sugar-activity: import and make independent of sugar-toolkit GTK versions

As we move to adding support for a second UI toolkit (GTK+ 3.x),
the sugar-activity binary used by all activities must become
backend-toolkit-independent. It would be wasteful to have two backend
toolkits loaded in memory, and in the GTK2/GTK3 case, it is impossible
(importing both results in an instant crash).

To achieve this, we split the existing sugar-toolkit activity/main.py:main()
functionality into two parts, moving it into the sugar-activity binary and
the Activity class as follows:
 1. All toolkit-specific stuff is moved into the Activity class (i.e.
   everything that interacts with GTK)
 2. Everything that can be reasonably/easily moved into the Activity class
   is also moved.
 3. What remains is the stuff that is inherently involved with the
   construction of the Activity object, not related to UI toolkits. This
   is moved into the sugar-activity binary.

main.py is then removed from sugar-toolkit, and sugar-activity is moved
from sugar to sugar-toolkit-gtk3 in order to keep toolkit-related code
with the toolkit itself.

With this work done, the one remaining question is how to invoke the main
loop. An optional run_main_loop() method is added to the activity class,
for GTK2 this will run the GTK2 main loop, for GTK3 the GTK3 main loop will
be run, etc.

Signed-off-by: Daniel Drake <dsd@laptop.org>

src/sugar3/activity/activity.py

@@ -71,8 +71,10 @@ from telepathy.interfaces import CHANNEL, \
 from telepathy.constants import CONNECTION_HANDLE_TYPE_CONTACT
 from telepathy.constants import CONNECTION_HANDLE_TYPE_ROOM
 
+import sugar3
 from sugar3 import util
 from sugar3.presence import presenceservice
+from sugar3.activity import i18n
 from sugar3.activity.activityservice import ActivityService
 from sugar3.activity.namingalert import NamingAlert
 from sugar3.graphics import style
@@ -259,6 +261,22 @@ class Activity(Window, Gtk.Container):
             the base class __init()__ before doing Activity specific things.
 
         """
+        # Stuff that needs to be done early
+
+        locale_path = i18n.get_locale_path(self.get_bundle_id())
+        gettext.bindtextdomain(self.get_bundle_id(), locale_path)
+        gettext.bindtextdomain('sugar-toolkit', sugar3.locale_path)
+        gettext.textdomain(self.get_bundle_id())
+
+        icons_path = os.path.join(get_bundle_path(), 'icons')
+        Gtk.IconTheme.get_default().append_search_path(icons_path)
+
+        # This code can be removed when we grow an xsettings daemon (the GTK+
+        # init routines will then automatically figure out the font settings)
+        settings = Gtk.Settings.get_default()
+        settings.set_property('gtk-font-name',
+                              '%s %f' % (style.FONT_FACE, style.FONT_SIZE))
+
         Window.__init__(self)
 
         if 'SUGAR_ACTIVITY_ROOT' in os.environ:
@@ -349,6 +367,9 @@ class Activity(Window, Gtk.Container):
                                            self.__jobject_updated_cb)
         self.set_title(self._jobject.metadata['title'])
 
+    def run_main_loop(self):
+        Gtk.main()
+
     def _initialize_journal_object(self):
         title = _('%s Activity') % get_bundle_name()
         client = GConf.Client.get_default()