Although together we've built Delphi applications since the beginning of the book, we haven't focused on the structure and the architecture of an application built with Delphi's class libraries. For example, I haven't included much coverage about the global Application object, techniques for keeping tracks of forms you've created, the flow of messages in the system, and other such elements.
In Chapter 7, "Working with Forms," you saw how to create applications with multiple forms and dialog boxes. However, I haven't discussed how these forms can be related one to the other, how you can share similar features of forms, and how you can operate on multiple similar forms in a consistent way.
My ambitious goal in this chapter is to discuss all these topics. The chapter covers both basic and advanced techniques, including visual form inheritance, the use of frames, and MDI development, as well as the use of interfaces for building complex hierarchies of form classes.