Since it is javascript you can mix in js libs, then you should have a look at Hammer.js:  http://eightmedia.github.io/hammer.js/

Thank you. Looks interesting. This should work on canvas element level, since it requires binding the event to an element with a named id (which is appropriate in the case of my project). However, how would that work on sub-elements, e.g. a graphic element of Processingjs itself, since there are no named ids for these?