/lib/outputlib.php

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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Functions for generating the HTML that Moodle should output.
 *
 * Please see http://docs.moodle.org/en/Developement:How_Moodle_outputs_HTML
 * for an overview.
 *
 * @copyright 2009 Tim Hunt
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @package core
 * @category output
 */

defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir.'/outputcomponents.php');
require_once($CFG->libdir.'/outputactions.php');
require_once($CFG->libdir.'/outputfactories.php');
require_once($CFG->libdir.'/outputrenderers.php');
require_once($CFG->libdir.'/outputrequirementslib.php');

/**
 * Returns current theme revision number.
 *
 * @return int
 */
function theme_get_revision() {
    global $CFG;

    if (empty($CFG->themedesignermode)) {
        if (empty($CFG->themerev)) {
            // This only happens during install. It doesn't matter what themerev we use as long as it's positive.
            return 1;
        } else {
            return $CFG->themerev;
        }

    } else {
        return -1;
    }
}

/**
 * Returns current theme sub revision number. This is the revision for
 * this theme exclusively, not the global theme revision.
 *
 * @param string $themename The non-frankenstyle name of the theme
 * @return int
 */
function theme_get_sub_revision_for_theme($themename) {
    global $CFG;

    if (empty($CFG->themedesignermode)) {
        $pluginname = "theme_{$themename}";
        $revision = during_initial_install() ? null : get_config($pluginname, 'themerev');

        if (empty($revision)) {
            // This only happens during install. It doesn't matter what themerev we use as long as it's positive.
            return 1;
        } else {
            return $revision;
        }
    } else {
        return -1;
    }
}

/**
 * Calculates and returns the next theme revision number.
 *
 * @return int
 */
function theme_get_next_revision() {
    global $CFG;

    $next = time();
    if (isset($CFG->themerev) and $next <= $CFG->themerev and $CFG->themerev - $next < 60*60) {
        // This resolves problems when reset is requested repeatedly within 1s,
        // the < 1h condition prevents accidental switching to future dates
        // because we might not recover from it.
        $next = $CFG->themerev+1;
    }

    return $next;
}

/**
 * Calculates and returns the next theme revision number.
 *
 * @param string $themename The non-frankenstyle name of the theme
 * @return int
 */
function theme_get_next_sub_revision_for_theme($themename) {
    global $CFG;

    $next = time();
    $current = theme_get_sub_revision_for_theme($themename);
    if ($next <= $current and $current - $next < 60 * 60) {
        // This resolves problems when reset is requested repeatedly within 1s,
        // the < 1h condition prevents accidental switching to future dates
        // because we might not recover from it.
        $next = $current + 1;
    }

    return $next;
}

/**
 * Sets the current theme revision number.
 *
 * @param int $revision The new theme revision number
 */
function theme_set_revision($revision) {
    set_config('themerev', $revision);
}

/**
 * Sets the current theme revision number for a specific theme.
 * This does not affect the global themerev value.
 *
 * @param string $themename The non-frankenstyle name of the theme
 * @param int    $revision  The new theme revision number
 */
function theme_set_sub_revision_for_theme($themename, $revision) {
    set_config('themerev', $revision, "theme_{$themename}");
}

/**
 * Get the path to a theme config.php file.
 *
 * @param string $themename The non-frankenstyle name of the theme to check
 */
function theme_get_config_file_path($themename) {
    global $CFG;

    if (file_exists("{$CFG->dirroot}/theme/{$themename}/config.php")) {
        return "{$CFG->dirroot}/theme/{$themename}/config.php";
    } else if (!empty($CFG->themedir) and file_exists("{$CFG->themedir}/{$themename}/config.php")) {
        return "{$CFG->themedir}/{$themename}/config.php";
    } else {
        return null;
    }
}

/**
 * Get the path to the local cached CSS file.
 *
 * @param string $themename      The non-frankenstyle theme name.
 * @param int    $globalrevision The global theme revision.
 * @param int    $themerevision  The theme specific revision.
 * @param string $direction      Either 'ltr' or 'rtl' (case sensitive).
 */
function theme_get_css_filename($themename, $globalrevision, $themerevision, $direction) {
    global $CFG;

    $path = "{$CFG->localcachedir}/theme/{$globalrevision}/{$themename}/css";
    $filename = $direction == 'rtl' ? "all-rtl_{$themerevision}" : "all_{$themerevision}";
    return "{$path}/{$filename}.css";
}

/**
 * Generates and saves the CSS files for the given theme configs.
 *
 * @param theme_config[] $themeconfigs An array of theme_config instances.
 * @param array          $directions   Must be a subset of ['rtl', 'ltr'].
 * @param bool           $cache        Should the generated files be stored in local cache.
 * @return array         The built theme content in a multi-dimensional array of name => direction => content
 */
function theme_build_css_for_themes($themeconfigs = [], $directions = ['rtl', 'ltr'],
        $cache = true, $mtraceprogress = false): array {
    global $CFG;

    if (empty($themeconfigs)) {
        return [];
    }

    require_once("{$CFG->libdir}/csslib.php");

    $themescss = [];
    $themerev = theme_get_revision();
    // Make sure the local cache directory exists.
    make_localcache_directory('theme');

    foreach ($themeconfigs as $themeconfig) {
        $themecss = [];
        $oldrevision = theme_get_sub_revision_for_theme($themeconfig->name);
        $newrevision = theme_get_next_sub_revision_for_theme($themeconfig->name);

