HTML Examples/WP.iso/wordpress/wp-admin/includes/class-wp-screen.php

PHP Script | 2017-10-23 | 33.5 KB | 1,243 lines

<?php
/**
 * Screen API: WP_Screen class
 *
 * @package WordPress
 * @subpackage Administration
 * @since 4.4.0
 */

/**
 * Core class used to implement an admin screen API.
 *
 * @since 3.3.0
 */
final class WP_Screen {
    /**
     * Any action associated with the screen. 'add' for *-add.php and *-new.php screens. Empty otherwise.
     *
     * @since 3.3.0
     * @var string
     */
    public $action;

    /**
     * The base type of the screen. This is typically the same as $id but with any post types and taxonomies stripped.
     * For example, for an $id of 'edit-post' the base is 'edit'.
     *
     * @since 3.3.0
     * @var string
     */
    public $base;

    /**
     * The number of columns to display. Access with get_columns().
     *
     * @since 3.4.0
     * @var int
     */
    private $columns = 0;

    /**
     * The unique ID of the screen.
     *
     * @since 3.3.0
     * @var string
     */
    public $id;

    /**
     * Which admin the screen is in. network | user | site | false
     *
     * @since 3.5.0
     * @var string
     */
    protected $in_admin;

    /**
     * Whether the screen is in the network admin.
     *
     * Deprecated. Use in_admin() instead.
     *
     * @since 3.3.0
     * @deprecated 3.5.0
     * @var bool
     */
    public $is_network;

    /**
     * Whether the screen is in the user admin.
     *
     * Deprecated. Use in_admin() instead.
     *
     * @since 3.3.0
     * @deprecated 3.5.0
     * @var bool
     */
    public $is_user;

    /**
     * The base menu parent.
     * This is derived from $parent_file by removing the query string and any .php extension.
     * $parent_file values of 'edit.php?post_type=page' and 'edit.php?post_type=post' have a $parent_base of 'edit'.
     *
     * @since 3.3.0
     * @var string
     */
    public $parent_base;

    /**
     * The parent_file for the screen per the admin menu system.
     * Some $parent_file values are 'edit.php?post_type=page', 'edit.php', and 'options-general.php'.
     *
     * @since 3.3.0
     * @var string
     */
    public $parent_file;

    /**
     * The post type associated with the screen, if any.
     * The 'edit.php?post_type=page' screen has a post type of 'page'.
     * The 'edit-tags.php?taxonomy=$taxonomy&post_type=page' screen has a post type of 'page'.
     *
     * @since 3.3.0
     * @var string
     */
    public $post_type;

    /**
     * The taxonomy associated with the screen, if any.
     * The 'edit-tags.php?taxonomy=category' screen has a taxonomy of 'category'.
     * @since 3.3.0
     * @var string
     */
    public $taxonomy;

    /**
     * The help tab data associated with the screen, if any.
     *
     * @since 3.3.0
     * @var array
     */
    private $_help_tabs = array();

    /**
     * The help sidebar data associated with screen, if any.
     *
     * @since 3.3.0
     * @var string
     */
    private $_help_sidebar = '';

     /**
     * The accessible hidden headings and text associated with the screen, if any.
     *
     * @since 4.4.0
     * @var array
     */
    private $_screen_reader_content = array();

    /**
     * Stores old string-based help.
     *
     * @static
     *
     * @var array
     */
    private static $_old_compat_help = array();

    /**
     * The screen options associated with screen, if any.
     *
     * @since 3.3.0
     * @var array
     */
    private $_options = array();

    /**
     * The screen object registry.
     *
     * @since 3.3.0
     *
     * @static
     *
     * @var array
     */
    private static $_registry = array();

    /**
     * Stores the result of the public show_screen_options function.
     *
     * @since 3.3.0
     * @var bool
     */
    private $_show_screen_options;

    /**
     * Stores the 'screen_settings' section of screen options.
     *
     * @since 3.3.0
     * @var string
     */
    private $_screen_settings;

    /**
     * Fetches a screen object.
     *
     * @since 3.3.0
     *
     * @static
     *
     * @global string $hook_suffix
     *
     * @param string|WP_Screen $hook_name Optional. The hook name (also known as the hook suffix) used to determine the screen.
     *                                       Defaults to the current $hook_suffix global.
     * @return WP_Screen Screen object.
     */
    public static function get( $hook_name = '' ) {
        if ( $hook_name instanceof WP_Screen ) {
            return $hook_name;
        }

        $post_type = $taxonomy = null;
        $in_admin = false;
        $action = '';

        if ( $hook_name )
            $id = $hook_name;
        else
            $id = $GLOBALS['hook_suffix'];

