Dear Wong,
I am no expert in Mouse events but here is what I can tell.
Mouse options that you can choose through the Mouse Manager in the runSofa GUI are described in the component: MouseOperations.cpp. This MouseOperation enumerates the different options.
Each Mouse option is actually a InteractionPerformer. For instance, the option allowing for cutting with the mouse wheel (in TriangleSurfaceCutting.scn) is the InciseAlongPathPerformer.
Check these components out, this will help.
Cheers,
Hugo