        // First generate all the new css.
        foreach ($directions as $direction) {
            if ($mtraceprogress) {
                $timestart = microtime(true);
                mtrace('Building theme CSS for ' . $themeconfig->name . ' [' .
                        $direction . '] ...', '');
            }
            // Lock it on. Technically we should build all themes for SVG and no SVG - but ie9 is out of support.
            $themeconfig->force_svg_use(true);
            $themeconfig->set_rtl_mode(($direction === 'rtl'));

            $themecss[$direction] = $themeconfig->get_css_content();
            if ($cache) {
                $themeconfig->set_css_content_cache($themecss[$direction]);
                $filename = theme_get_css_filename($themeconfig->name, $themerev, $newrevision, $direction);
                css_store_css($themeconfig, $filename, $themecss[$direction]);
            }
            if ($mtraceprogress) {
                mtrace(' done in ' . round(microtime(true) - $timestart, 2) . ' seconds.');
            }
        }
        $themescss[$themeconfig->name] = $themecss;

        if ($cache) {
            // Only update the theme revision after we've successfully created the
            // new CSS cache.
            theme_set_sub_revision_for_theme($themeconfig->name, $newrevision);

            // Now purge old files. We must purge all old files in the local cache
            // because we've incremented the theme sub revision. This will leave any
            // files with the old revision inaccessbile so we might as well removed
            // them from disk.
            foreach (['ltr', 'rtl'] as $direction) {
                $oldcss = theme_get_css_filename($themeconfig->name, $themerev, $oldrevision, $direction);
                if (file_exists($oldcss)) {
                    unlink($oldcss);
                }
            }
        }
    }

    return $themescss;
}

/**
 * Invalidate all server and client side caches.
 *
 * This method deletes the physical directory that is used to cache the theme
 * files used for serving.
 * Because it deletes the main theme cache directory all themes are reset by
 * this function.
 */
function theme_reset_all_caches() {
    global $CFG, $PAGE;
    require_once("{$CFG->libdir}/filelib.php");

    $next = theme_get_next_revision();
    theme_set_revision($next);

    if (!empty($CFG->themedesignermode)) {
        $cache = cache::make_from_params(cache_store::MODE_APPLICATION, 'core', 'themedesigner');
        $cache->purge();
    }

    // Purge compiled post processed css.
    cache::make('core', 'postprocessedcss')->purge();

    // Delete all old theme localcaches.
    $themecachedirs = glob("{$CFG->localcachedir}/theme/*", GLOB_ONLYDIR);
    foreach ($themecachedirs as $localcachedir) {
        fulldelete($localcachedir);
    }

    if ($PAGE) {
        $PAGE->reload_theme();
    }
}

/**
 * Reset static caches.
 *
 * This method indicates that all running cron processes should exit at the
 * next opportunity.
 */
function theme_reset_static_caches() {
    \core\task\manager::clear_static_caches();
}

/**
 * Enable or disable theme designer mode.
 *
 * @param bool $state
 */
function theme_set_designer_mod($state) {
    set_config('themedesignermode', (int)!empty($state));
    // Reset caches after switching mode so that any designer mode caches get purged too.
    theme_reset_all_caches();
}

/**
 * Checks if the given device has a theme defined in config.php.
 *
 * @return bool
 */
function theme_is_device_locked($device) {
    global $CFG;
    $themeconfigname = core_useragent::get_device_type_cfg_var_name($device);
    return isset($CFG->config_php_settings[$themeconfigname]);
}

/**
 * Returns the theme named defined in config.php for the given device.
 *
 * @return string or null
 */
function theme_get_locked_theme_for_device($device) {
    global $CFG;

    if (!theme_is_device_locked($device)) {
        return null;
    }

    $themeconfigname = core_useragent::get_device_type_cfg_var_name($device);
    return $CFG->config_php_settings[$themeconfigname];
}

/**
 * This class represents the configuration variables of a Moodle theme.
 *
 * All the variables with access: public below (with a few exceptions that are marked)
 * are the properties you can set in your themes config.php file.
 *
 * There are also some methods and protected variables that are part of the inner
 * workings of Moodle's themes system. If you are just editing a themes config.php
 * file, you can just ignore those, and the following information for developers.
 *
 * Normally, to create an instance of this class, you should use the
 * {@link theme_config::load()} factory method to load a themes config.php file.
 * However, normally you don't need to bother, because moodle_page (that is, $PAGE)
 * will create one for you, accessible as $PAGE->theme.
 *
 * @copyright 2009 Tim Hunt
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @since Moodle 2.0
 * @package core
 * @category output
 */
class theme_config {

    /**
     * @var string Default theme, used when requested theme not found.
     */
    const DEFAULT_THEME = 'boost';

    /** The key under which the SCSS file is stored amongst the CSS files. */
    const SCSS_KEY = '__SCSS__';

    /**
     * @var array You can base your theme on other themes by linking to the other theme as
     * parents. This lets you use the CSS and layouts from the other themes
     * (see {@link theme_config::$layouts}).
     * That makes it easy to create a new theme that is similar to another one
     * but with a few changes. In this themes CSS you only need to override
     * those rules you want to change.
     */
    public $parents;

    /**
     * @var array The names of all the stylesheets from this theme that you would
     * like included, in order. Give the names of the files without .css.
     */
    public $sheets = array();

