Added application that adds a topology overlay displaying additional statistics of links.

Change-Id: Ie82ce67ead64b9b62d6ab55f3ef8ac0f62946d9f
diff --git a/apps/linkprops/src/main/java/org/onosproject/linkprops/LpLink.java b/apps/linkprops/src/main/java/org/onosproject/linkprops/LpLink.java
new file mode 100644
index 0000000..8b74dd2
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+++ b/apps/linkprops/src/main/java/org/onosproject/linkprops/LpLink.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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.linkprops;
+
+import org.onosproject.net.Link;
+import org.onosproject.net.LinkKey;
+import org.onosproject.ui.topo.BiLink;
+import org.onosproject.ui.topo.LinkHighlight;
+import org.onosproject.ui.topo.LinkHighlight.Flavor;
+
+/**
+ * Our demo concrete class of a bi-link. We give it state so we can decide
+ * how to create link highlights.
+ */
+public class LpLink extends BiLink {
+
+    private boolean important = false;
+    private String label = null;
+
+    public LpLink(LinkKey key, Link link) {
+        super(key, link);
+    }
+
+    public LpLink makeImportant() {
+        important = true;
+        return this;
+    }
+
+    public LpLink setLabel(String label) {
+        this.label = label;
+        return this;
+    }
+
+    @Override
+    public LinkHighlight highlight(Enum<?> anEnum) {
+        Flavor flavor = important ? Flavor.PRIMARY_HIGHLIGHT
+                : Flavor.SECONDARY_HIGHLIGHT;
+        return new LinkHighlight(this.linkId(), flavor)
+                .setLabel(label);
+    }
+}