While Presentation Manager supports and facilitates the implementation of object-oriented design techniques and provides support for the user interface constructs and guidelines laid down by the CUA component of Systems Application Architecture, it does not force an application developer to conform to object-oriented design principles or CUA-conforming user interface guidelines. While the rich function set provided by the Presentation Manager programming interface allows an application developer to interpret and implement CUA guidelines in a number of ways, there are emerging conventions with regard to the implementation of these guidelines.
In order to achieve the benefits which accrue from adherence to object-oriented and CUA principles, a measure of discipline is required on the part of the application developer, so as to implement the application in such a way that the maximum degree of object-independence and reusability is attained, and that the optimal level of conformance to CUA conventions is achieved. The subject of CUA conformance is discussed in detail in Systems Application Architecture CUA Considerations.
Note that CUA conformance, along with consistency in the implementation of application functions and user interface constructs, may be enforced or enhanced through the use of standard functions and subroutines contained in code libraries. The creation of such libraries is facilitated by the modular nature of the Presentation Manager environment, and by the dynamic linking capabilities of the OS/2 operating system. This subject is discussed further in Generic Application Modules.