Oracle Help for Java (OHJ) is a set of Java components and an API for developing and displaying HTML-based help content in a Java environment. OHJ is designed primarily for displaying help for Java applications, although it can also be implemented as a stand-alone do(edited)ent viewer for use in a Java environment.
Oracle Help for Java: Full-Featured Help for Java Applications
Oracle Help for Java (OHJ) is a set of Java components and an API for developing and displaying HTML-based help content in a Java environment. The Oracle Help for Java Developer's Kit (OHJDK) includes the OHJ technology plus tools and documentation for developing context-sensitive help for Java applets and applications. The OHJDK is available for free from this Web site. You may redistribute OHJ as the help system for your application at no cost.
Why Java-based Help?
OHJ is designed primarily for displaying help for Java applications, although it can also be implemented as a stand-alone document viewer for use in a Java environment.
One of they key reasons for developing applications in Java is that they must run on multiple platforms. If you want a single implementation of your help system for a cross-platform application, you need a cross-platform help system. That is why you can't use a help system such as Microsoft's HTML Help, which is built into Windows and is not available on other operating systems. Oracle Help for Java runs on any system with a Java Virtual Machine (JVM) (we recommend JDK 1.1.7 or higher). All Java applications run in a JVM, so you can use OHJ with your Java application, without worrying about special support from any native platform in which it runs.
Why not use a help system that runs in a Web browser? It is possible to implement a help system that is displayed directly in a Web browser; in fact several authoring tool vendors provide such systems. However, with this approach, you must be certain that your users have a supported browser installed, which may not be appropriate for the environments where your applications are installed. OHJ does not require the presence of a Web browser. It uses a built-in Java component for displaying HTML content. Also, OHJ has an API that makes it easy to integrate a help system into an application, including context-sensitive help. OHJ also has many additional features that are not available in Web browser-based help systems. Many of these features are discussed later in this document.
Development on OHJ began at Oracle in 1996. Oracle had begun a company-wide initiative to convert existing technology to Java and to develop new technology in Java. These products were not small Java applets running in Web browsers; they were complex applications that had to run in a JVM in a variety of environments, including Windows, UNIX, and network computers (that is, Web appliances). At that time, no complete, full-featured Java help system was available, so we had to build it ourselves.
OHJ is proven technology that is now used by over 40 Oracle products and by a diverse array of other organizations, including software companies, financial institutions, communications and networking providers, and government agencies. We continue to actively develop and improve OHJ, based on input from within and outside Oracle and on our review and analysis of trends in the field.
OHJ is developed and maintained at Oracle by the same team that provides core technology for building graphical user interfaces (GUIs) for Oracle's Java and Web applications. That means it is based on the same technology that is used for building dozens of products within Oracle and many products outside Oracle. This team is also closely affiliated with the Oracle Interface Design and Usability group, which provides considerable input into our designs. These affiliations ensure that OHJ benefits from all the work that is done to make Oracle's GUIs localizable, accessible, and usable.
What You Get
When you download OHJ from our Web site, you get the following:
- Java components: OHJ includes a set of default Java user interface components that together comprise a complete help system, including table of contents, index, full-text search, and topic windows.
- API: The OHJ API includes features for implementing context-sensitive help, for programmatically controlling how help is displayed (size, position, etc.), and for customizing and extending the help system. For example, you can replace a default component with your own, create custom controls, or embed selected components in an application.
- Documentation: Documentation includes API reference, a File Formats specification, and a Programmer's Guide.
- HelpSet Authoring wizard: The OHJ HelpSet Authoring Wizard helps you create OHJ control files without requiring an authoring tool that directly creates OHJ systems.
- Redistribution License: You are free to use OHJ and to redistribute OHJ free of charge, subject to the conditions of the license.
The default HTML display component included in the OHJDK is a special implementation of the ICE Browser from Wind River Systems (www.windriver.com). You may use and redistribute this component free of charge as long as it is used as part of a help system using OHJ. This HTML display component supports the following:
- HTML 4.0
- Cascading Style Sheets (CSS) 1 and most of CSS 2
- Java applets
- Limited multimedia (requires Java Media Framework (JMF) 2.0)
- Single topic and multiple topic printing
- GIF animation
- Popups with limited HTML support
- Associative links, where a single index word or phrase can be associated with multiple topics. When the user selects one of these links, a list of all topics associated with the link is presented, and the user can choose a topic from the list.
- Author-defined window types, where authors can specify colors (background, text, and links), window size and position, window title, and toolbar buttons.
- Topic ID linking (that is, hyperlink targets are specified by ID rather than URL)
- Synchronization with items in the table of contents
You do not have to use the default HTML display. You can replace it with a different HTML display component. Or, if your application and the help system are running as an applet in a Web browser, you can use a browser window as the topic window. Consequently, the display capabilities for your implementation of OHJ rely on the HTML display you chose to embed in the system.
The Navigator window is a tabbed control for navigating and finding topics in the help system. By default, the Navigator window contains tabs for a table of contents, a keyword index, and a full-text search. Authors can control several characteristics of the Navigator window simply by setting parameters for the help system. For example, you can change the labels on the tabs and add icons. You could also display multiple tables of contents, for example, one for product help and one for a tutorial. For a more complex system, a Java programmer can create custom tabs, and the author can add them to the Navigator window.