org.openbp.common.util.SortingArrayList.java Source code

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Here is the source code for org.openbp.common.util.SortingArrayList.java

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/*
 *   Copyright 2007 skynamics AG
 *
 *   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.openbp.common.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;

import org.apache.commons.collections.comparators.ComparableComparator;

/**
 * Array list that sorts its contents.
 * If the {@link #setAutoSort} property is set to true, the list will sort after any add operation to the list.
 * Otherwise, the {@link #sort} method must be called.
 *
 * The list will use the comparator 
 * You may set the sorter using {@link #setComparator} method.
 *
 * @author Heiko Erhardt
 */
public class SortingArrayList extends ArrayList {
    //////////////////////////////////////////////////
    // @@ Properties
    //////////////////////////////////////////////////

    /** Element comparator */
    private Comparator comparator = ComparableComparator.getInstance();

    /** Auto sort property */
    private boolean autoSort = true;

    //////////////////////////////////////////////////
    // @@ Construction
    //////////////////////////////////////////////////

    /**
     * Default constructor.
     */
    public SortingArrayList() {
    }

    /**
     * Gets the element comparator.
     * @nowarn
     */
    public Comparator getComparator() {
        return comparator;
    }

    /**
     * Sets the element comparator.
     * @nowarn
     */
    public void setComparator(Comparator comparator) {
        this.comparator = comparator;
    }

    /**
     * Gets the auto sort property.
     * @nowarn
     */
    public boolean isAutoSort() {
        return autoSort;
    }

    /**
     * Sets the auto sort property.
     * @nowarn
     */
    public void setAutoSort(boolean autoSort) {
        this.autoSort = autoSort;
    }

    /**
     * Sorts the list.
     */
    public void sort() {
        if (size() > 1) {
            if (comparator != null)
                Collections.sort(this, comparator);
            else
                Collections.sort(this);
        }
    }

    /**
     * Invokes the automatic sorting if enabled.
     */
    protected void autoSort() {
        if (autoSort) {
            sort();
        }
    }

    //////////////////////////////////////////////////
    // @@ ArrayList overrides
    //////////////////////////////////////////////////

    public boolean add(Object o) {
        boolean ret = super.add(o);
        autoSort();
        return ret;
    }

    public void add(int index, Object element) {
        super.add(index, element);
        autoSort();
    }

    public boolean addAll(Collection c) {
        boolean ret = super.addAll(c);
        autoSort();
        return ret;
    }

    public boolean addAll(int index, Collection c) {
        boolean ret = super.addAll(index, c);
        autoSort();
        return ret;
    }
}