| /* |
| * 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 com.android.server.wm; |
| |
| import java.util.ArrayList; |
| |
| /** |
| * An {@link ArrayList} with extended functionality to be used as the children data structure in |
| * {@link WindowContainer}. |
| */ |
| class WindowList<E> extends ArrayList<E> { |
| |
| void addFirst(E e) { |
| add(0, e); |
| } |
| |
| E peekLast() { |
| return size() > 0 ? get(size() - 1) : null; |
| } |
| |
| E peekFirst() { |
| return size() > 0 ? get(0) : null; |
| } |
| } |