def set_canvas(self, canvas):
        """Sets the 'work area' of your activity with the canvas of your
        choice.

        One commonly used canvas is Gtk.ScrolledWindow
        """
        Window.set_canvas(self, canvas)
        if not self._read_file_called:
            canvas.connect('map', self.__canvas_map_cb)

    def __init__(self):

        global _journal_window
        Window.__init__(self)
        _journal_window = self
        self.set_icon_name('activity-journal')
        self.set_title(_('Journal'))

        # Stop the user from closing the journal window.
        self.connect('delete-event', lambda widget, event: True)

    def _initialize_display(self):
        main_widget = self.initialize_display()
        Window.set_canvas(self, main_widget)
        self.initialized = True

        if self.shared_activity and not self._processed_share:
            # We are joining a shared activity, but when_shared has not yet
            # been called
            self.when_shared()
            self._processed_share = True
        self.show_all()
        self.after_init()

    def set_canvas(self, canvas):
        '''
        Sets the 'work area' of your activity with the canvas of your choice.

        One commonly used canvas is Gtk.ScrolledWindow

        Args:
            canvas (:class:`Gtk.Widget`): the widget used as canvas
        '''

        Window.set_canvas(self, canvas)
        if not self._read_file_called:
            canvas.connect('map', self.__canvas_map_cb)

 def get_canvas(self):
     '''
     Returns:
         :class:`Gtk.Widget`: the widget used as canvas
     '''
     return Window.get_canvas(self)

    def __init__(self, handle, create_jobject=True):
        '''
        Initialise the Activity

        Args:

        handle (sugar3.activity.activityhandle.ActivityHandle)
            instance providing the activity id and access to the
            presence service which *may* provide sharing for this
            application
        create_jobject (boolean)
            define if it should create a journal object if we are
            not resuming

        Side effects:

            Sets the gdk screen DPI setting (resolution) to the
            Sugar screen resolution.

            Connects our "destroy" message to our _destroy_cb
            method.

            Creates a base Gtk.Window within this window.

            Creates an ActivityService (self._bus) servicing
            this application.

        Usage:
            If your Activity implements __init__(), it should call
            the base class __init()__ before doing Activity specific things.

        '''

        # Stuff that needs to be done early
        icons_path = os.path.join(get_bundle_path(), 'icons')
        Gtk.IconTheme.get_default().append_search_path(icons_path)

        sugar_theme = 'sugar-72'
        if 'SUGAR_SCALING' in os.environ:
            if os.environ['SUGAR_SCALING'] == '100':
                sugar_theme = 'sugar-100'

        # 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-theme-name', sugar_theme)
        settings.set_property('gtk-icon-theme-name', 'sugar')
        settings.set_property('gtk-font-name',
                              '%s %f' % (style.FONT_FACE, style.FONT_SIZE))

        Window.__init__(self)

        if 'SUGAR_ACTIVITY_ROOT' in os.environ:
            # If this activity runs inside Sugar, we want it to take all the
            # screen. Would be better if it was the shell to do this, but we
            # haven't found yet a good way to do it there. See #1263.
            self.connect('window-state-event', self.__window_state_event_cb)
            screen = Gdk.Screen.get_default()
            screen.connect('size-changed', self.__screen_size_changed_cb)
            self._adapt_window_to_screen()

        # process titles will only show 15 characters
        # but they get truncated anyway so if more characters
        # are supported in the future we will get a better view
        # of the processes
        proc_title = '%s <%s>' % (get_bundle_name(), handle.activity_id)
        util.set_proc_title(proc_title)

        self.connect('realize', self.__realize_cb)
        self.connect('delete-event', self.__delete_event_cb)

        self._active = False
        self._active_time = None
        self._spent_time = 0
        self._activity_id = handle.activity_id
        self.shared_activity = None
        self._join_id = None
        self._updating_jobject = False
        self._closing = False
        self._quit_requested = False
        self._deleting = False
        self._max_participants = None
        self._invites_queue = []
        self._jobject = None
        self._read_file_called = False

        self._session = _get_session()
        self._session.register(self)
        self._session.connect('quit-requested',
                              self.__session_quit_requested_cb)
        self._session.connect('quit', self.__session_quit_cb)

        accel_group = Gtk.AccelGroup()
        self.sugar_accel_group = accel_group
        self.add_accel_group(accel_group)

        self._bus = ActivityService(self)
        self._owns_file = False

        share_scope = SCOPE_PRIVATE
#.........这里部分代码省略.........

    def __init__(self):

        global _journal_window
        Window.__init__(self)
        _journal_window = self

 def get_canvas(self):
     return Window.get_canvas(self)

    def __init__(self, handle):
        # self.initiating indicates whether this instance has initiated sharing
        # it always starts false, but will be set to true if this activity
        # initiates sharing. In particular, if Activity.__init__ calls
        # self.share(), self.initiating will be set to True.
        self.initiating = False
        # self._processed_share indicates whether when_shared() has been called
        self._processed_share = False
        # self.initialized tracks whether the Activity's display is up and running
        self.initialized = False
        
        self.early_setup()
        
        super(GroupActivity, self).__init__(handle)
        self.dbus_name = self.get_bundle_id()
        self.logger = logging.getLogger(self.dbus_name)
        
        self._handle = handle

        ##GObject.threads_init()

        self._sharing_completed = not self.shared_activity
        self._readfile_completed = not handle.object_id

        if self.shared_activity:
            self.message = self.message_joining
        elif handle.object_id:
            self.message = self.message_loading
        else:
            self.message = self.message_preparing

        toolbar_box = ToolbarBox()
        self.activity_button = ActivityToolbarButton(self)
        toolbar_box.toolbar.insert(self.activity_button, 0)
        self.set_toolbar_box(toolbar_box)

        v = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
        self.startup_label = Gtk.Label(label=self.message)
        v.pack_start(self.startup_label, True, True, 0)
        Window.set_canvas(self,v)
        self.show_all()
        
        # The show_all method queues up draw events, but they aren't executed
        # until the mainloop has a chance to process them.  We want to process
        # them immediately, because we need to show the waiting screen
        # before the waiting starts, not after.
        exhaust_event_loop()
        # exhaust_event_loop() provides the possibility that write_file could
        # be called at this time, so write_file is designed to trigger read_file
        # itself if that path occurs.
        
        self.tubebox = groupthink.TubeBox()
        self.timer = groupthink.TimeHandler("main", self.tubebox)
        self.cloud = groupthink.Group(self.tubebox)
        # self.cloud is extremely important.  It is the unified reference point
        # that contains all state in the system.  Everything else is stateless.
        # self.cloud has to be defined before the call to self.set_canvas, because
        # set_canvas can trigger almost anything, including pending calls to read_file,
        # which relies on self.cloud.
        
        # get the Presence Service
        self.pservice = presenceservice.get_instance()
        # Buddy object for you
        owner = self.pservice.get_owner()
        self.owner = owner

        self.connect('shared', self._shared_cb)
        self.connect('joined', self._joined_cb)
        if self.get_shared():
            if self.initiating:
                self._shared_cb(self)
            else:
                self._joined_cb(self)
        
        self.add_events(Gdk.EventMask.VISIBILITY_NOTIFY_MASK)
        self.connect("visibility-notify-event", self._visible_cb)
        self.connect("notify::active", self._active_cb)
        
        if not self._readfile_completed:
            self.read_file(self._jobject.file_path)
        elif not self.shared_activity:
            GObject.idle_add(self._initialize_cleanstart)