playlist: Split out the ControlBox as a base class

And create a PlaylistBox inheriting from it containing the buttons.

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

playlist/header.py

@@ -74,20 +74,9 @@ class JumpButton(Gtk.Button):
 
 class ControlBox(Gtk.Box):
     def __init__(self):
-        Gtk.Box.__init__(self)
+        Gtk.Box.__init__(self, margin_top=5, margin_bottom=5,
+                               margin_end=5, margin_start=5)
         self.add_css_class("linked")
-        self.append(RandomToggle())
-        self.append(LoopToggle())
-        self.append(SortButton())
-        self.append(JumpButton())
-
-        self.set_margin_top(5)
-        self.set_margin_bottom(5)
-        self.set_margin_start(5)
-        self.set_margin_end(5)
-
-    def get_jump_button(self):
-        return self.get_last_child()
 
     def set_playlist(self, plist):
         child = self.get_first_child()
@@ -96,11 +85,23 @@ class ControlBox(Gtk.Box):
             child = child.get_next_sibling()
 
 
+class PlaylistBox(ControlBox):
+    def __init__(self):
+        ControlBox.__init__(self)
+        self.append(RandomToggle())
+        self.append(LoopToggle())
+        self.append(SortButton())
+        self.append(JumpButton())
+
+    def get_jump_button(self):
+        return self.get_last_child()
+
+
 class Header(Gtk.Box):
     def __init__(self):
         Gtk.Box.__init__(self)
         self.append(FilterEntry())
-        self.append(ControlBox())
+        self.append(PlaylistBox())
 
     def get_jump_button(self):
         return self.get_last_child().get_jump_button()

playlist/test_header.py

@@ -138,9 +138,15 @@ class TestControlBox(unittest.TestCase):
         self.assertEqual(box.get_margin_end(), 5)
         self.assertTrue(box.has_css_class("linked"))
 
+
+class TestPlaylistBox(unittest.TestCase):
+    def test_init(self):
+        box = header.PlaylistBox()
+        self.assertIsInstance(box, header.ControlBox)
+
     def test_children(self):
         collection = db.user.Table.find("Collection")
-        box = header.ControlBox()
+        box = header.PlaylistBox()
         box.set_playlist(collection)
 
         child = box.get_first_child()