        // For those pesky meta boxes.
        if ( $hook_name && post_type_exists( $hook_name ) ) {
            $post_type = $id;
            $id = 'post'; // changes later. ends up being $base.
        } else {
            if ( '.php' == substr( $id, -4 ) )
                $id = substr( $id, 0, -4 );

            if ( 'post-new' == $id || 'link-add' == $id || 'media-new' == $id || 'user-new' == $id ) {
                $id = substr( $id, 0, -4 );
                $action = 'add';
            }
        }

        if ( ! $post_type && $hook_name ) {
            if ( '-network' == substr( $id, -8 ) ) {
                $id = substr( $id, 0, -8 );
                $in_admin = 'network';
            } elseif ( '-user' == substr( $id, -5 ) ) {
                $id = substr( $id, 0, -5 );
                $in_admin = 'user';
            }

            $id = sanitize_key( $id );
            if ( 'edit-comments' != $id && 'edit-tags' != $id && 'edit-' == substr( $id, 0, 5 ) ) {
                $maybe = substr( $id, 5 );
                if ( taxonomy_exists( $maybe ) ) {
                    $id = 'edit-tags';
                    $taxonomy = $maybe;
                } elseif ( post_type_exists( $maybe ) ) {
                    $id = 'edit';
                    $post_type = $maybe;
                }
            }

            if ( ! $in_admin )
                $in_admin = 'site';
        } else {
            if ( defined( 'WP_NETWORK_ADMIN' ) && WP_NETWORK_ADMIN )
                $in_admin = 'network';
            elseif ( defined( 'WP_USER_ADMIN' ) && WP_USER_ADMIN )
                $in_admin = 'user';
            else
                $in_admin = 'site';
        }

        if ( 'index' == $id )
            $id = 'dashboard';
        elseif ( 'front' == $id )
            $in_admin = false;

        $base = $id;

        // If this is the current screen, see if we can be more accurate for post types and taxonomies.
        if ( ! $hook_name ) {
            if ( isset( $_REQUEST['post_type'] ) )
                $post_type = post_type_exists( $_REQUEST['post_type'] ) ? $_REQUEST['post_type'] : false;
            if ( isset( $_REQUEST['taxonomy'] ) )
                $taxonomy = taxonomy_exists( $_REQUEST['taxonomy'] ) ? $_REQUEST['taxonomy'] : false;

            switch ( $base ) {
                case 'post' :
                    if ( isset( $_GET['post'] ) )
                        $post_id = (int) $_GET['post'];
                    elseif ( isset( $_POST['post_ID'] ) )
                        $post_id = (int) $_POST['post_ID'];
                    else
                        $post_id = 0;

                    if ( $post_id ) {
                        $post = get_post( $post_id );
                        if ( $post )
                            $post_type = $post->post_type;
                    }
                    break;
                case 'edit-tags' :
                case 'term' :
                    if ( null === $post_type && is_object_in_taxonomy( 'post', $taxonomy ? $taxonomy : 'post_tag' ) )
                        $post_type = 'post';
                    break;
                case 'upload':
                    $post_type = 'attachment';
                    break;
            }
        }

        switch ( $base ) {
            case 'post' :
                if ( null === $post_type )
                    $post_type = 'post';
                $id = $post_type;
                break;
            case 'edit' :
                if ( null === $post_type )
                    $post_type = 'post';
                $id .= '-' . $post_type;
                break;
            case 'edit-tags' :
            case 'term' :
                if ( null === $taxonomy )
                    $taxonomy = 'post_tag';
                // The edit-tags ID does not contain the post type. Look for it in the request.
                if ( null === $post_type ) {
                    $post_type = 'post';
                    if ( isset( $_REQUEST['post_type'] ) && post_type_exists( $_REQUEST['post_type'] ) )
                        $post_type = $_REQUEST['post_type'];
                }

                $id = 'edit-' . $taxonomy;
                break;
        }

        if ( 'network' == $in_admin ) {
            $id   .= '-network';
            $base .= '-network';
        } elseif ( 'user' == $in_admin ) {
            $id   .= '-user';
            $base .= '-user';
        }

        if ( isset( self::$_registry[ $id ] ) ) {
            $screen = self::$_registry[ $id ];
            if ( $screen === get_current_screen() )
                return $screen;
        } else {
            $screen = new WP_Screen();
            $screen->id     = $id;
        }

        $screen->base       = $base;
        $screen->action     = $action;
        $screen->post_type  = (string) $post_type;
        $screen->taxonomy   = (string) $taxonomy;
        $screen->is_user    = ( 'user' == $in_admin );
        $screen->is_network = ( 'network' == $in_admin );
        $screen->in_admin   = $in_admin;

        self::$_registry[ $id ] = $screen;

        return $screen;
    }

    /**
     * Makes the screen object the current screen.
     *
     * @see set_current_screen()
     * @since 3.3.0
     *
     * @global WP_Screen $current_screen
     * @global string    $taxnow
     * @global string    $typenow
     */
    public function set_current_screen() {
        global $current_screen, $taxnow, $typenow;
        $current_screen = $this;
        $taxnow = $this->taxonomy;
        $typenow = $this->post_type;

