Supporting mixed presence groupware in tabletop applications

In this paper, we present the transparent input device layer framework to extend Java applications with support for multiple distributed input devices, a major requirement for tabletop applications. This overcomes a key restriction of current graphical environments to support only a single system cursor and one keyboard, and allows the cursor and keyboard control of applications to be performed by input devices that are connected to other hosts on the network. Applications can be developed with this framework and therefore allow operations such as simultaneous drag and drop by multiple users. Additionally, we have created a wrapper application to inject support for multiple input devices into legacy applications at runtime - without the need for code alteration or recompilation. We present two tabletop applications that make use of our framework: one is a graphical front end to a military course of action scheduling application and was developed with the framework. The second application, a component based data visualisation application, employs the injection wrapper application to gain support for distributed multiple input devices at runtime.