| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * 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.android.inputmethod.latin.common; |
| |
| import com.android.inputmethod.annotations.UsedForTesting; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Map; |
| |
| import javax.annotation.Nonnull; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Utility methods for working with collections. |
| */ |
| public final class CollectionUtils { |
| private CollectionUtils() { |
| // This utility class is not publicly instantiable. |
| } |
| |
| /** |
| * Converts a sub-range of the given array to an ArrayList of the appropriate type. |
| * @param array Array to be converted. |
| * @param start First index inclusive to be converted. |
| * @param end Last index exclusive to be converted. |
| * @throws IllegalArgumentException if start or end are out of range or start > end. |
| */ |
| @Nonnull |
| public static <E> ArrayList<E> arrayAsList(@Nonnull final E[] array, final int start, |
| final int end) { |
| if (start < 0 || start > end || end > array.length) { |
| throw new IllegalArgumentException("Invalid start: " + start + " end: " + end |
| + " with array.length: " + array.length); |
| } |
| |
| final ArrayList<E> list = new ArrayList<>(end - start); |
| for (int i = start; i < end; i++) { |
| list.add(array[i]); |
| } |
| return list; |
| } |
| |
| /** |
| * Tests whether c contains no elements, true if c is null or c is empty. |
| * @param c Collection to test. |
| * @return Whether c contains no elements. |
| */ |
| @UsedForTesting |
| public static boolean isNullOrEmpty(@Nullable final Collection c) { |
| return c == null || c.isEmpty(); |
| } |
| |
| /** |
| * Tests whether map contains no elements, true if map is null or map is empty. |
| * @param map Map to test. |
| * @return Whether map contains no elements. |
| */ |
| @UsedForTesting |
| public static boolean isNullOrEmpty(@Nullable final Map map) { |
| return map == null || map.isEmpty(); |
| } |
| } |