Fixes changing the font scale of a background user should not affect UI

It also fixes the same issue with the font weight.

Bug: 190043007
Test: atest MultiUserTests
Change-Id: I90c5a7f74613b6032f501c8b53ad79025f09a211

services/core/java/com/android/server/wm/ActivityTaskManagerService.java

@@ -4406,6 +4406,10 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
     }
 
     private void updateFontScaleIfNeeded(@UserIdInt int userId) {
+        if (userId != getCurrentUserId()) {
+            return;
+        }
+
         final float scaleFactor = Settings.System.getFloatForUser(mContext.getContentResolver(),
                 FONT_SCALE, 1.0f, userId);
 
@@ -4422,6 +4426,10 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
     }
 
     private void updateFontWeightAdjustmentIfNeeded(@UserIdInt int userId) {
+        if (userId != getCurrentUserId()) {
+            return;
+        }
+
         final int fontWeightAdjustment =
                 Settings.Secure.getIntForUser(
                         mContext.getContentResolver(),

tests/MultiUser/Android.bp

@@ -0,0 +1,27 @@
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_license"],
+}
+
+android_test {
+    name: "MultiUserTests",
+    platform_apis: true,
+    srcs: ["src/**/*.java"],
+
+    static_libs: [
+        "androidx.test.rules",
+        "androidx.test.runner",
+        "services.core",
+    ],
+    libs: [
+        "android.test.runner",
+        "android.test.base",
+        "android.test.mock",
+    ],
+    certificate: "platform",
+    test_suites: ["device-tests"],
+}

tests/MultiUser/AndroidManifest.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="com.android.test.multiuser">
+    <uses-permission android:name="android.permission.WRITE_SETTINGS" />
+    <uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS" />
+    <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS_FULL" />
+    <uses-permission android:name="android.permission.MANAGE_USERS" />
+
+
+    <application android:debuggable="true">
+        <uses-library android:name="android.test.runner" />
+    </application>
+
+    <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"
+                     android:targetPackage="com.android.test.multiuser">
+    </instrumentation>
+</manifest>

tests/MultiUser/TEST_MAPPING

@@ -0,0 +1,7 @@
+{
+  "presubmit": [
+    {
+      "name": "MultiUserTests"
+    }
+  ]
+}

