When the search control is toggled, set visibility and hand down cats

def on_click_search_widget(self, event):
        """ When the search control is toggled, set visibility and hand down cats"""
        self.search.cats = self.cats
        self.search.visible = event.new
        if self.search.visible:
            self.search.watchers.append(
                self.select.widget.link(self.search, value='cats'))