Abacus's first decision was to provide an XY layout with object anchoring, similar to Delphi or VB (see Figure 1). The XY layout transforms the JFrame into a canvas where a developer can drop Swing objects from the class palette. In contrast, most Java layouts managers dynamically render screens according to the resolution of the display. |
You should have a solid understanding of coding in the Java language and a basic understanding of how to make a Java GUI accessible. This tutorial is not designed to be an introduction to writing accessible Java GUIs. It serves as a guide on how to handle problem areas. |
Joe Winchester is a software developer at the IBM Research Triangle Park lab in North Carolina, working on development tools for WebSphere. He is currently working on builders that enable developers to create rich GUI applications by connecting together JavaBeans. Contact Joe at [email protected]. |
For most people, an application's look and feel is only a matter of preferences and aesthetics. But in some cases it is necessary to customize the application's look and feel so that it uses specific fonts, color schemes, or icons. Visually impaired users, for example, often need a look and feel with a high contrast between text and background, as well as large fonts and icons. The "IBM Java Accessibility Checklist" (see Resources) specifies that all user interface objects in an application must support high contrast settings. |
For Java developers JUnit is the tool of choice when developing unit tests. It provides a simple and easy-to-use framework for creating and running unit tests. JUnit is a great tool but it doesn't provide the ability to test Swing applications or Web interfaces. Most developers today usually test their user interfaces manually, which is tedious and error-prone. There are a number of commercially available products that can be used to test user interfaces, but these products can be expensive and involve a significant investment in time. They are more geared toward final system testing and are not really meant for unit testing. Two JUnit extensions, JFCUnit and HTTPUnit, are now available that allow users to unit test both Swing applications and Web interfaces with the same ease that the original JUnit is used to test non-GUI code. This article will explain both of these extensions. |
This defines a task that NetBeans calls automatically to roll the GroupLayout class into the jar file so that it will run anywhere. This is a useful thing to know for other such dependencies, without doubt, but if Matisse is going to be the way to create Java GUIs now, how much better it would be to make this step much easier with a project-level setting. |
In those cases, you must get back to basics and either find an API of GUI components appropriate for the purpose, or develop the GUI components yourself. |
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As you can see from Listing 6, the default value for the data length is an even power of two. As explained in the earlier lesson entitled A Recursive Filtering Workbench in Java, this value must be an even power of two for the FFT program that is used to estimate the frequency response to work properly. If the user enters a new value that is not an even power of two, that value is automatically modified to cause it to become an even power of two. The code to accomplish this was explained in the previous lesson. |
Before revealing the second implementation, I’ll introduce you to the Resource Interchange File Format (RIFF), explore the ca.mb.javajeff.riff package, and describe the RIFF-based ANI format that defines the structure of .ani files. Collectively, this material will help you make sense of this latest library implementation. |
Because the java.awt.Cursor class does not support animated cursors, I’ve developed a Java library that lets you assign Windows .ani file-based animated cursors to arbitrary Swing components. Articles one and two in this three-part series presented basic and improved implementations of this library. This article reveals the final implementation, which focuses on supporting translucency. |
Although the GBLDemo application’s GridBagLayout-based layout code is helpful in understanding how a GUI’s layout is affected when you apply different combinations of constraints, it’s also important to observe this layout manager’s effectiveness when it comes to laying out a realistic GUI. To that end, I’ve created an address book application. This application uses GridBagLayout to lay out a more realistic GUI, shown in Figure 1. |
If there's one thing that differentiates the computer users of today from ten years ago, it's the need for motion! We've all become very impatient, and nowhere is this more apparent than in the area of GUI programming. The idea of waiting around for some clunky old GUI just seems to go against the grain. Indeed, some front-end technologies such as Ajax now seek to comprehensively solve the problem of screen updating by supporting asynchronous operation from the outset. The good news for Java developers is that making your Swing GUI code multithreaded isn't so very difficult. |
Animated cursors are supported by most of Microsoft’s Windows operating systems. For example, Windows XP makes it possible to change the default arrow pointer to a walking dinosaur, or to a pointer with animated rainbow colors. Because Java doesn’t support animated cursors, though, I’ve developed a library that brings Windows-based animated cursors to Java. |
One of the most accurate complaints users have against Java GUIs is that they do not feel native. While this is partially due to the way that Swing is designed, it is also partially the fault of the developer. It is quite common for a developer to design the GUI to work on his or her platform of choice and then rely solely on Java’s cross-platform nature to make the application available for other operating systems. This behavior naturally leads to users on the other platforms complaining about the lack of a native feel for the application. |
The widespread availability of .ICO files is a good reason to think about using Windows icons with buttons and other GUI components to enhance Java GUIs. Because Java provides no direct support for reading Windows icons from .ICO files, this article introduces a Java library that accomplishes this task. |