ONOS-1479 -- GUI - augmenting topology view for extensibility: WIP.
- Major refactoring of TopologyViewMessageHandler and related classes.

Change-Id: I920f7f9f7317f3987a9a8da35ac086e9f8cab8d3
diff --git a/core/api/src/main/java/org/onosproject/ui/topo/Highlights.java b/core/api/src/main/java/org/onosproject/ui/topo/Highlights.java
new file mode 100644
index 0000000..107fdd3
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/topo/Highlights.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.onosproject.ui.topo;
+
+import java.text.DecimalFormat;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Encapsulates highlights to be applied to the topology view, such as
+ * highlighting links, displaying link labels, perhaps even decorating
+ * nodes with badges, etc.
+ */
+public class Highlights {
+
+    private static final DecimalFormat DF0 = new DecimalFormat("#,###");
+
+    private final Set<DeviceHighlight> devices = new HashSet<>();
+    private final Set<HostHighlight> hosts = new HashSet<>();
+    private final Set<LinkHighlight> links = new HashSet<>();
+
+
+    public Highlights add(DeviceHighlight d) {
+        devices.add(d);
+        return this;
+    }
+
+    public Highlights add(HostHighlight h) {
+        hosts.add(h);
+        return this;
+    }
+
+    public Highlights add(LinkHighlight lh) {
+        links.add(lh);
+        return this;
+    }
+
+
+    public Set<DeviceHighlight> devices() {
+        return Collections.unmodifiableSet(devices);
+    }
+
+    public Set<HostHighlight> hosts() {
+        return Collections.unmodifiableSet(hosts);
+    }
+
+    public Set<LinkHighlight> links() {
+        return Collections.unmodifiableSet(links);
+    }
+}