Wordpress - A textual language chooser widget compatible with qTranslate and qTranslate-slug

WP-Widget_Language_Chooser

/**
 * A textual language chooser widget compatible with qTranslate and qTranslate-slug
 * Author: Mauro Mascia
 * License: WTFPL (www.wtfpl.net)
 */
class Widget_Language_Chooser extends WP_Widget {

	function __construct() {
		parent::__construct(
			'widget_language_chooser',
			__('Language Chooser'),
			array( 'description' => __('Language Chooser'), )
		);
	}

	// Create front-end widget: this is where the action happens
	public function widget( $args, $instance ) {
		global $q_config;
		$languages = qtrans_getSortedLanguages();
		$num_langs = count( $languages );
		$url = is_404() ? get_option( 'home' ) : '';
		$sep = " ";

		$qtrans_list = '';

		foreach ( $languages as $language ) {
			$classes = array( 'lang-' . $language );
			if ( $language == $q_config['language'] ) {
				$classes[] = 'active';
				$classes[] = 'current-menu-item';
			}

			if ( !empty( $element ) )
				$qtrans_list.= '<span class="' . implode( ' ', $classes ) . '">';

			$qtrans_list.= '<a href="' . $this->convert_url( $url, $language ) . '"';
			$qtrans_list.= ' hreflang="' . $language . '" title="' . $q_config['language_name'][$language] . '"';
			$qtrans_list.= '>' . $language . '</a>';

			if ( !empty( $element ) )
				$qtrans_list.= '</span>';

			if ( --$num_langs > 0 ) {
				$qtrans_list.= '<span class="qtrans_separator">' . $sep . '</span>';
			}
		}

		echo '<div class="widget widget-element widget-language-chooser" id="' . $args['widget_id'] . '">' . $qtrans_list. '</div>';
	}

	public function convert_url( $url, $lang ) {
		if ( class_exists( 'QtranslateSlug' ) && is_plugin_active( 'qtranslate-slug/qtranslate-slug.php' ) ) {
			global $qtranslate_slug;
			$url = $qtranslate_slug->get_current_url( $lang );
			return remove_query_arg( 'lang', $url );
		}
		else {
			// Use the qTranslate function.
			return qtrans_convertURL( $url, $lang );
		}
	}
}