Themes

The relatively new logo serving code uses the method 'setting_file_url' in '/lib/outputlib.php' and that has some https code that could be adapted:

    public function setting_file_url($setting, $filearea) {
        global $CFG;

        if (empty($this->settings->$setting)) {
            return null;
        }

        $component = 'theme_'.$this->name;
        $itemid = theme_get_revision();
        $filepath = $this->settings->$setting;
        $syscontext = context_system::instance();

        $url = moodle_url::make_file_url("$CFG->wwwroot/pluginfile.php", "/$syscontext->id/$component/$filearea/$itemid".$filepath);

        // Now this is tricky because the we can not hardcode http or https here, lets use the relative link.
        // Note: unfortunately moodle_url does not support //urls yet.

        $url = preg_replace('|^https?://|i', '//', $url->out(false));

        return $url;
    } 

 as I do in the Shoelace theme:

function theme_shoelace_set_fontwww($css) {
    global $CFG;
    $tag = 'setting:fontwww';

    $syscontext = context_system::instance();
    $itemid = theme_get_revision();
    $url = moodle_url::make_file_url("$CFG->wwwroot/pluginfile.php", "/$syscontext->id/theme_shoelace/font/$itemid/");
    // Now this is tricky because the we can not hard code http or https here, lets use the relative link.
    // Note: unfortunately moodle_url does not support //urls yet.
    $url = preg_replace('|^https?://|i', '//', $url->out(false));

    $css = str_replace($tag, $url, $css);
    return $css;
}

 and then serve:

function theme_shoelace_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options = array()) {
    if ($context->contextlevel == CONTEXT_SYSTEM) {
        if ($filearea === 'logo') {
           $theme = theme_config::load('shoelace');
           return $theme->setting_file_serve('logo', $args, $forcedownload, $options);
        } else if ($filearea === 'font') {
            global $CFG;
            if (!empty($CFG->themedir)) {
                $thefontpath = $CFG->themedir . '/shoelace/style/font/';
            } else {
                $thefontpath = $CFG->dirroot . '/theme/shoelace/style/font/';
            }

            // Use log as a way of seeing what is going on.
            //add_to_log(24, 'theme_shoelace', '$thefontpath', $thefontpath);
            //add_to_log(24, 'theme_shoelace', 'args[1]', $args[1]);

            //send_file($thefontpath.$args[1], $args[1]);  // Mime type detection not working?
            // Note: Third parameter is normally 'default' which is the 'lifetime' of the file.  Here set lower for development purposes.
            send_file($thefontpath.$args[1], $args[1], 20 , 0, false, false, 'font/opentype');
        } else {
            send_file_not_found();
        }
    } else {
        send_file_not_found();
    }
}