audio: Implement a Header bar

This moves the code out of ui/ and turns it into a class for easier
testing.

Implements: Issue #22 (Move Gtk.HeaderBar code into audio/)
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

audio/__init__.py

@@ -1,6 +1,7 @@
 # Copyright 2021 (c) Anna Schumaker.
 import sys
 import tagdb
+from gi.repository import Gtk
 
 from . import player
 Player = player.Player()
@@ -23,6 +24,14 @@ def SeekControl():
     return scale.ScaleButtonBox(scale.SeekScale(Player))
 
 
+class Header(Gtk.HeaderBar):
+    def __init__(self):
+        Gtk.HeaderBar.__init__(self)
+        self.pack_start(controls.AudioControls(Player, Player.Autopause))
+        self.pack_end(scale.ScaleButtonBox(scale.SeekScale(Player)))
+        self.set_title_widget(nowplaying.NowPlaying(Player))
+
+
 def play_track(track):
     if track == Player.track:
         return False

audio/test_audio.py

@@ -3,14 +3,15 @@ import audio
 import pathlib
 import tagdb
 import unittest
+from gi.repository import Gtk
 
 test_album = pathlib.Path("./data/Test Album/")
 
 class TestAudio(unittest.TestCase):
-    def test_audio_init(self):
+    def test_init(self):
         self.assertIsInstance(audio.Player, audio.player.Player)
 
-    def test_audio_play_track(self):
+    def test_play_track(self):
         lib = tagdb.Library.add(test_album)
         lib.scan().join()
         track = [ t for t in lib.tracks if t.tracknumber == 1 ][0]
@@ -20,7 +21,13 @@ class TestAudio(unittest.TestCase):
         self.assertFalse(audio.play_track(track))
         audio.Player.playing = False
 
-    def test_audio_widgets(self):
+    def test_header(self):
+        header = audio.Header()
+        self.assertIsInstance(header, Gtk.HeaderBar)
+        self.assertIsInstance(header.get_title_widget(),
+                              audio.nowplaying.NowPlaying)
+
+    def test_widgets(self):
         seeker = audio.SeekControl()
 
         self.assertIsInstance(audio.AudioControls(),