Bernstein presents a C++ object-oriented interface to Motif, a popular toolkit built on top of the X Window System. He describes the creation of a graphical interface library that provides Motif’s functionality through a set of C++ class definitions.

Chapter 2 provides a brief introduction to the Motif toolkit, and presents the main concepts of modern graphical interface toolkits. Chapter 3 is a short presentation of desirable design principles. The remainder of the book presents the details of the interface library, separated into major areas such as data types, graphical class definitions, and specification of the behavior of the interface objects.

The goal of this book is interesting and relevant: the creation of object-oriented interfaces to existing toolkits requires skills and experience, and is important in both the research and the commercial sectors. The book does not achieve the full potential implicit in the goals, however, primarily for two reasons. First, the author assumes extensive prior knowledge of the Xt toolkit (the foundation upon which Motif is built), Motif, C++, and object-oriented programming. Clearly, a book of this type must make certain assumptions about prior knowledge; in this case, however, the assumptions are excessive, and severely limit the potential readership. Given the lack of even cursory explanations for some of the intricate problems with which the book deals, only people who already know how to put it all together (that is, people who do not particularly need to read the book) can benefit from it fully. A more disciplined approach to introducing material more gently, with ample references to additional reading material and tutorials, would have served readers better.

My second criticism of the book is related to the level of detail. In several areas, the author is working at the appropriate level, providing some of the details and suggesting how to fill in the rest. In other places, the balance is not so successful, and the book gets so much into the lowest-level details that the overall picture is obscured. In such places, the book reads like a code walk-through, rather than an explanation of general principles. The extensive (sometimes excessive) code listings, some of which cover up to six pages at a stretch, reinforce this impression.

Overall, I felt that this book is more an attempt to explain the details of one particular user interface library design than to provide general, transferable principles or perspectives. While many of the actual details are interesting, and the overall design approach is sound (if not radically new), the requirement for so much previous knowledge limits the potential usefulness of the work, and affects the overall balance.

The bibliography is concise, and there is little attempt to provide pointers to work that might fill some of the gaps for readers with limited experience. The writing style is clear, and the typesetting is adequate. Several of the figures have curious text boxes superimposed, with messages like “prt to strip from postscript file Motif.PS,” which clearly were not meant to be included and make some of the contents impossible to read.