ULTRIX Worksystem Software Guide to the XUl Toolkit Intrinsics: C Language Binding

This document, "Guide to the XUI Toolkit Intrinsics: C Language Binding, Version 2.0" (1988) by Digital Equipment Corporation, serves as a comprehensive technical reference for application and widget programmers developing graphical user interfaces with the ULTRIX Worksystem Software.

The guide details the lower-level C functions (Intrinsics) used to build XUI-based applications, presenting them as a library layered on Xlib that provides foundational mechanisms for GUI development. Key topics covered include:

1. Intrinsics and Widgets: Introduces fundamental concepts, terminology, the structure of Core, Composite, and Constraint widgets, and principles of widget classing and inheritance.
2. Widget Instantiation: Explains the lifecycle of widgets, from initializing the XUI Toolkit and loading resources to creating, realizing (creating associated X windows), and destroying widget instances.
3. Widget Management: Covers how Composite widgets manage their children (adding, deleting, managing sets, mapping), defines different types of Shell widgets for top-level windows and window manager communication, and describes Pop-Up widgets.
4. Geometry Management: Discusses how widgets negotiate size and position with their parents, handle resize requests, and manage child geometry.
5. Event Management: Details the XUI Toolkit's event handling mechanism, including adding/deleting event sources (input, timeouts), constraining and focusing events, dispatching events, managing widget sensitivity, and using X event filters.
6. Callbacks: Explains the use, identification, addition, removal, and execution of callback procedures for specific widget actions.
7. Resource Management: Describes how resources define widget state, including resource lists, byte offset calculations, resource chaining, subresources, obtaining application resources, and various resource conversion mechanisms.
8. Translation Management: Covers action tables and translation tables for mapping X event sequences to widget actions, and the use of accelerators and KeyCode-to-KeySym conversions.
9. Utility Functions: Provides a collection of general-purpose functions for tasks such as array manipulation, string-to-widget translation, memory management, graphics contexts, selection management, and error handling.

The document is tailored to the C programming language, providing specific function signatures and data structures relevant to the XUI Toolkit. It also includes appendices on resource file format, translation table syntax, conversion notes for earlier versions, and a list of standard errors and warnings.