nav menu walker class wordpress

<?php


// collection of walker classes

class Walker_Mobile_Menu extends Walker_Nav_Menu
{
    function start_lvl(&$output, $depth = 0, $args = null)
    {
        $output .= "\n<ul class=\"dropdown-menu\">\n";
    }

    function start_el(&$output, $item, $depth = 0, $args = null, $id = 0)
    {
        $classnames = '';

        $classes = empty($item->classes) ? '' : (array) $item->classes;
        $classes[] = ($args->walker->has_children) ? 'dropdown' : '';

        $classnames = join(' ', apply_filters('nav_menu_css_class', array_filter($classes), $item, $args));
        $classnames = ' class="' . esc_attr($classnames) . '"';
        $id = apply_filters('nav_menu_item_id', 'menu-item-' . $item->ID, $item, $args);
        $id = strlen($id) ? ' id="' . esc_attr($id) . '"' : '';

        $output .= '<li' . $id . $classnames . '>';

        $attributes .= !empty($item->url) ? ' href="' . esc_attr($item->url) . '"' : '';


        $item_output = $args->before;
        $item_output .= '<a' . $attributes . '>';
        $item_output .= $args->link_before . apply_filters('the_title', $item->title, $item->ID) . $args->link_after;
        $item_output .= '</a>';
        $item_output .= $args->after;

        $output .= apply_filters('walker_nav_menu_start_el', $item_output, $item, $depth, $args);
    }
}

class Walker_Desktop_Menu extends Walker_Nav_Menu
{
    function start_lvl(&$output, $depth = 0, $args = null)
    {
        if ($depth == 0) {
            $output .= "\n<ul class=\"dropdown\">\n";
        } else {
            $output .= "\n<ul class=\"dropdown2\">\n";
        }
    }

    function start_el(&$output, $item, $depth = 0, $args = null, $id = 0)
    {
        $classnames = '';

        $classes = empty($item->classes) ? '' : (array) $item->classes;

        $classnames = join(' ', apply_filters('nav_menu_css_class', array_filter($classes), $item, $args));
        $classnames = ' class="' . esc_attr($classnames) . '"';
        $id = apply_filters('nav_menu_item_id', 'menu-item-' . $item->ID, $item, $args);
        $id = strlen($id) ? ' id="' . esc_attr($id) . '"' : '';

        $output .= '<li' . $id . $classnames . '>';

        $attributes .= !empty($item->url) ? ' href="' . esc_attr($item->url) . '"' : '';

        $item_output = $args->before;
        $item_output .= '<a' . $attributes . '>';
        $item_output .= $args->link_before . apply_filters('the_title', $item->title, $item->ID) . $args->link_after;
        $item_output .= ($depth == 0 && $args->walker->has_children) ? '<span class="toggle"></span>' : '';
        $item_output .= ($depth > 0 && $args->walker->has_children) ? '<span class="toggle2"></span>' : '';
        $item_output .= '</a>';
        $item_output .= $args->after;

        $output .= apply_filters('walker_nav_menu_start_el', $item_output, $item, $depth, $args);
    }
}