UBC Theses and Dissertations

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UBC Theses and Dissertations

LACOME : early evaluation and further development of a multi-user collaboration system for shared large displays MacKenzie, Russell


Large screen displays are becoming more prevalent as their prices continue to fall. For these large screens, the paradigm of one-user-per-display begins to break down because there is adequate space and resolution for a variety of simultaneous content. LACOME, the Large Collaborative Meeting Environment, is a set of software tools that allow multiple users to simultaneously publish their personal computer displays onto a large shared display using any VNC server. Once published, windows or even full desktops can be moved, resized, and iconified; optionally, they may even be controlled by other users. LACOME is groupware: multiple users can interact with the shared display simultaneously. Our work focuses on enhancing the stability and usability of the LACOME system, which previously existed only as a rough, proof-of-concept prototype. The LACOME Server was originally developed using C++ on Linux. To simplify administration and provide cross-platform support, the LACOME Server is ported to Java. A new engine provides performance-guaranteed rendering. The secure transmission of VNC passwords is now supported using SSL, instead of relying on default passwords. Interactive widgets such as an IP address display and a ‘Return to Desktop’ button support usability. The LACOME Client has been converted into a JavaTM Web Start application, eliminating the need for installation or configuration by new users. Additionally, LACOME Client settings now persist across usage sessions and a new feature, “Publish Me,” automatically determines the user’s IP address to initiate a VNC connection. We also develop a new window manipulation technique, the Large Screen Optimized (LSO) technique, which features larger interaction handles. Clicking near the edge of a window ‘snaps’ the cursor precisely to the edge of that window, allowing a user to quickly place objects against the edges or corners of the screen. The addition of an explicit mode switch to take control of the contents of a window allows us to utilize the entire window area for manipulation and provide a ‘zooming resize’ feature. An initial user study shows that users preferred and were able to manipulate windows more quickly using the LSO technique than with a more traditional technique.

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