Display: add System Settings Flow & Delegate

Added System Settings Flow that allows to observe and react on
Integer System settings values using Kotlin Coroutines. Also add
System Settings Integer delegate.

Flag: EXEMPT only usage guarded by another flag
Test: atest com.android.settingslib.spaprivileged.settingsprovider
Test: atest --iteration 30 -c frameworks/base/packages/SettingsLib/SpaPrivileged/tests/robotests
Test: verified that SettingsSystemIntegerFlow works with
`display_color_mode` Int setting w/ and /wo set value.
Bug: 390644464

Change-Id: Iacda050b9ff44bda4358756848b15319c699eef1

5 files changed, 296 insertions, 0 deletions

diff --git a/packages/SettingsLib/SpaPrivileged/src/com/android/settingslib/spaprivileged/settingsprovider/SettingsSystemInteger.kt b/packages/SettingsLib/SpaPrivileged/src/com/android/settingslib/spaprivileged/settingsprovider/SettingsSystemInteger.kt
new file mode 100644
index 000000000000..db7a640be893
--- /dev/null
+++ b/packages/SettingsLib/SpaPrivileged/src/com/android/settingslib/spaprivileged/settingsprovider/SettingsSystemInteger.kt
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2025 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.settingslib.spaprivileged.settingsprovider
+
+import android.content.ContentResolver
+import android.content.Context
+import android.provider.Settings
+import com.android.settingslib.spaprivileged.database.contentChangeFlow
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.conflate
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
+
+fun Context.settingsSystemInteger(
+    name: String,
+    defaultValue: Int
+): ReadWriteProperty<Any?, Int> = SettingsSystemIntegerDelegate(this, name, defaultValue)
+
+fun Context.settingsSystemIntegerFlow(name: String, defaultValue: Int): Flow<Int> {
+    val value by settingsSystemInteger(name, defaultValue)
+    return contentChangeFlow(Settings.System.getUriFor(name))
+        .map { value }
+        .distinctUntilChanged()
+        .conflate()
+        .flowOn(Dispatchers.IO)
+}
+
+private class SettingsSystemIntegerDelegate(
+    context: Context,
+    private val name: String,
+    private val defaultValue: Int,
+) : ReadWriteProperty<Any?, Int> {
+
+    private val contentResolver: ContentResolver = context.contentResolver
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): Int =
+        Settings.System.getInt(contentResolver, name, defaultValue)
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
+        Settings.System.putInt(contentResolver, name, value)
+    }
+}
diff --git a/packages/SettingsLib/SpaPrivileged/tests/robotests/Android.bp b/packages/SettingsLib/SpaPrivileged/tests/robotests/Android.bp
new file mode 100644
index 000000000000..e3faf73a69fb
--- /dev/null
+++ b/packages/SettingsLib/SpaPrivileged/tests/robotests/Android.bp
@@ -0,0 +1,59 @@
+//
+// Copyright (C) 2025 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 {
+    default_applicable_licenses: ["frameworks_base_license"],
+}
+
+android_app {
+    name: "SpaPrivilegedRoboTestStub",
+    defaults: [
+        "SpaPrivilegedLib-defaults",
+    ],
+    platform_apis: true,
+    certificate: "platform",
+    privileged: true,
+}
+
+android_robolectric_test {
+    name: "SpaPrivilegedRoboTests",
+    srcs: [
+        ":SpaPrivilegedLib_srcs",
+        "src/**/*.java",
+        "src/**/*.kt",
+    ],
+
+    defaults: [
+        "SpaPrivilegedLib-defaults",
+    ],
+
+    static_libs: [
+        "SpaLibTestUtils",
+        "androidx.test.ext.junit",
+        "androidx.test.runner",
+    ],
+
+    java_resource_dirs: [
+        "config",
+    ],
+
+    instrumentation_for: "SpaPrivilegedRoboTestStub",
+
+    test_options: {
+        timeout: 36000,
+    },
+
+    strict_mode: false,
+}
diff --git a/packages/SettingsLib/SpaPrivileged/tests/robotests/AndroidManifest.xml b/packages/SettingsLib/SpaPrivileged/tests/robotests/AndroidManifest.xml
new file mode 100644
index 000000000000..113852d74f69
--- /dev/null
+++ b/packages/SettingsLib/SpaPrivileged/tests/robotests/AndroidManifest.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2025 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.
+-->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
+    coreApp="true"
+    package="com.android.settingslib.spaprivileged.settingsprovider">
+
+    <uses-permission android:name="android.permission.WRITE_SETTINGS" />
+
+    <application/>
+</manifest>
\ No newline at end of file
diff --git a/packages/SettingsLib/SpaPrivileged/tests/robotests/config/robolectric.properties b/packages/SettingsLib/SpaPrivileged/tests/robotests/config/robolectric.properties
new file mode 100644
index 000000000000..95a24bde00f6