        /**
         * Fires after the current screen has been set.
         *
         * @since 3.0.0
         *
         * @param WP_Screen $current_screen Current WP_Screen object.
         */
        do_action( 'current_screen', $current_screen );
    }

    /**
     * Constructor
     *
     * @since 3.3.0
     */
    private function __construct() {}

    /**
     * Indicates whether the screen is in a particular admin
     *
     * @since 3.5.0
     *
     * @param string $admin The admin to check against (network | user | site).
     *                      If empty any of the three admins will result in true.
     * @return bool True if the screen is in the indicated admin, false otherwise.
     */
    public function in_admin( $admin = null ) {
        if ( empty( $admin ) )
            return (bool) $this->in_admin;

        return ( $admin == $this->in_admin );
    }

    /**
     * Sets the old string-based contextual help for the screen for backward compatibility.
     *
     * @since 3.3.0
     *
     * @static
     *
     * @param WP_Screen $screen A screen object.
     * @param string $help Help text.
     */
    public static function add_old_compat_help( $screen, $help ) {
        self::$_old_compat_help[ $screen->id ] = $help;
    }

    /**
     * Set the parent information for the screen.
     * This is called in admin-header.php after the menu parent for the screen has been determined.
     *
     * @since 3.3.0
     *
     * @param string $parent_file The parent file of the screen. Typically the $parent_file global.
     */
    public function set_parentage( $parent_file ) {
        $this->parent_file = $parent_file;
        list( $this->parent_base ) = explode( '?', $parent_file );
        $this->parent_base = str_replace( '.php', '', $this->parent_base );
    }

    /**
     * Adds an option for the screen.
     * Call this in template files after admin.php is loaded and before admin-header.php is loaded to add screen options.
     *
     * @since 3.3.0
     *
     * @param string $option Option ID
     * @param mixed $args Option-dependent arguments.
     */
    public function add_option( $option, $args = array() ) {
        $this->_options[ $option ] = $args;
    }

    /**
     * Remove an option from the screen.
     *
     * @since 3.8.0
     *
     * @param string $option Option ID.
     */
    public function remove_option( $option ) {
        unset( $this->_options[ $option ] );
    }

    /**
     * Remove all options from the screen.
     *
     * @since 3.8.0
     */
    public function remove_options() {
        $this->_options = array();
    }

    /**
     * Get the options registered for the screen.
     *
     * @since 3.8.0
     *
     * @return array Options with arguments.
     */
    public function get_options() {
        return $this->_options;
    }

    /**
     * Gets the arguments for an option for the screen.
     *
     * @since 3.3.0
     *
     * @param string $option Option name.
     * @param string $key    Optional. Specific array key for when the option is an array.
     *                       Default false.
     * @return string The option value if set, null otherwise.
     */
    public function get_option( $option, $key = false ) {
        if ( ! isset( $this->_options[ $option ] ) )
            return null;
        if ( $key ) {
            if ( isset( $this->_options[ $option ][ $key ] ) )
                return $this->_options[ $option ][ $key ];
            return null;
        }
        return $this->_options[ $option ];
    }

    /**
     * Gets the help tabs registered for the screen.
     *
     * @since 3.4.0
     * @since 4.4.0 Help tabs are ordered by their priority.
     *
     * @return array Help tabs with arguments.
     */
    public function get_help_tabs() {
        $help_tabs = $this->_help_tabs;

        $priorities = array();
        foreach ( $help_tabs as $help_tab ) {
            if ( isset( $priorities[ $help_tab['priority'] ] ) ) {
                $priorities[ $help_tab['priority'] ][] = $help_tab;
            } else {
                $priorities[ $help_tab['priority'] ] = array( $help_tab );
            }
        }

        ksort( $priorities );

        $sorted = array();
        foreach ( $priorities as $list ) {
            foreach ( $list as $tab ) {
                $sorted[ $tab['id'] ] = $tab;
            }
        }

        return $sorted;
    }

    /**
     * Gets the arguments for a help tab.
     *
     * @since 3.4.0
     *
     * @param string $id Help Tab ID.
     * @return array Help tab arguments.
     */
    public function get_help_tab( $id ) {
        if ( ! isset( $this->_help_tabs[ $id ] ) )
            return null;
        return $this->_help_tabs[ $id ];
    }

