Volume 6A: Motif Programming Manual

22 Advanced Dialog Programming

This chapter describes some Motif features that have not been described, or at least not completely, in earlier chapters.

The topics, which all deal with dialogs, include the creation of multi−stage help systems, the development of

WorkingDialogs that allow the user to interrupt long−running tasks, and a method for dynamically changing the

pixmaps displayed in a dialog.

In one sense, this chapter isn't about dialogs at all, but about various aspects of X programming that become most

evident when working with dialogs. Here we address some issues involved in creating multi−stage help systems, we

show you how to create a WorkingDialogs that allows the user to interrupt a long−running task, and we describe a

method for dynamically changing the pixmaps that are displayed in a dialog. These topics explore some of the most

interesting problems in this book.

These topics take us deeper into the lower layers of X than anything we've discussed so far in this book. You should

have a good basic understanding of X event−processing, as implemented both in Xlib and Xt. Otherwise, be prepared

to refer frequently to Volume One, Xlib Programming Manual, and Volume Four, X Toolkit Intrinsics Programming

Manual, when faced with references to lower−level functions.

22.1 Help Systems

The Motif Style Guide doesn't have much to say about how help is presented to the user, although it does discuss the

ways in which the user can request help from an application. The user can request help ...