Add Channel unset event.

Fixes #120

src/com/dmdirc/ChannelEventHandler.java

@@ -24,6 +24,7 @@ package com.dmdirc;
 
 import com.dmdirc.events.ChannelActionEvent;
 import com.dmdirc.events.ChannelCtcpEvent;
+import com.dmdirc.events.ChannelDisplayableEvent;
 import com.dmdirc.events.ChannelGotnamesEvent;
 import com.dmdirc.events.ChannelGottopicEvent;
 import com.dmdirc.events.ChannelJoinEvent;
@@ -39,6 +40,7 @@ import com.dmdirc.events.ChannelNotopicEvent;
 import com.dmdirc.events.ChannelPartEvent;
 import com.dmdirc.events.ChannelQuitEvent;
 import com.dmdirc.events.ChannelTopicChangeEvent;
+import com.dmdirc.events.ChannelTopicUnsetEvent;
 import com.dmdirc.events.ChannelUserAwayEvent;
 import com.dmdirc.events.ChannelUserBackEvent;
 import com.dmdirc.events.ChannelUserEvent;
@@ -170,12 +172,20 @@ public class ChannelEventHandler extends EventHandler implements
                 owner.doNotification(date, format, newTopic);
             }
         } else {
-            final ChannelTopicChangeEvent event = new ChannelTopicChangeEvent(owner,
-                    channel.getChannelClient(channel.getTopicSetter(), true),
-                    channel.getTopic());
-            final String format = EventUtils.postDisplayable(eventBus, event,
-                    Strings.isNullOrEmpty(channel.getTopic())
-                    ? "channelTopicRemoved" : "channelTopicChanged");
+            final ChannelDisplayableEvent event;
+            final String format;
+            if (Strings.isNullOrEmpty(channel.getTopic())) {
+                event = new ChannelTopicChangeEvent(owner,
+                        channel.getChannelClient(channel.getTopicSetter(), true),
+                        channel.getTopic());
+                format = EventUtils.postDisplayable(eventBus, event,
+                        "channelTopicRemoved");
+            } else {
+                event = new ChannelTopicUnsetEvent(owner,
+                        channel.getChannelClient(channel.getTopicSetter(), true));
+                format = EventUtils.postDisplayable(eventBus, event,
+                        "channelTopicChanged");
+            }
             eventBus.publish(event);
             owner.doNotification(date, format, channel.getChannelClient(channel.getTopicSetter(),
                     true), channel.getTopic());

src/com/dmdirc/events/ChannelTopicUnsetEvent.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2006-2014 DMDirc Developers
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.dmdirc.events;
+
+import com.dmdirc.Channel;
+import com.dmdirc.parser.interfaces.ChannelClientInfo;
+
+/**
+ * Fired when a topic is cleared.
+ */
+public class ChannelTopicUnsetEvent extends ChannelDisplayableEvent {
+
+    private final ChannelClientInfo client;
+
+    public ChannelTopicUnsetEvent(final long timestamp, final Channel channel,
+            final ChannelClientInfo client) {
+        super(timestamp, channel);
+        this.client = client;
+    }
+
+    public ChannelTopicUnsetEvent(final Channel channel, final ChannelClientInfo client) {
+        super(channel);
+        this.client = client;
+    }
+
+    public ChannelClientInfo getClient() {
+        return client;
+    }
+
+}