Merge "Move the compose code to tm-qpr-dev (1/2)" into tm-qpr-dev am: b8ea807587

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19494150

Change-Id: Ia9ead9a0c07c13a6f8f07ed91f1cd87214e1053c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

packages/SystemUI/compose/core/Android.bp

@@ -0,0 +1,38 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+android_library {
+    name: "SystemUIComposeCore",
+    manifest: "AndroidManifest.xml",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.material3_material3",
+    ],
+
+    kotlincflags: ["-Xjvm-default=all"],
+}

packages/SystemUI/compose/core/AndroidManifest.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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"
+    package="com.android.systemui.compose.core">
+
+
+</manifest>

packages/SystemUI/compose/core/TEST_MAPPING

@@ -0,0 +1,37 @@
+{
+  "presubmit": [
+    {
+      "name": "SystemUIComposeCoreTests",
+      "options": [
+        {
+          "exclude-annotation": "org.junit.Ignore"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        }
+      ]
+    },
+    {
+      "name": "SystemUIComposeFeaturesTests",
+      "options": [
+        {
+          "exclude-annotation": "org.junit.Ignore"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        }
+      ]
+    },
+    {
+      "name": "SystemUIComposeGalleryTests",
+      "options": [
+        {
+          "exclude-annotation": "org.junit.Ignore"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        }
+      ]
+    }
+  ]
+}

packages/SystemUI/compose/core/src/com/android/systemui/compose/SystemUiController.kt

@@ -0,0 +1,294 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose
+
+import android.app.Activity
+import android.content.Context
+import android.content.ContextWrapper
+import android.os.Build
+import android.view.View
+import android.view.Window
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.compositeOver
+import androidx.compose.ui.graphics.luminance
+import androidx.compose.ui.graphics.toArgb
+import androidx.compose.ui.platform.LocalView
+import androidx.compose.ui.window.DialogWindowProvider
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowCompat
+import androidx.core.view.WindowInsetsCompat
+
+/**
+ * *************************************************************************************************
+ * This file was forked from
+ * https://github.com/google/accompanist/blob/main/systemuicontroller/src/main/java/com/google/accompanist/systemuicontroller/SystemUiController.kt
+ * and will be removed once it lands in AndroidX.
+ */
+
+/**
+ * A class which provides easy-to-use utilities for updating the System UI bar colors within Jetpack
+ * Compose.
+ *
+ * @sample com.google.accompanist.sample.systemuicontroller.SystemUiControllerSample
+ */
+@Stable
+interface SystemUiController {
+
+    /**
+     * Property which holds the status bar visibility. If set to true, show the status bar,
+     * otherwise hide the status bar.
+     */
+    var isStatusBarVisible: Boolean
+
+    /**
+     * Property which holds the navigation bar visibility. If set to true, show the navigation bar,
+     * otherwise hide the navigation bar.
+     */
+    var isNavigationBarVisible: Boolean
+
+    /**
+     * Property which holds the status & navigation bar visibility. If set to true, show both bars,
+     * otherwise hide both bars.
+     */
+    var isSystemBarsVisible: Boolean
+        get() = isNavigationBarVisible && isStatusBarVisible
+        set(value) {
+            isStatusBarVisible = value
+            isNavigationBarVisible = value
+        }
+
+    /**
+     * Set the status bar color.
+     *
+     * @param color The **desired** [Color] to set. This may require modification if running on an
+     * API level that only supports white status bar icons.
+     * @param darkIcons Whether dark status bar icons would be preferable.
+     * @param transformColorForLightContent A lambda which will be invoked to transform [color] if
+     * dark icons were requested but are not available. Defaults to applying a black scrim.
+     *
+     * @see statusBarDarkContentEnabled
+     */
+    fun setStatusBarColor(
+        color: Color,
+        darkIcons: Boolean = color.luminance() > 0.5f,
+        transformColorForLightContent: (Color) -> Color = BlackScrimmed
+    )
+
+    /**
+     * Set the navigation bar color.
+     *
+     * @param color The **desired** [Color] to set. This may require modification if running on an
+     * API level that only supports white navigation bar icons. Additionally this will be ignored
+     * and [Color.Transparent] will be used on API 29+ where gesture navigation is preferred or the
+     * system UI automatically applies background protection in other navigation modes.
+     * @param darkIcons Whether dark navigation bar icons would be preferable.
+     * @param navigationBarContrastEnforced Whether the system should ensure that the navigation bar
+     * has enough contrast when a fully transparent background is requested. Only supported on API
+     * 29+.
+     * @param transformColorForLightContent A lambda which will be invoked to transform [color] if
+     * dark icons were requested but are not available. Defaults to applying a black scrim.
+     *
+     * @see navigationBarDarkContentEnabled
+     * @see navigationBarContrastEnforced
+     */
+    fun setNavigationBarColor(
+        color: Color,
+        darkIcons: Boolean = color.luminance() > 0.5f,
+        navigationBarContrastEnforced: Boolean = true,
+        transformColorForLightContent: (Color) -> Color = BlackScrimmed
+    )
+
+    /**
+     * Set the status and navigation bars to [color].
+     *
+     * @see setStatusBarColor
+     * @see setNavigationBarColor
+     */
+    fun setSystemBarsColor(
+        color: Color,
+        darkIcons: Boolean = color.luminance() > 0.5f,
+        isNavigationBarContrastEnforced: Boolean = true,
+        transformColorForLightContent: (Color) -> Color = BlackScrimmed
+    ) {
+        setStatusBarColor(color, darkIcons, transformColorForLightContent)
+        setNavigationBarColor(
+            color,
+            darkIcons,
+            isNavigationBarContrastEnforced,
+            transformColorForLightContent
+        )
+    }
+
+    /** Property which holds whether the status bar icons + content are 'dark' or not. */
+    var statusBarDarkContentEnabled: Boolean
+
+    /** Property which holds whether the navigation bar icons + content are 'dark' or not. */
+    var navigationBarDarkContentEnabled: Boolean
+
+    /**
+     * Property which holds whether the status & navigation bar icons + content are 'dark' or not.
+     */
+    var systemBarsDarkContentEnabled: Boolean
+        get() = statusBarDarkContentEnabled && navigationBarDarkContentEnabled
+        set(value) {
+            statusBarDarkContentEnabled = value
+            navigationBarDarkContentEnabled = value
+        }
+
+    /**
+     * Property which holds whether the system is ensuring that the navigation bar has enough
+     * contrast when a fully transparent background is requested. Only has an affect when running on
+     * Android API 29+ devices.
+     */
+    var isNavigationBarContrastEnforced: Boolean
+}
+
+/**
+ * Remembers a [SystemUiController] for the given [window].
+ *
+ * If no [window] is provided, an attempt to find the correct [Window] is made.
+ *
+ * First, if the [LocalView]'s parent is a [DialogWindowProvider], then that dialog's [Window] will
+ * be used.
+ *
+ * Second, we attempt to find [Window] for the [Activity] containing the [LocalView].
+ *
+ * If none of these are found (such as may happen in a preview), then the functionality of the
+ * returned [SystemUiController] will be degraded, but won't throw an exception.
+ */
+@Composable
+fun rememberSystemUiController(
+    window: Window? = findWindow(),
+): SystemUiController {
+    val view = LocalView.current
+    return remember(view, window) { AndroidSystemUiController(view, window) }
+}
+
+@Composable
+private fun findWindow(): Window? =
+    (LocalView.current.parent as? DialogWindowProvider)?.window
+        ?: LocalView.current.context.findWindow()
+
+private tailrec fun Context.findWindow(): Window? =
+    when (this) {
+        is Activity -> window
+        is ContextWrapper -> baseContext.findWindow()
+        else -> null
+    }
+
+/**
+ * A helper class for setting the navigation and status bar colors for a [View], gracefully
+ * degrading behavior based upon API level.
+ *
+ * Typically you would use [rememberSystemUiController] to remember an instance of this.
+ */
+internal class AndroidSystemUiController(private val view: View, private val window: Window?) :
+    SystemUiController {
+    private val windowInsetsController = window?.let { WindowCompat.getInsetsController(it, view) }
+
+    override fun setStatusBarColor(
+        color: Color,
+        darkIcons: Boolean,
+        transformColorForLightContent: (Color) -> Color
+    ) {
+        statusBarDarkContentEnabled = darkIcons
+
+        window?.statusBarColor =
+            when {
+                darkIcons && windowInsetsController?.isAppearanceLightStatusBars != true -> {
+                    // If we're set to use dark icons, but our windowInsetsController call didn't
+                    // succeed (usually due to API level), we instead transform the color to
+                    // maintain contrast
+                    transformColorForLightContent(color)
+                }
+                else -> color
+            }.toArgb()
+    }
+
+    override fun setNavigationBarColor(
+        color: Color,
+        darkIcons: Boolean,
+        navigationBarContrastEnforced: Boolean,
+        transformColorForLightContent: (Color) -> Color
+    ) {
+        navigationBarDarkContentEnabled = darkIcons
+        isNavigationBarContrastEnforced = navigationBarContrastEnforced
+
+        window?.navigationBarColor =
+            when {
+                darkIcons && windowInsetsController?.isAppearanceLightNavigationBars != true -> {
+                    // If we're set to use dark icons, but our windowInsetsController call didn't
+                    // succeed (usually due to API level), we instead transform the color to
+                    // maintain contrast
+                    transformColorForLightContent(color)
+                }
+                else -> color
+            }.toArgb()
+    }
+
+    override var isStatusBarVisible: Boolean
+        get() {
+            return ViewCompat.getRootWindowInsets(view)
+                ?.isVisible(WindowInsetsCompat.Type.statusBars()) == true
+        }
+        set(value) {
+            if (value) {
+                windowInsetsController?.show(WindowInsetsCompat.Type.statusBars())
+            } else {
+                windowInsetsController?.hide(WindowInsetsCompat.Type.statusBars())
+            }
+        }
+
+    override var isNavigationBarVisible: Boolean
+        get() {
+            return ViewCompat.getRootWindowInsets(view)
+                ?.isVisible(WindowInsetsCompat.Type.navigationBars()) == true
+        }
+        set(value) {
+            if (value) {
+                windowInsetsController?.show(WindowInsetsCompat.Type.navigationBars())
+            } else {
+                windowInsetsController?.hide(WindowInsetsCompat.Type.navigationBars())
+            }
+        }
+
+    override var statusBarDarkContentEnabled: Boolean
+        get() = windowInsetsController?.isAppearanceLightStatusBars == true
+        set(value) {
+            windowInsetsController?.isAppearanceLightStatusBars = value
+        }
+
+    override var navigationBarDarkContentEnabled: Boolean
+        get() = windowInsetsController?.isAppearanceLightNavigationBars == true
+        set(value) {
+            windowInsetsController?.isAppearanceLightNavigationBars = value
+        }
+
+    override var isNavigationBarContrastEnforced: Boolean
+        get() = Build.VERSION.SDK_INT >= 29 && window?.isNavigationBarContrastEnforced == true
+        set(value) {
+            if (Build.VERSION.SDK_INT >= 29) {
+                window?.isNavigationBarContrastEnforced = value
+            }
+        }
+}
+
+private val BlackScrim = Color(0f, 0f, 0f, 0.3f) // 30% opaque black
+private val BlackScrimmed: (Color) -> Color = { original -> BlackScrim.compositeOver(original) }