    /**
     * @var array The names of all the stylesheets from parents that should be excluded.
     * true value may be used to specify all parents or all themes from one parent.
     * If no value specified value from parent theme used.
     */
    public $parents_exclude_sheets = null;

    /**
     * @var array List of plugin sheets to be excluded.
     * If no value specified value from parent theme used.
     */
    public $plugins_exclude_sheets = null;

    /**
     * @var array List of style sheets that are included in the text editor bodies.
     * Sheets from parent themes are used automatically and can not be excluded.
     */
    public $editor_sheets = array();

    /**
     * @var bool Whether a fallback version of the stylesheet will be used
     * whilst the final version is generated.
     */
    public $usefallback = false;

    /**
     * @var array The names of all the javascript files this theme that you would
     * like included from head, in order. Give the names of the files without .js.
     */
    public $javascripts = array();

    /**
     * @var array The names of all the javascript files this theme that you would
     * like included from footer, in order. Give the names of the files without .js.
     */
    public $javascripts_footer = array();

    /**
     * @var array The names of all the javascript files from parents that should
     * be excluded. true value may be used to specify all parents or all themes
     * from one parent.
     * If no value specified value from parent theme used.
     */
    public $parents_exclude_javascripts = null;

    /**
     * @var array Which file to use for each page layout.
     *
     * This is an array of arrays. The keys of the outer array are the different layouts.
     * Pages in Moodle are using several different layouts like 'normal', 'course', 'home',
     * 'popup', 'form', .... The most reliable way to get a complete list is to look at
     * {@link http://cvs.moodle.org/moodle/theme/base/config.php?view=markup the base theme config.php file}.
     * That file also has a good example of how to set this setting.
     *
     * For each layout, the value in the outer array is an array that describes
     * how you want that type of page to look. For example
     * <pre>
     *   $THEME->layouts = array(
     *       // Most pages - if we encounter an unknown or a missing page type, this one is used.
     *       'standard' => array(
     *           'theme' = 'mytheme',
     *           'file' => 'normal.php',
     *           'regions' => array('side-pre', 'side-post'),
     *           'defaultregion' => 'side-post'
     *       ),
     *       // The site home page.
     *       'home' => array(
     *           'theme' = 'mytheme',
     *           'file' => 'home.php',
     *           'regions' => array('side-pre', 'side-post'),
     *           'defaultregion' => 'side-post'
     *       ),
     *       // ...
     *   );
     * </pre>
     *
     * 'theme' name of the theme where is the layout located
     * 'file' is the layout file to use for this type of page.
     * layout files are stored in layout subfolder
     * 'regions' This lists the regions on the page where blocks may appear. For
     * each region you list here, your layout file must include a call to
     * <pre>
     *   echo $OUTPUT->blocks_for_region($regionname);
     * </pre>
     * or equivalent so that the blocks are actually visible.
     *
     * 'defaultregion' If the list of regions is non-empty, then you must pick
     * one of the one of them as 'default'. This has two meanings. First, this is
     * where new blocks are added. Second, if there are any blocks associated with
     * the page, but in non-existent regions, they appear here. (Imaging, for example,
     * that someone added blocks using a different theme that used different region
     * names, and then switched to this theme.)
     */
    public $layouts = array();

    /**
     * @var string Name of the renderer factory class to use. Must implement the
     * {@link renderer_factory} interface.
     *
     * This is an advanced feature. Moodle output is generated by 'renderers',
     * you can customise the HTML that is output by writing custom renderers,
     * and then you need to specify 'renderer factory' so that Moodle can find
     * your renderers.
     *
     * There are some renderer factories supplied with Moodle. Please follow these
     * links to see what they do.
     * <ul>
     * <li>{@link standard_renderer_factory} - the default.</li>
     * <li>{@link theme_overridden_renderer_factory} - use this if you want to write
     *      your own custom renderers in a lib.php file in this theme (or the parent theme).</li>
     * </ul>
     */
    public $rendererfactory = 'standard_renderer_factory';

    /**
     * @var string Function to do custom CSS post-processing.
     *
     * This is an advanced feature. If you want to do custom post-processing on the
     * CSS before it is output (for example, to replace certain variable names
     * with particular values) you can give the name of a function here.
     */
    public $csspostprocess = null;

    /**
     * @var string Function to do custom CSS post-processing on a parsed CSS tree.
     *
     * This is an advanced feature. If you want to do custom post-processing on the
     * CSS before it is output, you can provide the name of the function here. The
     * function will receive a CSS tree document as first parameter, and the theme_config
     * object as second parameter. A return value is not required, the tree can
     * be edited in place.
     */
    public $csstreepostprocessor = null;

    /**
     * @var string Accessibility: Right arrow-like character is
     * used in the breadcrumb trail, course navigation menu
     * (previous/next activity), calendar, and search forum block.
     * If the theme does not set characters, appropriate defaults
     * are set automatically. Please DO NOT
     * use &lt; &gt; &raquo; - these are confusing for blind users.
     */
    public $rarrow = null;

    /**
     * @var string Accessibility: Left arrow-like character is
     * used in the breadcrumb trail, course navigation menu
     * (previous/next activity), calendar, and search forum block.
     * If the theme does not set characters, appropriate defaults
     * are set automatically. Please DO NOT
     * use &lt; &gt; &raquo; - these are confusing for blind users.
     */
    public $larrow = null;

    /**
     * @var string Accessibility: Up arrow-like character is used in
     * the book heirarchical navigation.
     * If the theme does not set characters, appropriate defaults
     * are set automatically. Please DO NOT
     * use ^ - this is confusing for blind users.
     */
    public $uarrow = null;

