1   /* Copyright 2013 Applied Defense Solutions, Inc.
2    * Licensed to CS Communication & Systèmes (CS) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.orekit.propagation.events.handlers;
18  
19  import org.hipparchus.CalculusFieldElement;
20  import org.hipparchus.ode.events.Action;
21  import org.orekit.propagation.FieldSpacecraftState;
22  import org.orekit.propagation.events.FieldEventDetector;
23  
24  
25  /** Handle a detection event and choose what to do next.
26   * <p>The implementation behavior is to {@link
27   * Action#CONTINUE continue} propagation when descending and to
28   * {@link Action#STOP stop} propagation when ascending.</p>
29   *
30   * @author Hank Grabowski
31   *
32   * @param <T> type of the field element
33   */
34  public class FieldStopOnIncreasing <T extends CalculusFieldElement<T>> implements FieldEventHandler<T> {
35  
36      /** Empty constructor.
37       * <p>
38       * This constructor is not strictly necessary, but it prevents spurious
39       * javadoc warnings with JDK 18 and later.
40       * </p>
41       * @since 12.0
42       */
43      public FieldStopOnIncreasing() {
44          // nothing to do
45      }
46  
47      /** Handle a detection event and choose what to do next.
48       * <p>The implementation behavior is to {@link
49       * Action#CONTINUE continue} propagation when descending and to
50       * {@link Action#STOP stop} propagation when ascending.</p>
51       * @param s the current state information : date, kinematics, attitude
52       * @param detector the detector object calling this method (not used in the evaluation)
53       * @param increasing if true, the value of the switching function increases
54       * when times increases around event
55       * @return {@link Action#STOP} or {@link Action#CONTINUE}
56       */
57      @Override
58      public Action eventOccurred(final FieldSpacecraftState<T> s, final FieldEventDetector<T> detector, final boolean increasing) {
59          return increasing ? Action.STOP : Action.CONTINUE;
60      }
61  
62  }