db: Give the Media table a custom Filter

We want to filter out Medium playlists with empty names in the sidebar,
and the easiest way to do that is through a custom filter attached to
the Media table.

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

emmental/db/media.py

@@ -2,8 +2,10 @@
 """A custom Gio.ListModel for managing individual media in an album."""
 import sqlite3
 from gi.repository import GObject
+from gi.repository import Gtk
 from .. import format
 from . import playlist
+from . import table
 from . import tracks
 
 
@@ -34,12 +36,26 @@ class Medium(playlist.Playlist):
         return self.get_album()
 
 
+class Filter(table.KeySet):
+    """Custom filter to hide media with empty names."""
+
+    def do_get_strictness(self) -> Gtk.FilterMatch:
+        """Get the strictness of the filter."""
+        if (res := super().do_get_strictness()) == Gtk.FilterMatch.ALL:
+            res = Gtk.FilterMatch.SOME
+        return res
+
+    def do_match(self, medium: Medium) -> bool:
+        """Check if the Medium matches the filter."""
+        return len(medium.name) > 0 if super().do_match(medium) else False
+
+
 class Table(playlist.Table):
     """Our Media Table."""
 
     def __init__(self, sql: GObject.TYPE_PYOBJECT, **kwargs):
         """Initialize the Media Table."""
-        super().__init__(sql=sql, autodelete=True,
+        super().__init__(sql=sql, filter=Filter(), autodelete=True,
                          system_tracks=False, **kwargs)
 
     def do_construct(self, **kwargs) -> Medium:

tests/db/test_media.py

@@ -4,6 +4,7 @@ import pathlib
 import unittest.mock
 import emmental.db
 import tests.util
+from gi.repository import Gtk
 
 
 class TestMediumObject(tests.util.TestCase):
@@ -46,6 +47,36 @@ class TestMediumObject(tests.util.TestCase):
             mock_rename.assert_called_with(self.medium, "New Name")
 
 
+class TestFilter(tests.util.TestCase):
+    """Test the medium filter."""
+
+    def setUp(self):
+        """Set up common variables."""
+        super().setUp()
+        self.filter = emmental.db.media.Filter()
+
+    def test_init(self):
+        """Test that the filter is initialized properly."""
+        self.assertIsInstance(self.filter, emmental.db.table.KeySet)
+
+    def test_strictness(self):
+        """Test checking strictness."""
+        self.filter.keys = None
+        self.assertEqual(self.filter.get_strictness(), Gtk.FilterMatch.SOME)
+        self.filter.keys = set()
+        self.assertEqual(self.filter.get_strictness(), Gtk.FilterMatch.NONE)
+        self.filter.keys = {1, 2, 3}
+        self.assertEqual(self.filter.get_strictness(), Gtk.FilterMatch.SOME)
+
+    def test_match(self):
+        """Test matching a Medium."""
+        album = self.sql.albums.create("Test Album", "Test Artist", "123")
+        medium = self.sql.media.create(album, "", number=1)
+        self.assertFalse(self.filter.match(medium))
+        medium.name = "abcde"
+        self.assertTrue(self.filter.match(medium))
+
+
 class TestMediumsTable(tests.util.TestCase):
     """Tests our mediums table."""
 
@@ -61,6 +92,8 @@ class TestMediumsTable(tests.util.TestCase):
     def test_init(self):
         """Test that the medium model is configured corretly."""
         self.assertIsInstance(self.table, emmental.db.playlist.Table)
+        self.assertIsInstance(self.table.get_filter(),
+                              emmental.db.media.Filter)
         self.assertEqual(len(self.table), 0)
         self.assertTrue(self.table.autodelete)
         self.assertFalse(self.table.system_tracks)
@@ -172,17 +205,19 @@ class TestMediumsTable(tests.util.TestCase):
         self.assertEqual(len(mediums2), 0)
 
         mediums2.load(now=True)
-        self.assertEqual(len(mediums2), 2)
+        self.assertEqual(len(mediums2.store), 2)
 
-        self.assertEqual(mediums2.get_item(0).albumid, self.album.albumid)
+        self.assertEqual(mediums2.store.get_item(0).albumid,
-        self.assertEqual(mediums2.get_item(0).name, "")
+                         self.album.albumid)
-        self.assertEqual(mediums2.get_item(0).number, 1)
+        self.assertEqual(mediums2.store.get_item(0).name, "")
-        self.assertEqual(mediums2.get_item(0).type, "")
+        self.assertEqual(mediums2.store.get_item(0).number, 1)
+        self.assertEqual(mediums2.store.get_item(0).type, "")
 
-        self.assertEqual(mediums2.get_item(1).albumid, self.album.albumid)
+        self.assertEqual(mediums2.store.get_item(1).albumid,
-        self.assertEqual(mediums2.get_item(1).name, "Medium 2")
+                         self.album.albumid)
-        self.assertEqual(mediums2.get_item(1).number, 2)
+        self.assertEqual(mediums2.store.get_item(1).name, "Medium 2")
-        self.assertEqual(mediums2.get_item(1).type, "Digital Media")
+        self.assertEqual(mediums2.store.get_item(1).number, 2)
+        self.assertEqual(mediums2.store.get_item(1).type, "Digital Media")
 
     def test_lookup(self):
         """Test looking up medium playlists."""