packages/SystemUI/compose/core/src/com/android/systemui/compose/theme/AndroidColorScheme.kt

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.theme
+
+import android.annotation.ColorInt
+import android.content.Context
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.graphics.Color
+import com.android.internal.R
+
+/** CompositionLocal used to pass [AndroidColorScheme] down the tree. */
+val LocalAndroidColorScheme =
+    staticCompositionLocalOf<AndroidColorScheme> {
+        throw IllegalStateException(
+            "No AndroidColorScheme configured. Make sure to use LocalAndroidColorScheme in a " +
+                "Composable surrounded by a SystemUITheme {}."
+        )
+    }
+
+/**
+ * The Android color scheme.
+ *
+ * Important: Use M3 colors from MaterialTheme.colorScheme whenever possible instead. In the future,
+ * most of the colors in this class will be removed in favor of their M3 counterpart.
+ */
+class AndroidColorScheme internal constructor(context: Context) {
+    val colorPrimary = getColor(context, R.attr.colorPrimary)
+    val colorPrimaryDark = getColor(context, R.attr.colorPrimaryDark)
+    val colorAccent = getColor(context, R.attr.colorAccent)
+    val colorAccentPrimary = getColor(context, R.attr.colorAccentPrimary)
+    val colorAccentSecondary = getColor(context, R.attr.colorAccentSecondary)
+    val colorAccentTertiary = getColor(context, R.attr.colorAccentTertiary)
+    val colorAccentPrimaryVariant = getColor(context, R.attr.colorAccentPrimaryVariant)
+    val colorAccentSecondaryVariant = getColor(context, R.attr.colorAccentSecondaryVariant)
+    val colorAccentTertiaryVariant = getColor(context, R.attr.colorAccentTertiaryVariant)
+    val colorSurface = getColor(context, R.attr.colorSurface)
+    val colorSurfaceHighlight = getColor(context, R.attr.colorSurfaceHighlight)
+    val colorSurfaceVariant = getColor(context, R.attr.colorSurfaceVariant)
+    val colorSurfaceHeader = getColor(context, R.attr.colorSurfaceHeader)
+    val colorError = getColor(context, R.attr.colorError)
+    val colorBackground = getColor(context, R.attr.colorBackground)
+    val colorBackgroundFloating = getColor(context, R.attr.colorBackgroundFloating)
+    val panelColorBackground = getColor(context, R.attr.panelColorBackground)
+    val textColorPrimary = getColor(context, R.attr.textColorPrimary)
+    val textColorSecondary = getColor(context, R.attr.textColorSecondary)
+    val textColorTertiary = getColor(context, R.attr.textColorTertiary)
+    val textColorPrimaryInverse = getColor(context, R.attr.textColorPrimaryInverse)
+    val textColorSecondaryInverse = getColor(context, R.attr.textColorSecondaryInverse)
+    val textColorTertiaryInverse = getColor(context, R.attr.textColorTertiaryInverse)
+    val textColorOnAccent = getColor(context, R.attr.textColorOnAccent)
+    val colorForeground = getColor(context, R.attr.colorForeground)
+    val colorForegroundInverse = getColor(context, R.attr.colorForegroundInverse)
+
+    private fun getColor(context: Context, attr: Int): Color {
+        val ta = context.obtainStyledAttributes(intArrayOf(attr))
+        @ColorInt val color = ta.getColor(0, 0)
+        ta.recycle()
+        return Color(color)
+    }
+}

