Add a new(Empty) system service for AppFunctions project

A.K.A: Maestro

Flag: android.app.appfunctions.flags.enable_app_function_manager
BUG: 357551503
Test: Setup device with new service. No crash :).

Change-Id: I27e1782181ecda5f80574b1109c18e1d40608754
diff --git a/AconfigFlags.bp b/AconfigFlags.bp
index 4e34b63..59a7cbc 100644
--- a/AconfigFlags.bp
+++ b/AconfigFlags.bp
@@ -21,6 +21,7 @@
         // !!! KEEP THIS LIST ALPHABETICAL !!!
         "aconfig_mediacodec_flags_java_lib",
         "android.adaptiveauth.flags-aconfig-java",
+        "android.app.appfunctions.flags-aconfig-java",
         "android.app.contextualsearch.flags-aconfig-java",
         "android.app.flags-aconfig-java",
         "android.app.ondeviceintelligence-aconfig-java",
@@ -1383,6 +1384,21 @@
     defaults: ["framework-minus-apex-aconfig-java-defaults"],
 }
 
+// AppFunctions
+aconfig_declarations {
+    name: "android.app.appfunctions.flags-aconfig",
+    exportable: true,
+    package: "android.app.appfunctions.flags",
+    container: "system",
+    srcs: ["core/java/android/app/appfunctions/flags/flags.aconfig"],
+}
+
+java_aconfig_library {
+    name: "android.app.appfunctions.flags-aconfig-java",
+    aconfig_declarations: "android.app.appfunctions.flags-aconfig",
+    defaults: ["framework-minus-apex-aconfig-java-defaults"],
+}
+
 // Adaptive Auth
 aconfig_declarations {
     name: "android.adaptiveauth.flags-aconfig",
diff --git a/core/api/current.txt b/core/api/current.txt
index ea039a7..36c91758 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -10684,6 +10684,7 @@
     field public static final String ACTIVITY_SERVICE = "activity";
     field public static final String ALARM_SERVICE = "alarm";
     field public static final String APPWIDGET_SERVICE = "appwidget";
+    field @FlaggedApi("android.app.appfunctions.flags.enable_app_function_manager") public static final String APP_FUNCTION_SERVICE = "app_function";
     field public static final String APP_OPS_SERVICE = "appops";
     field public static final String APP_SEARCH_SERVICE = "app_search";
     field public static final String AUDIO_SERVICE = "audio";
diff --git a/core/java/android/app/SystemServiceRegistry.java b/core/java/android/app/SystemServiceRegistry.java
index e73f471..114a2c4 100644
--- a/core/java/android/app/SystemServiceRegistry.java
+++ b/core/java/android/app/SystemServiceRegistry.java
@@ -16,6 +16,8 @@
 
 package android.app;
 
+import static android.app.appfunctions.flags.Flags.enableAppFunctionManager;
+
 import android.accounts.AccountManager;
 import android.accounts.IAccountManager;
 import android.adservices.AdServicesFrameworkInitializer;
@@ -28,6 +30,8 @@
 import android.app.admin.IDevicePolicyManager;
 import android.app.ambientcontext.AmbientContextManager;
 import android.app.ambientcontext.IAmbientContextManager;
+import android.app.appfunctions.AppFunctionManager;
+import android.app.appfunctions.IAppFunctionManager;
 import android.app.appsearch.AppSearchManagerFrameworkInitializer;
 import android.app.blob.BlobStoreManagerFrameworkInitializer;
 import android.app.contentsuggestions.ContentSuggestionsManager;
@@ -925,6 +929,21 @@
                 return new CompanionDeviceManager(service, ctx.getOuterContext());
             }});
 
