audio: Add a custom TrackArtist label

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

audio/nowplaying.py

@@ -14,6 +14,18 @@ class TrackTitle(Gtk.Label):
         self.set_markup(f"<big>{GLib.markup_escape_text(text)}</big>")
 
 
+class TrackArtist(Gtk.Label):
+    def __init__(self, player):
+        Gtk.Label.__init__(self)
+        player.connect("track-changed", self.on_track_changed)
+        self.on_track_changed(player, None, player.track)
+        self.add_css_class("subtitle")
+
+    def on_track_changed(self, player, old, new):
+        text = f"by {new.artist}" if new else "The Cheesy Music Player"
+        self.set_markup(f"<big>{GLib.markup_escape_text(text)}</big>")
+
+
 class NowPlaying(Gtk.ScrolledWindow):
     def __init__(self):
         Gtk.ScrolledWindow.__init__(self)

audio/test_nowplaying.py

@@ -8,6 +8,7 @@ class FakeTrack(GObject.GObject):
     def __init__(self):
         GObject.GObject.__init__(self)
         self.title = "Test Title"
+        self.artist = "Test Artist"
 
 class FakePlayer(GObject.GObject):
     def __init__(self):
@@ -31,6 +32,19 @@ class TestAudioTrackTitle(unittest.TestCase):
         self.assertEqual(title.get_text(), "Test Title")
 
 
+class TestAudioTrackArtist(unittest.TestCase):
+    def test_track_artist(self):
+        fake  = FakePlayer()
+        artist = nowplaying.TrackArtist(fake)
+
+        self.assertIsInstance(artist, Gtk.Label)
+        self.assertTrue(artist.has_css_class("subtitle"))
+        self.assertEqual(artist.get_text(), "The Cheesy Music Player")
+
+        fake.emit("track-changed", None, FakeTrack())
+        self.assertEqual(artist.get_text(), "by Test Artist")
+
+
 class TestNowPlaying(unittest.TestCase):
     def test_now_playing_init(self):
         now = nowplaying.NowPlaying()