    /**
     * Add a help tab to the contextual help for the screen.
     * Call this on the load-$pagenow hook for the relevant screen.
     *
     * @since 3.3.0
     * @since 4.4.0 The `$priority` argument was added.
     *
     * @param array $args {
     *     Array of arguments used to display the help tab.
     *
     *     @type string $title    Title for the tab. Default false.
     *     @type string $id       Tab ID. Must be HTML-safe. Default false.
     *     @type string $content  Optional. Help tab content in plain text or HTML. Default empty string.
     *     @type string $callback Optional. A callback to generate the tab content. Default false.
     *     @type int    $priority Optional. The priority of the tab, used for ordering. Default 10.
     * }
     */
    public function add_help_tab( $args ) {
        $defaults = array(
            'title'    => false,
            'id'       => false,
            'content'  => '',
            'callback' => false,
            'priority' => 10,
        );
        $args = wp_parse_args( $args, $defaults );

        $args['id'] = sanitize_html_class( $args['id'] );

        // Ensure we have an ID and title.
        if ( ! $args['id'] || ! $args['title'] )
            return;

        // Allows for overriding an existing tab with that ID.
        $this->_help_tabs[ $args['id'] ] = $args;
    }

    /**
     * Removes a help tab from the contextual help for the screen.
     *
     * @since 3.3.0
     *
     * @param string $id The help tab ID.
     */
    public function remove_help_tab( $id ) {
        unset( $this->_help_tabs[ $id ] );
    }

    /**
     * Removes all help tabs from the contextual help for the screen.
     *
     * @since 3.3.0
     */
    public function remove_help_tabs() {
        $this->_help_tabs = array();
    }

    /**
     * Gets the content from a contextual help sidebar.
     *
     * @since 3.4.0
     *
     * @return string Contents of the help sidebar.
     */
    public function get_help_sidebar() {
        return $this->_help_sidebar;
    }

    /**
     * Add a sidebar to the contextual help for the screen.
     * Call this in template files after admin.php is loaded and before admin-header.php is loaded to add a sidebar to the contextual help.
     *
     * @since 3.3.0
     *
     * @param string $content Sidebar content in plain text or HTML.
     */
    public function set_help_sidebar( $content ) {
        $this->_help_sidebar = $content;
    }

    /**
     * Gets the number of layout columns the user has selected.
     *
     * The layout_columns option controls the max number and default number of
     * columns. This method returns the number of columns within that range selected
     * by the user via Screen Options. If no selection has been made, the default
     * provisioned in layout_columns is returned. If the screen does not support
     * selecting the number of layout columns, 0 is returned.
     *
     * @since 3.4.0
     *
     * @return int Number of columns to display.
     */
    public function get_columns() {
        return $this->columns;
    }

     /**
     * Get the accessible hidden headings and text used in the screen.
     *
     * @since 4.4.0
     *
     * @see set_screen_reader_content() For more information on the array format.
     *
     * @return array An associative array of screen reader text strings.
     */
    public function get_screen_reader_content() {
        return $this->_screen_reader_content;
    }

    /**
     * Get a screen reader text string.
     *
     * @since 4.4.0
     *
     * @param string $key Screen reader text array named key.
     * @return string Screen reader text string.
     */
    public function get_screen_reader_text( $key ) {
        if ( ! isset( $this->_screen_reader_content[ $key ] ) ) {
            return null;
        }
        return $this->_screen_reader_content[ $key ];
    }

    /**
     * Add accessible hidden headings and text for the screen.
     *
     * @since 4.4.0
     *
     * @param array $content {
     *     An associative array of screen reader text strings.
     *
     *     @type string $heading_views      Screen reader text for the filter links heading.
     *                                      Default 'Filter items list'.
     *     @type string $heading_pagination Screen reader text for the pagination heading.
     *                                      Default 'Items list navigation'.
     *     @type string $heading_list       Screen reader text for the items list heading.
     *                                      Default 'Items list'.
     * }
     */
    public function set_screen_reader_content( $content = array() ) {
        $defaults = array(
            'heading_views'      => __( 'Filter items list' ),
            'heading_pagination' => __( 'Items list navigation' ),
            'heading_list'       => __( 'Items list' ),
        );
        $content = wp_parse_args( $content, $defaults );

        $this->_screen_reader_content = $content;
    }

    /**
     * Remove all the accessible hidden headings and text for the screen.
     *
     * @since 4.4.0
     */
    public function remove_screen_reader_content() {
        $this->_screen_reader_content = array();
    }

    /**
     * Render the screen's help section.
     *
     * This will trigger the deprecated filters for backward compatibility.
     *
     * @since 3.3.0
     *
     * @global string $screen_layout_columns
     */
    public function render_screen_meta() {