+        if (enableAppFunctionManager()) {
+            registerService(Context.APP_FUNCTION_SERVICE, AppFunctionManager.class,
+                    new CachedServiceFetcher<>() {
+                        @Override
+                        public AppFunctionManager createService(ContextImpl ctx)
+                                throws ServiceNotFoundException {
+                            IAppFunctionManager service;
+                            //TODO(b/357551503): If the feature not present avoid look up every time
+                            service = IAppFunctionManager.Stub.asInterface(
+                                    ServiceManager.getServiceOrThrow(Context.APP_FUNCTION_SERVICE));
+                            return new AppFunctionManager(service, ctx.getOuterContext());
+                        }
+                    });
+        }
+
         registerService(Context.VIRTUAL_DEVICE_SERVICE, VirtualDeviceManager.class,
                 new CachedServiceFetcher<VirtualDeviceManager>() {
             @Override
diff --git a/core/java/android/app/appfunctions/AppFunctionManager.java b/core/java/android/app/appfunctions/AppFunctionManager.java
new file mode 100644
index 0000000..a01e373
--- /dev/null
+++ b/core/java/android/app/appfunctions/AppFunctionManager.java
@@ -0,0 +1,44 @@
+/*
+ * 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 android.app.appfunctions;
+
+import android.annotation.SystemService;
+import android.content.Context;
+
+/**
+ * Provides app functions related functionalities.
+ *
+ * <p>App function is a specific piece of functionality that an app offers to the system. These
+ * functionalities can be integrated into various system features.
+ *
+ * @hide
+ */
+@SystemService(Context.APP_FUNCTION_SERVICE)
+public final class AppFunctionManager {
+    private final IAppFunctionManager mService;
+    private final Context mContext;
+
+    /**
+     * TODO(b/357551503): add comments when implement this class
+     *
+     * @hide
+     */
+    public AppFunctionManager(IAppFunctionManager mService, Context context) {
+        this.mService = mService;
+        this.mContext = context;
+    }
+}
diff --git a/core/java/android/app/appfunctions/IAppFunctionManager.aidl b/core/java/android/app/appfunctions/IAppFunctionManager.aidl
new file mode 100644
index 0000000..018bc75
--- /dev/null
+++ b/core/java/android/app/appfunctions/IAppFunctionManager.aidl
@@ -0,0 +1,24 @@
+/*
+ * 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 android.app.appfunctions;
+
+/**
+* Interface between an app and the server implementation service (AppFunctionManagerService).
+* @hide
+*/
+oneway interface IAppFunctionManager {
+}
\ No newline at end of file
diff --git a/core/java/android/app/appfunctions/flags/flags.aconfig b/core/java/android/app/appfunctions/flags/flags.aconfig
new file mode 100644
index 0000000..367effc
--- /dev/null
+++ b/core/java/android/app/appfunctions/flags/flags.aconfig
@@ -0,0 +1,11 @@
+package: "android.app.appfunctions.flags"
+container: "system"
+
+flag {
+    name: "enable_app_function_manager"
+    is_exported: true
+    is_fixed_read_only: true
+    namespace: "machine_learning"
+    description: "This flag the new App Function manager system service."
+    bug: "357551503"
+}
\ No newline at end of file
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index 9aebfc8..9dccc9a 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -16,6 +16,7 @@
 
 package android.content;
 
+import static android.app.appfunctions.flags.Flags.FLAG_ENABLE_APP_FUNCTION_MANAGER;
 import static android.content.flags.Flags.FLAG_ENABLE_BIND_PACKAGE_ISOLATED_PROCESS;
 
 import android.annotation.AttrRes;
@@ -51,6 +52,7 @@
 import android.app.IServiceConnection;
 import android.app.VrManager;
 import android.app.ambientcontext.AmbientContextManager;
+import android.app.appfunctions.AppFunctionManager;
 import android.app.people.PeopleManager;
 import android.app.time.TimeManager;
 import android.companion.virtual.VirtualDeviceManager;
@@ -6310,6 +6312,16 @@
 
