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1   /*
2    *  Copyright 2001-2005 Stephen Colebourne
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License");
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License.
15   */
16  package org.joda.time.field;
17  
18  import org.joda.time.DurationField;
19  import org.joda.time.DurationFieldType;
20  
21  /**
22   * <code>DecoratedDurationField</code> extends {@link BaseDurationField},
23   * implementing only the minimum required set of methods. These implemented
24   * methods delegate to a wrapped field.
25   * <p>
26   * This design allows new DurationField types to be defined that piggyback on
27   * top of another, inheriting all the safe method implementations from
28   * BaseDurationField. Should any method require pure delegation to the
29   * wrapped field, simply override and use the provided getWrappedField method.
30   * <p>
31   * DecoratedDurationField is thread-safe and immutable, and its subclasses must
32   * be as well.
33   *
34   * @author Brian S O'Neill
35   * @see DelegatedDurationField
36   * @since 1.0
37   */
38  public class DecoratedDurationField extends BaseDurationField {
39  
40      private static final long serialVersionUID = 8019982251647420015L;
41  
42      /** The DurationField being wrapped */
43      private final DurationField iField;
44  
45      /**
46       * Constructor.
47       * 
48       * @param field  the base field
49       * @param type  the type to actually use
50       */
51      public DecoratedDurationField(DurationField field, DurationFieldType type) {
52          super(type);
53          if (field == null) {
54              throw new IllegalArgumentException("The field must not be null");
55          }
56          if (!field.isSupported()) {
57              throw new IllegalArgumentException("The field must be supported");
58          }
59          iField = field;
60      }
61  
62      //-----------------------------------------------------------------------
63      /**
64       * Gets the wrapped duration field.
65       * 
66       * @return the wrapped DurationField
67       */
68      public final DurationField getWrappedField() {
69          return iField;
70      }
71  
72      public boolean isPrecise() {
73          return iField.isPrecise();
74      }
75  
76      public long getValueAsLong(long duration, long instant) {
77          return iField.getValueAsLong(duration, instant);
78      }
79  
80      public long getMillis(int value, long instant) {
81          return iField.getMillis(value, instant);
82      }
83  
84      public long getMillis(long value, long instant) {
85          return iField.getMillis(value, instant);
86      }
87  
88      public long add(long instant, int value) {
89          return iField.add(instant, value);
90      }
91  
92      public long add(long instant, long value) {
93          return iField.add(instant, value);
94      }
95  
96      public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) {
97          return iField.getDifferenceAsLong(minuendInstant, subtrahendInstant);
98      }
99  
100     public long getUnitMillis() {
101         return iField.getUnitMillis();
102     }
103 
104 }