        /**
         * Filters the legacy contextual help list.
         *
         * @since 2.7.0
         * @deprecated 3.3.0 Use get_current_screen()->add_help_tab() or
         *                   get_current_screen()->remove_help_tab() instead.
         *
         * @param array     $old_compat_help Old contextual help.
         * @param WP_Screen $this            Current WP_Screen instance.
         */
        self::$_old_compat_help = apply_filters( 'contextual_help_list', self::$_old_compat_help, $this );

        $old_help = isset( self::$_old_compat_help[ $this->id ] ) ? self::$_old_compat_help[ $this->id ] : '';

        /**
         * Filters the legacy contextual help text.
         *
         * @since 2.7.0
         * @deprecated 3.3.0 Use get_current_screen()->add_help_tab() or
         *                   get_current_screen()->remove_help_tab() instead.
         *
         * @param string    $old_help  Help text that appears on the screen.
         * @param string    $screen_id Screen ID.
         * @param WP_Screen $this      Current WP_Screen instance.
         *
         */
        $old_help = apply_filters( 'contextual_help', $old_help, $this->id, $this );

        // Default help only if there is no old-style block of text and no new-style help tabs.
        if ( empty( $old_help ) && ! $this->get_help_tabs() ) {

            /**
             * Filters the default legacy contextual help text.
             *
             * @since 2.8.0
             * @deprecated 3.3.0 Use get_current_screen()->add_help_tab() or
             *                   get_current_screen()->remove_help_tab() instead.
             *
             * @param string $old_help_default Default contextual help text.
             */
            $default_help = apply_filters( 'default_contextual_help', '' );
            if ( $default_help )
                $old_help = '<p>' . $default_help . '</p>';
        }

        if ( $old_help ) {
            $this->add_help_tab( array(
                'id'      => 'old-contextual-help',
                'title'   => __('Overview'),
                'content' => $old_help,
            ) );
        }

        $help_sidebar = $this->get_help_sidebar();

        $help_class = 'hidden';
        if ( ! $help_sidebar )
            $help_class .= ' no-sidebar';

        // Time to render!
        ?>
        <div id="screen-meta" class="metabox-prefs">

            <div id="contextual-help-wrap" class="<?php echo esc_attr( $help_class ); ?>" tabindex="-1" aria-label="<?php esc_attr_e('Contextual Help Tab'); ?>">
                <div id="contextual-help-back"></div>
                <div id="contextual-help-columns">
                    <div class="contextual-help-tabs">
                        <ul>
                        <?php
                        $class = ' class="active"';
                        foreach ( $this->get_help_tabs() as $tab ) :
                            $link_id  = "tab-link-{$tab['id']}";
                            $panel_id = "tab-panel-{$tab['id']}";
                            ?>

                            <li id="<?php echo esc_attr( $link_id ); ?>"<?php echo $class; ?>>
                                <a href="<?php echo esc_url( "#$panel_id" ); ?>" aria-controls="<?php echo esc_attr( $panel_id ); ?>">
                                    <?php echo esc_html( $tab['title'] ); ?>
                                </a>
                            </li>
                        <?php
                            $class = '';
                        endforeach;
                        ?>
                        </ul>
                    </div>

                    <?php if ( $help_sidebar ) : ?>
                    <div class="contextual-help-sidebar">
                        <?php echo $help_sidebar; ?>
                    </div>
                    <?php endif; ?>

                    <div class="contextual-help-tabs-wrap">
                        <?php
                        $classes = 'help-tab-content active';
                        foreach ( $this->get_help_tabs() as $tab ):
                            $panel_id = "tab-panel-{$tab['id']}";
                            ?>

                            <div id="<?php echo esc_attr( $panel_id ); ?>" class="<?php echo $classes; ?>">
                                <?php
                                // Print tab content.
                                echo $tab['content'];

                                // If it exists, fire tab callback.
                                if ( ! empty( $tab['callback'] ) )
                                    call_user_func_array( $tab['callback'], array( $this, $tab ) );
                                ?>
                            </div>
                        <?php
                            $classes = 'help-tab-content';
                        endforeach;
                        ?>
                    </div>
                </div>
            </div>
        <?php
        // Setup layout columns

        /**
         * Filters the array of screen layout columns.
         *
         * This hook provides back-compat for plugins using the back-compat
         * Filters instead of add_screen_option().
         *
         * @since 2.8.0
         *
         * @param array     $empty_columns Empty array.
         * @param string    $screen_id     Screen ID.
         * @param WP_Screen $this          Current WP_Screen instance.
         */
        $columns = apply_filters( 'screen_layout_columns', array(), $this->id, $this );

        if ( ! empty( $columns ) && isset( $columns[ $this->id ] ) )
            $this->add_option( 'layout_columns', array('max' => $columns[ $this->id ] ) );

        if ( $this->get_option( 'layout_columns' ) ) {
            $this->columns = (int) get_user_option("screen_layout_$this->id");

            if ( ! $this->columns && $this->get_option( 'layout_columns', 'default' ) )
                $this->columns = $this->get_option( 'layout_columns', 'default' );
        }
        $GLOBALS[ 'screen_layout_columns' ] = $this->columns; // Set the global for back-compat.

