IBM* OS/2* Presentation Manager* is a graphical user interface facility that allows the creation of object-oriented, event-driven applications which conform to IBM Systems Application Architecture* (SAA*) Common User Access* (CUA*) guidelines. Presentation Manager provides an application execution environment under which such applications are executed, and under which they may take full advantage of the advanced capabilities of the OS/2 operating system environment, as well as a system-level mechanism to handle interaction between the application and the user in a consistent and intuitive manner.
The object-based Presentation Manager application model facilitates the use of object-oriented software engineering principles such as data abstraction and encapsulation. The application of these principles enhances application modularity and thereby contributes to increased potential for code reuse and easier application maintenance through containment of change, thereby achieving higher levels of productivity in the areas of application development and maintenance.
This document examines the Presentation Manager execution environment in order to describe the structure and implementation of Presentation Manager applications, and to illustrate the facilities provided by Presentation Manager to support object-oriented techniques. In addition, the document examines the ways in which CUA guidelines may be implemented by Presentation Manager applications within the object-oriented application model. Particular emphasis is given to the use of software engineering principles which facilitate the creation of reusable code for common application services. This is one of the primary concerns of the object-oriented approach to application design, and is also one aspect of the Systems Application Architecture Common Applications ("red layer") component.
The document also discusses the management of workstation-based application development projects. Historically, workstation applications have typically fallen into the systems software category, or have been "one-off" applications and hence have not been subject to the same rules and disciplines imposed upon the traditionally host-based line-of-business applications. However, as the OS/2 environment begins to provide a viable platform for the implementation of workstation-based and cooperative line-of-business applications, typical corporate investments in workstation software are increasing rapidly, and therefore the management and maintenance of these investments must be considered. Some suggestions on the management of the workstation-based development process are given in Managing Development.