Windows Help

If your target platform is Windows, the obvious help processor to use is Windows Help. You can access Windows Help through the $WINHELP library routine. Note however, that $WINHELP is not supported in Microsoft Windows Vista. $WINHELP takes an OP-CODE parameter that indicates the operation to perform. These codes are defined in the COPY library winhelp.def. For context-sensitive help, the two most useful op-codes are HELP-CONTEXT (value 1) and HELP-CONTEXTPOPUP (value 8). In both cases, a context ID is passed as the last parameter to $WINHELP. Typically, you would use the control's help ID as the context ID.

$WINHELP's HELP-CONTEXT operation starts Windows Help in a separate window and positions the user at the topic identified by the context ID. The user is then free to navigate through the help text at will. The HELP-CONTEXTPOPUP operation causes Windows Help to pop-up a small window over the application that contains the topic identified by the context ID. The window is removed as soon as the user types a key or clicks the mouse.

Preparing your application to use Windows Help requires several steps.

In order to use Windows Help you must have a Windows compatible help compiler to produce your help files. ACUCOBOL-GT does not come with a help compiler and does not include documentation on the construction of help files. A help compiler is included with most Microsoft language products. Third-party help compilers are also available. If this is your first effort to interface to Windows Help, be sure to carefully read the documentation that comes with your Windows help compiler.

The help compiler takes two files as input: the help text source and the help project file. It produces .HLP format help files that are used by Windows Help. The help text source is a rich-text format (.RTF) file that contains a marked-up form of the help text. The markings describe the various sections of the help file, their look, and how they are cross-referenced. The help project file (.HPJ) is a text file that contains project-specific instructions to the help compiler. For information about how to create and use these files, refer to your help compiler documentation.