Delegation! Since it's clear that extracting services into delegation

classes is only going to become more common, I've gone and created a
comprehensive facility for creating and using delegates in the place
controller and manager as well as the game controller and manager. With
the pattern nicely set, it is also easy to extend to controller/managers
further up the hierarchy that might need to delegate special methods of
their own. Whee!


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@994 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/crowd/client/PlaceControllerDelegate.java

@@ -0,0 +1,67 @@
+//
+// $Id: PlaceControllerDelegate.java,v 1.1 2002/02/13 03:21:28 mdb Exp $
+
+package com.threerings.crowd.client;
+
+import java.awt.event.ActionEvent;
+
+import com.threerings.crowd.data.PlaceConfig;
+import com.threerings.crowd.data.PlaceObject;
+import com.threerings.crowd.util.CrowdContext;
+
+/**
+ * Provides an extensible mechanism for encapsulating delegated
+ * functionality that works with the place services.
+ *
+ * <p> Thanks to Java's lack of multiple inheritance, it will likely
+ * become necessary to factor certain services that might be used by a
+ * variety of {@link PlaceController} derived classes into delegate
+ * classes because they do not fit into the single inheritance hierarchy
+ * that makes sense for a particular application. To facilitate this
+ * process, this delegate class is provided which the standard place
+ * controller can be made to call out to for all of the standard methods.
+ */
+public class PlaceControllerDelegate
+{
+    /**
+     * Constructs the delegate with the controller for which it is
+     * delegating.
+     */
+    public PlaceControllerDelegate (PlaceController controller)
+    {
+        _controller = controller;
+    }
+
+    /**
+     * Called to initialize the delegate.
+     */
+    public void init (CrowdContext ctx, PlaceConfig config)
+    {
+    }
+
+    /**
+     * Called to let the delegate know that we're entering a place.
+     */
+    public void willEnterPlace (PlaceObject plobj)
+    {
+    }
+
+    /**
+     * Called to let the delegate know that we've left the place.
+     */
+    public void didLeavePlace (PlaceObject plobj)
+    {
+    }
+
+    /**
+     * Called to give the delegate a chance to handle controller actions
+     * that weren't handled by the main controller.
+     */
+    public boolean handleAction (ActionEvent action)
+    {
+        return false;
+    }
+
+    /** A reference to the controller for which we are delegating. */
+    protected PlaceController _controller;
+}