Method and apparatus for displaying hardware dependent graphics in an object-oriented operating system

摘要

Screen objects used by the application programs to draw or paint on the display screen are created in accordance with a predefined class structure which represents a generic display system. Developers of specialized hardware develop specialized classes based on the predefined structure to handle specific command sets and protocols. When the system is initially powered up or reconfigured, the screen objects are created from the generic and specialized classes as necessary by examining the actual display hardware present in the system. When the specialized classes are used to create the screen objects, the screen objects receive the specialized command sets and protocols necessary to interact with display hardware which have been provided by the hardware developers.