The context toolkit

TLDR

Context‑enabled applications promise richer interaction by incorporating environmental context, yet they are difficult to build because of their distributed nature and unconventional sensors, though existing GUI toolkit concepts provide a promising foundation. The paper introduces context widgets that mediate between the environment and the application, analogous to graphical widgets mediating between user and application. The authors develop a preliminary widget library for sensing presence, identity, and activity of people and things, and evaluate it through two new context‑enabled applications and an existing application enhanced with context sensing. The approach proved successful, as demonstrated by the two new context‑enabled applications and the existing application augmented with context‑sensing capabilities.

Abstract

Context-enabled applications are just emerging and promise richer interaction by taking environmental context into account. However, they are difficult to build due to their distributed nature and the use of unconventional sensors. The concepts of toolkits and widget libraries in graphical user interfaces has been tremendously successtil, allowing programmers to leverage off existing building blocks to build interactive systems more easily. We introduce the concept of context widgets that mediate between the environment and the application in the same way graphical widgets mediate between the user and the application. We illustrate the concept of context widgets with the beginnings of a widget library we have developed for sensing presence, identity and activity of people and things. We assess the success of our approach with two example context-enabled applications we have built and an existing application to which we have added context-sensing capabilities.