Refactored the creation of control widgets.

widgethelper.h

@@ -8,10 +8,13 @@ class QWidget;
 class WidgetHelper {
  public:
   static QWidget* createControlWidget(const UserRoles role, QWidget* parent);
-  static QWidget* createComboBox(const UserRoles role, QWidget* parent);
 
  private:
   explicit WidgetHelper();
+
+  static QWidget* createLineEdit(const UserRoles role, QWidget* parent);
+  static QWidget* createSpinBox(const UserRoles role, QWidget* parent);
+  static QWidget* createComboBox(const UserRoles role, QWidget* parent);
 };
 
 #endif  // WIDGETHELPER_H