public function init()
    {
        parent::init();

        // add selectors of this view but not selectors of sub-views
        $selectors = $this->getDescendants('SwatViewSelector');
        foreach ($selectors as $selector) {
            if ($selector->getFirstAncestor('SwatView') === $this) {
                $this->addSelector($selector);
            }
        }
    }