(defun touch--scroll (event)
  (interactive (list last-input-event))
  (message "%s" event)
  (set-window-vscroll (caadr event) (- (window-vscroll (caadr event) t)
				       (cadr (caddr event))) t))

(defun touch--pinch (event)
  (interactive (list last-input-event))
  (message "%s" event)
  (let ((delta (caddr event)))
    (cond ((> delta 0)
  	   (text-scale-increase delta))
	  ((< delta 0)
	   (text-scale-decrease (- delta))))))

(global-set-key [touch-pinch] 'touch--pinch)
(global-set-key [touch-scroll] 'touch--scroll)