com.github.errantlinguist.collections.DelegateListIteratorHolder.java Source code

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Here is the source code for com.github.errantlinguist.collections.DelegateListIteratorHolder.java

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/*
 *    Copyright 2014 Todd Shore
 *
 *   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.github.errantlinguist.collections;

import java.util.ListIterator;
import java.util.Objects;

import com.google.common.collect.ForwardingListIterator;

/**
 * A subclass of {@link ForwardingListIterator} which holds a reference to
 * {@link #delegate() the iterator it delegates to}.
 * 
 * @author <a href="mailto:errantlinguist+github@gmail.com">Todd Shore</a>
 * @version 2014-02-10
 * @since 2014-02-10
 *
 * @param <E>
 *            The type of the elements to be iterated.
 * 
 */
public class DelegateListIteratorHolder<E> extends ForwardingListIterator<E> {

    /**
     * The {@link ListIterator} to delegate to.
     */
    private final ListIterator<E> delegate;

    /**
     * 
     * @param delegate
     *            The {@link ListIterator} to delegate to.
     */
    public DelegateListIteratorHolder(final ListIterator<E> delegate) {
        this.delegate = delegate;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(final Object obj) {
        final boolean result;

        if (super.equals(obj)) {
            result = true;
        } else if (obj == null) {
            result = false;
        } else if (obj instanceof DelegateListIteratorHolder<?>) {
            final DelegateListIteratorHolder<?> other = (DelegateListIteratorHolder<?>) obj;
            result = Objects.equals(delegate(), other.delegate());
        } else {
            result = false;
        }

        return result;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        final Object decorated = delegate();
        result = (prime * result) + ((decorated == null) ? 0 : decorated.hashCode());
        return result;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        final String delegatePrefix = "DelegateListIteratorHolder [delegate()=";
        final String delegateStr = Objects.toString(delegate());
        final StringBuilder builder = new StringBuilder(delegatePrefix.length() + delegateStr.length() + 1);
        builder.append(delegatePrefix);
        builder.append(delegateStr);
        builder.append(']');
        return builder.toString();
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.google.common.collect.ForwardingListIterator#delegate()
     */
    @Override
    protected final ListIterator<E> delegate() {
        return delegate;
    }
}