packages/SystemUI/compose/core/src/com/android/systemui/compose/theme/SystemUITheme.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.theme
+
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Typography
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.platform.LocalContext
+
+/** The Material 3 theme that should wrap all SystemUI Composables. */
+@Composable
+fun SystemUITheme(
+    isDarkTheme: Boolean = isSystemInDarkTheme(),
+    content: @Composable () -> Unit,
+) {
+    val context = LocalContext.current
+
+    // TODO(b/230605885): Define our typography and color scheme.
+    val colorScheme =
+        if (isDarkTheme) {
+            dynamicDarkColorScheme(context)
+        } else {
+            dynamicLightColorScheme(context)
+        }
+    val androidColorScheme = AndroidColorScheme(context)
+    val typography = Typography()
+
+    MaterialTheme(colorScheme, typography = typography) {
+        CompositionLocalProvider(
+            LocalAndroidColorScheme provides androidColorScheme,
+        ) {
+            content()
+        }
+    }
+}

packages/SystemUI/compose/core/tests/Android.bp

@@ -0,0 +1,48 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+// TODO(b/230606318): Make those host tests instead of device tests.
+android_test {
+    name: "SystemUIComposeCoreTests",
+    manifest: "AndroidManifest.xml",
+    test_suites: ["device-tests"],
+    sdk_version: "current",
+    certificate: "platform",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "SystemUIComposeCore",
+
+        "androidx.test.runner",
+        "androidx.test.ext.junit",
+
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.ui_ui-test-junit4",
+        "androidx.compose.ui_ui-test-manifest",
+    ],
+
+    kotlincflags: ["-Xjvm-default=enable"],
+}

packages/SystemUI/compose/core/tests/AndroidManifest.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2022 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"
+    package="com.android.systemui.compose.core.tests" >
+
+    <application>
+        <uses-library android:name="android.test.runner" />
+    </application>
+
+    <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"
+                     android:targetPackage="com.android.systemui.compose.core.tests"
+                     android:label="Tests for SystemUIComposeCore"/>
+
+</manifest>

packages/SystemUI/compose/core/tests/src/com/android/systemui/compose/theme/SystemUIThemeTest.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.theme
+
+import androidx.compose.material3.Text
+import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithText
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.Assert.assertThrows
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class SystemUIThemeTest {
+    @get:Rule val composeRule = createComposeRule()
+
+    @Test
+    fun testThemeShowsContent() {
+        composeRule.setContent { SystemUITheme { Text("foo") } }
+
+        composeRule.onNodeWithText("foo").assertIsDisplayed()
+    }
+
+    @Test
+    fun testAndroidColorsAreAvailableInsideTheme() {
+        composeRule.setContent {
+            SystemUITheme { Text("foo", color = LocalAndroidColorScheme.current.colorAccent) }
+        }
+
+        composeRule.onNodeWithText("foo").assertIsDisplayed()
+    }
+
+    @Test
+    fun testAccessingAndroidColorsWithoutThemeThrows() {
+        assertThrows(IllegalStateException::class.java) {
+            composeRule.setContent {
+                Text("foo", color = LocalAndroidColorScheme.current.colorAccent)
+            }
+        }
+    }
+}

packages/SystemUI/compose/features/Android.bp

@@ -0,0 +1,40 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+android_library {
+    name: "SystemUIComposeFeatures",
+    manifest: "AndroidManifest.xml",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "SystemUIComposeCore",
+
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.material3_material3",
+    ],
+
+    kotlincflags: ["-Xjvm-default=all"],
+}

packages/SystemUI/compose/features/AndroidManifest.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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"
+    package="com.android.systemui.compose.features">
+
+
+</manifest>

packages/SystemUI/compose/features/TEST_MAPPING

@@ -0,0 +1,26 @@
+{
+  "presubmit": [
+    {
+      "name": "SystemUIComposeFeaturesTests",
+      "options": [
+        {
+          "exclude-annotation": "org.junit.Ignore"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        }
+      ]
+    },
+    {
+      "name": "SystemUIComposeGalleryTests",
+      "options": [
+        {
+          "exclude-annotation": "org.junit.Ignore"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        }
+      ]
+    }
+  ]
+}

packages/SystemUI/compose/features/src/com/android/systemui/ExampleFeature.kt

@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2022 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.systemui
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.BoxWithConstraints
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import kotlin.math.roundToInt
+
+/**
+ * This is an example Compose feature, which shows a text and a count that is incremented when
+ * clicked. We also show the max width available to this component, which is displayed either next
+ * to or below the text depending on that max width.
+ */
+@Composable
+fun ExampleFeature(text: String, modifier: Modifier = Modifier) {
+    BoxWithConstraints(modifier) {
+        val maxWidth = maxWidth
+        if (maxWidth < 600.dp) {
+            Column {
+                CounterTile(text)
+                Spacer(Modifier.size(16.dp))
+                MaxWidthTile(maxWidth)
+            }
+        } else {
+            Row {
+                CounterTile(text)
+                Spacer(Modifier.size(16.dp))
+                MaxWidthTile(maxWidth)
+            }
+        }
+    }
+}
+
+@Composable
+private fun CounterTile(text: String, modifier: Modifier = Modifier) {
+    Surface(
+        modifier,
+        color = MaterialTheme.colorScheme.primaryContainer,
+        shape = RoundedCornerShape(28.dp),
+    ) {
+        var count by remember { mutableStateOf(0) }
+        Column(
+            Modifier.clickable { count++ }.padding(16.dp),
+        ) {
+            Text(text)
+            Text("I was clicked $count times.")
+        }
+    }
+}
+
+@Composable
+private fun MaxWidthTile(maxWidth: Dp, modifier: Modifier = Modifier) {
+    Surface(
+        modifier,
+        color = MaterialTheme.colorScheme.tertiaryContainer,
+        shape = RoundedCornerShape(28.dp),
+    ) {
+        Text(
+            "The max available width to me is: ${maxWidth.value.roundToInt()}dp",
+            Modifier.padding(16.dp)
+        )
+    }
+}

