New API: UserManager.isUserForeground().

Test: m update-api
Test: atest android.multiuser.cts.UserManagerTest#testIsUserForeground_currentUser

Bug: 173541467
Bug: 179163496

Change-Id: Id44f37c9c105b319f308c927ddefcc6671293a46

core/api/current.txt

@@ -31482,6 +31482,7 @@ package android.os {
     method public boolean isQuietModeEnabled(android.os.UserHandle);
     method public boolean isSystemUser();
     method public boolean isUserAGoat();
+    method public boolean isUserForeground();
     method @RequiresPermission(anyOf={"android.permission.MANAGE_USERS", "android.permission.INTERACT_ACROSS_USERS"}, conditional=true) public boolean isUserRunning(android.os.UserHandle);
     method @RequiresPermission(anyOf={"android.permission.MANAGE_USERS", "android.permission.INTERACT_ACROSS_USERS"}, conditional=true) public boolean isUserRunningOrStopping(android.os.UserHandle);
     method public boolean isUserUnlocked();

core/java/android/os/IUserManager.aidl

@@ -113,6 +113,7 @@ interface IUserManager {
     boolean hasBadge(int userId);
     boolean isUserUnlocked(int userId);
     boolean isUserRunning(int userId);
+    boolean isUserForeground();
     boolean isUserNameSet(int userId);
     boolean hasRestrictedProfiles();
     boolean requestQuietModeEnabled(String callingPackage, boolean enableQuietMode, int userId, in IntentSender target, int flags);

core/java/android/os/UserManager.java

@@ -2299,6 +2299,19 @@ public class UserManager {
         }
     }
 
+    /**
+     * Checks if the calling user is running on foreground.
+     *
+     * @return whether the calling user is running on foreground.
+     */
+    public boolean isUserForeground() {
+        try {
+            return mService.isUserForeground();
+        } catch (RemoteException re) {
+            throw re.rethrowFromSystemServer();
+        }
+    }
+
     /**
      * Return whether the calling user is running in an "unlocked" state.
      * <p>

services/core/java/com/android/server/pm/UserManagerService.java

@@ -1521,6 +1521,14 @@ public class UserManagerService extends IUserManager.Stub {
         return mLocalService.isUserRunning(userId);
     }
 
+    @Override
+    public boolean isUserForeground() {
+        int callingUserId = Binder.getCallingUserHandle().getIdentifier();
+        int currentUser = Binder.withCleanCallingIdentity(() -> ActivityManager.getCurrentUser());
+        // TODO(b/179163496): should return true for profile users of the current user as well
+        return currentUser == callingUserId;
+    }
+
     @Override
     public String getUserName() {
         if (!hasManageUsersOrPermission(android.Manifest.permission.GET_ACCOUNTS_PRIVILEGED)) {