## A.4 Summary and Conclusions

Though the dialog editor has attracted quite some attention when it was developed, it remains a difficult product. Using WYSIWYG style of interface building appears attractive, but looses generalisations that can be made in a programming language. If you have been in a country of which you don't speak the language you understand that pointing is a rather crippled way to express your needs. Especially XPCE/Prolog is strong in meta-representation and symbolic layout and the combination can easily be exploited to automate most of the simple control generation.

A good WYSIWYG should provide a smooth transition between the beginners choice for WYSIWYG and the expert choice of using language. It was one of the aims of this project to achieve this transaction but modern XPCE/Prolog applications are generally programmed in classes and the dialog editor presented here is build around direct relations between objects.