_custom_header_background_just_in_time

WordPress Version: 4.3

/**
 * Registers the internal custom header and background routines.
 *
 * @since 3.4.0
 * @access private
 *
 * @global Custom_Image_Header $custom_image_header
 * @global Custom_Background   $custom_background
 */
function _custom_header_background_just_in_time()
{
    global $custom_image_header, $custom_background;
    if (current_theme_supports('custom-header')) {
        // In case any constants were defined after an add_custom_image_header() call, re-run.
        add_theme_support('custom-header', array('__jit' => true));
        $args = get_theme_support('custom-header');
        if ($args[0]['wp-head-callback']) {
            add_action('wp_head', $args[0]['wp-head-callback']);
        }
        if (is_admin()) {
            require_once ABSPATH . 'wp-admin/custom-header.php';
            $custom_image_header = new Custom_Image_Header($args[0]['admin-head-callback'], $args[0]['admin-preview-callback']);
        }
    }
    if (current_theme_supports('custom-background')) {
        // In case any constants were defined after an add_custom_background() call, re-run.
        add_theme_support('custom-background', array('__jit' => true));
        $args = get_theme_support('custom-background');
        add_action('wp_head', $args[0]['wp-head-callback']);
        if (is_admin()) {
            require_once ABSPATH . 'wp-admin/custom-background.php';
            $custom_background = new Custom_Background($args[0]['admin-head-callback'], $args[0]['admin-preview-callback']);
        }
    }
}