Infra for SysUI to monitor FGSes

There's now a way for it to track what apps currently have services in
the FGS state in real time.

Bug: 192504071
Test: manual
Test: atest CtsAppTestCases:android.app.cts.ServiceTest
Ignore-AOSP-First: new API should not be revealed in AOSP prior to drop
Change-Id: Ief1b6f8ef7deba6abbbf42f20b3f498861c1fe69

3 files changed, 35 insertions, 0 deletions

diff --git a/core/java/android/app/IActivityManager.aidl b/core/java/android/app/IActivityManager.aidl
index 658c1309b94e..6b4319ac06e3 100644
--- a/core/java/android/app/IActivityManager.aidl
+++ b/core/java/android/app/IActivityManager.aidl
@@ -26,6 +26,7 @@ import android.app.GrantedUriPermission;
 import android.app.IApplicationThread;
 import android.app.IActivityController;
 import android.app.IAppTask;
+import android.app.IForegroundServiceObserver;
 import android.app.IInstrumentationWatcher;
 import android.app.IProcessObserver;
 import android.app.IServiceConnection;
@@ -279,6 +280,8 @@ interface IActivityManager {
     boolean clearApplicationUserData(in String packageName, boolean keepState,
             in IPackageDataObserver observer, int userId);
     void makeServicesNonForeground(in String packageName, int userId);
+    /** Returns {@code false} if the callback could not be registered, {@true} otherwise. */
+    boolean registerForegroundServiceObserver(in IForegroundServiceObserver callback);
     @UnsupportedAppUsage
     void forceStopPackage(in String packageName, int userId);
     boolean killPids(in int[] pids, in String reason, boolean secure);
diff --git a/core/java/android/app/IForegroundServiceObserver.aidl b/core/java/android/app/IForegroundServiceObserver.aidl
new file mode 100644
index 000000000000..2b0cbed8a507
--- /dev/null
+++ b/core/java/android/app/IForegroundServiceObserver.aidl
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.app;
+
+/**
+ * Notify the client of all changes to services' foreground state.
+ * @param serviceToken unique identifier for a service instance
+ * @param packageName identifies the app hosting the service
+ * @param userId identifies the started user in which the app is running
+ * @param isForeground whether the service is in the "foreground" mode now, i.e.
+ *     whether it is an FGS
+ *
+ * @hide
+ */
+oneway interface IForegroundServiceObserver {
+    void onForegroundStateChanged(in IBinder serviceToken, in String packageName, int userId, boolean isForeground);
+}
diff --git a/core/java/android/app/OWNERS b/core/java/android/app/OWNERS
index 4da51c13045b..9da5693ff480 100644
--- a/core/java/android/app/OWNERS
+++ b/core/java/android/app/OWNERS
@@ -15,6 +15,7 @@ per-file IActivityController.aidl = file:/services/core/java/com/android/server/
 per-file IActivityManager.aidl = file:/services/core/java/com/android/server/am/OWNERS
 per-file IApplicationThread.aidl = file:/services/core/java/com/android/server/am/OWNERS
 per-file IAppTraceRetriever.aidl = file:/services/core/java/com/android/server/am/OWNERS
+per-file IForegroundServiceObserver.aidl = file:/services/core/java/com/android/server/am/OWNERS
 per-file IInstrumentationWatcher.aidl = file:/services/core/java/com/android/server/am/OWNERS
 per-file IntentService.aidl = file:/services/core/java/com/android/server/am/OWNERS
 per-file IServiceConnection.aidl = file:/services/core/java/com/android/server/am/OWNERS