FieldEventHandler.java
/* Copyright 2013 Applied Defense Solutions, Inc.
* Licensed to CS Communication & Systèmes (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.ode.events.Action;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.events.FieldEventDetector;
import org.orekit.time.FieldAbsoluteDate;
/** An interface defining how to handle events occurring during propagation..
*
* @author Hank Grabowski
*
* @param <T> type of the field element
* @since 6.1
*/
public interface FieldEventHandler<T extends CalculusFieldElement<T>> {
/** Initialize event handler at the start of a propagation.
* <p>
* This method is called once at the start of the propagation. It
* may be used by the event handler to initialize some internal data
* if needed.
* </p>
* <p>
* The default implementation does nothing
* </p>
* @param initialState initial state
* @param target target date for the propagation
* @param detector event detector related to the event handler
* @since 11.1
*/
default void init(FieldSpacecraftState<T> initialState, FieldAbsoluteDate<T> target, FieldEventDetector<T> detector) {
// nothing by default
}
/** Handle an event.
*
* @param s SpaceCraft state to be used in the evaluation
* @param detector object with appropriate type that can be used in determining correct return state
* @param increasing with the event occurred in an "increasing" or "decreasing" slope direction
* @return the Action that the calling detector should pass back to the evaluation system
*
*/
Action eventOccurred(FieldSpacecraftState<T> s, FieldEventDetector<T> detector, boolean increasing);
/** Reset the state prior to continue propagation.
* <p>This method is called after the step handler has returned and
* before the next step is started, but only when {@link
* #eventOccurred} has itself returned the {@link Action#RESET_STATE}
* indicator. It allows the user to reset the state for the next step,
* without perturbing the step handler of the finishing step. If the
* {@link #eventOccurred} never returns the {@link Action#RESET_STATE}
* indicator, this function will never be called, and it is safe to simply return null.</p>
* <p>
* The default implementation simply return its argument.
* </p>
* @param detector object with appropriate type that can be used in determining correct return state
* @param oldState old state
* @return new state
*/
default FieldSpacecraftState<T> resetState(FieldEventDetector<T> detector, FieldSpacecraftState<T> oldState) {
return oldState;
}
}