| 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.DateTimeField; |
| 19 | import org.joda.time.DateTimeFieldType; |
| 20 | import org.joda.time.DurationField; |
| 21 | |
| 22 | /** |
| 23 | * Divides a DateTimeField such that the retrieved values are reduced by a |
| 24 | * fixed divisor. The field's unit duration is scaled accordingly, but the |
| 25 | * range duration is unchanged. |
| 26 | * <p> |
| 27 | * DividedDateTimeField is thread-safe and immutable. |
| 28 | * |
| 29 | * @see RemainderDateTimeField |
| 30 | * |
| 31 | * @author Stephen Colebourne |
| 32 | * @author Brian S O'Neill |
| 33 | * @since 1.0 |
| 34 | */ |
| 35 | public class DividedDateTimeField extends DecoratedDateTimeField { |
| 36 | |
| 37 | private static final long serialVersionUID = 8318475124230605365L; |
| 38 | |
| 39 | // Shared with RemainderDateTimeField. |
| 40 | final int iDivisor; |
| 41 | final DurationField iDurationField; |
| 42 | |
| 43 | private final int iMin; |
| 44 | private final int iMax; |
| 45 | |
| 46 | /** |
| 47 | * Constructor. |
| 48 | * |
| 49 | * @param field the field to wrap, like "year()". |
| 50 | * @param type the field type this field will actually use |
| 51 | * @param divisor divisor, such as 100 years in a century |
| 52 | * @throws IllegalArgumentException if divisor is less than two |
| 53 | */ |
| 54 | public DividedDateTimeField(DateTimeField field, |
| 55 | DateTimeFieldType type, int divisor) { |
| 56 | super(field, type); |
| 57 | |
| 58 | if (divisor < 2) { |
| 59 | throw new IllegalArgumentException("The divisor must be at least 2"); |
| 60 | } |
| 61 | |
| 62 | DurationField unitField = field.getDurationField(); |
| 63 | if (unitField == null) { |
| 64 | iDurationField = null; |
| 65 | } else { |
| 66 | iDurationField = new ScaledDurationField( |
| 67 | unitField, type.getDurationType(), divisor); |
| 68 | } |
| 69 | |
| 70 | iDivisor = divisor; |
| 71 | |
| 72 | int i = field.getMinimumValue(); |
| 73 | int min = (i >= 0) ? i / divisor : ((i + 1) / divisor - 1); |
| 74 | |
| 75 | int j = field.getMaximumValue(); |
| 76 | int max = (j >= 0) ? j / divisor : ((j + 1) / divisor - 1); |
| 77 | |
| 78 | iMin = min; |
| 79 | iMax = max; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Construct a DividedDateTimeField that compliments the given |
| 84 | * RemainderDateTimeField. |
| 85 | * |
| 86 | * @param remainderField complimentary remainder field, like "yearOfCentury()". |
| 87 | * @param type the field type this field will actually use |
| 88 | */ |
| 89 | public DividedDateTimeField(RemainderDateTimeField remainderField, DateTimeFieldType type) { |
| 90 | super(remainderField.getWrappedField(), type); |
| 91 | int divisor = iDivisor = remainderField.iDivisor; |
| 92 | iDurationField = remainderField.iRangeField; |
| 93 | |
| 94 | DateTimeField field = getWrappedField(); |
| 95 | int i = field.getMinimumValue(); |
| 96 | int min = (i >= 0) ? i / divisor : ((i + 1) / divisor - 1); |
| 97 | |
| 98 | int j = field.getMaximumValue(); |
| 99 | int max = (j >= 0) ? j / divisor : ((j + 1) / divisor - 1); |
| 100 | |
| 101 | iMin = min; |
| 102 | iMax = max; |
| 103 | } |
| 104 | |
| 105 | /** |
| 106 | * Get the amount of scaled units from the specified time instant. |
| 107 | * |
| 108 | * @param instant the time instant in millis to query. |
| 109 | * @return the amount of scaled units extracted from the input. |
| 110 | */ |
| 111 | public int get(long instant) { |
| 112 | int value = getWrappedField().get(instant); |
| 113 | if (value >= 0) { |
| 114 | return value / iDivisor; |
| 115 | } else { |
| 116 | return ((value + 1) / iDivisor) - 1; |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Add the specified amount of scaled units to the specified time |
| 122 | * instant. The amount added may be negative. |
| 123 | * |
| 124 | * @param instant the time instant in millis to update. |
