Geoscience Reference
In-Depth Information
TUIO protocol.
QGIS and the Ilight tabletop communicate via the TUIO
protocol. TUIO is an open protocol for multi-touch surfaces allowing
touch events to be sent to the application over the network (Kaltenbrunner
et al 2005). TUIO has been adopted by various academic (NUI group) and
commercial (Flash) projects and can be used on a wide range of hardware
setups.
As Qt provides support for multi-touch input, we developed a library for
translating TUIO messages to the Qt native multi-touch events used in our
plug-in.
QGIS-MT plug-in.
This plug-in creates a full screen window which is dis-
played on the tabletop and detects the position and the number of finger
contacts, which are then used by the menubar of the application.
Finger-Count Shortcuts
rely on the application menubar, which was modi-
fied according to the needs of our new technique. First, it is able to activate
appropriate commands according to finger contacts. Second, item rendition
was slightly modified to provide appropriate feedback to users: FC
numbers are displayed instead of keyboard shortcuts, horizontal arrows
indicate a command that allows direct manipulation and vertical arrows
indicate that the item can be selected using
Relative Finger Count.
Finally, the application provides 57 frequent commands that can be acti-
vated by performing gestures. These commands are organized in 5 menus
(“Geometry”, “Layer”, “Edit”, “Tools” and “File”) and more commands
could be added if needed.
5- Conclusion
We proposed an environment and a novel interaction technique for aug-
menting the QGIS software. Using an interactive tabletop, our environ-
ment favors communication among users, enhances social awareness and
facilitates the decision-making process. Our interaction technique, called
Finger-Count shortcuts, facilitates navigation and quickly allows to acti-
vate numerous commands by performing simple multi-touch gestures.
QGIS-MT, a plug-in that augments QGIS with multi-touch capability via
FC shortcuts, was also presented. Finally, an interview was conducted with
GIS users to choose a coherent set of commands that are especially well
suited for collaborative work on tabletops.
