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.propagation.sampling;
18  
19  import java.util.List;
20  
21  import org.orekit.propagation.SpacecraftState;
22  import org.orekit.time.AbsoluteDate;
23  
24  /** This interface is a space-dynamics aware step handler for {@link
25   * org.orekit.propagation.PropagatorsParallelizer multi-sat propagation}.
26   *
27   * <p>It is a multi-satellite version of the {@link OrekitStepHandler}.</p>
28   * @author Luc Maisonobe
29   * @since 9.0
30   */
31  public interface MultiSatStepHandler {
32  
33      /** Initialize step handler at the start of a propagation.
34       * <p>
35       * This method is called once at the start of the propagation. It
36       * may be used by the step handler to initialize some internal data
37       * if needed.
38       * </p>
39       * <p>
40       * The default method does nothing
41       * </p>
42       * @param states0 initial states, one for each satellite in the same order
43       * used to {@link org.orekit.propagation.PropagatorsParallelizer#PropagatorsParallelizer(List, MultiSatStepHandler)
44       * build} the {@link org.orekit.propagation.PropagatorsParallelizer multi-sat propagator}.
45       * @param t target time for the integration
46       */
47      default void init(final List<SpacecraftState> states0, final AbsoluteDate t) {
48          // nothing by default
49      }
50  
51      /** Handle the current step.
52       * <p>
53       * When called by {@link org.orekit.propagation.PropagatorsParallelizer PropagatorsParallelizer},
54       * all interpolators have the same time range.
55       * </p>
56       * @param interpolators interpolators set up for the current step in the same order
57       * used to {@link org.orekit.propagation.PropagatorsParallelizer#PropagatorsParallelizer(List, MultiSatStepHandler)
58       * build} the {@link org.orekit.propagation.PropagatorsParallelizer multi-sat propagator}
59       */
60      void handleStep(List<OrekitStepInterpolator> interpolators);
61  
62      /**
63       * Finalize propagation.
64       * @param finalStates states at propagation end
65       * @since 11.0
66       */
67      default void finish(final List<SpacecraftState> finalStates) {
68          // nothing by default
69      }
70  
71  }