Increase maximumCount by one if guest user exists

Guest user doesn't limit the number of users that can be created. It is,
however, an actual user so it is counted in count. Change maximumCount
to depend on whether guest user is enabled or not.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

src/usermodel.cpp

@@ -83,6 +83,8 @@ UserModel::UserModel(QObject *parent)
                     QDBusServiceWatcher::WatchForRegistration | QDBusServiceWatcher::WatchForUnregistration, this))
     , m_guestEnabled(getpwuid((uid_t)SAILFISH_USERMANAGER_GUEST_UID))
 {
+    connect(this, &UserModel::guestEnabledChanged,
+            this, &UserModel::maximumCountChanged);
     qDBusRegisterMetaType<SailfishUserManagerEntry>();
     connect(m_dBusWatcher, &QDBusServiceWatcher::serviceRegistered,
             this, &UserModel::createInterface);
@@ -154,7 +156,7 @@ int UserModel::count() const
  */
 int UserModel::maximumCount() const
 {
-    return SAILFISH_USERMANAGER_MAX_USERS;
+    return m_guestEnabled ? SAILFISH_USERMANAGER_MAX_USERS+1 : SAILFISH_USERMANAGER_MAX_USERS;
 }
 
 QHash<int, QByteArray> UserModel::roleNames() const

src/usermodel.h

@@ -51,7 +51,7 @@ class SYSTEMSETTINGS_EXPORT UserModel: public QAbstractListModel
     Q_OBJECT
     Q_PROPERTY(bool placeholder READ placeholder WRITE setPlaceholder NOTIFY placeholderChanged)
     Q_PROPERTY(int count READ count NOTIFY countChanged)
-    Q_PROPERTY(int maximumCount READ maximumCount CONSTANT)
+    Q_PROPERTY(int maximumCount READ maximumCount NOTIFY maximumCountChanged)
     Q_PROPERTY(bool guestEnabled READ guestEnabled WRITE setGuestEnabled NOTIFY guestEnabledChanged)
 
 public:
@@ -125,6 +125,7 @@ class SYSTEMSETTINGS_EXPORT UserModel: public QAbstractListModel
 signals:
     void placeholderChanged();
     void countChanged();
+    void maximumCountChanged();
     void guestEnabledChanged();
     void userGroupsChanged(int row);
     void userAddFailed(int error);