nowplaying: Add a widget for displaying the current track's tags

And expose properties for setting their values.

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

emmental/nowplaying/tags.py

@@ -0,0 +1,53 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Widgets for information about the current track."""
+from gi.repository import GObject
+from gi.repository import GLib
+from gi.repository import Gtk
+from . import label
+
+
+class TagInfo(Gtk.ScrolledWindow):
+    """A widget for displaying information about the current track."""
+
+    title = GObject.Property(type=str)
+    album = GObject.Property(type=str)
+    artist = GObject.Property(type=str)
+    album_artist = GObject.Property(type=str)
+    prefer_artist = GObject.Property(type=bool, default=True)
+
+    def __init__(self):
+        """Initialize the TagInfo widget."""
+        super().__init__(hexpand=True, vexpand=True)
+        self._box = Gtk.Box.new(Gtk.Orientation.VERTICAL, 0)
+        self._title = label.Label()
+        self._album = label.Label(prefix="from ")
+        self._artist = label.ArtistLabel(prefix="by ")
+        self._saved_height = 0
+        self._idle_id = None
+
+        self.bind_property("title", self._title, "text")
+        self.bind_property("album", self._album, "text")
+        self.bind_property("artist", self._artist, "artist")
+        self.bind_property("album-artist", self._artist, "album-artist")
+        self.bind_property("prefer-artist", self._artist, "prefer-artist",
+                           GObject.BindingFlags.BIDIRECTIONAL)
+
+        self._box.append(self._title)
+        self._box.append(self._album)
+        self._box.append(self._artist)
+        self.set_child(self._box)
+
+    def __set_label_size(self):
+        self._title.size = self._saved_height / 2.5
+        for tag in [self._album, self._artist]:
+            tag.size = self._saved_height / 5
+        self._idle_id = None
+        return GLib.SOURCE_REMOVE
+
+    def do_size_allocate(self, width, height, baseline) -> None:
+        """Monitor for size changes."""
+        Gtk.ScrolledWindow.do_size_allocate(self, width, height, baseline)
+        if height != self._saved_height:
+            self._saved_height = height
+            if not self._idle_id:
+                self._idle_id = GLib.idle_add(self.__set_label_size)

tests/nowplaying/test_tags.py

@@ -0,0 +1,82 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Tests our TagInfo widget."""
+import unittest
+import emmental.nowplaying.label
+import emmental.nowplaying.tags
+from gi.repository import Gtk
+
+
+class TestTagInfo(unittest.TestCase):
+    """Tests the tags.Info widget."""
+
+    def setUp(self):
+        """Set up common variables."""
+        self.info = emmental.nowplaying.tags.TagInfo()
+
+    def test_init(self):
+        """Test that the TagInfo widget is set up correctly."""
+        self.assertIsInstance(self.info, Gtk.ScrolledWindow)
+        self.assertIsInstance(self.info.get_child(), Gtk.Viewport)
+        self.assertIsInstance(self.info._box, Gtk.Box)
+
+        self.assertTrue(self.info.get_hexpand())
+        self.assertTrue(self.info.get_vexpand())
+        self.assertEqual(self.info._saved_height, 0)
+        self.assertIsNone(self.info._idle_id)
+
+        self.assertEqual(self.info.get_child().get_child(), self.info._box)
+        self.assertEqual(self.info._box.get_orientation(),
+                         Gtk.Orientation.VERTICAL)
+        self.assertEqual(self.info._box.get_spacing(), 0)
+
+    def test_title(self):
+        """Test the title label."""
+        self.assertIsInstance(self.info._title,
+                              emmental.nowplaying.label.Label)
+        self.assertEqual(self.info._box.get_first_child(), self.info._title)
+
+        self.assertEqual(self.info.title, "")
+        self.assertEqual(self.info._title.prefix, "")
+        self.info.title = "Test Title"
+        self.assertEqual(self.info.title, "Test Title")
+        self.assertEqual(self.info._title.get_text(), "Test Title")
+
+    def test_album(self):
+        """Test the album label."""
+        self.assertIsInstance(self.info._album,
+                              emmental.nowplaying.label.Label)
+        self.assertEqual(self.info._title.get_next_sibling(),
+                         self.info._album)
+
+        self.assertEqual(self.info.album, "")
+        self.assertEqual(self.info._album.prefix, "from ")
+        self.info.album = "Test Album"
+        self.assertEqual(self.info.album, "Test Album")
+        self.assertEqual(self.info._album.get_text(), "from Test Album")
+
+    def test_artist(self):
+        """Test the artist label."""
+        self.assertIsInstance(self.info._artist,
+                              emmental.nowplaying.label.ArtistLabel)
+        self.assertEqual(self.info._album.get_next_sibling(),
+                         self.info._artist)
+
+        self.assertEqual(self.info.artist, "")
+        self.assertEqual(self.info._artist.prefix, "by ")
+        self.assertTrue(self.info.prefer_artist)
+
+        self.info.artist = "Test Artist"
+        self.assertEqual(self.info.artist, "Test Artist")
+        self.assertEqual(self.info._artist.artist, "Test Artist")
+
+        self.info.album_artist = "Test Album Artist"
+        self.assertEqual(self.info.album_artist, "Test Album Artist")
+        self.assertEqual(self.info._artist.album_artist, "Test Album Artist")
+
+        self.info.prefer_artist = False
+        self.assertFalse(self.info._artist.prefer_artist)
+        self.assertEqual(self.info._artist.get_text(), "by Test Album Artist")
+
+        self.info._artist.prefer_artist = True
+        self.assertTrue(self.info.prefer_artist)
+        self.assertEqual(self.info._artist.get_text(), "by Test Artist")