Decouple user limit from guest creation

Allow Guest to be created even if there are N users.
Allow N users to be created even if there are N-1 users
   and a Guest.
Limit number of guests and managed profiles that can
be added.

Added unit tests.

Bug: 15934700
Change-Id: I1a8f0fa38a91d71ef7b2980e05c974244dfc337a

1 files changed, 20 insertions, 0 deletions

diff --git a/core/java/android/os/UserManager.java b/core/java/android/os/UserManager.java
index 3087506..f9e7b78 100644
--- a/core/java/android/os/UserManager.java
+++ b/core/java/android/os/UserManager.java
@@ -696,6 +696,26 @@ public class UserManager {
     }
 
     /**
+     * Checks whether it's possible to add more users. Caller must hold the MANAGE_USERS
+     * permission.
+     *
+     * @return true if more users can be added, false if limit has been reached.
+     * @hide
+     */
+    public boolean canAddMoreUsers() {
+        final List<UserInfo> users = getUsers(true);
+        final int totalUserCount = users.size();
+        int aliveUserCount = 0;
+        for (int i = 0; i < totalUserCount; i++) {
+            UserInfo user = users.get(i);
+            if (!user.isGuest()) {
+                aliveUserCount++;
+            }
+        }
+        return aliveUserCount < getMaxSupportedUsers();
+    }
+
+    /**
      * Returns list of the profiles of userHandle including
      * userHandle itself.
      * Note that it this returns both enabled and not enabled profiles. See