Add roomDestroyed callback to MUC UserStatusListener

Fixes SMACK-619

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/DefaultUserStatusListener.java

@@ -66,4 +66,7 @@ public class DefaultUserStatusListener implements UserStatusListener {
     public void adminRevoked() {
     }
 
+    public void roomDestroyed(MultiUserChat alternateMUC, String reason) {
+    }
+
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChat.java

@@ -2179,6 +2179,18 @@ public class MultiUserChat {
                 listener.nicknameChanged(from, mucUser.getItem().getNick());
             }
         }
+        //The room has been destroyed
+        if (mucUser.getDestroy() != null) {
+            MultiUserChat alternateMUC = multiUserChatManager.getMultiUserChat(mucUser.getDestroy().getJid());
+            for (UserStatusListener listener : userStatusListeners) {
+                listener.roomDestroyed(alternateMUC, mucUser.getDestroy().getReason());
+            }
+
+            // Reset occupant information.
+            occupantsMap.clear();
+            nickname = null;
+            userHasLeft();
+        }
     }
 
     @Override

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/UserStatusListener.java

@@ -21,7 +21,7 @@ import org.jxmpp.jid.Jid;
 
 /**
  * A listener that is fired anytime your participant's status in a room is changed, such as the 
- * user being kicked, banned, or granted admin permissions.
+ * user being kicked, banned, or granted admin permissions or the room is destroyed.
  * 
  * @author Gaston Dombiak
  */
@@ -123,4 +123,12 @@ public interface UserStatusListener {
      */
     public abstract void adminRevoked();
 
+    /**
+     * Called when the room is destroyed.
+     * 
+     * @param alternateMUC an alternate MultiUserChat, may be null.
+     * @param reason the reason why the room was closed, may be null.
+     */
+    public abstract void roomDestroyed(MultiUserChat alternateMUC, String reason);
+
 }