activating in gtk3

Once again i'm stumped porting to GTK3.
I have no idea what to do when activating plugins using pygobject
while trying to port my other plugin over.

When i start rhythmbox the plugin fails to activate because there is
no song selected. That part makes sense but I don't really have any
understanding of how to fix it.

For some reason this worked in GTK2.

    def do_activate(self):
        shell = self.object
        self.shell = shell
        self.db = shell.props.db
****   self.music_view = shell.props.selected_page
        self.library_source = shell.props.library_source
        self.signal_id = self.music_view.connect('event',
self.event_handler, shell)

I use this plugin to check for click events in the event_handler
function but because when you start you haven't selected anything it
will fail to activate unless i click a song then reactivate in the
plugin menu. Then it all works.

I've looked into Gdk and Gtk from gi.repository but i haven't been
able to find an example to help.