Chat channel filters support

Signed-off-by: Rogiel <rogiel@rogiel.com>

src/main/java/com/l2jserver/service/game/chat/ChatChannel.java

@@ -68,6 +68,23 @@ public interface ChatChannel {
 	 */
 	void removeChatChannelListener(ChatChannelListener listener);
 
+	/**
+	 * Adds a {@link ChatChannelFilter} that will be used to filter each message
+	 * sent in the channel.
+	 * 
+	 * @param filter
+	 *            the filter
+	 */
+	void addChatChannelFilter(ChatChannelFilter filter);
+
+	/**
+	 * Removes a {@link ChatChannelListener}.
+	 * 
+	 * @param filter
+	 *            the filter
+	 */
+	void removeChatChannelFilter(ChatChannelFilter filter);
+
 	/**
 	 * @return the chat channel numeric ID
 	 */

src/main/java/com/l2jserver/service/game/chat/ChatChannelFilter.java

@@ -0,0 +1,42 @@
+/*
+ * This file is part of l2jserver <l2jserver.com>.
+ *
+ * l2jserver is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * l2jserver is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with l2jserver.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.l2jserver.service.game.chat;
+
+import com.l2jserver.model.id.object.CharacterID;
+
+/**
+ * This is a filter that can filter messages sent into an given
+ * {@link ChatChannel}. The filter is applied in a individual basis per each
+ * message. Note that the filter is called <b>before</b> the message is logged
+ * or sent to listeners.
+ * 
+ * @author <a href="http://www.rogiel.com">Rogiel</a>
+ */
+public interface ChatChannelFilter {
+	/**
+	 * Filter the message
+	 * 
+	 * @param sender
+	 *            the sender
+	 * @param channel
+	 *            the chat channel
+	 * @param message
+	 *            the message
+	 * @return true if message was accepted, false otherwise
+	 */
+	boolean filter(CharacterID sender, ChatChannel channel, String message);
+}

src/main/java/com/l2jserver/service/game/chat/SimpleChatService.java

@@ -105,8 +105,9 @@ public class SimpleChatService extends AbstractService implements ChatService {
 	}
 
 	@Override
-	public ChatMessage send(CharacterID sender, ChatMessageType chat, String message,
-			String extra) throws TargetNotFoundChatServiceException,
+	public ChatMessage send(CharacterID sender, ChatMessageType chat,
+			String message, String extra)
+			throws TargetNotFoundChatServiceException,
 			CannotChatToSelfChatServiceException,
 			ChatBanActiveChatServiceException,
 			ChatTargetOfflineServiceException {
@@ -213,6 +214,11 @@ public class SimpleChatService extends AbstractService implements ChatService {
 		 */
 		protected final Set<ChatChannelListener> listeners = CollectionFactory
 				.newSet();
+		/**
+		 * The list of all filters on this channel
+		 */
+		protected final Set<ChatChannelFilter> filters = CollectionFactory
+				.newSet();
 
 		@Override
 		public ChatMessage send(CharacterID sender, String textMessage) {
@@ -220,6 +226,14 @@ public class SimpleChatService extends AbstractService implements ChatService {
 			Preconditions.checkNotNull(textMessage, "message");
 			// TODO throw exception if sender is banned from chat
 
+			// filter the message. if a single filter refuses it, the message
+			// will be discarded
+			for (final ChatChannelFilter filter : filters) {
+				if (!filter.filter(sender, this, textMessage))
+					// discard message
+					return null;
+			}
+
 			// log this chat message
 			ChatMessage message = chatLoggingService.log(sender, this,
 					textMessage);
@@ -243,6 +257,18 @@ public class SimpleChatService extends AbstractService implements ChatService {
 			listeners.remove(listener);
 		}
 
+		@Override
+		public void addChatChannelFilter(ChatChannelFilter filter) {
+			Preconditions.checkNotNull(filter, "filter");
+			filters.add(filter);
+		}
+
+		@Override
+		public void removeChatChannelFilter(ChatChannelFilter filter) {
+			Preconditions.checkNotNull(filter, "filter");
+			filters.remove(filter);
+		}
+
 		@Override
 		public String getChannelName() {
 			return getMessageType().name();