Chapter 4. Graphical User Interfaces

I l @ ve RuBoard

Java has had libraries for building graphical user interfaces (GUIs) since the earliest days of the JDK. The original library was called the Alternative Window Toolkit, and it later became the Abstract Window Toolkit (AWT) in version 1.1 of the JDK. The goal of the AWT was to provide a set of tools for defining the essential structure of a GUI application that would be independent of the operating system. This circumstance would allow a developer to build applications that could function on a wide range of desktops, ranging from X-Windows under UNIX, to Apple Macintosh, to Microsoft Windows.

A GUI application typically comprises forms, controls that can be placed on those forms, and code that's executed in response to events raised by those controls. With Visual J++ 6.0, Microsoft extended the AWT and added some features specific to Windows, which resulted in the Windows Foundation Class (WFC) library. Meanwhile, the AWT followed its own development track and was later replaced by Swing in version 1.2 of the JDK. As we've mentioned in earlier chapters, Microsoft made the strategic decision to use the JDK 1.1.4 as the foundation for Visual J# .NET but to also support much of the added functionality in Visual J++ 6.0. This means that Visual J# .NET allows you to use the AWT and WFC to support existing applications that are ported to J#. But what about Swing? Well, the Microsoft .NET Framework includes the Windows Forms library, which is comparable to Swing and is available to any program that executes using the common language runtime. It can also be used by programs written in languages other than J#, such as C# and Microsoft Visual Basic .NET.

In this chapter, you'll learn more about the implementation of the AWT in J#, and you'll learn how to use the Windows Forms library for building GUIs from scratch with Visual Studio .NET. However, this chapter is intended only to be an overview of the Windows Forms library, so it does not cover building GUI applications with .NET in detail.

I l @ ve RuBoard