ViewHelper is a class containing display information about view elements such as height, width, x and y, however, it is part of the Model.
This exception to strict
separation is justifiable by the fact that the Model cannot access View to get this information (i.e. for saving and loading) and by the need for this information in most of imaginable View implementations.
References to ViewHelpers are stored in Diagram class.
They are created and passed when calling Diagram.AddModelElement() for addition of a element to a diagram.
Viewhelper inheritance diagram