Comment 1 for bug 1558498

Sure, should be relatively straight forward to add this to the gestures module (there is already a 2 finger pinch).

Some questions; What are the requirements?

  - How far apart should the fingers be on screen, does it make sense if this is configurable.
  - What would you want to do with the drag? Should the api just be a start x,y tuple and an end x,y tuple (with maybe the finger spacing) or does it need to be more complex like a vector for the finger angle and end destination (so one can do a diagonal swipe from corner to corner)
  - Perhaps with the api the start x,y should be the middle finger and the others are spaced either side and perpendicular to the swipe vector?