[Expressive design] create helper class on the device.

Helper function to check if expressive theme is enabled on the device.

Bug: 366336385
Test: manual
Flag: EXEMPT resource only update
Change-Id: Ib18e1073ae137ab44eb44a042ff939a00e9f71a6

2 files changed, 82 insertions, 0 deletions

diff --git a/packages/SettingsLib/SettingsTheme/Android.bp b/packages/SettingsLib/SettingsTheme/Android.bp
index 996477cf7960..baeff7e6c006 100644
--- a/packages/SettingsLib/SettingsTheme/Android.bp
+++ b/packages/SettingsLib/SettingsTheme/Android.bp
@@ -10,6 +10,10 @@ package {
 android_library {
     name: "SettingsLibSettingsTheme",
     use_resource_processor: true,
+    srcs: [
+        "src/**/*.java",
+        "src/**/*.kt",
+    ],
     resource_dirs: ["res"],
     static_libs: ["androidx.preference_preference"],
     sdk_version: "system_current",
diff --git a/packages/SettingsLib/SettingsTheme/src/com/android/settingslib/widget/SettingsThemeHelper.kt b/packages/SettingsLib/SettingsTheme/src/com/android/settingslib/widget/SettingsThemeHelper.kt
new file mode 100644
index 000000000000..10e5267c02d3
--- /dev/null
+++ b/packages/SettingsLib/SettingsTheme/src/com/android/settingslib/widget/SettingsThemeHelper.kt
@@ -0,0 +1,78 @@
+/*
+* Copyright (C) 2024 The Android Open Source Project
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+package com.android.settingslib.widget
+
+import android.content.Context
+import android.os.Build
+import android.os.SystemProperties
+
+object SettingsThemeHelper {
+    private const val IS_EXPRESSIVE_DESIGN_ENABLED = "is_expressive_design_enabled"
+    private var expressiveThemeState: ExpressiveThemeState = ExpressiveThemeState.UNKNOWN
+
+    enum class ExpressiveThemeState {
+        UNKNOWN,
+        ENABLED,
+        DISABLED,
+    }
+
+    @JvmStatic
+    fun isExpressiveTheme(context: Context): Boolean {
+        tryInit(context)
+        if (expressiveThemeState == ExpressiveThemeState.UNKNOWN) {
+            throw Exception(
+                "need to call com.android.settingslib.widget.SettingsThemeHelper.init(Context) first."
+            )
+        }
+
+        return expressiveThemeState == ExpressiveThemeState.ENABLED
+    }
+
+    private fun tryInit(context: Context) {
+        if (expressiveThemeState != ExpressiveThemeState.UNKNOWN) {
+            return
+        }
+
+        expressiveThemeState =
+            if (
+                (Build.VERSION.SDK_INT >= Build.VERSION_CODES.VANILLA_ICE_CREAM) &&
+                    (SystemProperties.getBoolean(IS_EXPRESSIVE_DESIGN_ENABLED, false) ||
+                        getPropBoolean(context, IS_EXPRESSIVE_DESIGN_ENABLED, false))
+            ) {
+                ExpressiveThemeState.ENABLED
+            } else {
+                ExpressiveThemeState.DISABLED
+            }
+    }
+
+    private fun getPropBoolean(context: Context, property: String, def: Boolean): Boolean {
+        return try {
+            val systemProperties = context.classLoader.loadClass("android.os.SystemProperties")
+
+            val paramTypes =
+                arrayOf<Class<*>?>(String::class.java, Boolean::class.javaPrimitiveType)
+            val getBoolean = systemProperties.getMethod("getBoolean", *paramTypes)
+
+            val params = arrayOf<Any>(property, def)
+            getBoolean.invoke(systemProperties, *params) as Boolean
+        } catch (iae: IllegalArgumentException) {
+            throw iae
+        } catch (exception: Exception) {
+            def
+        }
+    }
+}