Java™ Application Development on Linux - Dator

378Chapter 17Other Ways: Alternatives to Swing17.2THE IBM SWT TOOLKITThe Standard Widget Toolkit is a complete GUI library for Java, completelyindependent of Swing and AWT. It is implemented as a library of nativemethods, so it cannot be ported to any Java runtime unless that platform hasthe native part of the SWT library implemented for it.17.2.1 Another GUI Toolkit. Why?The first question one should ask, perhaps, is why create an alternative GUI?Good question. The answer, according to the SWT FAQ, 3 primarily has to dowith execution speed and look-and-feel similarity to native GUI applicationson each platform.If we may editorialize, we find neither reason particularly compelling, althoughthe execution speed argument made some sense when the Eclipseproject started. Swing is unlikely to win any performance awards, even thougheach version brings some improvements in speed. 4 Still, these reasons do notseem particularly compelling for such a large duplication of effort and functionality.Whatever the reason, SWT exists. SWT works by providing a thin abstractionlayer over native GUI features. It is a small GUI library. It is implementedusing the Java Native Interface, so it requires that a native binary library beimplemented for your platform. Fortunately, such implementations exist forall platforms Eclipse runs on. So if you can run Eclipse, you can write and runSWT applications.3. http://dev.eclipse.org/viewcvs/index.cgi/~checkout~/platform-swt-home/faq.html4. The question of speed in Java is a rather tired argument. If maximum speed is a primaryconcern, Java is probably not your first choice of a development language. In our experience,speed is something everybody says they need, but more often than not other considerationssuch as development time and error rate are much more important. Java is fast enough for virtuallyall MIS applications, and that is the market Java is squarely aimed at. Our computerskeep getting faster, disk drives and memory keep getting cheaper. The “resource” and “performance”arguments only apply to applications where experienced designers would already havechosen C or assembly language. Besides, with the JIT compilers in both Sun’s and IBM’s JDKs,a well-written Java application is often as fast or faster than some other compiled languages, atleast on the second run of the code.