window: Add a GtkGrid as the window's main child

We'll pack in more widgets later

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

ui/test_window.py

@@ -17,7 +17,10 @@ class TestUIWindow(unittest.TestCase):
 
     def test_window_init(self):
         self.assertIsInstance(window.Window, Gtk.ApplicationWindow)
+        self.assertIsInstance(window.Grid, Gtk.Grid)
+
         self.assertEqual(window.Window.get_titlebar(), header.Header)
+        self.assertEqual(window.Window.get_child(), window.Grid)
         window.Window.present()
 
         self.assertEqual(window.Window.get_title(), version.string())

ui/window.py

@@ -7,6 +7,7 @@ from gi.repository import Gtk
 from . import header
 
 Window = Gtk.ApplicationWindow()
+Grid = Gtk.Grid()
 
 def initialize():
     settings.initialize("window.width", 1100)
@@ -17,6 +18,7 @@ initialize()
 Window.set_title(version.string())
 Window.set_icon_name("emmental")
 Window.set_titlebar(header.Header)
+Window.set_child(Grid)
 Window.set_default_size(settings.get_int("window.width"),
                         settings.get_int("window.height"))
 if settings.get_bool("window.maximized"):