1   /* Copyright 2002-2021 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.frames;
18  
19  import java.io.Serializable;
20  
21  import org.orekit.annotation.DefaultDataContext;
22  import org.orekit.data.DataContext;
23  import org.orekit.errors.OrekitException;
24  import org.orekit.errors.OrekitInternalError;
25  
26  
27  /** Base class for the predefined frames that are managed by {@link Frames}.
28   * @author Luc Maisonobe
29   */
30  public class FactoryManagedFrame extends Frame {
31  
32      /** Serializable UID. */
33      private static final long serialVersionUID = -8176399341069422724L;
34  
35      /** Key of the frame within the factory. */
36      private final Predefined factoryKey;
37  
38      /** Simple constructor.
39       * @param parent parent frame (must be non-null)
40       * @param transformProvider provider for transform from parent frame to instance
41       * @param pseudoInertial true if frame is considered pseudo-inertial
42       * (i.e. suitable for propagating orbit)
43       * @param factoryKey key of the frame within the factory
44       */
45      public FactoryManagedFrame(final Frame parent, final TransformProvider transformProvider,
46                                 final boolean pseudoInertial, final Predefined factoryKey) {
47          super(parent, transformProvider, factoryKey.getName(), pseudoInertial);
48          this.factoryKey = factoryKey;
49      }
50  
51      /** Get the key of the frame within the factory.
52       * @return key of the frame within the factory
53       */
54      public Predefined getFactoryKey() {
55          return factoryKey;
56      }
57  
58      /** Replace the instance with a data transfer object for serialization.
59       * <p>
60       * This intermediate class serializes only the frame key.
61       * </p>
62       * @return data transfer object that will be serialized
63       */
64      @DefaultDataContext
65      private Object writeReplace() {
66          return new DataTransferObject(factoryKey);
67      }
68  
69      /** Internal class used only for serialization. */
70      @DefaultDataContext
71      private static class DataTransferObject implements Serializable {
72  
73          /** Serializable UID. */
74          private static final long serialVersionUID = 2970971575793609756L;
75  
76          /** Name of the frame within the factory. */
77          private final String name;
78  
79          /** Simple constructor.
80           * @param factoryKey key of the frame within the factory
81           */
82          private DataTransferObject(final Predefined factoryKey) {
83              this.name = factoryKey.name();
84          }
85  
86          /** Replace the deserialized data transfer object with a {@link FactoryManagedFrame}.
87           * @return replacement {@link FactoryManagedFrame}
88           */
89          private Object readResolve() {
90              try {
91                  // retrieve a managed frame
92                  return DataContext.getDefault().getFrames()
93                          .getFrame(Predefined.valueOf(name));
94              } catch (OrekitException oe) {
95                  throw new OrekitInternalError(oe);
96              }
97          }
98  
99      }
100 
101 }