| 125 | * @param amount the amount of scaled units to add (can be negative). |
| 126 | * @return the updated time instant. |
| 127 | */ |
| 128 | public long add(long instant, int amount) { |
| 129 | return getWrappedField().add(instant, amount * iDivisor); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Add the specified amount of scaled units to the specified time |
| 134 | * instant. The amount added may be negative. |
| 135 | * |
| 136 | * @param instant the time instant in millis to update. |
| 137 | * @param amount the amount of scaled units to add (can be negative). |
| 138 | * @return the updated time instant. |
| 139 | */ |
| 140 | public long add(long instant, long amount) { |
| 141 | return getWrappedField().add(instant, amount * iDivisor); |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Add to the scaled component of the specified time instant, |
| 146 | * wrapping around within that component if necessary. |
| 147 | * |
| 148 | * @param instant the time instant in millis to update. |
| 149 | * @param amount the amount of scaled units to add (can be negative). |
| 150 | * @return the updated time instant. |
| 151 | */ |
| 152 | public long addWrapField(long instant, int amount) { |
| 153 | return set(instant, FieldUtils.getWrappedValue(get(instant), amount, iMin, iMax)); |
| 154 | } |
| 155 | |
| 156 | public int getDifference(long minuendInstant, long subtrahendInstant) { |
| 157 | return getWrappedField().getDifference(minuendInstant, subtrahendInstant) / iDivisor; |
| 158 | } |
| 159 | |
| 160 | public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) { |
| 161 | return getWrappedField().getDifferenceAsLong(minuendInstant, subtrahendInstant) / iDivisor; |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Set the specified amount of scaled units to the specified time instant. |
| 166 | * |
| 167 | * @param instant the time instant in millis to update. |
| 168 | * @param value value of scaled units to set. |
| 169 | * @return the updated time instant. |
| 170 | * @throws IllegalArgumentException if value is too large or too small. |
| 171 | */ |
| 172 | public long set(long instant, int value) { |
| 173 | FieldUtils.verifyValueBounds(this, value, iMin, iMax); |
| 174 | int remainder = getRemainder(getWrappedField().get(instant)); |
| 175 | return getWrappedField().set(instant, value * iDivisor + remainder); |
| 176 | } |
| 177 | |
| 178 | /** |
| 179 | * Returns a scaled version of the wrapped field's unit duration field. |
| 180 | */ |
| 181 | public DurationField getDurationField() { |
| 182 | return iDurationField; |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Get the minimum value for the field. |
| 187 | * |
| 188 | * @return the minimum value |
| 189 | */ |
| 190 | public int getMinimumValue() { |
| 191 | return iMin; |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Get the maximum value for the field. |
| 196 | * |
| 197 | * @return the maximum value |
| 198 | */ |
| 199 | public int getMaximumValue() { |
| 200 | return iMax; |
| 201 | } |
| 202 | |
| 203 | public long roundFloor(long instant) { |
| 204 | DateTimeField field = getWrappedField(); |
| 205 | return field.roundFloor(field.set(instant, get(instant) * iDivisor)); |
| 206 | } |
| 207 | |
| 208 | public long remainder(long instant) { |
| 209 | return set(instant, get(getWrappedField().remainder(instant))); |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * Returns the divisor applied, in the field's units. |
| 214 | * |
| 215 | * @return the divisor |
| 216 | */ |
| 217 | public int getDivisor() { |
| 218 | return iDivisor; |
| 219 | } |
| 220 | |
| 221 | private int getRemainder(int value) { |
| 222 | if (value >= 0) { |
| 223 | return value % iDivisor; |
| 224 | } else { |
| 225 | return (iDivisor - 1) + ((value + 1) % iDivisor); |
| 226 | } |
| 227 | } |
| 228 | |
| 229 | } |