+protected:
+ virtual void quit();
+
+private:
+ /**
+ * Migrate settings if neccessary and possible
+ *
+ * If unsuccessful (major version changed, minor version upgrade failed), returning false, the
+ * settings are in an unknown state and the client should quit.
+ *
+ * @return True if settings successfully migrated, otherwise false
+ */
+ bool migrateSettings();
+
+ /**
+ * Migrate from one minor settings version to the next
+ *
+ * Settings can only be migrated one version at a time. Start from the current version, calling
+ * this function for each intermediate version up until the latest version.
+ *
+ * @param[in] settings Current settings instance
+ * @param[in] newVersion Next target version for migration, at most 1 from the current version
+ * @return True if minor revision of settings successfully migrated, otherwise false
+ */
+ bool applySettingsMigration(QtUiSettings settings, const uint newVersion);
+
+ bool _aboutToQuit;