The following code allows me to change the size of a disk back and forth with a one-finger trackpad click, and change the color of a disk back and forth with a two-finger trackpad click.
DynamicModule[{col = Green, size = 1},
EventHandler[
Graphics[{Dynamic@col, Disk[{0, 0}, Dynamic@size]},
PlotRange -> 2],
{
{"MouseDown",
1} :> (size = size /. {1 -> 2, 2 -> 1}),
{"MouseDown",
2} :> (col = col /. {Red -> Green, Green -> Red})}]]
I'd like to be able to do a three-finger click to do something else. For example, a three-finger click might change the shape back and forth between a square and a disk. I can't figure out how to get Mathematica to recognize a three-finger click. Using "MouseDown"->3 does not work.
Any ideas?