packages/SystemUI/compose/features/tests/Android.bp

@@ -0,0 +1,48 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+// TODO(b/230606318): Make those host tests instead of device tests.
+android_test {
+    name: "SystemUIComposeFeaturesTests",
+    manifest: "AndroidManifest.xml",
+    test_suites: ["device-tests"],
+    sdk_version: "current",
+    certificate: "platform",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "SystemUIComposeFeatures",
+
+        "androidx.test.runner",
+        "androidx.test.ext.junit",
+
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.ui_ui-test-junit4",
+        "androidx.compose.ui_ui-test-manifest",
+    ],
+
+    kotlincflags: ["-Xjvm-default=enable"],
+}

packages/SystemUI/compose/features/tests/AndroidManifest.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2022 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"
+    package="com.android.systemui.compose.features.tests" >
+
+    <application>
+        <uses-library android:name="android.test.runner" />
+    </application>
+
+    <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"
+                     android:targetPackage="com.android.systemui.compose.features.tests"
+                     android:label="Tests for SystemUIComposeFeatures"/>
+
+</manifest>

packages/SystemUI/compose/features/tests/src/com/android/systemui/ExampleFeatureTest.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2022 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.systemui
+
+import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ExampleFeatureTest {
+    @get:Rule val composeRule = createComposeRule()
+
+    @Test
+    fun testProvidedTextIsDisplayed() {
+        composeRule.setContent { ExampleFeature("foo") }
+
+        composeRule.onNodeWithText("foo").assertIsDisplayed()
+    }
+
+    @Test
+    fun testCountIsIncreasedWhenClicking() {
+        composeRule.setContent { ExampleFeature("foo") }
+
+        composeRule.onNodeWithText("I was clicked 0 times.").assertIsDisplayed().performClick()
+        composeRule.onNodeWithText("I was clicked 1 times.").assertIsDisplayed()
+    }
+}

packages/SystemUI/compose/gallery/Android.bp

@@ -0,0 +1,72 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+android_library {
+    name: "SystemUIComposeGalleryLib",
+    manifest: "AndroidManifest.xml",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    resource_dirs: [
+        "res",
+    ],
+
+    static_libs: [
+        "SystemUI-core",
+        "SystemUIComposeCore",
+        "SystemUIComposeFeatures",
+
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.material3_material3",
+        "androidx.compose.material_material-icons-extended",
+        "androidx.activity_activity-compose",
+        "androidx.navigation_navigation-compose",
+
+        "androidx.appcompat_appcompat",
+    ],
+
+    kotlincflags: ["-Xjvm-default=all"],
+}
+
+android_app {
+    name: "SystemUIComposeGallery",
+    defaults: ["platform_app_defaults"],
+    manifest: "app/AndroidManifest.xml",
+
+    static_libs: [
+        "SystemUIComposeGalleryLib",
+    ],
+
+    platform_apis: true,
+    system_ext_specific: true,
+    certificate: "platform",
+    privileged: true,
+
+    optimize: {
+        proguard_flags_files: ["proguard-rules.pro"],
+    },
+
+    dxflags: ["--multi-dex"],
+}

packages/SystemUI/compose/gallery/AndroidManifest.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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:tools="http://schemas.android.com/tools"
+    package="com.android.systemui.compose.gallery">
+    <!-- To emulate a display size and density. -->
+    <uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS" />
+
+    <application
+        android:name="android.app.Application"
+        android:appComponentFactory="androidx.core.app.AppComponentFactory"
+        tools:replace="android:name,android:appComponentFactory">
+        <!-- Disable providers from SystemUI -->
+        <provider android:name="com.android.systemui.keyguard.KeyguardSliceProvider"
+            android:authorities="com.android.systemui.test.keyguard.disabled"
+            android:enabled="false"
+            tools:replace="android:authorities"
+            tools:node="remove" />
+        <provider android:name="com.google.android.systemui.keyguard.KeyguardSliceProviderGoogle"
+            android:authorities="com.android.systemui.test.keyguard.disabled"
+            android:enabled="false"
+            tools:replace="android:authorities"
+            tools:node="remove" />
+        <provider android:name="com.android.keyguard.clock.ClockOptionsProvider"
+            android:authorities="com.android.systemui.test.keyguard.clock.disabled"
+            android:enabled="false"
+            tools:replace="android:authorities"
+            tools:node="remove" />
+        <provider android:name="com.android.systemui.people.PeopleProvider"
+            android:authorities="com.android.systemui.test.people.disabled"
+            android:enabled="false"
+            tools:replace="android:authorities"
+            tools:node="remove" />
+        <provider android:name="androidx.core.content.FileProvider"
+            android:authorities="com.android.systemui.test.fileprovider.disabled"
+            android:enabled="false"
+            tools:replace="android:authorities"
+            tools:node="remove"/>
+    </application>
+</manifest>

packages/SystemUI/compose/gallery/TEST_MAPPING

@@ -0,0 +1,15 @@
+{
+  "presubmit": [
+    {
+      "name": "SystemUIComposeGalleryTests",
+      "options": [
+        {
+          "exclude-annotation": "org.junit.Ignore"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        }
+      ]
+    }
+  ]
+}

packages/SystemUI/compose/gallery/app/AndroidManifest.xml

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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:tools="http://schemas.android.com/tools"
+    package="com.android.systemui.compose.gallery.app">
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.SystemUI.Gallery"
+        tools:replace="android:icon,android:theme,android:label">
+        <activity
+            android:name="com.android.systemui.compose.gallery.GalleryActivity"
+            android:exported="true"
+            android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

packages/SystemUI/compose/gallery/proguard-rules.pro

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

packages/SystemUI/compose/gallery/res/drawable-v24/ic_launcher_foreground.xml

@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+  <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+    <aapt:attr name="android:fillColor">
+      <gradient
+          android:endX="85.84757"
+          android:endY="92.4963"
+          android:startX="42.9492"
+          android:startY="49.59793"
+          android:type="linear">
+        <item
+            android:color="#44000000"
+            android:offset="0.0" />
+        <item
+            android:color="#00000000"
+            android:offset="1.0" />
+      </gradient>
+    </aapt:attr>
+  </path>
+  <path
+      android:fillColor="#FFFFFF"
+      android:fillType="nonZero"
+      android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+      android:strokeColor="#00000000"
+      android:strokeWidth="1" />
+</vector>