        // Add screen options
        if ( $this->show_screen_options() )
            $this->render_screen_options();
        ?>
        </div>
        <?php
        if ( ! $this->get_help_tabs() && ! $this->show_screen_options() )
            return;
        ?>
        <div id="screen-meta-links">
        <?php if ( $this->get_help_tabs() ) : ?>
            <div id="contextual-help-link-wrap" class="hide-if-no-js screen-meta-toggle">
            <button type="button" id="contextual-help-link" class="button show-settings" aria-controls="contextual-help-wrap" aria-expanded="false"><?php _e( 'Help' ); ?></button>
            </div>
        <?php endif;
        if ( $this->show_screen_options() ) : ?>
            <div id="screen-options-link-wrap" class="hide-if-no-js screen-meta-toggle">
            <button type="button" id="show-settings-link" class="button show-settings" aria-controls="screen-options-wrap" aria-expanded="false"><?php _e( 'Screen Options' ); ?></button>
            </div>
        <?php endif; ?>
        </div>
        <?php
    }

    /**
     *
     * @global array $wp_meta_boxes
     *
     * @return bool
     */
    public function show_screen_options() {
        global $wp_meta_boxes;

        if ( is_bool( $this->_show_screen_options ) )
            return $this->_show_screen_options;

        $columns = get_column_headers( $this );

        $show_screen = ! empty( $wp_meta_boxes[ $this->id ] ) || $columns || $this->get_option( 'per_page' );

        switch ( $this->base ) {
            case 'widgets':
                $nonce = wp_create_nonce( 'widgets-access' );
                $this->_screen_settings = '<p><a id="access-on" href="widgets.php?widgets-access=on&_wpnonce=' . urlencode( $nonce ) . '">' . __('Enable accessibility mode') . '</a><a id="access-off" href="widgets.php?widgets-access=off&_wpnonce=' . urlencode( $nonce ) . '">' . __('Disable accessibility mode') . "</a></p>\n";
                break;
            case 'post' :
                $expand = '<fieldset class="editor-expand hidden"><legend>' . __( 'Additional settings' ) . '</legend><label for="editor-expand-toggle">';
                $expand .= '<input type="checkbox" id="editor-expand-toggle"' . checked( get_user_setting( 'editor_expand', 'on' ), 'on', false ) . ' />';
                $expand .= __( 'Enable full-height editor and distraction-free functionality.' ) . '</label></fieldset>';
                $this->_screen_settings = $expand;
                break;
            default:
                $this->_screen_settings = '';
                break;
        }

        /**
         * Filters the screen settings text displayed in the Screen Options tab.
         *
         * This filter is currently only used on the Widgets screen to enable
         * accessibility mode.
         *
         * @since 3.0.0
         *
         * @param string    $screen_settings Screen settings.
         * @param WP_Screen $this            WP_Screen object.
         */
        $this->_screen_settings = apply_filters( 'screen_settings', $this->_screen_settings, $this );

        if ( $this->_screen_settings || $this->_options )
            $show_screen = true;

        /**
         * Filters whether to show the Screen Options tab.
         *
         * @since 3.2.0
         *
         * @param bool      $show_screen Whether to show Screen Options tab.
         *                               Default true.
         * @param WP_Screen $this        Current WP_Screen instance.
         */
        $this->_show_screen_options = apply_filters( 'screen_options_show_screen', $show_screen, $this );
        return $this->_show_screen_options;
    }

    /**
     * Render the screen options tab.
     *
     * @since 3.3.0
     *
     * @param array $options {
     *     @type bool $wrap  Whether the screen-options-wrap div will be included. Defaults to true.
     * }
     */
    public function render_screen_options( $options = array() ) {
        $options = wp_parse_args( $options, array(
            'wrap' => true,
        ) );

        $wrapper_start = $wrapper_end = $form_start = $form_end = '';

        // Output optional wrapper.
        if ( $options['wrap'] ) {
            $wrapper_start = '<div id="screen-options-wrap" class="hidden" tabindex="-1" aria-label="' . esc_attr__( 'Screen Options Tab' ) . '">';
            $wrapper_end = '</div>';
        }

