ONOS-1479 -- GUI - augmenting topology view for extensibility:
- Preliminary work in implementing installation of custom buttons to details panel for selected device.

Change-Id: Id26ac301f72b4521d2a388d34ee0a287f400c68c
diff --git a/web/gui/src/main/webapp/_sdh/overlaywork/AppUiTopoOverlay.java b/web/gui/src/main/webapp/_sdh/overlaywork/AppUiTopoOverlay.java
new file mode 100644
index 0000000..494885d
--- /dev/null
+++ b/web/gui/src/main/webapp/_sdh/overlaywork/AppUiTopoOverlay.java
@@ -0,0 +1,69 @@
+/*
+ * 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.meowster.over;
+
+import org.onosproject.ui.UiTopoOverlay;
+import org.onosproject.ui.topo.PropertyPanel;
+import org.onosproject.ui.topo.TopoConstants.Glyphs;
+
+import static org.onosproject.ui.topo.TopoConstants.Properties.*;
+
+/**
+ * Our topology overlay.
+ */
+public class AppUiTopoOverlay extends UiTopoOverlay {
+
+    // NOTE: this must match the ID defined in topov.js
+    private static final String OVERLAY_ID = "meowster-overlay";
+
+    private static final String MY_TITLE = "I changed the title";
+    private static final String MY_VERSION = "Beta-1.0.0042";
+    private static final String FOO = "foo";
+    private static final String BAR = "bar";
+
+
+    public AppUiTopoOverlay() {
+        super(OVERLAY_ID);
+    }
+
+
+    @Override
+    public void modifySummary(PropertyPanel pp) {
+        pp.title("My App Rocks!")
+                .typeId(Glyphs.CROWN)
+                .removeProps(
+                        TOPOLOGY_SSCS,
+                        INTENTS,
+                        TUNNELS,
+                        FLOWS,
+                        VERSION
+                )
+                .addProp(VERSION, MY_VERSION);
+
+    }
+
+    @Override
+    public void modifyDeviceDetails(PropertyPanel pp) {
+        pp.title(MY_TITLE);
+        pp.removeProps(LATITUDE, LONGITUDE);
+        pp.addButton(FOO).addButton(BAR);
+    }
+
+// TODO: override more methods, as required...
+
+}