BRUWIN: An adaptable design strategy for window manager/virtual terminal systems

Abstract

With only one process viewable and operational at any moment, the standard terminal forces the user to continually switch between contexts. Yet this is unnatural and counter-intuitive to the normal working environment of a desk where the worker is able to view and base subsequent actions on multiple pieces of information. The window manager is an emerging computing paradigm which allows the user to create multiple terminals on the same viewing surface and to display and act upon these simultaneous processes without loss of context. Though several research efforts in the past decade have introduced window managers, they have been based on the design or major overhaul of a language or operating system; the window manager becomes a focus of—rather than a tool of—the system. While many of the existing implementations provide wide functionality, most implementations and their associated designs are not readily available for common use; extensibility is minimal. This paper describes the design and implementation of BRUWIN, the BRown University WINdow manager, stressing how such a design can be adapted to a variety of computer systems and output devices, ranging from alphanumeric terminals to high-resolution raster graphics displays. The paper first gives a brief overview of the general window manager paradigm and existing examples. Next we present an explanation of the user-level functions we have chosen to include in our general design. We then describe the structure and design of a window manager, outlining the five important parts in detail. Finally, we describe our current implementation and provide a sample session to highlight important features.