        // Don't output the form and nonce for the widgets accessibility mode links.
        if ( 'widgets' !== $this->base ) {
            $form_start = "\n<form id='adv-settings' method='post'>\n";
            $form_end = "\n" . wp_nonce_field( 'screen-options-nonce', 'screenoptionnonce', false, false ) . "\n</form>\n";
        }

        echo $wrapper_start . $form_start;

        $this->render_meta_boxes_preferences();
        $this->render_list_table_columns_preferences();
        $this->render_screen_layout();
        $this->render_per_page_options();
        $this->render_view_mode();
        echo $this->_screen_settings;

        /**
         * Filters whether to show the Screen Options submit button.
         *
         * @since 4.4.0
         *
         * @param bool      $show_button Whether to show Screen Options submit button.
         *                               Default false.
         * @param WP_Screen $this        Current WP_Screen instance.
         */
        $show_button = apply_filters( 'screen_options_show_submit', false, $this );

        if ( $show_button ) {
            submit_button( __( 'Apply' ), 'primary', 'screen-options-apply', true );
        }

        echo $form_end . $wrapper_end;
    }

    /**
     * Render the meta boxes preferences.
     *
     * @since 4.4.0
     *
     * @global array $wp_meta_boxes
     */
    public function render_meta_boxes_preferences() {
        global $wp_meta_boxes;

        if ( ! isset( $wp_meta_boxes[ $this->id ] ) ) {
            return;
        }
        ?>
        <fieldset class="metabox-prefs">
        <legend><?php _e( 'Boxes' ); ?></legend>
        <?php
            meta_box_prefs( $this );

            if ( 'dashboard' === $this->id && has_action( 'welcome_panel' ) && current_user_can( 'edit_theme_options' ) ) {
                if ( isset( $_GET['welcome'] ) ) {
                    $welcome_checked = empty( $_GET['welcome'] ) ? 0 : 1;
                    update_user_meta( get_current_user_id(), 'show_welcome_panel', $welcome_checked );
                } else {
                    $welcome_checked = get_user_meta( get_current_user_id(), 'show_welcome_panel', true );
                    if ( 2 == $welcome_checked && wp_get_current_user()->user_email != get_option( 'admin_email' ) ) {
                        $welcome_checked = false;
                    }
                }
                echo '<label for="wp_welcome_panel-hide">';
                echo '<input type="checkbox" id="wp_welcome_panel-hide"' . checked( (bool) $welcome_checked, true, false ) . ' />';
                echo _x( 'Welcome', 'Welcome panel' ) . "</label>\n";
            }
        ?>
        </fieldset>
        <?php
    }

    /**
     * Render the list table columns preferences.
     *
     * @since 4.4.0
     */
    public function render_list_table_columns_preferences() {

        $columns = get_column_headers( $this );
        $hidden  = get_hidden_columns( $this );

        if ( ! $columns ) {
            return;
        }

        $legend = ! empty( $columns['_title'] ) ? $columns['_title'] : __( 'Columns' );
        ?>
        <fieldset class="metabox-prefs">
        <legend><?php echo $legend; ?></legend>
        <?php
        $special = array( '_title', 'cb', 'comment', 'media', 'name', 'title', 'username', 'blogname' );

        foreach ( $columns as $column => $title ) {
            // Can't hide these for they are special
            if ( in_array( $column, $special ) ) {
                continue;
            }

            if ( empty( $title ) ) {
                continue;
            }

            /*
             * The Comments column uses HTML in the display name with some screen
             * reader text. Make sure to strip tags from the Comments column
             * title and any other custom column title plugins might add.
             */
            $title = wp_strip_all_tags( $title );

            $id = "$column-hide";
            echo '<label>';
            echo '<input class="hide-column-tog" name="' . $id . '" type="checkbox" id="' . $id . '" value="' . $column . '"' . checked( ! in_array( $column, $hidden ), true, false ) . ' />';
            echo "$title</label>\n";
        }
        ?>
        </fieldset>
        <?php
    }

    /**
     * Render the option for number of columns on the page
     *
     * @since 3.3.0
     */
    public function render_screen_layout() {
        if ( ! $this->get_option( 'layout_columns' ) ) {
            return;
        }

        $screen_layout_columns = $this->get_columns();
        $num = $this->get_option( 'layout_columns', 'max' );

        ?>
        <fieldset class='columns-prefs'>
        <legend class="screen-layout"><?php _e( 'Layout' ); ?></legend><?php
            for ( $i = 1; $i <= $num; ++$i ):
                ?>
                <label class="columns-prefs-<?php echo $i; ?>">
                    <input type='radio' name='screen_columns' value='<?php echo esc_attr( $i ); ?>'
                        <?php checked( $screen_layout_columns, $i ); ?> />
                    <?php printf( _n( '%s column', '%s columns', $i ), number_format_i18n( $i ) ); ?>
                </label>
                <?php
            endfor; ?>
        </fieldset>
        <?php
    }

