1   /* Copyright 2002-2025 CS GROUP
2    * Licensed to CS GROUP (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.forces.maneuvers.trigger;
18  
19  import org.orekit.propagation.SpacecraftState;
20  import org.orekit.time.AbsoluteDate;
21  
22  /** Resetter for maneuver triggers.
23   * @see AbstractManeuverTriggers
24   * @author Luc Maisonobe
25   * @since 11.1
26   */
27  public interface ManeuverTriggersResetter {
28  
29      /** Initialization method called at propagation start.
30       * <p>
31       * The default implementation does nothing.
32       * </p>
33       * @param initialState initial spacecraft state (at the start of propagation).
34       * @param target date of propagation. Not equal to {@code initialState.getDate()}.
35       */
36      default void init(SpacecraftState initialState, AbsoluteDate target) {
37          // nothing by default
38      }
39  
40      /** Observe a maneuver trigger.
41       * <p>
42       * The {@code start} parameter corresponds to physical flow of time
43       * from past to future, not to propagation direction which can be backward.
44       * This means that during forward propagations, the first call will have
45       * {@code start} set to {@code true} and the second call will have
46       * {@code start} set to {@code false}, whereas in backward propagation,
47       * the first call will have {@code start} set to {@code false} and the second
48       * call will have {@code start} set to {@code true}.
49       * </p>
50       * @param state spacecraft state at trigger date (before applying the maneuver)
51       * @param start if true, the trigger is the start of the maneuver
52       */
53      void maneuverTriggered(SpacecraftState state, boolean start);
54  
55      /** Reset state as a maneuver triggers.
56       * @param state spacecraft state at trigger date
57       * @return reset state taking into account maneuver start/stop
58       */
59      SpacecraftState resetState(SpacecraftState state);
60  
61  }