Add partition event and listener.

primitive/src/main/java/io/atomix/primitive/partition/PartitionEvent.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2019-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 io.atomix.primitive.partition;
+
+import io.atomix.utils.event.AbstractEvent;
+
+/**
+ * Partition event.
+ */
+public class PartitionEvent extends AbstractEvent<PartitionEvent.Type, Partition> {
+
+  /**
+   * Partition event type.
+   */
+  public enum Type {
+    /**
+     * Event type indicating the partition primary has changed.
+     */
+    PRIMARY_CHANGED,
+
+    /**
+     * Event type indicating the partition backups have changed.
+     */
+    BACKUPS_CHANGED,
+
+    /**
+     * Event type indicating the partition membership has changed.
+     */
+    MEMBERS_CHANGED,
+  }
+
+  public PartitionEvent(Type type, Partition partition) {
+    super(type, partition);
+  }
+
+  public PartitionEvent(Type type, Partition partition, long time) {
+    super(type, partition, time);
+  }
+
+  /**
+   * Returns the partition.
+   *
+   * @return the partition
+   */
+  public Partition partition() {
+    return subject();
+  }
+}

primitive/src/main/java/io/atomix/primitive/partition/PartitionEventListener.java

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+/*
+ * Copyright 2019-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 io.atomix.primitive.partition;
+
+import io.atomix.utils.event.EventListener;
+
+/**
+ * Partition event listener.
+ */
+public interface PartitionEventListener extends EventListener<PartitionEvent> {
+}