    /**
     * @var string Accessibility: Down arrow-like character.
     * If the theme does not set characters, appropriate defaults
     * are set automatically.
     */
    public $darrow = null;

    /**
     * @var bool Some themes may want to disable ajax course editing.
     */
    public $enablecourseajax = true;

    /**
     * @var string Determines served document types
     *  - 'html5' the only officially supported doctype in Moodle
     *  - 'xhtml5' may be used in development for validation (not intended for production servers!)
     *  - 'xhtml' XHTML 1.0 Strict for legacy themes only
     */
    public $doctype = 'html5';

    /**
     * @var string requiredblocks If set to a string, will list the block types that cannot be deleted. Defaults to
     *                                   navigation and settings.
     */
    public $requiredblocks = false;

    //==Following properties are not configurable from theme config.php==

    /**
     * @var string The name of this theme. Set automatically when this theme is
     * loaded. This can not be set in theme config.php
     */
    public $name;

    /**
     * @var string The folder where this themes files are stored. This is set
     * automatically. This can not be set in theme config.php
     */
    public $dir;

    /**
     * @var stdClass Theme settings stored in config_plugins table.
     * This can not be set in theme config.php
     */
    public $settings = null;

    /**
     * @var bool If set to true and the theme enables the dock then  blocks will be able
     * to be moved to the special dock
     */
    public $enable_dock = false;

    /**
     * @var bool If set to true then this theme will not be shown in the theme selector unless
     * theme designer mode is turned on.
     */
    public $hidefromselector = false;

    /**
     * @var array list of YUI CSS modules to be included on each page. This may be used
     * to remove cssreset and use cssnormalise module instead.
     */
    public $yuicssmodules = array('cssreset', 'cssfonts', 'cssgrids', 'cssbase');

    /**
     * An associative array of block manipulations that should be made if the user is using an rtl language.
     * The key is the original block region, and the value is the block region to change to.
     * This is used when displaying blocks for regions only.
     * @var array
     */
    public $blockrtlmanipulations = array();

    /**
     * @var renderer_factory Instance of the renderer_factory implementation
     * we are using. Implementation detail.
     */
    protected $rf = null;

    /**
     * @var array List of parent config objects.
     **/
    protected $parent_configs = array();

    /**
     * Used to determine whether we can serve SVG images or not.
     * @var bool
     */
    private $usesvg = null;

    /**
     * Whether in RTL mode or not.
     * @var bool
     */
    protected $rtlmode = false;

    /**
     * The SCSS file to compile (without .scss), located in the scss/ folder of the theme.
     * Or a Closure, which receives the theme_config as argument and must
     * return the SCSS content.
     * @var string|Closure
     */
    public $scss = false;

    /**
     * Local cache of the SCSS property.
     * @var false|array
     */
    protected $scsscache = null;

    /**
     * The name of the function to call to get the SCSS code to inject.
     * @var string
     */
    public $extrascsscallback = null;

    /**
     * The name of the function to call to get SCSS to prepend.
     * @var string
     */
    public $prescsscallback = null;

    /**
     * Sets the render method that should be used for rendering custom block regions by scripts such as my/index.php
     * Defaults to {@link core_renderer::blocks_for_region()}
     * @var string
     */
    public $blockrendermethod = null;

    /**
     * Remember the results of icon remapping for the current page.
     * @var array
     */
    public $remapiconcache = [];

    /**
     * The name of the function to call to get precompiled CSS.
     * @var string
     */
    public $precompiledcsscallback = null;

    /**
     * Whether the theme uses course index.
     * @var bool
     */
    public $usescourseindex = false;

    /**
     * Load the config.php file for a particular theme, and return an instance
     * of this class. (That is, this is a factory method.)
     *
     * @param string $themename the name of the theme.
     * @return theme_config an instance of this class.
     */
    public static function load($themename) {
        global $CFG;

        // load theme settings from db
        try {
            $settings = get_config('theme_'.$themename);
        } catch (dml_exception $e) {
            // most probably moodle tables not created yet
            $settings = new stdClass();
        }

        if ($config = theme_config::find_theme_config($themename, $settings)) {
            return new theme_config($config);

        } else if ($themename == theme_config::DEFAULT_THEME) {
            throw new coding_exception('Default theme '.theme_config::DEFAULT_THEME.' not available or broken!');

        } else if ($config = theme_config::find_theme_config($CFG->theme, $settings)) {
            debugging('This page should be using theme ' . $themename .
                    ' which cannot be initialised. Falling back to the site theme ' . $CFG->theme, DEBUG_NORMAL);
            return new theme_config($config);

        } else {
            // bad luck, the requested theme has some problems - admin see details in theme config
            debugging('This page should be using theme ' . $themename .
                    ' which cannot be initialised. Nor can the site theme ' . $CFG->theme .
                    '. Falling back to ' . theme_config::DEFAULT_THEME, DEBUG_NORMAL);
            return new theme_config(theme_config::find_theme_config(theme_config::DEFAULT_THEME, $settings));
        }
    }

    /**
     * Theme diagnostic code. It is very problematic to send debug output
     * to the actual CSS file, instead this functions is supposed to
     * diagnose given theme and highlights all potential problems.
     * This information should be available from the theme selection page
     * or some other debug page for theme designers.
     *
     * @param string $themename
     * @return array description of problems
     */
    public static function diagnose($themename) {
        //TODO: MDL-21108
        return array();
    }