packages/SystemUI/compose/gallery/res/drawable/ic_launcher_background.xml

@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+  <path
+      android:fillColor="#3DDC84"
+      android:pathData="M0,0h108v108h-108z" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M9,0L9,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,0L19,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M29,0L29,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M39,0L39,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M49,0L49,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M59,0L59,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M69,0L69,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M79,0L79,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M89,0L89,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M99,0L99,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,9L108,9"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,19L108,19"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,29L108,29"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,39L108,39"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,49L108,49"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,59L108,59"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,69L108,69"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,79L108,79"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,89L108,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,99L108,99"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,29L89,29"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,39L89,39"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,49L89,49"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,59L89,59"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,69L89,69"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,79L89,79"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M29,19L29,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M39,19L39,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M49,19L49,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M59,19L59,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M69,19L69,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M79,19L79,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8" />
+</vector>

packages/SystemUI/compose/gallery/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@drawable/ic_launcher_background" />
+  <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

packages/SystemUI/compose/gallery/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@drawable/ic_launcher_background" />
+  <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

packages/SystemUI/compose/gallery/res/values/colors.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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.
+-->
+<resources>
+    <color name="ic_launcher_background">#FFFFFF</color>
+</resources>

packages/SystemUI/compose/gallery/res/values/strings.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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.
+-->
+<resources>
+    <!-- Application name [CHAR LIMIT=NONE] -->
+    <string name="app_name">SystemUI Gallery</string>
+</resources>

packages/SystemUI/compose/gallery/res/values/themes.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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.
+-->
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <style name="Theme.SystemUI.Gallery">
+        <item name="android:windowActionBar">false</item>
+        <item name="android:windowNoTitle">true</item>
+
+        <item name="android:statusBarColor" tools:targetApi="l">
+            @android:color/transparent
+        </item>
+        <item name="android:navigationBarColor" tools:targetApi="l">
+            @android:color/transparent
+        </item>
+        <item name="android:windowLightStatusBar">true</item>
+    </style>
+</resources>

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/ColorsScreen.kt

@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.gallery
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import com.android.systemui.compose.theme.LocalAndroidColorScheme
+
+/** The screen that shows all the Material 3 colors. */
+@Composable
+fun MaterialColorsScreen() {
+    val colors = MaterialTheme.colorScheme
+    ColorsScreen(
+        listOf(
+            "primary" to colors.primary,
+            "onPrimary" to colors.onPrimary,
+            "primaryContainer" to colors.primaryContainer,
+            "onPrimaryContainer" to colors.onPrimaryContainer,
+            "inversePrimary" to colors.inversePrimary,
+            "secondary" to colors.secondary,
+            "onSecondary" to colors.onSecondary,
+            "secondaryContainer" to colors.secondaryContainer,
+            "onSecondaryContainer" to colors.onSecondaryContainer,
+            "tertiary" to colors.tertiary,
+            "onTertiary" to colors.onTertiary,
+            "tertiaryContainer" to colors.tertiaryContainer,
+            "onTertiaryContainer" to colors.onTertiaryContainer,
+            "background" to colors.background,
+            "onBackground" to colors.onBackground,
+            "surface" to colors.surface,
+            "onSurface" to colors.onSurface,
+            "surfaceVariant" to colors.surfaceVariant,
+            "onSurfaceVariant" to colors.onSurfaceVariant,
+            "inverseSurface" to colors.inverseSurface,
+            "inverseOnSurface" to colors.inverseOnSurface,
+            "error" to colors.error,
+            "onError" to colors.onError,
+            "errorContainer" to colors.errorContainer,
+            "onErrorContainer" to colors.onErrorContainer,
+            "outline" to colors.outline,
+        )
+    )
+}
+
+/** The screen that shows all the Android colors. */
+@Composable
+fun AndroidColorsScreen() {
+    val colors = LocalAndroidColorScheme.current
+    ColorsScreen(
+        listOf(
+            "colorPrimary" to colors.colorPrimary,
+            "colorPrimaryDark" to colors.colorPrimaryDark,
+            "colorAccent" to colors.colorAccent,
+            "colorAccentPrimary" to colors.colorAccentPrimary,
+            "colorAccentSecondary" to colors.colorAccentSecondary,
+            "colorAccentTertiary" to colors.colorAccentTertiary,
+            "colorAccentPrimaryVariant" to colors.colorAccentPrimaryVariant,
+            "colorAccentSecondaryVariant" to colors.colorAccentSecondaryVariant,
+            "colorAccentTertiaryVariant" to colors.colorAccentTertiaryVariant,
+            "colorSurface" to colors.colorSurface,
+            "colorSurfaceHighlight" to colors.colorSurfaceHighlight,
+            "colorSurfaceVariant" to colors.colorSurfaceVariant,
+            "colorSurfaceHeader" to colors.colorSurfaceHeader,
+            "colorError" to colors.colorError,
+            "colorBackground" to colors.colorBackground,
+            "colorBackgroundFloating" to colors.colorBackgroundFloating,
+            "panelColorBackground" to colors.panelColorBackground,
+            "textColorPrimary" to colors.textColorPrimary,
+            "textColorSecondary" to colors.textColorSecondary,
+            "textColorTertiary" to colors.textColorTertiary,
+            "textColorPrimaryInverse" to colors.textColorPrimaryInverse,
+            "textColorSecondaryInverse" to colors.textColorSecondaryInverse,
+            "textColorTertiaryInverse" to colors.textColorTertiaryInverse,
+            "textColorOnAccent" to colors.textColorOnAccent,
+            "colorForeground" to colors.colorForeground,
+            "colorForegroundInverse" to colors.colorForegroundInverse,
+        )
+    )
+}
+
+@Composable
+private fun ColorsScreen(
+    colors: List<Pair<String, Color>>,
+) {
+    LazyColumn(
+        Modifier.fillMaxWidth(),
+    ) {
+        colors.forEach { (name, color) -> item { ColorTile(color, name) } }
+    }
+}
+
+@Composable
+private fun ColorTile(
+    color: Color,
+    name: String,
+) {
+    Row(
+        Modifier.padding(16.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        val shape = RoundedCornerShape(16.dp)
+        Spacer(
+            Modifier.border(1.dp, MaterialTheme.colorScheme.onBackground, shape)
+                .background(color, shape)
+                .size(64.dp)
+        )
+        Spacer(Modifier.width(16.dp))
+        Text(name)
+    }
+}

