Use User in Topic.

src/com/dmdirc/Channel.java

@@ -461,11 +461,13 @@ public class Channel extends MessageTarget implements GroupChat {
             return true;
         } else if (arg instanceof Topic) {
             // Format topics
-
+            final Topic topic = (Topic) arg;
             args.add("");
-            args.addAll(Arrays.asList(server.parseHostmask(((Topic) arg).getClient())));
-            args.add(((Topic) arg).getTopic());
-            args.add(((Topic) arg).getTime() * 1000);
+            args.add(topic.getClient().getNickname());
+            args.add(topic.getClient().getUsername().orElse(""));
+            args.add(topic.getClient().getHostname().orElse(""));
+            args.add(topic.getTopic());
+            args.add(topic.getTime() * 1000);
 
             return true;
         } else {

src/com/dmdirc/ChannelEventHandler.java

@@ -160,7 +160,8 @@ public class ChannelEventHandler extends EventHandler implements
                 final String format = EventUtils.postDisplayable(eventBus, event, "channelNoTopic");
                 owner.doNotification(date, format);
             } else {
-                final Topic newTopic = new Topic(channel.getTopic(), channel.getTopicSetter(),
+                final Topic newTopic = new Topic(channel.getTopic(),
+                        getConnection().getUser(channel.getTopicSetter()).orElse(null),
                         channel.getTopicTime());
                 final ChannelGottopicEvent event = new ChannelGottopicEvent(owner, newTopic);
                 final String format = EventUtils.postDisplayable(eventBus, event,
@@ -189,7 +190,8 @@ public class ChannelEventHandler extends EventHandler implements
             //  - It's being set while we're in the channel (rather than discovered on join), or
             //  - We think the current topic is empty and are discovering a new one, or
             //  - The newly discovered topic is different to what we thought the current topic was.
-            owner.addTopic(new Topic(channel.getTopic(), channel.getTopicSetter(),
+            owner.addTopic(new Topic(channel.getTopic(),
+                    getConnection().getUser(channel.getTopicSetter()).orElse(null),
                     channel.getTopicTime()));
         }
     }

src/com/dmdirc/Topic.java

@@ -22,6 +22,8 @@
 
 package com.dmdirc;
 
+import com.dmdirc.interfaces.User;
+
 /**
  * Stores information about a channel topic.
  */
@@ -30,7 +32,7 @@ public class Topic {
     /** Topic. */
     private final String topic;
     /** Topic client. */
-    private final String client;
+    private final User client;
     /** Topic time. */
     private final long time;
 
@@ -41,7 +43,7 @@ public class Topic {
      * @param client Topic client
      * @param time   Topic time
      */
-    public Topic(final String topic, final String client, final long time) {
+    public Topic(final String topic, final User client, final long time) {
         this.topic = topic;
         this.client = client;
         this.time = time;
@@ -50,9 +52,9 @@ public class Topic {
     /**
      * Returns the client who set the topic.
      *
-     * @return client host
+     * @return client
      */
-    public String getClient() {
+    public User getClient() {
         return client;
     }
 

test/com/dmdirc/TopicTest.java

@@ -22,33 +22,42 @@
 
 package com.dmdirc;
 
+import com.dmdirc.interfaces.User;
+
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
 
 import static org.junit.Assert.*;
 
+@RunWith(MockitoJUnitRunner.class)
 public class TopicTest {
 
+    @Mock
+    private User user;
+
     @Test
     public void testGetClient() {
-        final Topic test = new Topic("abc", "123!456@789", 1);
-        assertEquals("123!456@789", test.getClient());
+        final Topic test = new Topic("abc", user, 1);
+        assertEquals(user, test.getClient());
     }
 
     @Test
     public void testGetTime() {
-        final Topic test = new Topic("abc", "123!456@789", 1);
+        final Topic test = new Topic("abc", user, 1);
         assertEquals(1L, test.getTime());
     }
 
     @Test
     public void testGetTopic() {
-        final Topic test = new Topic("abc", "123!456@789", 1);
+        final Topic test = new Topic("abc", user, 1);
         assertEquals("abc", test.getTopic());
     }
 
     @Test
     public void testToString() {
-        final Topic test = new Topic("abc", "123!456@789", 1);
+        final Topic test = new Topic("abc", user, 1);
         assertEquals("abc", test.toString());
     }