    /**
     * Private constructor, can be called only from the factory method.
     * @param stdClass $config
     */
    private function __construct($config) {
        global $CFG; //needed for included lib.php files

        $this->settings = $config->settings;
        $this->name     = $config->name;
        $this->dir      = $config->dir;

        if ($this->name != self::DEFAULT_THEME) {
            $baseconfig = self::find_theme_config(self::DEFAULT_THEME, $this->settings);
        } else {
            $baseconfig = $config;
        }

        $configurable = array(
            'parents', 'sheets', 'parents_exclude_sheets', 'plugins_exclude_sheets', 'usefallback',
            'javascripts', 'javascripts_footer', 'parents_exclude_javascripts',
            'layouts', 'enablecourseajax', 'requiredblocks',
            'rendererfactory', 'csspostprocess', 'editor_sheets', 'editor_scss', 'rarrow', 'larrow', 'uarrow', 'darrow',
            'hidefromselector', 'doctype', 'yuicssmodules', 'blockrtlmanipulations', 'blockrendermethod',
            'scss', 'extrascsscallback', 'prescsscallback', 'csstreepostprocessor', 'addblockposition',
            'iconsystem', 'precompiledcsscallback', 'haseditswitch', 'usescourseindex');

        foreach ($config as $key=>$value) {
            if (in_array($key, $configurable)) {
                $this->$key = $value;
            }
        }

        // verify all parents and load configs and renderers
        foreach ($this->parents as $parent) {
            if (!$parent_config = theme_config::find_theme_config($parent, $this->settings)) {
                // this is not good - better exclude faulty parents
                continue;
            }
            $libfile = $parent_config->dir.'/lib.php';
            if (is_readable($libfile)) {
                // theme may store various function here
                include_once($libfile);
            }
            $renderersfile = $parent_config->dir.'/renderers.php';
            if (is_readable($renderersfile)) {
                // may contain core and plugin renderers and renderer factory
                include_once($renderersfile);
            }
            $this->parent_configs[$parent] = $parent_config;
        }
        $libfile = $this->dir.'/lib.php';
        if (is_readable($libfile)) {
            // theme may store various function here
            include_once($libfile);
        }
        $rendererfile = $this->dir.'/renderers.php';
        if (is_readable($rendererfile)) {
            // may contain core and plugin renderers and renderer factory
            include_once($rendererfile);
        } else {
            // check if renderers.php file is missnamed renderer.php
            if (is_readable($this->dir.'/renderer.php')) {
                debugging('Developer hint: '.$this->dir.'/renderer.php should be renamed to ' . $this->dir."/renderers.php.
                    See: http://docs.moodle.org/dev/Output_renderers#Theme_renderers.", DEBUG_DEVELOPER);
            }
        }

        // cascade all layouts properly
        foreach ($baseconfig->layouts as $layout=>$value) {
            if (!isset($this->layouts[$layout])) {
                foreach ($this->parent_configs as $parent_config) {
                    if (isset($parent_config->layouts[$layout])) {
                        $this->layouts[$layout] = $parent_config->layouts[$layout];
                        continue 2;
                    }
                }
                $this->layouts[$layout] = $value;
            }
        }

        //fix arrows if needed
        $this->check_theme_arrows();
    }

    /**
     * Let the theme initialise the page object (usually $PAGE).
     *
     * This may be used for example to request jQuery in add-ons.
     *
     * @param moodle_page $page
     */
    public function init_page(moodle_page $page) {
        $themeinitfunction = 'theme_'.$this->name.'_page_init';
        if (function_exists($themeinitfunction)) {
            $themeinitfunction($page);
        }
    }

    /**
     * Checks if arrows $THEME->rarrow, $THEME->larrow, $THEME->uarrow, $THEME->darrow have been set (theme/-/config.php).
     * If not it applies sensible defaults.
     *
     * Accessibility: right and left arrow Unicode characters for breadcrumb, calendar,
     * search forum block, etc. Important: these are 'silent' in a screen-reader
     * (unlike &gt; &raquo;), and must be accompanied by text.
     */
    private function check_theme_arrows() {
        if (!isset($this->rarrow) and !isset($this->larrow)) {
            // Default, looks good in Win XP/IE 6, Win/Firefox 1.5, Win/Netscape 8...
            // Also OK in Win 9x/2K/IE 5.x
            $this->rarrow = '&#x25BA;';
            $this->larrow = '&#x25C4;';
            $this->uarrow = '&#x25B2;';
            $this->darrow = '&#x25BC;';
            if (empty($_SERVER['HTTP_USER_AGENT'])) {
                $uagent = '';
            } else {
                $uagent = $_SERVER['HTTP_USER_AGENT'];
            }
            if (false !== strpos($uagent, 'Opera')
                || false !== strpos($uagent, 'Mac')) {
                // Looks good in Win XP/Mac/Opera 8/9, Mac/Firefox 2, Camino, Safari.
                // Not broken in Mac/IE 5, Mac/Netscape 7 (?).
                $this->rarrow = '&#x25B6;&#xFE0E;';
                $this->larrow = '&#x25C0;&#xFE0E;';
            }
            elseif ((false !== strpos($uagent, 'Konqueror'))
                || (false !== strpos($uagent, 'Android')))  {
                // The fonts on Android don't include the characters required for this to work as expected.
                // So we use the same ones Konqueror uses.
                $this->rarrow = '&rarr;';
                $this->larrow = '&larr;';
                $this->uarrow = '&uarr;';
                $this->darrow = '&darr;';
            }
            elseif (isset($_SERVER['HTTP_ACCEPT_CHARSET'])
                && false === stripos($_SERVER['HTTP_ACCEPT_CHARSET'], 'utf-8')) {
                // (Win/IE 5 doesn't set ACCEPT_CHARSET, but handles Unicode.)
                // To be safe, non-Unicode browsers!
                $this->rarrow = '&gt;';
                $this->larrow = '&lt;';
                $this->uarrow = '^';
                $this->darrow = 'v';
            }