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/ConfigurationControls.kt

@@ -0,0 +1,210 @@
+package com.android.systemui.compose.gallery
+
+import android.graphics.Point
+import android.os.UserHandle
+import android.view.Display
+import android.view.WindowManagerGlobal
+import androidx.compose.foundation.layout.RowScope
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyRow
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.DarkMode
+import androidx.compose.material.icons.filled.FormatSize
+import androidx.compose.material.icons.filled.FormatTextdirectionLToR
+import androidx.compose.material.icons.filled.FormatTextdirectionRToL
+import androidx.compose.material.icons.filled.InvertColors
+import androidx.compose.material.icons.filled.LightMode
+import androidx.compose.material.icons.filled.Smartphone
+import androidx.compose.material.icons.filled.Tablet
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.unit.LayoutDirection
+import androidx.compose.ui.unit.dp
+import kotlin.math.max
+import kotlin.math.min
+
+enum class FontScale(val scale: Float) {
+    Small(0.85f),
+    Normal(1f),
+    Big(1.15f),
+    Bigger(1.30f),
+}
+
+/** A configuration panel that allows to toggle the theme, font scale and layout direction. */
+@Composable
+fun ConfigurationControls(
+    theme: Theme,
+    fontScale: FontScale,
+    layoutDirection: LayoutDirection,
+    onChangeTheme: () -> Unit,
+    onChangeLayoutDirection: () -> Unit,
+    onChangeFontScale: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    // The display we are emulating, if any.
+    var emulatedDisplayName by rememberSaveable { mutableStateOf<String?>(null) }
+    val emulatedDisplay =
+        emulatedDisplayName?.let { name -> EmulatedDisplays.firstOrNull { it.name == name } }
+
+    LaunchedEffect(emulatedDisplay) {
+        val wm = WindowManagerGlobal.getWindowManagerService()
+
+        val defaultDisplayId = Display.DEFAULT_DISPLAY
+        if (emulatedDisplay == null) {
+            wm.clearForcedDisplayDensityForUser(defaultDisplayId, UserHandle.myUserId())
+            wm.clearForcedDisplaySize(defaultDisplayId)
+        } else {
+            val density = emulatedDisplay.densityDpi
+
+            // Emulate the display and make sure that we use the maximum available space possible.
+            val initialSize = Point()
+            wm.getInitialDisplaySize(defaultDisplayId, initialSize)
+            val width = emulatedDisplay.width
+            val height = emulatedDisplay.height
+            val minOfSize = min(width, height)
+            val maxOfSize = max(width, height)
+            if (initialSize.x < initialSize.y) {
+                wm.setForcedDisplaySize(defaultDisplayId, minOfSize, maxOfSize)
+            } else {
+                wm.setForcedDisplaySize(defaultDisplayId, maxOfSize, minOfSize)
+            }
+            wm.setForcedDisplayDensityForUser(defaultDisplayId, density, UserHandle.myUserId())
+        }
+    }
+
+    // TODO(b/231131244): Fork FlowRow from Accompanist and use that instead to make sure that users
+    // don't miss any available configuration.
+    LazyRow(modifier) {
+        // Dark/light theme.
+        item {
+            TextButton(onChangeTheme) {
+                val text: String
+                val icon: ImageVector
+
+                when (theme) {
+                    Theme.System -> {
+                        icon = Icons.Default.InvertColors
+                        text = "System"
+                    }
+                    Theme.Dark -> {
+                        icon = Icons.Default.DarkMode
+                        text = "Dark"
+                    }
+                    Theme.Light -> {
+                        icon = Icons.Default.LightMode
+                        text = "Light"
+                    }
+                }
+
+                Icon(icon, null)
+                Spacer(Modifier.width(8.dp))
+                Text(text)
+            }
+        }
+
+        // Font scale.
+        item {
+            TextButton(onChangeFontScale) {
+                Icon(Icons.Default.FormatSize, null)
+                Spacer(Modifier.width(8.dp))
+
+                Text(fontScale.name)
+            }
+        }
+
+        // Layout direction.
+        item {
+            TextButton(onChangeLayoutDirection) {
+                when (layoutDirection) {
+                    LayoutDirection.Ltr -> {
+                        Icon(Icons.Default.FormatTextdirectionLToR, null)
+                        Spacer(Modifier.width(8.dp))
+                        Text("LTR")
+                    }
+                    LayoutDirection.Rtl -> {
+                        Icon(Icons.Default.FormatTextdirectionRToL, null)
+                        Spacer(Modifier.width(8.dp))
+                        Text("RTL")
+                    }
+                }
+            }
+        }
+
+        // Display emulation.
+        EmulatedDisplays.forEach { display ->
+            item {
+                DisplayButton(
+                    display,
+                    emulatedDisplay == display,
+                    { emulatedDisplayName = it?.name },
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun DisplayButton(
+    display: EmulatedDisplay,
+    selected: Boolean,
+    onChangeEmulatedDisplay: (EmulatedDisplay?) -> Unit,
+) {
+    val onClick = {
+        if (selected) {
+            onChangeEmulatedDisplay(null)
+        } else {
+            onChangeEmulatedDisplay(display)
+        }
+    }
+
+    val content: @Composable RowScope.() -> Unit = {
+        Icon(display.icon, null)
+        Spacer(Modifier.width(8.dp))
+        Text(display.name)
+    }
+
+    if (selected) {
+        Button(onClick, contentPadding = ButtonDefaults.TextButtonContentPadding, content = content)
+    } else {
+        TextButton(onClick, content = content)
+    }
+}
+
+/** The displays that can be emulated from this Gallery app. */
+private val EmulatedDisplays =
+    listOf(
+        EmulatedDisplay(
+            "Phone",
+            Icons.Default.Smartphone,
+            width = 1440,
+            height = 3120,
+            densityDpi = 560,
+        ),
+        EmulatedDisplay(
+            "Tablet",
+            Icons.Default.Tablet,
+            width = 2560,
+            height = 1600,
+            densityDpi = 320,
+        ),
+    )
+
+private data class EmulatedDisplay(
+    val name: String,
+    val icon: ImageVector,
+    val width: Int,
+    val height: Int,
+    val densityDpi: Int,
+)

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/ExampleFeatureScreen.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.gallery
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import com.android.systemui.ExampleFeature
+
+/** The screen that shows ExampleFeature. */
+@Composable
+fun ExampleFeatureScreen(modifier: Modifier = Modifier) {
+    Column(modifier) { ExampleFeature("This is an example feature!") }
+}

