Just implemented that for myself. You can find the code at https://github.com/JanKoehnlein/JavaFX-SWT-Gesture-Bridge
. It's kind of a hack, as I have to access two private fields in order to hook into JavaFX, but it contains all the logic necessary to convert and transfer the gesture events.
Unfortunately, it's not a patch, as I currently don't have the time to setup a working JavaFX development environment. But feel free to reuse the code / idea. If licensing is a problem (currently EPL) I can change it to whatever you want.