[ONOS-3117] Adding Port-Pair-Group event

Change-Id: Ifde70f24e77cbae4686a5f7113122afaa7c4088e

+/*
+ * 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.vtnrsc.portpairgroup;
+
+import org.onosproject.event.AbstractEvent;
+import org.onosproject.vtnrsc.PortPairGroup;
+
+/**
+ * Describes network Port-Pair-Group event.
+ */
+public class PortPairGroupEvent extends AbstractEvent<PortPairGroupEvent.Type, PortPairGroup> {
+    /**
+     * Type of port-pair-group events.
+     */
+    public enum Type {
+        /**
+         * Signifies that port-pair-group has been created.
+         */
+        PORT_PAIR_GROUP_PUT,
+        /**
+         * Signifies that port-pair-group has been deleted.
+         */
+        PORT_PAIR_GROUP_DELETE,
+        /**
+         * Signifies that port-pair-group has been updated.
+         */
+        PORT_PAIR_GROUP_UPDATE
+    }
+
+    /**
+     * Creates an event of a given type and for the specified Port-Pair-Group.
+     *
+     * @param type Port-Pair-Group event type
+     * @param portPairGroup Port-Pair-Group subject
+     */
+    public PortPairGroupEvent(Type type, PortPairGroup portPairGroup) {
+        super(type, portPairGroup);
+    }
+
+    /**
+     * Creates an event of a given type and for the specified Port-Pair-Group.
+     *
+     * @param type Port-Pair-Group event type
+     * @param portPairGroup Port-Pair-Group subject
+     * @param time occurrence time
+     */
+    public PortPairGroupEvent(Type type, PortPairGroup portPairGroup, long time) {
+        super(type, portPairGroup, time);
+    }
+}