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/GalleryActivity.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.gallery
+
+import android.app.UiModeManager
+import android.content.Context
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.runtime.SideEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.graphics.Color
+import androidx.core.view.WindowCompat
+import com.android.systemui.compose.rememberSystemUiController
+
+class GalleryActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        WindowCompat.setDecorFitsSystemWindows(window, false)
+        val uiModeManager = getSystemService(Context.UI_MODE_SERVICE) as UiModeManager
+
+        setContent {
+            var theme by rememberSaveable { mutableStateOf(Theme.System) }
+            val onChangeTheme = {
+                // Change to the next theme for a toggle behavior.
+                theme =
+                    when (theme) {
+                        Theme.System -> Theme.Dark
+                        Theme.Dark -> Theme.Light
+                        Theme.Light -> Theme.System
+                    }
+            }
+
+            val isSystemInDarkTheme = isSystemInDarkTheme()
+            val isDark = theme == Theme.Dark || (theme == Theme.System && isSystemInDarkTheme)
+            val useDarkIcons = !isDark
+            val systemUiController = rememberSystemUiController()
+            SideEffect {
+                systemUiController.setSystemBarsColor(
+                    color = Color.Transparent,
+                    darkIcons = useDarkIcons,
+                )
+
+                uiModeManager.setApplicationNightMode(
+                    when (theme) {
+                        Theme.System -> UiModeManager.MODE_NIGHT_AUTO
+                        Theme.Dark -> UiModeManager.MODE_NIGHT_YES
+                        Theme.Light -> UiModeManager.MODE_NIGHT_NO
+                    }
+                )
+            }
+
+            GalleryApp(theme, onChangeTheme)
+        }
+    }
+}
+
+enum class Theme {
+    System,
+    Dark,
+    Light,
+}

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/GalleryApp.kt

@@ -0,0 +1,125 @@
+package com.android.systemui.compose.gallery
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.systemBarsPadding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalLayoutDirection
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.LayoutDirection
+import androidx.compose.ui.unit.dp
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.rememberNavController
+import com.android.systemui.compose.theme.SystemUITheme
+
+/** The gallery app screens. */
+object GalleryAppScreens {
+    val Typography = ChildScreen("typography") { TypographyScreen() }
+    val MaterialColors = ChildScreen("material_colors") { MaterialColorsScreen() }
+    val AndroidColors = ChildScreen("android_colors") { AndroidColorsScreen() }
+    val ExampleFeature = ChildScreen("example_feature") { ExampleFeatureScreen() }
+
+    val Home =
+        ParentScreen(
+            "home",
+            mapOf(
+                "Typography" to Typography,
+                "Material colors" to MaterialColors,
+                "Android colors" to AndroidColors,
+                "Example feature" to ExampleFeature,
+            )
+        )
+}
+
+/** The main content of the app, that shows [GalleryAppScreens.Home] by default. */
+@Composable
+private fun MainContent() {
+    Box(Modifier.fillMaxSize()) {
+        val navController = rememberNavController()
+        NavHost(
+            navController = navController,
+            startDestination = GalleryAppScreens.Home.identifier,
+        ) {
+            screen(GalleryAppScreens.Home, navController)
+        }
+    }
+}
+
+/**
+ * The top-level composable shown when starting the app. This composable always shows a
+ * [ConfigurationControls] at the top of the screen, above the [MainContent].
+ */
+@Composable
+fun GalleryApp(
+    theme: Theme,
+    onChangeTheme: () -> Unit,
+) {
+    val systemFontScale = LocalDensity.current.fontScale
+    var fontScale: FontScale by remember {
+        mutableStateOf(
+            FontScale.values().firstOrNull { it.scale == systemFontScale } ?: FontScale.Normal
+        )
+    }
+    val context = LocalContext.current
+    val density = Density(context.resources.displayMetrics.density, fontScale.scale)
+    val onChangeFontScale = {
+        fontScale =
+            when (fontScale) {
+                FontScale.Small -> FontScale.Normal
+                FontScale.Normal -> FontScale.Big
+                FontScale.Big -> FontScale.Bigger
+                FontScale.Bigger -> FontScale.Small
+            }
+    }
+
+    val systemLayoutDirection = LocalLayoutDirection.current
+    var layoutDirection by remember { mutableStateOf(systemLayoutDirection) }
+    val onChangeLayoutDirection = {
+        layoutDirection =
+            when (layoutDirection) {
+                LayoutDirection.Ltr -> LayoutDirection.Rtl
+                LayoutDirection.Rtl -> LayoutDirection.Ltr
+            }
+    }
+
+    CompositionLocalProvider(
+        LocalDensity provides density,
+        LocalLayoutDirection provides layoutDirection,
+    ) {
+        SystemUITheme {
+            Surface(
+                Modifier.fillMaxSize(),
+                color = MaterialTheme.colorScheme.background,
+            ) {
+                Column(Modifier.fillMaxSize().systemBarsPadding().padding(16.dp)) {
+                    ConfigurationControls(
+                        theme,
+                        fontScale,
+                        layoutDirection,
+                        onChangeTheme,
+                        onChangeLayoutDirection,
+                        onChangeFontScale,
+                    )
+
+                    Spacer(Modifier.height(4.dp))
+
+                    MainContent()
+                }
+            }
+        }
+    }
+}

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/Screen.kt

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.gallery
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.navigation.NavController
+import androidx.navigation.NavGraphBuilder
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.navigation
+
+/**
+ * A screen in an app. It is either an [ParentScreen] which lists its child screens to navigate to
+ * them or a [ChildScreen] which shows some content.
+ */
+sealed class Screen(val identifier: String)
+
+class ParentScreen(
+    identifier: String,
+    val children: Map<String, Screen>,
+) : Screen(identifier)
+
+class ChildScreen(
+    identifier: String,
+    val content: @Composable (NavController) -> Unit,
+) : Screen(identifier)
+
+/** Create the navigation graph for [screen]. */
+fun NavGraphBuilder.screen(screen: Screen, navController: NavController) {
+    when (screen) {
+        is ChildScreen -> composable(screen.identifier) { screen.content(navController) }
+        is ParentScreen -> {
+            val menuRoute = "${screen.identifier}_menu"
+            navigation(startDestination = menuRoute, route = screen.identifier) {
+                // The menu to navigate to one of the children screens.
+                composable(menuRoute) { ScreenMenu(screen, navController) }
+
+                // The content of the child screens.
+                screen.children.forEach { (_, child) -> screen(child, navController) }
+            }
+        }
+    }
+}
+
+@Composable
+private fun ScreenMenu(
+    screen: ParentScreen,
+    navController: NavController,
+) {
+    LazyColumn(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+        screen.children.forEach { (name, child) ->
+            item {
+                Surface(
+                    Modifier.fillMaxWidth(),
+                    color = MaterialTheme.colorScheme.secondaryContainer,
+                    shape = CircleShape,
+                ) {
+                    Column(
+                        Modifier.clickable { navController.navigate(child.identifier) }
+                            .padding(16.dp),
+                        horizontalAlignment = Alignment.CenterHorizontally,
+                    ) {
+                        Text(name)
+                    }
+                }
+            }
+        }
+    }
+}

