1 /*
2  * Copyright (C) 2021 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 android.window;
18 
19 import static android.view.Display.INVALID_DISPLAY;
20 
21 import android.annotation.NonNull;
22 import android.annotation.Nullable;
23 import android.app.ResourcesManager;
24 import android.content.Context;
25 import android.content.pm.ActivityInfo;
26 import android.content.res.Configuration;
27 import android.graphics.Canvas;
28 import android.graphics.Rect;
29 import android.os.IBinder;
30 import android.view.Display;
31 import android.view.WindowManager;
32 
33 /**
34  * A helper class to maintain {@link android.content.res.Configuration} related methods used both
35  * in {@link android.app.Activity} and {@link WindowContext}.
36  *
37  * @hide
38  */
39 public class ConfigurationHelper {
ConfigurationHelper()40     private ConfigurationHelper() {}
41 
42     /** Ask text layout engine to free its caches if there is a locale change. */
freeTextLayoutCachesIfNeeded(int configDiff)43     public static void freeTextLayoutCachesIfNeeded(int configDiff) {
44         if ((configDiff & ActivityInfo.CONFIG_LOCALE) != 0) {
45             Canvas.freeTextLayoutCaches();
46         }
47     }
48 
49     /**
50      * A helper method to filter out {@link ActivityInfo#CONFIG_SCREEN_SIZE} if the
51      * {@link Configuration#diffPublicOnly(Configuration) diff} of two {@link Configuration}
52      * doesn't cross the boundary.
53      *
54      * @see SizeConfigurationBuckets#filterDiff(int, Configuration, Configuration,
55      * SizeConfigurationBuckets)
56      */
diffPublicWithSizeBuckets(@ullable Configuration currentConfig, @NonNull Configuration newConfig, @Nullable SizeConfigurationBuckets buckets)57     public static int diffPublicWithSizeBuckets(@Nullable Configuration currentConfig,
58             @NonNull Configuration newConfig, @Nullable SizeConfigurationBuckets buckets) {
59         // If current configuration is null, it is definitely different from updated Configuration.
60         if (currentConfig == null) {
61             return 0xffffffff;
62         }
63         int publicDiff = currentConfig.diffPublicOnly(newConfig);
64         return SizeConfigurationBuckets.filterDiff(publicDiff, currentConfig, newConfig, buckets);
65     }
66 
67     /**
68      * Returns {@code true} if the {@link android.content.res.Resources} associated with
69      * a {@code token} needs to be updated.
70      *
71      * @param token A {@link Context#getActivityToken() activity token} or
72      * {@link Context#getWindowContextToken() window context token}
73      * @param config The original {@link Configuration}
74      * @param newConfig The updated Configuration
75      * @param displayChanged a flag to indicate there's a display change
76      * @param configChanged a flag to indicate there's a Configuration change.
77      *
78      * @see ResourcesManager#updateResourcesForActivity(IBinder, Configuration, int)
79      */
shouldUpdateResources(IBinder token, @Nullable Configuration config, @NonNull Configuration newConfig, @NonNull Configuration overrideConfig, boolean displayChanged, @Nullable Boolean configChanged)80     public static boolean shouldUpdateResources(IBinder token, @Nullable Configuration config,
81             @NonNull Configuration newConfig, @NonNull Configuration overrideConfig,
82             boolean displayChanged, @Nullable Boolean configChanged) {
83         // The configuration has not yet been initialized. We should update it.
84         if (config == null) {
85             return true;
86         }
87         // If the token associated context is moved to another display, we should update the
88         // ResourcesKey.
89         if (displayChanged) {
90             return true;
91         }
92         // If the new config is the same as the config this Activity is already running with and
93         // the override config also didn't change, then don't update the Resources
94         if (!ResourcesManager.getInstance().isSameResourcesOverrideConfig(token, overrideConfig)) {
95             return true;
96         }
97         // If there's a update on WindowConfiguration#mBounds or maxBounds, we should update the
98         // Resources to make WindowMetrics API report the updated result.
99         if (shouldUpdateWindowMetricsBounds(config, newConfig)) {
100             return true;
101         }
102         return configChanged == null ? config.diff(newConfig) != 0 : configChanged;
103     }
104 
105     /**
106      * Returns {@code true} if {@code displayId} is different from {@code newDisplayId}.
107      * Note that {@link Display#INVALID_DISPLAY} means no difference.
108      */
isDifferentDisplay(int displayId, int newDisplayId)109     public static boolean isDifferentDisplay(int displayId, int newDisplayId) {
110         return newDisplayId != INVALID_DISPLAY && displayId != newDisplayId;
111     }
112 
113     // TODO(b/173090263): Remove this method after the improvement of AssetManager and ResourcesImpl
114     // constructions.
115     /**
116      * Returns {@code true} if the metrics reported by {@link android.view.WindowMetrics} APIs
117      * should be updated.
118      *
119      * @see WindowManager#getCurrentWindowMetrics()
120      * @see WindowManager#getMaximumWindowMetrics()
121      */
shouldUpdateWindowMetricsBounds(@onNull Configuration currentConfig, @NonNull Configuration newConfig)122     private static boolean shouldUpdateWindowMetricsBounds(@NonNull Configuration currentConfig,
123             @NonNull Configuration newConfig) {
124         final Rect currentBounds = currentConfig.windowConfiguration.getBounds();
125         final Rect newBounds = newConfig.windowConfiguration.getBounds();
126 
127         final Rect currentMaxBounds = currentConfig.windowConfiguration.getMaxBounds();
128         final Rect newMaxBounds = newConfig.windowConfiguration.getMaxBounds();
129 
130         return !currentBounds.equals(newBounds) || !currentMaxBounds.equals(newMaxBounds);
131     }
132 }
133