            // RTL support - in RTL languages, swap r and l arrows
            if (right_to_left()) {
                $t = $this->rarrow;
                $this->rarrow = $this->larrow;
                $this->larrow = $t;
            }
        }
    }

    /**
     * Returns output renderer prefixes, these are used when looking
     * for the overridden renderers in themes.
     *
     * @return array
     */
    public function renderer_prefixes() {
        global $CFG; // just in case the included files need it

        $prefixes = array('theme_'.$this->name);

        foreach ($this->parent_configs as $parent) {
            $prefixes[] = 'theme_'.$parent->name;
        }

        return $prefixes;
    }

    /**
     * Returns the stylesheet URL of this editor content
     *
     * @param bool $encoded false means use & and true use &amp; in URLs
     * @return moodle_url
     */
    public function editor_css_url($encoded=true) {
        global $CFG;
        $rev = theme_get_revision();
        if ($rev > -1) {
            $themesubrevision = theme_get_sub_revision_for_theme($this->name);

            // Provide the sub revision to allow us to invalidate cached theme CSS
            // on a per theme basis, rather than globally.
            if ($themesubrevision && $themesubrevision > 0) {
                $rev .= "_{$themesubrevision}";
            }

            $url = new moodle_url("/theme/styles.php");
            if (!empty($CFG->slasharguments)) {
                $url->set_slashargument('/'.$this->name.'/'.$rev.'/editor', 'noparam', true);
            } else {
                $url->params(array('theme'=>$this->name,'rev'=>$rev, 'type'=>'editor'));
            }
        } else {
            $params = array('theme'=>$this->name, 'type'=>'editor');
            $url = new moodle_url('/theme/styles_debug.php', $params);
        }
        return $url;
    }

    /**
     * Returns the content of the CSS to be used in editor content
     *
     * @return array
     */
    public function editor_css_files() {
        $files = array();

        // First editor plugins.
        $plugins = core_component::get_plugin_list('editor');
        foreach ($plugins as $plugin=>$fulldir) {
            $sheetfile = "$fulldir/editor_styles.css";
            if (is_readable($sheetfile)) {
                $files['plugin_'.$plugin] = $sheetfile;
            }
        }
        // Then parent themes - base first, the immediate parent last.
        foreach (array_reverse($this->parent_configs) as $parent_config) {
            if (empty($parent_config->editor_sheets)) {
                continue;
            }
            foreach ($parent_config->editor_sheets as $sheet) {
                $sheetfile = "$parent_config->dir/style/$sheet.css";
                if (is_readable($sheetfile)) {
                    $files['parent_'.$parent_config->name.'_'.$sheet] = $sheetfile;
                }
            }
        }
        // Finally this theme.
        if (!empty($this->editor_sheets)) {
            foreach ($this->editor_sheets as $sheet) {
                $sheetfile = "$this->dir/style/$sheet.css";
                if (is_readable($sheetfile)) {
                    $files['theme_'.$sheet] = $sheetfile;
                }
            }
        }

        return $files;
    }

    /**
     * Compiles and returns the content of the SCSS to be used in editor content
     *
     * @return string Compiled CSS from the editor SCSS
     */
    public function editor_scss_to_css() {
        $css = '';
        $dir = $this->dir;
        $filenames = [];

        // Use editor_scss file(s) provided by this theme if set.
        if (!empty($this->editor_scss)) {
            $filenames = $this->editor_scss;
        } else {
            // If no editor_scss set, move up theme hierarchy until one is found (if at all).
            // This is so child themes only need to set editor_scss if an override is required.
            foreach (array_reverse($this->parent_configs) as $parentconfig) {
                if (!empty($parentconfig->editor_scss)) {
                    $dir = $parentconfig->dir;
                    $filenames = $parentconfig->editor_scss;

                    // Config found, stop looking.
                    break;
                }
            }
        }

        if (!empty($filenames)) {
            $compiler = new core_scss();

            foreach ($filenames as $filename) {
                $compiler->set_file("{$dir}/scss/{$filename}.scss");

                try {
                    $css .= $compiler->to_css();
                } catch (\Exception $e) {
                    debugging('Error while compiling editor SCSS: ' . $e->getMessage(), DEBUG_DEVELOPER);
                }
            }
        }

        return $css;
    }

    /**
     * Get the stylesheet URL of this theme.
     *
     * @param moodle_page $page Not used... deprecated?
     * @return moodle_url[]
     */
    public function css_urls(moodle_page $page) {
        global $CFG;

        $rev = theme_get_revision();

        $urls = array();

        $svg = $this->use_svg_icons();
        $separate = (core_useragent::is_ie() && !core_useragent::check_ie_version('10'));

        if ($rev > -1) {
            $filename = right_to_left() ? 'all-rtl' : 'all';
            $url = new moodle_url("/theme/styles.php");
            $themesubrevision = theme_get_sub_revision_for_theme($this->name);