packages/SystemUI/compose/gallery/src/com/android/systemui/compose/gallery/TypographyScreen.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.gallery
+
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.style.TextOverflow
+
+/** The screen that shows the Material text styles. */
+@Composable
+fun TypographyScreen() {
+    val typography = MaterialTheme.typography
+
+    Column(
+        Modifier.fillMaxSize()
+            .horizontalScroll(rememberScrollState())
+            .verticalScroll(rememberScrollState()),
+    ) {
+        FontLine("displayLarge", typography.displayLarge)
+        FontLine("displayMedium", typography.displayMedium)
+        FontLine("displaySmall", typography.displaySmall)
+        FontLine("headlineLarge", typography.headlineLarge)
+        FontLine("headlineMedium", typography.headlineMedium)
+        FontLine("headlineSmall", typography.headlineSmall)
+        FontLine("titleLarge", typography.titleLarge)
+        FontLine("titleMedium", typography.titleMedium)
+        FontLine("titleSmall", typography.titleSmall)
+        FontLine("bodyLarge", typography.bodyLarge)
+        FontLine("bodyMedium", typography.bodyMedium)
+        FontLine("bodySmall", typography.bodySmall)
+        FontLine("labelLarge", typography.labelLarge)
+        FontLine("labelMedium", typography.labelMedium)
+        FontLine("labelSmall", typography.labelSmall)
+    }
+}
+
+@Composable
+private fun FontLine(name: String, style: TextStyle) {
+    Text(
+        "$name (${style.fontSize}/${style.lineHeight}, W${style.fontWeight?.weight})",
+        style = style,
+        maxLines = 1,
+        overflow = TextOverflow.Visible,
+    )
+}

packages/SystemUI/compose/gallery/tests/Android.bp

@@ -0,0 +1,47 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+android_test {
+    name: "SystemUIComposeGalleryTests",
+    manifest: "AndroidManifest.xml",
+    test_suites: ["device-tests"],
+    sdk_version: "current",
+    certificate: "platform",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "SystemUIComposeGalleryLib",
+
+        "androidx.test.runner",
+        "androidx.test.ext.junit",
+
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.ui_ui-test-junit4",
+        "androidx.compose.ui_ui-test-manifest",
+    ],
+
+    kotlincflags: ["-Xjvm-default=enable"],
+}

packages/SystemUI/compose/gallery/tests/AndroidManifest.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2022 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"
+    package="com.android.systemui.compose.gallery.tests" >
+
+    <application>
+        <uses-library android:name="android.test.runner" />
+    </application>
+
+    <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"
+                     android:targetPackage="com.android.systemui.compose.gallery.tests"
+                     android:label="Tests for SystemUIComposeGallery"/>
+
+</manifest>

packages/SystemUI/compose/gallery/tests/src/com/android/systemui/compose/gallery/ScreenshotsTests.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2022 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.systemui.compose.gallery
+
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.android.systemui.compose.theme.SystemUITheme
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ScreenshotsTests {
+    @get:Rule val composeRule = createComposeRule()
+
+    @Test
+    fun exampleFeatureScreenshotTest() {
+        // TODO(b/230832101): Wire this with the screenshot diff testing infra. We should reuse the
+        // configuration of the features in the gallery app to populate the UIs.
+        composeRule.setContent { SystemUITheme { ExampleFeatureScreen() } }
+    }
+}

packages/SystemUI/compose/testing/Android.bp

@@ -0,0 +1,43 @@
+// Copyright (C) 2022 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+android_library {
+    name: "SystemUIComposeTesting",
+    manifest: "AndroidManifest.xml",
+
+    srcs: [
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "SystemUIComposeCore",
+        "SystemUIScreenshotLib",
+
+        "androidx.compose.runtime_runtime",
+        "androidx.compose.material3_material3",
+        "androidx.compose.ui_ui-test-junit4",
+        "androidx.compose.ui_ui-test-manifest",
+    ],
+
+    kotlincflags: ["-Xjvm-default=all"],
+}

packages/SystemUI/compose/testing/AndroidManifest.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2022 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:tools="http://schemas.android.com/tools"
+    package="com.android.systemui.testing.compose">
+    <application
+        android:appComponentFactory="androidx.core.app.AppComponentFactory"
+        tools:replace="android:appComponentFactory">
+    </application>
+</manifest>

packages/SystemUI/compose/testing/src/com/android/systemui/testing/compose/ComposeScreenshotTestRule.kt

@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2022 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.systemui.testing.compose
+
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.platform.ViewRootForTest
+import androidx.compose.ui.test.junit4.createAndroidComposeRule
+import androidx.compose.ui.test.onRoot
+import com.android.systemui.compose.theme.SystemUITheme
+import com.android.systemui.testing.screenshot.ScreenshotActivity
+import com.android.systemui.testing.screenshot.SystemUIGoldenImagePathManager
+import com.android.systemui.testing.screenshot.UnitTestBitmapMatcher
+import com.android.systemui.testing.screenshot.drawIntoBitmap
+import org.junit.rules.RuleChain
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+import platform.test.screenshot.DeviceEmulationRule
+import platform.test.screenshot.DeviceEmulationSpec
+import platform.test.screenshot.MaterialYouColorsRule
+import platform.test.screenshot.ScreenshotTestRule
+import platform.test.screenshot.getEmulatedDevicePathConfig
+
+/** A rule for Compose screenshot diff tests. */
+class ComposeScreenshotTestRule(emulationSpec: DeviceEmulationSpec) : TestRule {
+    private val colorsRule = MaterialYouColorsRule()
+    private val deviceEmulationRule = DeviceEmulationRule(emulationSpec)
+    private val screenshotRule =
+        ScreenshotTestRule(
+            SystemUIGoldenImagePathManager(getEmulatedDevicePathConfig(emulationSpec))
+        )
+    private val composeRule = createAndroidComposeRule<ScreenshotActivity>()
+    private val delegateRule =
+        RuleChain.outerRule(colorsRule)
+            .around(deviceEmulationRule)
+            .around(screenshotRule)
+            .around(composeRule)
+    private val matcher = UnitTestBitmapMatcher
+
+    override fun apply(base: Statement, description: Description): Statement {
+        return delegateRule.apply(base, description)
+    }
+
+    /**
+     * Compare [content] with the golden image identified by [goldenIdentifier] in the context of
+     * [testSpec].
+     */
+    fun screenshotTest(
+        goldenIdentifier: String,
+        content: @Composable () -> Unit,
+    ) {
+        // Make sure that the activity draws full screen and fits the whole display instead of the
+        // system bars.
+        val activity = composeRule.activity
+        activity.mainExecutor.execute { activity.window.setDecorFitsSystemWindows(false) }
+
+        // Set the content using the AndroidComposeRule to make sure that the Activity is set up
+        // correctly.
+        composeRule.setContent {
+            SystemUITheme {
+                Surface(
+                    color = MaterialTheme.colorScheme.background,
+                ) {
+                    content()
+                }
+            }
+        }
+        composeRule.waitForIdle()
+
+        val view = (composeRule.onRoot().fetchSemanticsNode().root as ViewRootForTest).view
+        screenshotRule.assertBitmapAgainstGolden(view.drawIntoBitmap(), goldenIdentifier, matcher)
+    }
+}