Help

CDE help differs from OpenWindows help in three areas:

• User model

• Programming tasks

• Richness of help system

See Common Desktop Environment: Programmer's Overview and Common Desktop Environment: Help System Author's and Programmer's Guide for more information on the CDE help system.

User Model

The OpenWindows user model is very simple. The user places the pointer over the portion of the application he wants help on, and presses the Help key.

The CDE user model is similar but slightly different. The user receives help from that portion of the application that has input focus. That is, the user must select a portion of the application and then press the Help key to receive help on that portion.

CDE help provides on item help for those objects that cannot get input focus. You must provide an On Item selection in your application's Help menu so users can access help for those items.

Programming Tasks

Writing OLIT and XView help is very similar. In either case, your application provides the text appropriate for a widget or object, respectively. The OpenWindows window manager determines which application is responsible when the user presses the Help key, and dispatches an event to that application.

OLIT has a specialized Help widget, and XView has a Help frame, that puts the right information into the Help dialog display area and makes the dialog appear on the screen. You either have to include a function call to OLRegisterHelp() in OLIT, or set an object attribute in XView, to enable help on a widget (object).

To provide CDE help with your application, you must:

1. Establish help callbacks on all relevant widgets.

   These callbacks must be able to provide the help information for the associated widgets.

2. Create and manage the help dialogs.

   CDE provides DtHelpDialog and DtHelpQuickDialog widgets to create help dialog boxes and quick help dialogs. CDE has one shared help dialog that displays help.

3. Implement on item help.

   Common Desktop Environment: Help System Author's and Programmer's Guide provides source code to do this.

Richness of Help System

OpenWindows help has a single help dialog in which you can place text only. CDE help is much richer. CDE provides both quick and full help. You can also include much more than just text in your help dialogs; for example, color graphics and hyperlinks. The user can print help and also use navigation facilities to stack and traverse help attached to different widgets.