            // Provide the sub revision to allow us to invalidate cached theme CSS
            // on a per theme basis, rather than globally.
            if ($themesubrevision && $themesubrevision > 0) {
                $rev .= "_{$themesubrevision}";
            }

            if (!empty($CFG->slasharguments)) {
                $slashargs = '';
                if (!$svg) {
                    // We add a simple /_s to the start of the path.
                    // The underscore is used to ensure that it isn't a valid theme name.
                    $slashargs .= '/_s'.$slashargs;
                }
                $slashargs .= '/'.$this->name.'/'.$rev.'/'.$filename;
                if ($separate) {
                    $slashargs .= '/chunk0';
                }
                $url->set_slashargument($slashargs, 'noparam', true);
            } else {
                $params = array('theme' => $this->name, 'rev' => $rev, 'type' => $filename);
                if (!$svg) {
                    // We add an SVG param so that we know not to serve SVG images.
                    // We do this because all modern browsers support SVG and this param will one day be removed.
                    $params['svg'] = '0';
                }
                if ($separate) {
                    $params['chunk'] = '0';
                }
                $url->params($params);
            }
            $urls[] = $url;

        } else {
            $baseurl = new moodle_url('/theme/styles_debug.php');

            $css = $this->get_css_files(true);
            if (!$svg) {
                // We add an SVG param so that we know not to serve SVG images.
                // We do this because all modern browsers support SVG and this param will one day be removed.
                $baseurl->param('svg', '0');
            }
            if (right_to_left()) {
                $baseurl->param('rtl', 1);
            }
            if ($separate) {
                // We might need to chunk long files.
                $baseurl->param('chunk', '0');
            }
            if (core_useragent::is_ie()) {
                // Lalala, IE does not allow more than 31 linked CSS files from main document.
                $urls[] = new moodle_url($baseurl, array('theme'=>$this->name, 'type'=>'ie', 'subtype'=>'plugins'));
                foreach ($css['parents'] as $parent=>$sheets) {
                    // We need to serve parents individually otherwise we may easily exceed the style limit IE imposes (4096).
                    $urls[] = new moodle_url($baseurl, array('theme'=>$this->name,'type'=>'ie', 'subtype'=>'parents', 'sheet'=>$parent));
                }
                if ($this->get_scss_property()) {
                    // No need to define the type as IE here.
                    $urls[] = new moodle_url($baseurl, array('theme' => $this->name, 'type' => 'scss'));
                }
                $urls[] = new moodle_url($baseurl, array('theme'=>$this->name, 'type'=>'ie', 'subtype'=>'theme'));

            } else {
                foreach ($css['plugins'] as $plugin=>$unused) {
                    $urls[] = new moodle_url($baseurl, array('theme'=>$this->name,'type'=>'plugin', 'subtype'=>$plugin));
                }
                foreach ($css['parents'] as $parent=>$sheets) {
                    foreach ($sheets as $sheet=>$unused2) {
                        $urls[] = new moodle_url($baseurl, array('theme'=>$this->name,'type'=>'parent', 'subtype'=>$parent, 'sheet'=>$sheet));
                    }
                }
                foreach ($css['theme'] as $sheet => $filename) {
                    if ($sheet === self::SCSS_KEY) {
                        // This is the theme SCSS file.
                        $urls[] = new moodle_url($baseurl, array('theme' => $this->name, 'type' => 'scss'));
                    } else {
                        // Sheet first in order to make long urls easier to read.
                        $urls[] = new moodle_url($baseurl, array('sheet'=>$sheet, 'theme'=>$this->name, 'type'=>'theme'));
                    }
                }
            }
        }

        // Allow themes to change the css url to something like theme/mytheme/mycss.php.
        component_callback('theme_' . $this->name, 'alter_css_urls', [&$urls]);
        return $urls;
    }

    /**
     * Get the whole css stylesheet for production mode.
     *
     * NOTE: this method is not expected to be used from any addons.
     *
     * @return string CSS markup compressed
     */
    public function get_css_content() {

        $csscontent = '';
        foreach ($this->get_css_files(false) as $type => $value) {
            foreach ($value as $identifier => $val) {
                if (is_array($val)) {
                    foreach ($val as $v) {
                        $csscontent .= file_get_contents($v) . "\n";
                    }
                } else {
                    if ($type === 'theme' && $identifier === self::SCSS_KEY) {
                        // We need the content from SCSS because this is the SCSS file from the theme.
                        if ($compiled = $this->get_css_content_from_scss(false)) {
                            $csscontent .= $compiled;
                        } else {
                            // The compiler failed so default back to any precompiled css that might
                            // exist.
                            $csscontent .= $this->get_precompiled_css_content();
                        }
                    } else {
                        $csscontent .= file_get_contents($val) . "\n";
                    }
                }
            }
        }
        $csscontent = $this->post_process($csscontent);
        $csscontent = core_minify::css($csscontent);

        return $csscontent;
    }
    /**
     * Set post processed CSS content cache.
     *
     * @param string $csscontent The post processed CSS content.
     * @return bool True if the content was successfully cached.
     */
    public function set_css_content_cache($csscontent) {

        $cache = cache::make('core', 'postprocessedcss');
        $key = $this->get_css_cache_key();

        return $cache->set($key, $csscontent);
    }

    /**
     * Return whether the post processed CSS content has been cached.
     *
     * @return bool Whether the post-processed CSS is available in the cache.
     */
    public function has_css_cached_content() {

