FieldRecallLastOccurrence.java
/* Copyright 2022-2024 Romain Serra
* Licensed to CS GROUP (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS 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 org.orekit.propagation.events.handlers;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.Field;
import org.hipparchus.ode.events.Action;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.events.FieldEventDetector;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.FieldAbsoluteDate;
/**
* Event handler wrapping another, arbitrary one whilst remembering date of last detection.
* If never used, the cache is null.
* If used but nothing detected, it returns past infinity in case of forward propagation and future infinity otherwise.
* @author Romain Serra
* @see RecallLastOccurrence
* @since 12.1
* @param <T> field type
*/
public class FieldRecallLastOccurrence<T extends CalculusFieldElement<T>> implements FieldEventHandler<T> {
/** Wrapped event handler. */
private final FieldEventHandler<T> wrappedHandler;
/** Last date at which the wrapped event occurred. */
private FieldAbsoluteDate<T> lastOccurrence;
/** Constructor.
* @param wrappedHandler event handler to wrap
*/
public FieldRecallLastOccurrence(final FieldEventHandler<T> wrappedHandler) {
this.wrappedHandler = wrappedHandler;
}
/** Getter for last occurrence.
* @return last date when underlying event was detected
*/
public FieldAbsoluteDate<T> getLastOccurrence() {
return lastOccurrence;
}
/** {@inheritDoc} */
@Override
public void init(final FieldSpacecraftState<T> initialState, final FieldAbsoluteDate<T> target,
final FieldEventDetector<T> detector) {
final boolean isForward = target.isAfter(initialState.getDate());
final Field<T> field = target.getField();
final AbsoluteDate date = isForward ? AbsoluteDate.PAST_INFINITY : AbsoluteDate.FUTURE_INFINITY;
lastOccurrence = new FieldAbsoluteDate<>(field, date);
wrappedHandler.init(initialState, target, detector);
}
/** {@inheritDoc} */
@Override
public Action eventOccurred(final FieldSpacecraftState<T> s, final FieldEventDetector<T> detector,
final boolean increasing) {
lastOccurrence = s.getDate();
return wrappedHandler.eventOccurred(s, detector, increasing);
}
/** {@inheritDoc} */
@Override
public FieldSpacecraftState<T> resetState(final FieldEventDetector<T> detector,
final FieldSpacecraftState<T> oldState) {
return wrappedHandler.resetState(detector, oldState);
}
}