--- a/Implab/TaskController.cs	Tue Nov 05 01:09:58 2013 +0400
+++ b/Implab/TaskController.cs	Tue Nov 05 19:55:34 2013 +0400
@@ -12,7 +12,7 @@
     /// <remarks>
     /// Members of this object are thread safe.
     /// </remarks>
-    class TaskController
+    class TaskController: IProgressNotifier, ITaskController, ICancellable
     {
         readonly object m_lock;
         string m_message;
@@ -20,6 +20,8 @@
         float m_current;
         float m_max;
 
+        bool m_cancelled;
+
         public event EventHandler<ValueEventArgs<string>> MessageUpdated;
         public event EventHandler<ValueEventArgs<float>> ProgressUpdated;
         public event EventHandler<ProgressInitEventArgs> ProgressInit;
@@ -82,6 +84,24 @@
             }
         }
 
+        public bool Cancelled {
+            get {
+                lock (m_lock)
+                    return m_cancelled;
+            }
+        }
+
+        public bool Cancel() {
+            lock (m_lock) {
+                if (!m_cancelled) {
+                    m_cancelled = true;
+                    return true;
+                } else {
+                    return false;
+                }
+            }
+        }
+
         protected virtual void OnMessageUpdated()
         {
             var temp = MessageUpdated;