Active Window Tracking System
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
Using a list of flags to indicate which windows are currently active allows for an easy redraw function to display windows on a screen. These flags may be ordered so that overlapping windows appear on the screen correctly. Keeping track of a collection of overlapping windows is quite a programming chore. These windows must be written to the screen in the appropriate order to be displayed properly. Many interfaces use code to calculate what is on the screen and what space is available for windows. This creates a tremendous overhead cost. A solution is to use an ordered list of flags, each of which corresponds to a unique window. This list is ordered in such a way that if Window A overlaps Window B, then Window A has a higher flag number than Window B.