tests/MultiUser/src/com/android/test/multiuser/MultiUserSettingsTests.java

@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2021 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.test.multiuser;
+
+import static android.provider.Settings.Secure.FONT_WEIGHT_ADJUSTMENT;
+import static android.provider.Settings.System.FONT_SCALE;
+
+import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
+
+import static org.junit.Assert.assertEquals;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.os.UserManager;
+import android.provider.Settings;
+
+import androidx.test.platform.app.InstrumentationRegistry;
+
+import org.junit.Assume;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class MultiUserSettingsTests {
+    private final Context mContext = getInstrumentation().getTargetContext();
+    private final ContentResolver mContentResolver = mContext.getContentResolver();
+
+    private static void waitForBroadcastIdle() throws InterruptedException {
+        final int sleepDuration = 1000;
+        final String cmdAmWaitForBroadcastIdle = "am wait-for-broadcast-idle";
+
+        Thread.sleep(sleepDuration);
+        InstrumentationRegistry.getInstrumentation().getUiAutomation()
+                .executeShellCommand(cmdAmWaitForBroadcastIdle);
+        Thread.sleep(sleepDuration);
+    }
+
+    private float getGlobalFontScale() {
+        return mContext.getResources().getConfiguration().fontScale;
+    }
+
+    private int getGlobalFontWeight() {
+        return mContext.getResources().getConfiguration().fontWeightAdjustment;
+    }
+
+    private float getFontScaleOfUser(int userId) {
+        return Settings.System.getFloatForUser(mContentResolver, FONT_SCALE, 1, userId);
+    }
+
+    private int getFontWeightOfUser(int userId) {
+        return Settings.Secure.getIntForUser(mContentResolver, FONT_WEIGHT_ADJUSTMENT, 1, userId);
+    }
+
+    private void setFontScaleOfUser(float fontScale, int userId) throws InterruptedException {
+        Settings.System.putFloatForUser(mContentResolver, FONT_SCALE, fontScale, userId);
+        waitForBroadcastIdle();
+    }
+
+    private void setFontWeightOfUser(int fontWeight, int userId) throws InterruptedException {
+        Settings.Secure.putIntForUser(mContentResolver, FONT_WEIGHT_ADJUSTMENT, fontWeight, userId);
+        waitForBroadcastIdle();
+    }
+
+    @Test
+    public void testChangingFontScaleOfABackgroundUser_shouldNotAffectUI()
+            throws InterruptedException {
+
+        Assume.assumeTrue(UserManager.supportsMultipleUsers());
+
+        UserManager userManager = UserManager.get(mContext);
+
+        final int backgroundUserId = userManager.createUser("test_user",
+                UserManager.USER_TYPE_FULL_SECONDARY, 0).id;
+        final float oldFontScaleOfBgUser = getFontScaleOfUser(backgroundUserId);
+        final float oldGlobalFontScale = getGlobalFontScale();
+        final float newFontScaleOfBgUser = 1 + Math.max(oldGlobalFontScale, oldFontScaleOfBgUser);
+
+        try {
+            setFontScaleOfUser(newFontScaleOfBgUser, backgroundUserId);
+            final float newGlobalFontScale = getGlobalFontScale();
+            assertEquals(oldGlobalFontScale, newGlobalFontScale, 0);
+        } finally {
+            setFontScaleOfUser(oldFontScaleOfBgUser, backgroundUserId);
+            userManager.removeUser(backgroundUserId);
+        }
+    }
+
+    @Test
+    public void testChangingFontWeightOfABackgroundUser_shouldNotAffectUI()
+            throws InterruptedException {
+
+        Assume.assumeTrue(UserManager.supportsMultipleUsers());
+
+        UserManager userManager = UserManager.get(mContext);
+
+        final int backgroundUserId = userManager.createUser("test_user",
+                UserManager.USER_TYPE_FULL_SECONDARY, 0).id;
+        final int oldFontWeightOfBgUser = getFontWeightOfUser(backgroundUserId);
+        final int oldGlobalFontWeight = getGlobalFontWeight();
+        final int newFontWeightOfBgUser = 2 * Math.max(oldGlobalFontWeight, oldFontWeightOfBgUser);
+
+        try {
+            setFontWeightOfUser(newFontWeightOfBgUser, backgroundUserId);
+            final int newGlobalFontWeight = getGlobalFontWeight();
+            assertEquals(oldGlobalFontWeight, newGlobalFontWeight);
+        } finally {
+            setFontWeightOfUser(oldFontWeightOfBgUser, backgroundUserId);
+            userManager.removeUser(backgroundUserId);
+        }
+    }
+
+    @Test
+    public void testChangingFontScaleOfTheForegroundUser_shouldAffectUI()
+            throws InterruptedException {
+
+        Assume.assumeTrue(UserManager.supportsMultipleUsers());
+
+        final int currentUserId = mContext.getUserId();
+        final float oldFontScale = getFontScaleOfUser(currentUserId);
+        final float newFontScale = 1 + oldFontScale;
+
+        try {
+            setFontScaleOfUser(newFontScale, currentUserId);
+            final float globalFontScale = getGlobalFontScale();
+            assertEquals(newFontScale, globalFontScale, 0);
+        } finally {
+            setFontScaleOfUser(oldFontScale, currentUserId);
+        }
+    }
+
+    @Test
+    public void testChangingFontWeightOfTheForegroundUser_shouldAffectUI()
+            throws InterruptedException {
+
+        Assume.assumeTrue(UserManager.supportsMultipleUsers());
+
+        final int currentUserId = mContext.getUserId();
+        final int oldFontWeight = getFontWeightOfUser(currentUserId);
+        final int newFontWeight = 2 * oldFontWeight;
+
+        try {
+            setFontWeightOfUser(newFontWeight, currentUserId);
+            final int globalFontWeight = getGlobalFontWeight();
+            assertEquals(newFontWeight, globalFontWeight);
+        } finally {
+            setFontWeightOfUser(oldFontWeight, currentUserId);
+        }
+    }
+}