[gnome-tweak-tool] Add hooks for subclasses to modify style classes

[John Stowers <jstowers src gnome org>]

commit f9064c24d28ab37d7d5e1f9a2a5534ec56cf20a2
Author: John Stowers <john stowers gmail com>
Date:   Fri Aug 9 11:04:37 2013 +0200

    Add hooks for subclasses to modify style classes

 gtweak/widgets.py |   16 ++++++++++------
 1 files changed, 10 insertions(+), 6 deletions(-)
---
diff --git a/gtweak/widgets.py b/gtweak/widgets.py
index 79b3ccf..be8dcb3 100644
--- a/gtweak/widgets.py
+++ b/gtweak/widgets.py
@@ -220,18 +220,22 @@ class ListBoxTweakGroup(Gtk.ListBox, TweakGroup):
         Gtk.ListBox.__init__(self,
                         selection_mode=Gtk.SelectionMode.NONE,
                         name=options['uid'])
-        self.get_style_context().add_class("tweak-group")
+        self.get_style_context().add_class(
+                        options.get('css_class','tweak-group'))
         TweakGroup.__init__(self, name, *tweaks, **options)
         self._sg = Gtk.SizeGroup(
                         mode=Gtk.SizeGroupMode.HORIZONTAL)
         self._sg.props.ignore_hidden = True
 
         for t in self.tweaks:
-            row = Gtk.ListBoxRow(name=t.uid)
-            row.get_style_context().add_class("tweak")
-            if isinstance(t, Title):
-                row.get_style_context().add_class("title")
-            row.add(t)
+            if isinstance(t, Gtk.ListBoxRow):
+                row = t
+            else:
+                row = Gtk.ListBoxRow(name=t.uid)
+                row.get_style_context().add_class("tweak")
+                if isinstance(t, Title):
+                    row.get_style_context().add_class("title")
+                row.add(t)
             self.add(row)
             if t.widget_for_size_group:
                 self._sg.add_widget(t.widget_for_size_group)