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 
17 package com.android.server.wm.utils;
18 
19 import android.graphics.Rect;
20 import android.util.Size;
21 import android.view.DisplayCutout;
22 import android.view.Gravity;
23 
24 import java.util.List;
25 import 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  */
31 public 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 
WmDisplayCutout(DisplayCutout inner, Size frameSize)39     public WmDisplayCutout(DisplayCutout inner, Size frameSize) {
40         mInner = inner;
41         mFrameSize = frameSize;
42     }
43 
computeSafeInsets(DisplayCutout inner, int displayWidth, int displayHeight)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      */
inset(int insetLeft, int insetTop, int insetRight, int insetBottom)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      */
calculateRelativeTo(Rect frame)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      */
computeSafeInsets(int width, int height)97     public WmDisplayCutout computeSafeInsets(int width, int height) {
98         return computeSafeInsets(mInner, width, height);
99     }
100 
computeSafeInsets(Size displaySize, DisplayCutout cutout)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 
findInsetForSide(Size display, List<Rect> boundingRects, int gravity)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 
getDisplayCutout()155     public DisplayCutout getDisplayCutout() {
156         return mInner;
157     }
158 
159     @Override
equals(Object o)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
hashCode()170     public int hashCode() {
171         return Objects.hash(mInner, mFrameSize);
172     }
173 }
174