com.pushinginertia.commons.ui.TimePeriod.java Source code

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Here is the source code for com.pushinginertia.commons.ui.TimePeriod.java

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/* Copyright (c) 2011-2013 Pushing Inertia
 * All rights reserved.  http://pushinginertia.com
 *
 * Licensed 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 com.pushinginertia.commons.ui;

import com.pushinginertia.commons.core.validation.ValidateAs;
import com.pushinginertia.commons.lang.MathUtils;
import org.joda.time.Duration;

import java.io.Serializable;
import java.util.ResourceBundle;

/**
 * Accepts a duration and represents it in days, weeks, or months, depending on the length of the duration.
 * It is divided into the appropriate unit of measure and then rounded. This is useful for displaying a duration in
 * a UI where it's appropriate to show an approximate representation of the duration.
 * <p>
 * The period consists of a count of time and a unit of measure for that time, represented as a resource lookup key.
 * <p>
 * Strings for the following resource keys must exist:
 * <ul>
 *     <li>TimePeriod.Minute</li>
 *     <li>TimePeriod.Minutes</li>
 *     <li>TimePeriod.Hour</li>
 *     <li>TimePeriod.Hours</li>
 *     <li>TimePeriod.Day</li>
 *     <li>TimePeriod.Days</li>
 *     <li>TimePeriod.Week</li>
 *     <li>TimePeriod.Weeks</li>
 *     <li>TimePeriod.Month</li>
 *     <li>TimePeriod.Months</li>
 * </ul>
 */
public class TimePeriod implements Serializable {
    private static final long serialVersionUID = 1L;

    private final long quantity;
    private final String descriptorResourceKey;

    public TimePeriod(final Duration duration) {
        ValidateAs.notNull(duration, "duration");
        final long days = duration.getStandardDays();

        // about 30.4 days in a month
        // N days: if dayCount <= 31
        // N weeks: if 31 < dayCount <= 61 and
        // N months: if 61 < dayCount
        final StringBuilder key = new StringBuilder("TimePeriod.");
        if (days < 1) {
            final long minutes = duration.getStandardMinutes();
            if (minutes < 60) {
                quantity = minutes;
                key.append("Minute");
            } else {
                quantity = duration.getStandardHours();
                key.append("Hour");
            }
        } else if (days <= 31) {
            quantity = days;
            key.append("Day");
        } else if (days <= 61) {
            quantity = MathUtils.integerDivisionRound(days, 7);
            key.append("Week");
        } else {
            quantity = MathUtils.integerDivisionRound(days, 30);
            key.append("Month");
        }
        if (quantity != 1)
            key.append('s');
        descriptorResourceKey = key.toString();
    }

    /**
     * The resource key to look up when presenting the time period. The string associated with the returned key must
     * contain a '${i}' placeholder, which will be replaced with the quantity.
     * @return resource key
     */
    public String getDescriptorResourceKey() {
        return descriptorResourceKey;
    }

    /**
     * The quantity that is substituted into the '${i}' placeholder in the resource string matching
     * {@link #descriptorResourceKey}.
     * @return calculated quantity
     */
    public long getQuantity() {
        return quantity;
    }

    /**
     * Looks up the appropriate resource string defined by {@link #getDescriptorResourceKey()} and applies a substitution
     * on all instances of '${i}' with the quantity for the time period.
     * @param rb resource bundle to use
     * @return constructed string
     */
    public String getString(final ResourceBundle rb) {
        final String s = rb.getString(descriptorResourceKey);
        return s.replace("${i}", Long.toString(quantity));
    }

    /**
     * A simple interface used by {@link TimePeriod#getString(com.pushinginertia.commons.ui.TimePeriod.TimePeriodResourceBundle)}
     * to enclose a custom resource bundle definition.
     */
    public interface TimePeriodResourceBundle {
        public String getString(String resourceKey);
    }

    /**
     * Looks up the appropriate resource string defined by {@link #getDescriptorResourceKey()} and applies a substitution
     * on all instances of '${i}' with the quantity for the time period.
     * @param rb resource bundle to use
     * @return constructed string
     */
    public String getString(final TimePeriodResourceBundle rb) {
        final String s = rb.getString(descriptorResourceKey);
        return s.replace("${i}", Long.toString(quantity));
    }
}