1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.hardware.camera2.utils;
18
19import android.util.Size;
20
21import java.util.Collections;
22import java.util.Comparator;
23import java.util.List;
24
25import static com.android.internal.util.Preconditions.*;
26
27/**
28 * Comparator for {@link Size} objects by the area.
29 *
30 * <p>This comparator totally orders by rectangle area. Tie-breaks on width.</p>
31 */
32public class SizeAreaComparator implements Comparator<Size> {
33    /**
34     * {@inheritDoc}
35     */
36    @Override
37    public int compare(Size size, Size size2) {
38        checkNotNull(size, "size must not be null");
39        checkNotNull(size2, "size2 must not be null");
40
41        if (size.equals(size2)) {
42            return 0;
43        }
44
45        long width = size.getWidth();
46        long width2 = size2.getWidth();
47        long area = width * size.getHeight();
48        long area2 = width2 * size2.getHeight();
49
50        if (area == area2) {
51            return (width > width2) ? 1 : -1;
52        }
53
54        return (area > area2) ? 1 : -1;
55    }
56
57    /**
58     * Get the largest {@code Size} from the list by comparing each size's area
59     * by each other using {@link SizeAreaComparator}.
60     *
61     * @param sizes a non-{@code null} list of non-{@code null} sizes
62     * @return a non-{@code null} size
63     *
64     * @throws NullPointerException if {@code sizes} or any elements in it were {@code null}
65     */
66    public static Size findLargestByArea(List<Size> sizes) {
67        checkNotNull(sizes, "sizes must not be null");
68
69        return Collections.max(sizes, new SizeAreaComparator());
70    }
71}