Add an event for frame opened.

For some reason this was only exposed through the WindowManager
listeners.

src/main/java/com/dmdirc/events/FrameOpenedEvent.java

+package com.dmdirc.events;
+
+import com.dmdirc.interfaces.WindowModel;
+
+import java.util.Optional;
+
+/**
+ * Fired when a new window is opened.
+ */
+public class FrameOpenedEvent extends FrameEvent {
+
+    private final Optional<WindowModel> parent;
+
+    public FrameOpenedEvent(final WindowModel source, final WindowModel parent) {
+        super(source);
+        this.parent = Optional.of(parent);
+    }
+
+    public FrameOpenedEvent(final WindowModel source) {
+        super(source);
+        this.parent = Optional.empty();
+    }
+
+    public Optional<WindowModel> getParent() {
+        return parent;
+    }
+
+}

src/main/java/com/dmdirc/ui/WindowManager.java

 import com.dmdirc.DMDircMBassador;
 import com.dmdirc.Precondition;
 import com.dmdirc.events.FrameClosingEvent;
+import com.dmdirc.events.FrameOpenedEvent;
 import com.dmdirc.interfaces.WindowModel;
 import com.dmdirc.interfaces.ui.FrameListener;
 import com.dmdirc.util.collections.ListenerList;
     private final ListenerList listeners = new ListenerList();
     /** Counter to use for ID assignments. */
     private final AtomicLong nextId = new AtomicLong(0L);
+    /** Event bus to dispatch window events on. */
+    private final DMDircMBassador eventBus;
 
     /**
      * Creates a new instance of {@link WindowManager}.
      */
     @Inject
     public WindowManager(final DMDircMBassador eventBus) {
+        this.eventBus = eventBus;
         eventBus.subscribe(this);
     }
 
      *
      * @return True if the target is in the hierarchy, false otherwise
      */
-    protected boolean isInHierarchy(final WindowModel target) {
+    private boolean isInHierarchy(final WindowModel target) {
         return rootWindows.contains(target) || parents.containsKey(target);
     }
 
      * @param focus  Should this window become focused
      */
     private void fireAddWindow(final WindowModel window, final boolean focus) {
+        eventBus.publishAsync(new FrameOpenedEvent(window));
         for (FrameListener listener : listeners.get(FrameListener.class)) {
             listener.addWindow(window, focus);
         }
      */
     private void fireAddWindow(final WindowModel parent,
             final WindowModel child, final boolean focus) {
+        eventBus.publishAsync(new FrameOpenedEvent(child, parent));
         for (FrameListener listener : listeners.get(FrameListener.class)) {
             listener.addWindow(parent, child, focus);
         }