[gnome-tweak-tool] tweakview: Update decorations on settings changes

[Florian Müllner <fmuellner src gnome org>]

commit 4c976788ab9bbd3911c95e2091a203eddac1c9cd
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Sep 28 17:21:21 2014 +0200

    tweakview: Update decorations on settings changes
    
    It is a bit ironic that Tweak Tool allows users to tweak the
    titlebar decorations, but ignores the setting (at least until
    a restart). So listen for change notifications and update
    decorations accordingly.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=737531

 gtweak/tweakview.py |   19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)
---
diff --git a/gtweak/tweakview.py b/gtweak/tweakview.py
index cc0b914..ee432f5 100644
--- a/gtweak/tweakview.py
+++ b/gtweak/tweakview.py
@@ -55,6 +55,9 @@ class Window(Gtk.ApplicationWindow):
         self._model.load_tweaks(self)
         self.load_model_data()
 
+        Gtk.Settings.get_default().connect("notify::gtk-decoration-layout",
+                                          self._update_decorations);
+
         self.connect("key-press-event", self._on_key_press)
         self.add(main_box)
     
@@ -67,16 +70,15 @@ class Window(Gtk.ApplicationWindow):
         right_header = Gtk.HeaderBar()
         right_header.props.show_close_button = True
 
+        self._left_header = left_header;
+        self._right_header = right_header;
+
         left_header.get_style_context().add_class("titlebar")
         left_header.get_style_context().add_class("tweak-titlebar-left")
         right_header.get_style_context().add_class("titlebar")
         right_header.get_style_context().add_class("tweak-titlebar-right")
 
-        layout_desc = Gtk.Settings.get_default().props.gtk_decoration_layout;
-        tokens = layout_desc.split(":", 2)
-        if tokens != None:
-                right_header.props.decoration_layout = ":" + tokens[1]
-                left_header.props.decoration_layout = tokens[0]
+        self._update_decorations (Gtk.Settings.get_default(), None)
 
         self.title = Gtk.Label(label="")
         self.title.get_style_context().add_class("title")
@@ -187,6 +189,13 @@ class Window(Gtk.ApplicationWindow):
         if before and not row.get_header():
             row.set_header (Gtk.Separator(orientation=Gtk.Orientation.HORIZONTAL))
 
+    def _update_decorations(self, settings, pspec):
+        layout_desc = settings.props.gtk_decoration_layout;
+        tokens = layout_desc.split(":", 2)
+        if tokens != None:
+                self._right_header.props.decoration_layout = ":" + tokens[1]
+                self._left_header.props.decoration_layout = tokens[0]
+
     def _on_key_press(self, widget, event):
         keyname = Gdk.keyval_name(event.keyval)
         if keyname == 'Escape':