     /**
      * Use with {@link #getSystemService(String)} to retrieve an
+     * {@link AppFunctionManager} for
+     * executing app functions.
+     *
+     * @see #getSystemService(String)
+     */
+    @FlaggedApi(FLAG_ENABLE_APP_FUNCTION_MANAGER)
+    public static final String APP_FUNCTION_SERVICE = "app_function";
+
+    /**
+     * Use with {@link #getSystemService(String)} to retrieve an
      * {@link android.content.integrity.AppIntegrityManager}.
      * @hide
      */
diff --git a/services/Android.bp b/services/Android.bp
index ded7379..0006455 100644
--- a/services/Android.bp
+++ b/services/Android.bp
@@ -120,6 +120,7 @@
         ":services.backup-sources",
         ":services.companion-sources",
         ":services.contentcapture-sources",
+        ":services.appfunctions-sources",
         ":services.contentsuggestions-sources",
         ":services.contextualsearch-sources",
         ":services.coverage-sources",
@@ -217,6 +218,7 @@
         "services.autofill",
         "services.backup",
         "services.companion",
+        "services.appfunctions",
         "services.contentcapture",
         "services.contentsuggestions",
         "services.contextualsearch",
diff --git a/services/appfunctions/Android.bp b/services/appfunctions/Android.bp
new file mode 100644
index 0000000..f8ee823
--- /dev/null
+++ b/services/appfunctions/Android.bp
@@ -0,0 +1,25 @@
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_license"],
+}
+
+filegroup {
+    name: "services.appfunctions-sources",
+    srcs: ["java/**/*.java"],
+    path: "java",
+    visibility: ["//frameworks/base/services"],
+}
+
+java_library_static {
+    name: "services.appfunctions",
+    defaults: ["platform_service_defaults"],
+    srcs: [
+        ":services.appfunctions-sources",
+        "java/**/*.logtags",
+    ],
+    libs: ["services.core"],
+}
diff --git a/services/appfunctions/java/com/android/server/appfunctions/AppFunctionManagerService.java b/services/appfunctions/java/com/android/server/appfunctions/AppFunctionManagerService.java
new file mode 100644
index 0000000..f30e770
--- /dev/null
+++ b/services/appfunctions/java/com/android/server/appfunctions/AppFunctionManagerService.java
@@ -0,0 +1,45 @@
+/*
+ * 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.server.appfunctions;
+
+import static android.app.appfunctions.flags.Flags.enableAppFunctionManager;
+
+import android.app.appfunctions.IAppFunctionManager;
+import android.content.Context;
+
+import com.android.server.SystemService;
+
+/**
+ * Service that manages app functions.
+ */
+public class AppFunctionManagerService extends SystemService {
+
+    public AppFunctionManagerService(Context context) {
+        super(context);
+    }
+
+    @Override
+    public void onStart() {
+        if (enableAppFunctionManager()) {
+            publishBinderService(Context.APP_FUNCTION_SERVICE, new AppFunctionManagerStub());
+        }
+    }
+
+    private static class AppFunctionManagerStub extends IAppFunctionManager.Stub {
+
+    }
+}
diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index 622c36c..09c54cb 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -16,6 +16,7 @@
 
 package com.android.server;
 
+import static android.app.appfunctions.flags.Flags.enableAppFunctionManager;
 import static android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK;
 import static android.os.IServiceManager.DUMP_FLAG_PRIORITY_CRITICAL;
 import static android.os.IServiceManager.DUMP_FLAG_PRIORITY_HIGH;
@@ -120,6 +121,7 @@
 import com.android.server.ambientcontext.AmbientContextManagerService;
 import com.android.server.app.GameManagerService;
 import com.android.server.appbinding.AppBindingService;
+import com.android.server.appfunctions.AppFunctionManagerService;
 import com.android.server.apphibernation.AppHibernationService;
 import com.android.server.appop.AppOpMigrationHelper;
 import com.android.server.appop.AppOpMigrationHelperImpl;
@@ -1727,6 +1729,12 @@
             mSystemServiceManager.startService(LogcatManagerService.class);
             t.traceEnd();
 
+            t.traceBegin("StartAppFunctionManager");
+            if (enableAppFunctionManager()) {
+                mSystemServiceManager.startService(AppFunctionManagerService.class);
+            }
+            t.traceEnd();
+
         } catch (Throwable e) {
             Slog.e("System", "******************************************");
             Slog.e("System", "************ Failure starting core service");