory.db_visible = self.user_plist
+        self.assertNotEqual(id(self.factory.visible_playlist),
+                            id(self.factory.previous_playlist))