public function form( $instance ) {
    global $wp_customize;
    $title    = isset( $instance['title'] ) ? $instance['title'] : '';
    $nav_menu = isset( $instance['nav_menu'] ) ? $instance['nav_menu'] : '';

    // Get menus.
    $menus = wp_get_nav_menus();

    $empty_menus_style     = '';
    $not_empty_menus_style = '';
    if ( empty( $menus ) ) {
      $empty_menus_style = ' style="display:none" ';
    } else {
      $not_empty_menus_style = ' style="display:none" ';
    }

    $nav_menu_style = '';
    if ( ! $nav_menu ) {
      $nav_menu_style = 'display: none;';
    }

    // If no menus exists, direct the user to go and create some.
    ?>
		<p class="nav-menu-widget-no-menus-message" <?php echo $not_empty_menus_style; ?>>
			<?php
      if ( $wp_customize instanceof WP_Customize_Manager ) {
        $url = 'javascript: wp.customize.panel( "nav_menus" ).focus();';
      } else {
        $url = admin_url( 'nav-menus.php' );
      }

      printf(
        /* translators: %s: URL to create a new menu. */
        __( 'No menus have been created yet. <a href="%s">Create some</a>.' ),
        // The URL can be a `javascript:` link, so esc_attr() is used here instead of esc_url().
        esc_attr( $url )
      );
      ?>
		</p>
		<div class="nav-menu-widget-form-controls" <?php echo $empty_menus_style; ?>>
			<p>
				<label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
				<input type="text" class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" value="<?php echo esc_attr( $title ); ?>" />
			</p>
			<p>
				<label for="<?php echo $this->get_field_id( 'nav_menu' ); ?>"><?php _e( 'Select Menu:' ); ?></label>
				<select id="<?php echo $this->get_field_id( 'nav_menu' ); ?>" name="<?php echo $this->get_field_name( 'nav_menu' ); ?>">
					<option value="0"><?php _e( '&mdash; Select &mdash;' ); ?></option>
					<?php foreach ( $menus as $menu ) : ?>
						<option value="<?php echo esc_attr( $menu->term_id ); ?>" <?php selected( $nav_menu, $menu->term_id ); ?>>
							<?php echo esc_html( $menu->name ); ?>
						</option>
					<?php endforeach; ?>
				</select>
			</p>
			<?php if ( $wp_customize instanceof WP_Customize_Manager ) : ?>
				<p class="edit-selected-nav-menu" style="<?php echo $nav_menu_style; ?>">
					<button type="button" class="button"><?php _e( 'Edit Menu' ); ?></button>
				</p>
			<?php endif; ?>
		</div>
		<?php
  }