Adds Remarkup Rendering to Calendar Events' Descriptions.

Summary: Closes T8032

Test Plan: Verify that when editing a calendar event's description, there is a UI bar helping with adding markup to the description. Also verify that markup is displayed correctly on the event page once the event has been updated.

Reviewers: lpriestley, #blessed_reviewers, epriestley

Reviewed By: lpriestley, #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8032

Differential Revision: https://secure.phabricator.com/D13355

src/applications/calendar/controller/PhabricatorCalendarEventEditController.php

@@ -437,10 +437,11 @@ final class PhabricatorCalendarEventEditController
         ->setValue($end_disabled);
     }
 
-    $description = id(new AphrontFormTextAreaControl())
+    $description = id(new PhabricatorRemarkupControl())
       ->setLabel(pht('Description'))
       ->setName('description')
-      ->setValue($description);
+      ->setValue($description)
+      ->setUser($viewer);
 
     $view_policies = id(new AphrontFormPolicyControl())
       ->setUser($viewer)

src/applications/calendar/controller/PhabricatorCalendarEventViewController.php

@@ -362,10 +362,19 @@ final class PhabricatorCalendarEventViewController
       pht('Icon'),
       $icon_display);
 
-    $properties->addSectionHeader(
+    if (strlen($event->getDescription())) {
-      pht('Description'),
+
-      PHUIPropertyListView::ICON_SUMMARY);
+      $description = PhabricatorMarkupEngine::renderOneObject(
-    $properties->addTextContent($event->getDescription());
+        id(new PhabricatorMarkupOneOff())->setContent($event->getDescription()),
+        'default',
+        $viewer);
+
+      $properties->addSectionHeader(
+        pht('Description'),
+        PHUIPropertyListView::ICON_SUMMARY);
+
+      $properties->addTextContent($description);
+    }
 
     return $properties;
   }