Lists.java

// -*- mode: java; c-basic-offset: 2; -*-
// Copyright 2009-2011 Google, All Rights reserved
// Copyright 2011-2012 MIT, All rights reserved
// Released under the Apache License, Version 2.0
// http://www.apache.org/licenses/LICENSE-2.0

package com.google.appinventor.components.runtime.collect;

import java.util.ArrayList;
import java.util.Collections;

/**
 * Provides static methods for creating {@code List} instances easily, and other
 * utility methods for working with lists.
 *
 * Note: This was copied from the com.google.android.collect.Lists class
 *
 * @author markf@google.com (Mark Friedman)
 */
public class Lists {

  /**
   * Creates an empty {@code ArrayList} instance.
   *
   * <p><b>Note:</b> if you only need an <i>immutable</i> empty List, use
   * {@link Collections#emptyList} instead.
   *
   * @return a newly-created, initially-empty {@code ArrayList}
   */
  public static <E> ArrayList<E> newArrayList() {
    return new ArrayList<E>();
  }

  /**
   * Creates a resizable {@code ArrayList} instance containing the given
   * elements.
   *
   * <p><b>Note:</b> due to a bug in javac 1.5.0_06, we cannot support the
   * following:
   *
   * <p>{@code List<Base> list = Lists.newArrayList(sub1, sub2);}
   *
   * <p>where {@code sub1} and {@code sub2} are references to subtypes of
   * {@code Base}, not of {@code Base} itself. To get around this, you must
   * use:
   *
   * <p>{@code List<Base> list = Lists.<Base>newArrayList(sub1, sub2);}
   *
   * @param elements the elements that the list should contain, in order
   * @return a newly-created {@code ArrayList} containing those elements
   */
  public static <E> ArrayList<E> newArrayList(E... elements) {
    int capacity = (elements.length * 110) / 100 + 5;
    ArrayList<E> list = new ArrayList<E>(capacity);
    Collections.addAll(list, elements);
    return list;
  }
}