[ONOS-4195] Register sfc gui.

Change-Id: I4923cbe883eb1604c80476780b4c9e553b7ed952

+/*
+ * Copyright 2016 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.vtnweb.gui;
+
+import static com.google.common.collect.ImmutableList.of;
+import static org.onosproject.ui.UiView.Category.NETWORK;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.List;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onosproject.ui.UiExtension;
+import org.onosproject.ui.UiExtensionService;
+import org.onosproject.ui.UiMessageHandlerFactory;
+import org.onosproject.ui.UiView;
+import org.slf4j.Logger;
+
+import com.google.common.collect.ImmutableList;
+
+/**
+ * service function chain gui.
+ */
+@Component(immediate = true, enabled = true)
+@Service(value = SfcUiExtensionManager.class)
+public class SfcUiExtensionManager {
+    private final Logger log = getLogger(getClass());
+
+    private static final ClassLoader CL =
+            SfcUiExtensionManager.class.getClassLoader();
+    private static final String GUI = "gui";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected UiExtensionService uiExtensionService;
+
+    // service function chain extension
+    private final UiExtension sfc = createSfcExtension();
+
+    // Creates service function chain UI extension
+    private UiExtension createSfcExtension() {
+        List<UiView> coreViews = of(
+                //TODO add a new type of icon for sfc
+                new UiView(NETWORK, "sfc", "SFC", "nav_sfcs")
+        );
+
+        UiMessageHandlerFactory messageHandlerFactory =
+                () -> ImmutableList.of(
+                        new SfcViewMessageHandler()
+                );
+
+        return new UiExtension.Builder(CL, coreViews)
+                .messageHandlerFactory(messageHandlerFactory)
+                .resourcePath(GUI)
+                .build();
+    }
+
+    @Activate
+    public void activate() {
+        uiExtensionService.register(sfc);
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        uiExtensionService.unregister(sfc);
+        log.info("Stopped");
+    }
+}