Allow to choose a theme via preferences when there are themes

refs #10705

application/forms/PreferenceForm.php

@@ -6,12 +6,14 @@ namespace Icinga\Forms;
 use Exception;
 use DateTimeZone;
 use Icinga\Application\Config;
+use Icinga\Application\Icinga;
 use Icinga\Application\Logger;
 use Icinga\Authentication\Auth;
 use Icinga\User\Preferences;
 use Icinga\User\Preferences\PreferencesStore;
 use Icinga\Util\TimezoneDetect;
 use Icinga\Util\Translator;
+use Icinga\Web\Cookie;
 use Icinga\Web\Form;
 use Icinga\Web\Notification;
 use Icinga\Web\Session;
@@ -103,6 +105,14 @@ class PreferenceForm extends Form
 
         Session::getSession()->user->setPreferences($this->preferences);
 
+        if (($theme = $this->getElement('theme')) !== null
+            && ($theme = $theme->getValue()) !== $this->getRequest()->getCookie('theme')
+        ) {
+            $this->getResponse()
+                ->setCookie(new Cookie('theme', $theme))
+                ->setReloadCss(true);
+        }
+
         try {
             if ($this->store && $this->getElement('btn_submit_preferences')->isChecked()) {
                 $this->save();
@@ -142,6 +152,20 @@ class PreferenceForm extends Form
      */
     public function createElements(array $formData)
     {
+        if (! (bool) Config::app()->get('themes', 'disabled', false)) {
+            $themes = Icinga::app()->getThemes();
+            if (count($themes) > 1) {
+                $this->addElement(
+                    'select',
+                    'theme',
+                    array(
+                        'label'         => $this->translate('Theme', 'Form element label'),
+                        'multiOptions'  => $themes
+                    )
+                );
+            }
+        }
+
         $languages = array();
         $languages['autodetect'] = sprintf($this->translate('Browser (%s)', 'preferences.form'), $this->getLocale());
         foreach (Translator::getAvailableLocaleCodes() as $language) {