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.events;
18  
19  import org.orekit.propagation.SpacecraftState;
20  
21  import java.util.Arrays;
22  
23  /** This interface represents an event enabling predicate function.
24   * @author Luc Maisonobe
25   * @since 7.1
26   */
27  public interface EnablingPredicate {
28  
29      /** Compute an event enabling function of state.
30       * @param state current state
31       * @param detector underlying detector
32       * @param g value of the underlying detector for the current state
33       * @return true if the event is enabled (i.e. it can be
34       * triggered), false if it should be ignored
35       */
36      boolean eventIsEnabled(SpacecraftState state, EventDetector detector, double g);
37  
38      /**
39       * Method combining predicated based on the OR logic operator.
40       * @param enablingPredicates predicates
41       * @return combined predicate
42       * @since 13.1
43       */
44      static EnablingPredicate orCombine(EnablingPredicate... enablingPredicates) {
45          return (state, detector, g) -> Arrays.stream(enablingPredicates).anyMatch(p -> p.eventIsEnabled(state, detector, g));
46      }
47  
48      /**
49       * Method combining predicated based on the AND logic operator.
50       * @param enablingPredicates predicates
51       * @return combined predicate
52       * @since 13.1
53       */
54      static EnablingPredicate andCombine(EnablingPredicate... enablingPredicates) {
55          return (state, detector, g) -> Arrays.stream(enablingPredicates).allMatch(p -> p.eventIsEnabled(state, detector, g));
56      }
57  }