        $key = $this->get_css_cache_key();
        $cache = cache::make('core', 'postprocessedcss');

        return $cache->has($key);
    }

    /**
     * Return cached post processed CSS content.
     *
     * @return bool|string The cached css content or false if not found.
     */
    public function get_css_cached_content() {

        $key = $this->get_css_cache_key();
        $cache = cache::make('core', 'postprocessedcss');

        return $cache->get($key);
    }

    /**
     * Generate the css content cache key.
     *
     * @return string The post processed css cache key.
     */
    public function get_css_cache_key() {
        $nosvg = (!$this->use_svg_icons()) ? 'nosvg_' : '';
        $rtlmode = ($this->rtlmode == true) ? 'rtl' : 'ltr';

        return $nosvg . $this->name . '_' . $rtlmode;
    }

    /**
     * Get the theme designer css markup,
     * the parameters are coming from css_urls().
     *
     * NOTE: this method is not expected to be used from any addons.
     *
     * @param string $type
     * @param string $subtype
     * @param string $sheet
     * @return string CSS markup
     */
    public function get_css_content_debug($type, $subtype, $sheet) {
        if ($type === 'scss') {
            // The SCSS file of the theme is requested.
            $csscontent = $this->get_css_content_from_scss(true);
            if ($csscontent !== false) {
                return $this->post_process($csscontent);
            }
            return '';
        }

        $cssfiles = array();
        $css = $this->get_css_files(true);

        if ($type === 'ie') {
            // IE is a sloppy browser with weird limits, sorry.
            if ($subtype === 'plugins') {
                $cssfiles = $css['plugins'];

            } else if ($subtype === 'parents') {
                if (empty($sheet)) {
                    // Do not bother with the empty parent here.
                } else {
                    // Build up the CSS for that parent so we can serve it as one file.
                    foreach ($css[$subtype][$sheet] as $parent => $css) {
                        $cssfiles[] = $css;
                    }
                }
            } else if ($subtype === 'theme') {
                $cssfiles = $css['theme'];
                foreach ($cssfiles as $key => $value) {
                    if (in_array($key, [self::SCSS_KEY])) {
                        // Remove the SCSS file from the theme CSS files.
                        // The SCSS files use the type 'scss', not 'ie'.
                        unset($cssfiles[$key]);
                    }
                }
            }

        } else if ($type === 'plugin') {
            if (isset($css['plugins'][$subtype])) {
                $cssfiles[] = $css['plugins'][$subtype];
            }

        } else if ($type === 'parent') {
            if (isset($css['parents'][$subtype][$sheet])) {
                $cssfiles[] = $css['parents'][$subtype][$sheet];
            }

        } else if ($type === 'theme') {
            if (isset($css['theme'][$sheet])) {
                $cssfiles[] = $css['theme'][$sheet];
            }
        }

        $csscontent = '';
        foreach ($cssfiles as $file) {
            $contents = file_get_contents($file);
            $contents = $this->post_process($contents);
            $comment = "/** Path: $type $subtype $sheet.' **/\n";
            $stats = '';
            $csscontent .= $comment.$stats.$contents."\n\n";
        }

        return $csscontent;
    }

    /**
     * Get the whole css stylesheet for editor iframe.
     *
     * NOTE: this method is not expected to be used from any addons.
     *
     * @return string CSS markup
     */
    public function get_css_content_editor() {
        $css = '';
        $cssfiles = $this->editor_css_files();

        // If editor has static CSS, include it.
        foreach ($cssfiles as $file) {
            $css .= file_get_contents($file)."\n";
        }

        // If editor has SCSS, compile and include it.
        if (($convertedscss = $this->editor_scss_to_css())) {
            $css .= $convertedscss;
        }

        $output = $this->post_process($css);

        return $output;
    }

    /**
     * Returns an array of organised CSS files required for this output.
     *
     * @param bool $themedesigner
     * @return array nested array of file paths
     */
    protected function get_css_files($themedesigner) {
        global $CFG;

        $cache = null;
        $cachekey = 'cssfiles';
        if ($themedesigner) {
            require_once($CFG->dirroot.'/lib/csslib.php');
            // We need some kind of caching here because otherwise the page navigation becomes
            // way too slow in theme designer mode. Feel free to create full cache definition later...
            $cache = cache::make_from_params(cache_store::MODE_APPLICATION, 'core', 'themedesigner', array('theme' => $this->name));
            if ($files = $cache->get($cachekey)) {
                if ($files['created'] > time() - THEME_DESIGNER_CACHE_LIFETIME) {
                    unset($files['created']);
                    return $files;
                }
            }
        }

        $cssfiles = array('plugins'=>array(), 'parents'=>array(), 'theme'=>array());

        // Get all plugin sheets.
        $excludes = $this->resolve_excludes('plugins_exclude_sheets');
        if ($excludes !== true) {
            foreach (core_component::get_plugin_types() as $type=>$unused) {
                if ($type === 'theme' || (!empty($excludes[$type]) and $excludes[$type] === true)) {
                    continue;
                }
                $plugins = core_component::get_plugin_list($type);
                foreach ($plugins as $plugin=>$fulldir) {
                    if (!empty($excludes[$type]) and is_array($excludes[$type])
                            and in_array($plugin, $excludes[$type])) {
                        continue;
                    }

                    // Get the CSS from the plugin.
                   …

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