Introduce an OOP approach for Simple-Java-Calculator based on Design Patterns

[GiannisKarampinis]

There was an effort to refactor Simple-Java-Calculator on the occasion of a project-based essay during my Master in Applied Informatics. The suggested approach could be a way to present basic principles of Object Orientation in a relatively small project which does not require any significant domain knowledge, so as to be a point of reference for other efforts in the furture.

All refactoring efforts were introduced in order to reduce Coupling Between Objects thus making the project easily maintainable by other devs in the near future.

Now, a user can perform an abstract action through the provided GUI which finaly relates to a different object.