org.dmfs.rfc5545.recur.ByMonthExpander Maven / Gradle / Ivy

Go to download
/*
 * Copyright (C) 2013 Marten Gajda 
 *
 * 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 org.dmfs.rfc5545.recur;

import org.dmfs.rfc5545.Instance;
import org.dmfs.rfc5545.calendarmetrics.CalendarMetrics;
import org.dmfs.rfc5545.recur.RecurrenceRule.Part;


/**
 * A filter that expands recurrence rules by month. Months are expanded for yearly rules only.
 *
 * @author Marten Gajda
 */
final class ByMonthExpander extends ByExpander
{
    /**
     * The list of months to expand.
     */
    private final int[] mMonths;


    public ByMonthExpander(RecurrenceRule rule, RuleIterator previous, CalendarMetrics calendarTools, long start)
    {
        super(previous, calendarTools, start);
        // sort array to iterate the months in the right order, that saves an additional sorting of each interval
        mMonths = StaticUtils.ListToSortedArray(rule.getByPart(Part.BYMONTH));
    }


    @Override
    void expand(long instance, long start)
    {
        for (int month : mMonths)
        {
            long newInstance = Instance.setMonth(instance, month);
            if (newInstance < start)
            {
                // instance is before start, nothing to do here
                continue;
            }

            addInstance(newInstance);
        }
    }
}