androidx/app/slice/ArrayUtils.java

/*
 * Copyright (C) 2017 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 androidx.app.slice;


import android.support.annotation.RestrictTo;
import android.support.annotation.RestrictTo.Scope;

import java.lang.reflect.Array;
import java.util.Objects;

/**
 * @hide
 */
@RestrictTo(Scope.LIBRARY)
class ArrayUtils {

    public static <T> boolean contains(T[] array, T item) {
        for (T t : array) {
            if (Objects.equals(t, item)) {
                return true;
            }
        }
        return false;
    }

    public static <T> T[] appendElement(Class<T> kind, T[] array, T element) {
        final T[] result;
        final int end;
        if (array != null) {
            end = array.length;
            result = (T[]) Array.newInstance(kind, end + 1);
            System.arraycopy(array, 0, result, 0, end);
        } else {
            end = 0;
            result = (T[]) Array.newInstance(kind, 1);
        }
        result[end] = element;
        return result;
    }

    public static <T> T[] removeElement(Class<T> kind, T[] array, T element) {
        if (array != null) {
            if (!contains(array, element)) {
                return array;
            }
            final int length = array.length;
            for (int i = 0; i < length; i++) {
                if (Objects.equals(array[i], element)) {
                    if (length == 1) {
                        return null;
                    }
                    T[] result = (T[]) Array.newInstance(kind, length - 1);
                    System.arraycopy(array, 0, result, 0, i);
                    System.arraycopy(array, i + 1, result, i, length - i - 1);
                    return result;
                }
            }
        }
        return array;
    }
}