/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 backtype.storm.windowing;

/**
 * The callback fired by {@link TriggerPolicy} when the trigger
 * condition is satisfied.
 */
public interface TriggerHandler {
    /**
     * The code to execute when the {@link TriggerPolicy} condition is satisfied.
     *
     * @return true if the window was evaluated with at least one event in the window, false otherwise
     */
    boolean onTrigger();
}