Collections.java

/*
 * Copyright 2007 ZXing authors
 *
 * 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.google.zxing.common;

import java.util.Vector;

/**
 * <p>This is basically a substitute for <code>java.util.Collections</code>, which is not
 * present in MIDP 2.0 / CLDC 1.1.</p>
 *
 * @author Sean Owen
 */
public final class Collections {

  private Collections() {
  }

  /**
   * Sorts its argument (destructively) using insert sort; in the context of this package
   * insertion sort is simple and efficient given its relatively small inputs.
   *
   * @param vector vector to sort
   * @param comparator comparator to define sort ordering
   */
  public static void insertionSort(Vector vector, Comparator comparator) {
    int max = vector.size();
    for (int i = 1; i < max; i++) {
      Object value = vector.elementAt(i);
      int j = i - 1;
      Object valueB;
      while (j >= 0 && comparator.compare((valueB = vector.elementAt(j)), value) > 0) {
        vector.setElementAt(valueB, j + 1);
        j--;
      }
      vector.setElementAt(value, j + 1);
    }
  }

}