1/*
2 * Copyright (C) 2018 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 com.android.server.wm.utils;
18
19import android.graphics.Rect;
20import android.util.Size;
21import android.view.DisplayCutout;
22import android.view.Gravity;
23
24import java.util.List;
25import java.util.Objects;
26
27/**
28 * Wrapper for DisplayCutout that also tracks the display size and using this allows (re)calculating
29 * safe insets.
30 */
31public class WmDisplayCutout {
32
33    public static final WmDisplayCutout NO_CUTOUT = new WmDisplayCutout(DisplayCutout.NO_CUTOUT,
34            null);
35
36    private final DisplayCutout mInner;
37    private final Size mFrameSize;
38
39    public WmDisplayCutout(DisplayCutout inner, Size frameSize) {
40        mInner = inner;
41        mFrameSize = frameSize;
42    }
43
44    public static WmDisplayCutout computeSafeInsets(DisplayCutout inner,
45            int displayWidth, int displayHeight) {
46        if (inner == DisplayCutout.NO_CUTOUT || inner.isBoundsEmpty()) {
47            return NO_CUTOUT;
48        }
49
50        final Size displaySize = new Size(displayWidth, displayHeight);
51        final Rect safeInsets = computeSafeInsets(displaySize, inner);
52        return new WmDisplayCutout(inner.replaceSafeInsets(safeInsets), displaySize);
53    }
54
55    /**
56     * Insets the reference frame of the cutout in the given directions.
57     *
58     * @return a copy of this instance which has been inset
59     * @hide
60     */
61    public WmDisplayCutout inset(int insetLeft, int insetTop, int insetRight, int insetBottom) {
62        DisplayCutout newInner = mInner.inset(insetLeft, insetTop, insetRight, insetBottom);
63
64        if (mInner == newInner) {
65            return this;
66        }
67
68        Size frame = mFrameSize == null ? null : new Size(
69                mFrameSize.getWidth() - insetLeft - insetRight,
70                mFrameSize.getHeight() - insetTop - insetBottom);
71
72        return new WmDisplayCutout(newInner, frame);
73    }
74
75    /**
76     * Recalculates the cutout relative to the given reference frame.
77     *
78     * The safe insets must already have been computed, e.g. with {@link #computeSafeInsets}.
79     *
80     * @return a copy of this instance with the safe insets recalculated
81     * @hide
82     */
83    public WmDisplayCutout calculateRelativeTo(Rect frame) {
84        if (mInner.isEmpty()) {
85            return this;
86        }
87        return inset(frame.left, frame.top,
88                mFrameSize.getWidth() - frame.right, mFrameSize.getHeight() - frame.bottom);
89    }
90
91    /**
92     * Calculates the safe insets relative to the given display size.
93     *
94     * @return a copy of this instance with the safe insets calculated
95     * @hide
96     */
97    public WmDisplayCutout computeSafeInsets(int width, int height) {
98        return computeSafeInsets(mInner, width, height);
99    }
100
101    private static Rect computeSafeInsets(Size displaySize, DisplayCutout cutout) {
102        if (displaySize.getWidth() < displaySize.getHeight()) {
103            final List<Rect> boundingRects = cutout.replaceSafeInsets(
104                    new Rect(0, displaySize.getHeight() / 2, 0, displaySize.getHeight() / 2))
105                    .getBoundingRects();
106            int topInset = findInsetForSide(displaySize, boundingRects, Gravity.TOP);
107            int bottomInset = findInsetForSide(displaySize, boundingRects, Gravity.BOTTOM);
108            return new Rect(0, topInset, 0, bottomInset);
109        } else if (displaySize.getWidth() > displaySize.getHeight()) {
110            final List<Rect> boundingRects = cutout.replaceSafeInsets(
111                    new Rect(displaySize.getWidth() / 2, 0, displaySize.getWidth() / 2, 0))
112                    .getBoundingRects();
113            int leftInset = findInsetForSide(displaySize, boundingRects, Gravity.LEFT);
114            int right = findInsetForSide(displaySize, boundingRects, Gravity.RIGHT);
115            return new Rect(leftInset, 0, right, 0);
116        } else {
117            throw new UnsupportedOperationException("not implemented: display=" + displaySize +
118                    " cutout=" + cutout);
119        }
120    }
121
122    private static int findInsetForSide(Size display, List<Rect> boundingRects, int gravity) {
123        int inset = 0;
124        final int size = boundingRects.size();
125        for (int i = 0; i < size; i++) {
126            Rect boundingRect = boundingRects.get(i);
127            switch (gravity) {
128                case Gravity.TOP:
129                    if (boundingRect.top == 0) {
130                        inset = Math.max(inset, boundingRect.bottom);
131                    }
132                    break;
133                case Gravity.BOTTOM:
134                    if (boundingRect.bottom == display.getHeight()) {
135                        inset = Math.max(inset, display.getHeight() - boundingRect.top);
136                    }
137                    break;
138                case Gravity.LEFT:
139                    if (boundingRect.left == 0) {
140                        inset = Math.max(inset, boundingRect.right);
141                    }
142                    break;
143                case Gravity.RIGHT:
144                    if (boundingRect.right == display.getWidth()) {
145                        inset = Math.max(inset, display.getWidth() - boundingRect.left);
146                    }
147                    break;
148                default:
149                    throw new IllegalArgumentException("unknown gravity: " + gravity);
150            }
151        }
152        return inset;
153    }
154
155    public DisplayCutout getDisplayCutout() {
156        return mInner;
157    }
158
159    @Override
160    public boolean equals(Object o) {
161        if (!(o instanceof WmDisplayCutout)) {
162            return false;
163        }
164        WmDisplayCutout that = (WmDisplayCutout) o;
165        return Objects.equals(mInner, that.mInner) &&
166                Objects.equals(mFrameSize, that.mFrameSize);
167    }
168
169    @Override
170    public int hashCode() {
171        return Objects.hash(mInner, mFrameSize);
172    }
173}
174