(js,css) Style cancelled events in Calendar module

Fixes #2800

NEWS

@@ -6,6 +6,7 @@ New features
 
 Enhancements
  - [web] expunge drafts mailbox when a draft is sent and deleted
+ - [web] style cancelled events in Calendar module (#2800)
  - [web] updated CKEditor to version 4.5.10
 
 Bug fixes

UI/WebServerResources/SchedulerUI.css

@@ -1365,6 +1365,9 @@ DIV.eventInside.declined
 { -moz-opacity: 0.4;
   opacity: 0.4; }
 
+DIV.eventInside.cancelled .text
+{ text-decoration: line-through; }
+
 /* event DnD */
 DIV.event DIV.topDragGrip,
 DIV.event DIV.bottomDragGrip

UI/WebServerResources/SchedulerUI.js

@@ -1,3 +1,5 @@
+/* -*- Mode: javascript; indent-tabs-mode: nil; js-indent-level: 4; -*- */
+
 var eventListFilter = 'view_today';
 var taskListFilter = 'view_today';
 
@@ -2001,6 +2003,13 @@ function newBaseEventDIV(eventRep, event, eventText) {
         eventCell.observe("click", onCalendarSelectEvent);
         eventCell.observe("dblclick", Event.stop);
     }
+    else if (event[3] == 0) {
+        // Event is cancelled
+        eventCell.observe("mousedown", listRowMouseDownHandler);
+        eventCell.observe("click", onCalendarSelectEvent);
+        eventCell.observe("click", onViewEvent);
+        innerDiv.addClassName('cancelled');
+    }
     else {
         // Status field is defined -- user can read event
         eventCell.observe("mousedown", listRowMouseDownHandler);