core/src/main/java/org/apache/struts2/util/Counter.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.struts2.util;

import java.io.Serializable;

/**
 * A bean that can be used to keep track of a counter.
 * <p>
 * Since it is an Iterator it can be used by the iterator tag
 * </p>
 */
public class Counter implements java.util.Iterator, Serializable {

    private static final long serialVersionUID = 2796965884308060179L;

    boolean wrap = false;

    // Attributes ----------------------------------------------------
    long first = 1;
    long current = first;
    long interval = 1;
    long last = -1;


    public void setAdd(long addition) {
        current += addition;
    }

    public void setCurrent(long current) {
        this.current = current;
    }

    public long getCurrent() {
        return current;
    }

    public void setFirst(long first) {
        this.first = first;
        current = first;
    }

    public long getFirst() {
        return first;
    }

    public void setInterval(long interval) {
        this.interval = interval;
    }

    public long getInterval() {
        return interval;
    }

    public void setLast(long last) {
        this.last = last;
    }

    public long getLast() {
        return last;
    }

    // Public --------------------------------------------------------
    public long getNext() {
        long next = current;
        current += interval;

        if (wrap && (current > last)) {
            current -= ((1 + last) - first);
        }

        return next;
    }

    public long getPrevious() {
        current -= interval;

        if (wrap && (current < first)) {
            current += (last - first + 1);
        }

        return current;
    }

    public void setWrap(boolean wrap) {
        this.wrap = wrap;
    }

    public boolean isWrap() {
        return wrap;
    }

    public boolean hasNext() {
        return ((last == -1) || wrap) ? true : (current <= last);
    }

    public Object next() {
        return Long.valueOf(getNext());
    }

    public void remove() {
        // Do nothing
    }
}