--- /dev/null
+++ b/packages/SettingsLib/SpaPrivileged/tests/robotests/config/robolectric.properties
@@ -0,0 +1,16 @@
+/*
+* Copyright (C) 2025 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.
+*/
+sdk=NEWEST_SDK
\ No newline at end of file
diff --git a/packages/SettingsLib/SpaPrivileged/tests/robotests/src/com/android/settingslib/spaprivileged/settingsprovider/SettingsSystemIntegerTest.kt b/packages/SettingsLib/SpaPrivileged/tests/robotests/src/com/android/settingslib/spaprivileged/settingsprovider/SettingsSystemIntegerTest.kt
new file mode 100644
index 000000000000..67e4180a624b
--- /dev/null
+++ b/packages/SettingsLib/SpaPrivileged/tests/robotests/src/com/android/settingslib/spaprivileged/settingsprovider/SettingsSystemIntegerTest.kt
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2025 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.settingslib.spaprivileged.settingsprovider
+
+import android.content.Context
+import android.provider.Settings
+
+import androidx.test.core.app.ApplicationProvider
+
+import com.android.settingslib.spa.testutils.firstWithTimeoutOrNull
+import com.android.settingslib.spa.testutils.toListWithTimeout
+import com.google.common.truth.Truth.assertThat
+
+import kotlinx.coroutines.async
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.runBlocking
+
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class SettingsSystemIntegerTest {
+    private val context: Context = ApplicationProvider.getApplicationContext()
+
+    @Before
+    fun setUp() {
+        Settings.System.putString(context.contentResolver, TEST_NAME, null)
+    }
+
+    @Test
+    fun setIntValue_returnSameValueByDelegate() {
+        val settingValue = 250
+
+        Settings.System.putInt(context.contentResolver, TEST_NAME, settingValue)
+
+        val value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+
+        assertThat(value).isEqualTo(settingValue)
+    }
+
+    @Test
+    fun setZero_returnZeroByDelegate() {
+        val settingValue = 0
+        Settings.System.putInt(context.contentResolver, TEST_NAME, settingValue)
+
+        val value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+
+        assertThat(value).isEqualTo(settingValue)
+    }
+
+    @Test
+    fun setValueByDelegate_getValueFromSettings() {
+        val settingsValue = 5
+        var value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+
+        value = settingsValue
+
+        assertThat(Settings.System.getInt(context.contentResolver, TEST_NAME, TEST_SETTING_DEFAULT_VALUE)).isEqualTo(settingsValue)
+    }
+
+    @Test
+    fun setZeroByDelegate_getZeroFromSettings() {
+        val settingValue = 0
+        var value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+
+        value = settingValue
+
+        assertThat(Settings.System.getInt(context.contentResolver, TEST_NAME, TEST_SETTING_DEFAULT_VALUE)).isEqualTo(settingValue)
+    }
+
+    @Test
+    fun setValueByDelegate_returnValueFromsettingsSystemIntegerFlow() = runBlocking<Unit> {
+        val settingValue = 7
+        var value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+        value = settingValue
+
+        val flow = context.settingsSystemIntegerFlow(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+
+        assertThat(flow.firstWithTimeoutOrNull()).isEqualTo(settingValue)
+    }
+
+    @Test
+    fun setValueByDelegateTwice_collectAfterValueChanged_onlyKeepLatest() = runBlocking<Unit> {
+        val firstSettingValue = 5
+        val secondSettingValue = 10
+
+        var value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+        value = firstSettingValue
+
+        val flow = context.settingsSystemIntegerFlow(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+        value = secondSettingValue
+
+        assertThat(flow.firstWithTimeoutOrNull()).isEqualTo(value)
+    }
+
+    @Test
+    fun settingsSystemIntegerFlow_collectBeforeValueChanged_getBoth() = runBlocking<Unit> {
+        val firstSettingValue = 12
+        val secondSettingValue = 17
+        val delay_ms = 100L
+
+        var value by context.settingsSystemInteger(TEST_NAME, TEST_SETTING_DEFAULT_VALUE)
+        value = firstSettingValue
+
+
+        val listDeferred = async {
+            context.settingsSystemIntegerFlow(TEST_NAME, TEST_SETTING_DEFAULT_VALUE).toListWithTimeout()
+        }
+
+        delay(delay_ms)
+        value = secondSettingValue
+
+        assertThat(listDeferred.await())
+            .containsAtLeast(firstSettingValue, secondSettingValue).inOrder()
+    }
+
+    private companion object {
+        const val TEST_NAME = "test_system_integer_delegate"
+        const val TEST_SETTING_DEFAULT_VALUE = -1
+    }
+}