Added initial pieces for topology related notifications.
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
index 012f333..44607a9 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
@@ -31,6 +31,7 @@
 import net.onrc.onos.ofcontroller.flowmanager.web.FlowWebRoutable;
 import net.onrc.onos.ofcontroller.topology.ITopologyNetService;
 import net.onrc.onos.ofcontroller.topology.Topology;
+import net.onrc.onos.ofcontroller.topology.TopologyElement;
 import net.onrc.onos.ofcontroller.util.*;
 
 import org.openflow.protocol.OFType;
@@ -76,6 +77,10 @@
     protected BlockingQueue<EventEntry<FlowPath>> flowPathEvents =
 	new LinkedBlockingQueue<EventEntry<FlowPath>>();
 
+    // The queue with Topology Element updates
+    protected BlockingQueue<EventEntry<TopologyElement>> topologyEvents =
+	new LinkedBlockingQueue<EventEntry<TopologyElement>>();
+
     /**
      * Periodic task for reading the Flow Entries and pushing changes
      * into the switches.
@@ -494,8 +499,19 @@
 	// Initialize the Flow Entry ID generator
 	nextFlowEntryIdPrefix = randomGenerator.nextInt();
 
-	// Register with the Datagrid Service and obtain the initial state
+	// Register with the Datagrid Service
 	datagridService.registerFlowService(this);
+
+	// Obtain the initial Topology state
+	Collection<TopologyElement> topologyElements =
+	    datagridService.getAllTopologyElements();
+	for (TopologyElement topologyElement : topologyElements) {
+	    EventEntry<TopologyElement> eventEntry =
+		new EventEntry<TopologyElement>(EventEntry.Type.ENTRY_ADD, topologyElement);
+	    topologyEvents.add(eventEntry);
+	}
+
+	// Obtain the initial Flow state
 	Collection<FlowPath> flowPaths = datagridService.getAllFlows();
 	for (FlowPath flowPath : flowPaths) {
 	    EventEntry<FlowPath> eventEntry =
@@ -864,4 +880,34 @@
     public void notificationRecvFlowUpdated(FlowPath flowPath) {
 	// TODO
     }
+
+    /**
+     * Receive a notification that a Topology Element is added.
+     *
+     * @param topologyElement the Topology Element that is added.
+     */
+    @Override
+    public void notificationRecvTopologyElementAdded(TopologyElement topologyElement) {
+	// TODO
+    }
+
+    /**
+     * Receive a notification that a Topology Element is removed.
+     *
+     * @param topologyElement the Topology Element that is removed.
+     */
+    @Override
+    public void notificationRecvTopologyElementRemoved(TopologyElement topologyElement) {
+	// TODO
+    }
+
+    /**
+     * Receive a notification that a Topology Element is updated.
+     *
+     * @param topologyElement the Topology Element that is updated.
+     */
+    @Override
+    public void notificationRecvTopologyElementUpdated(TopologyElement topologyElement) {
+	// TODO
+    }
 }