001/*
002 *  Copyright 2001-2005 Stephen Colebourne
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.joda.time.field;
017
018import org.joda.time.DurationField;
019import org.joda.time.DurationFieldType;
020
021/**
022 * <code>DecoratedDurationField</code> extends {@link BaseDurationField},
023 * implementing only the minimum required set of methods. These implemented
024 * methods delegate to a wrapped field.
025 * <p>
026 * This design allows new DurationField types to be defined that piggyback on
027 * top of another, inheriting all the safe method implementations from
028 * BaseDurationField. Should any method require pure delegation to the
029 * wrapped field, simply override and use the provided getWrappedField method.
030 * <p>
031 * DecoratedDurationField is thread-safe and immutable, and its subclasses must
032 * be as well.
033 *
034 * @author Brian S O'Neill
035 * @see DelegatedDurationField
036 * @since 1.0
037 */
038public class DecoratedDurationField extends BaseDurationField {
039
040    private static final long serialVersionUID = 8019982251647420015L;
041
042    /** The DurationField being wrapped */
043    private final DurationField iField;
044
045    /**
046     * Constructor.
047     * 
048     * @param field  the base field
049     * @param type  the type to actually use
050     */
051    public DecoratedDurationField(DurationField field, DurationFieldType type) {
052        super(type);
053        if (field == null) {
054            throw new IllegalArgumentException("The field must not be null");
055        }
056        if (!field.isSupported()) {
057            throw new IllegalArgumentException("The field must be supported");
058        }
059        iField = field;
060    }
061
062    //-----------------------------------------------------------------------
063    /**
064     * Gets the wrapped duration field.
065     * 
066     * @return the wrapped DurationField
067     */
068    public final DurationField getWrappedField() {
069        return iField;
070    }
071
072    public boolean isPrecise() {
073        return iField.isPrecise();
074    }
075
076    public long getValueAsLong(long duration, long instant) {
077        return iField.getValueAsLong(duration, instant);
078    }
079
080    public long getMillis(int value, long instant) {
081        return iField.getMillis(value, instant);
082    }
083
084    public long getMillis(long value, long instant) {
085        return iField.getMillis(value, instant);
086    }
087
088    public long add(long instant, int value) {
089        return iField.add(instant, value);
090    }
091
092    public long add(long instant, long value) {
093        return iField.add(instant, value);
094    }
095
096    public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) {
097        return iField.getDifferenceAsLong(minuendInstant, subtrahendInstant);
098    }
099
100    public long getUnitMillis() {
101        return iField.getUnitMillis();
102    }
103
104}