Delphi2

Borland Delphi 2.0
by Ted Faison Ted Faison has written several books and articles on object-oriented programming and Windows. He is president of Faison Computing Inc., a firm that develops Delphi, C++ applications, class libraries and software components for Windows. Ted can be reached at tedfaison@msn.com.

Introduction
Everyone is talking about component software and rapid applicationdevelopment. Component software tends to mean different things to different people, and a lot of people associate components with custom controls. Software components are much more than mere custom controls, and no environment that I know of today uses components in a more integrated and sophisticated way than Delphi. Delphi 1.0 was released by Borland in 1995, and immediately heralded as a landmarkproduct. And justly so. Delphi 1.0 is not simply a “better Visual Basic”. It doesn’t even make sense to compare Delphi with Visual Basic. We’re talking apples and oranges. Just for starters, Delphi produces highly optimized compiled code. No interpreters to mess with or distribute with your applications. With Delphi 1.0 you can just as easily create graphical front ends, database applications,scientific programs or graphics programs. Database applications can be built using a desktop or client-server architecture. Now there is Delphi 2.0, which adds better support for OLE automation, MAPI applications and Windows 95 controls. Delphi 2.0 generates 32 bit applications, delivering a substantial performance increase over 16 bit Delphi applications. I tested a pre-release copy of the fullClient Server version of Delphi 2.0, which runs on both Windows 95 and Windows NT. Because Delphi 2.0 is a 32 bit environment, it doesn’t run under Windows 3.1. The Client/Server version comes with integrated PVCS version control system, allowing programmers on large teams to work together on the same files without undoing each other’s work. Delphi is available in 3 different configurations, to satisfythe needs of beginners or home users as well as corporate development teams.

Why ObjectPascal?
Probably the most frequently asked question by newcomers to Delphi is, “Why the heck didn’t they use C++ as the native language?”. Just as it seemed like Pascal’s days were numbered, Borland comes out with an entirely revamped version of the language and creates Delphi with it! There are two mainreasons for ObjectPascal: flexibility and performance. You appreciate the performance both at design time and runtime. Remember that Borland put the turbo into Pascal, and the Delphi compiler is nothing less than superb. Compiles execute in seconds. Complete project rebuilds require often less than a minute. One reason is that Pascal in general is a much simpler language than C++. Another is thatC++ source files are subject to the header file inclusion nightmare. It

DDJ - Delphi 2.0 Ted Faison

Mar 6, 1996

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isn’t uncommon to compile a simple C++ file and see the compiler reading over 50,000 lines of include files. No such penalties in ObjectPascal. You’ll also appreciate the performance of compiled ObjectPascal code at runtime. The compiler includes a full optimizer, andallows the inline inclusion of assembly language code for critical code. To create a package like Delphi requires language features that are not available in any off-theshelf language. Because Borland owns the ObjectPascal language, it doesn’t have to ask anybody’s permission, or get approval from any ANSI committees to make changes to ObjectPascal. Language features needed to be added to supportthe visual programming metaphor of Delphi and to deliver intrinsic support for the Windows messaging system. Here’s one example of a language feature Borland added. Delphi components use special properties that programmers edit at design time. Properties are special class data members that must be declared in the published section for a class. C++ programmers have only 3 choices for access...