    /**
     * Render the items per page option
     *
     * @since 3.3.0
     */
    public function render_per_page_options() {
        if ( null === $this->get_option( 'per_page' ) ) {
            return;
        }

        $per_page_label = $this->get_option( 'per_page', 'label' );
        if ( null === $per_page_label ) {
            $per_page_label = __( 'Number of items per page:' );
        }

        $option = $this->get_option( 'per_page', 'option' );
        if ( ! $option ) {
            $option = str_replace( '-', '_', "{$this->id}_per_page" );
        }

        $per_page = (int) get_user_option( $option );
        if ( empty( $per_page ) || $per_page < 1 ) {
            $per_page = $this->get_option( 'per_page', 'default' );
            if ( ! $per_page ) {
                $per_page = 20;
            }
        }

        if ( 'edit_comments_per_page' == $option ) {
            $comment_status = isset( $_REQUEST['comment_status'] ) ? $_REQUEST['comment_status'] : 'all';

            /** This filter is documented in wp-admin/includes/class-wp-comments-list-table.php */
            $per_page = apply_filters( 'comments_per_page', $per_page, $comment_status );
        } elseif ( 'categories_per_page' == $option ) {
            /** This filter is documented in wp-admin/includes/class-wp-terms-list-table.php */
            $per_page = apply_filters( 'edit_categories_per_page', $per_page );
        } else {
            /** This filter is documented in wp-admin/includes/class-wp-list-table.php */
            $per_page = apply_filters( "{$option}", $per_page );
        }

        // Back compat
        if ( isset( $this->post_type ) ) {
            /** This filter is documented in wp-admin/includes/post.php */
            $per_page = apply_filters( 'edit_posts_per_page', $per_page, $this->post_type );
        }

        // This needs a submit button
        add_filter( 'screen_options_show_submit', '__return_true' );

        ?>
        <fieldset class="screen-options">
        <legend><?php _e( 'Pagination' ); ?></legend>
            <?php if ( $per_page_label ) : ?>
                <label for="<?php echo esc_attr( $option ); ?>"><?php echo $per_page_label; ?></label>
                <input type="number" step="1" min="1" max="999" class="screen-per-page" name="wp_screen_options[value]"
                    id="<?php echo esc_attr( $option ); ?>" maxlength="3"
                    value="<?php echo esc_attr( $per_page ); ?>" />
            <?php endif; ?>
                <input type="hidden" name="wp_screen_options[option]" value="<?php echo esc_attr( $option ); ?>" />
        </fieldset>
        <?php
    }

    /**
     * Render the list table view mode preferences.
     *
     * @since 4.4.0
     *
     * @global string $mode List table view mode.
     */
    public function render_view_mode() {
        $screen = get_current_screen();

        // Currently only enabled for posts lists
        if ( 'edit' !== $screen->base ) {
            return;
        }

        $view_mode_post_types = get_post_types( array( 'hierarchical' => false, 'show_ui' => true ) );

        /**
         * Filters the post types that have different view mode options.
         *
         * @since 4.4.0
         *
         * @param array $view_mode_post_types Array of post types that can change view modes.
         *                                    Default non-hierarchical post types with show_ui on.
         */
        $view_mode_post_types = apply_filters( 'view_mode_post_types', $view_mode_post_types );

        if ( ! in_array( $this->post_type, $view_mode_post_types ) ) {
            return;
        }

        global $mode;

        // This needs a submit button
        add_filter( 'screen_options_show_submit', '__return_true' );
?>
        <fieldset class="metabox-prefs view-mode">
        <legend><?php _e( 'View Mode' ); ?></legend>
                <label for="list-view-mode">
                    <input id="list-view-mode" type="radio" name="mode" value="list" <?php checked( 'list', $mode ); ?> />
                    <?php _e( 'List View' ); ?>
                </label>
                <label for="excerpt-view-mode">
                    <input id="excerpt-view-mode" type="radio" name="mode" value="excerpt" <?php checked( 'excerpt', $mode ); ?> />
                    <?php _e( 'Excerpt View' ); ?>
                </label>
        </fieldset>
<?php
    }

    /**
     * Render screen reader text.
     *
     * @since 4.4.0
     *
     * @param string $key The screen reader text array named key.
     * @param string $tag Optional. The HTML tag to wrap the screen reader text. Default h2.
     */
    public function render_screen_reader_content( $key = '', $tag = 'h2' ) {

        if ( ! isset( $this->_screen_reader_content[ $key ] ) ) {
            return;
        }
        echo "<$tag class='screen-reader-text'>" . $this->_screen_reader_content[ $key ] . "</$tag>";
    }
}