Improve MUC message and presence listeners

instead of using a PacketListener, which means that the user has to
downcast the Packet to Message, we now use a Listener which callback
parameter is already Message/Presence.

It is necessary to introduce MessageListener and PresenceListener, which
are interfaces that have a callback for Message/Presence instead of
Packet. The 'old' MessageListener is renamed to ChatMessageListener.

Use Generics in ConnectionDetachedPacketCollector.

smack-core/src/main/java/org/jivesoftware/smack/Chat.java

@@ -40,7 +40,7 @@ public class Chat {
     private ChatManager chatManager;
     private String threadID;
     private String participant;
-    private final Set<MessageListener> listeners = new CopyOnWriteArraySet<MessageListener>();
+    private final Set<ChatMessageListener> listeners = new CopyOnWriteArraySet<ChatMessageListener>();
 
     /**
      * Creates a new chat with the specified user and thread ID.
@@ -118,7 +118,7 @@ public class Chat {
      *
      * @param listener a packet listener.
      */
-    public void addMessageListener(MessageListener listener) {
+    public void addMessageListener(ChatMessageListener listener) {
         if(listener == null) {
             return;
         }
@@ -126,7 +126,7 @@ public class Chat {
         listeners.add(listener);
     }
 
-    public void removeMessageListener(MessageListener listener) {
+    public void removeMessageListener(ChatMessageListener listener) {
         listeners.remove(listener);
     }
 
@@ -145,7 +145,7 @@ public class Chat {
      *
      * @return an unmodifiable collection of all of the listeners registered with this chat.
      */
-    public Collection<MessageListener> getListeners() {
+    public Collection<ChatMessageListener> getListeners() {
         return Collections.unmodifiableCollection(listeners);
     }
 
@@ -174,7 +174,7 @@ public class Chat {
         // probably never had one.
         message.setThread(threadID);
 
-        for (MessageListener listener : listeners) {
+        for (ChatMessageListener listener : listeners) {
             listener.processMessage(this, message);
         }
     }

smack-core/src/main/java/org/jivesoftware/smack/ChatManager.java

@@ -206,7 +206,7 @@ public class ChatManager extends Manager{
      * @param listener the listener which will listen for new messages from this chat.
      * @return the created chat.
      */
-    public Chat createChat(String userJID, MessageListener listener) {
+    public Chat createChat(String userJID, ChatMessageListener listener) {
         return createChat(userJID, null, listener);
     }
 
@@ -218,7 +218,7 @@ public class ChatManager extends Manager{
      * @param listener the listener to add to the chat
      * @return the created chat.
      */
-    public Chat createChat(String userJID, String thread, MessageListener listener) {
+    public Chat createChat(String userJID, String thread, ChatMessageListener listener) {
         if (thread == null) {
             thread = nextID();
         }

smack-core/src/main/java/org/jivesoftware/smack/ChatMessageListener.java

@@ -0,0 +1,27 @@
+/**
+ *
+ * Copyright 2003-2007 Jive Software.
+ *
+ * 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.smack;
+
+import org.jivesoftware.smack.packet.Message;
+
+/**
+ *
+ */
+public interface ChatMessageListener {
+    void processMessage(Chat chat, Message message);
+}

smack-core/src/main/java/org/jivesoftware/smack/MessageListener.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2003-2007 Jive Software.
+ * Copyright © 2014 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,5 +23,5 @@ import org.jivesoftware.smack.packet.Message;
  *
  */
 public interface MessageListener {
-    void processMessage(Chat chat, Message message);
+    void processMessage(Message message);
 }

smack-core/src/main/java/org/jivesoftware/smack/PresenceListener.java

@@ -0,0 +1,27 @@
+/**
+ *
+ * Copyright © 2014 Florian Schmaus
+ *
+ * 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.smack;
+
+import org.jivesoftware.smack.packet.Presence;
+
+/**
+ *
+ */
+public interface PresenceListener {
+    void processPresence(Presence presence);
+}

smack-core/src/main/java/org/jivesoftware/smack/filter/MessageWithSubjectFilter.java

@@ -0,0 +1,39 @@
+/**
+ *
+ * Copyright © 2014 Florian Schmaus
+ *
+ * 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.smack.filter;
+
+import org.jivesoftware.smack.packet.Message;
+
+/**
+ * Filters message stanzas which have at least one body
+ */
+public class MessageWithSubjectFilter extends FlexiblePacketTypeFilter<Message> {
+
+    public static final PacketFilter INSTANCE = new MessageWithSubjectFilter();
+
+    private MessageWithSubjectFilter() {
+        super(Message.class);
+    }
+
+    @Override
+    protected boolean acceptSpecific(Message message) {
+        // Accept only messages which have a subject set
+        return message.getSubject() != null;
+    }
+
+}

smack-core/src/test/java/org/jivesoftware/smack/ChatConnectionTest.java

@@ -386,7 +386,7 @@ public class ChatConnectionTest {
 
     class TestChatManagerListener implements ChatManagerListener {
         private Chat newChat;
-        private MessageListener listener;
+        private ChatMessageListener listener;
 
         public TestChatManagerListener(TestMessageListener msgListener) {
             listener = msgListener;
@@ -423,7 +423,7 @@ public class ChatConnectionTest {
         }
     }
 
-    private class TestMessageListener implements MessageListener {
+    private class TestMessageListener implements ChatMessageListener {
         private Chat msgChat;
         private int counter = 0;