Add a success callback for auto-join on reconnect.

When auto-join on reconnection is success, invoke a callback.

Conform to the proper copyright format.

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

@@ -0,0 +1,31 @@
+/**
+ *
+ * Copyright 2019 Vincent Lau
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.muc;
+
+import org.jxmpp.jid.parts.Resourcepart;
+
+public interface AutoJoinSuccessCallback {
+
+    /**
+     * Invoked after the automatic rejoin rooms on reconnect success.
+     *
+     * @param muc the joined MultiUserChat.
+     * @param nickname nickname used by participant to join the room.
+     */
+    void autoJoinSuccess(MultiUserChat muc, Resourcepart nickname);
+
+}

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

@@ -152,6 +152,8 @@ public final class MultiUserChatManager extends Manager {
 
     private AutoJoinFailedCallback autoJoinFailedCallback;
 
+    private AutoJoinSuccessCallback autoJoinSuccessCallback;
+
     private final ServiceDiscoveryManager serviceDiscoveryManager;
 
     private MultiUserChatManager(XMPPConnection connection) {
@@ -200,6 +202,7 @@ public final class MultiUserChatManager extends Manager {
                     @Override
                     public void run() {
                         final AutoJoinFailedCallback failedCallback = autoJoinFailedCallback;
+                        final AutoJoinSuccessCallback successCallback = autoJoinSuccessCallback;
                         for (EntityBareJid mucJid : mucs) {
                             MultiUserChat muc = getMultiUserChat(mucJid);
 
@@ -221,6 +224,9 @@ public final class MultiUserChatManager extends Manager {
                             }
                             try {
                                 muc.join(nickname);
+                                if (successCallback != null) {
+                                    successCallback.autoJoinSuccess(muc, nickname);
+                                }
                             } catch (NotAMucServiceException | NoResponseException | XMPPErrorException
                                     | NotConnectedException | InterruptedException e) {
                                 if (failedCallback != null) {
@@ -481,6 +487,21 @@ public final class MultiUserChatManager extends Manager {
         }
     }
 
+    /**
+     * Set a callback invoked by this manager when automatic join on reconnect success.
+     * If successCallback is not <code>null</code>, automatic rejoin will also
+     * be enabled.
+     *
+     * @param successCallback the callback
+     */
+    public void setAutoJoinSuccessCallback(AutoJoinSuccessCallback successCallback) {
+        autoJoinSuccessCallback = successCallback;
+        if (successCallback != null) {
+            setAutoJoinOnReconnect(true);
+        }
+    }
+
+
     void addJoinedRoom(EntityBareJid room) {
         joinedRooms.add(room);
     }