Event.TouchEvents from touch screens (but not graphics tablets or touchpads).
val get_time : [< any ] t -> Timestamp.tval get_slot :
[< `Touch_down | `Touch_up | `Touch_motion | `Touch_cancel ] t ->
intval get_seat_slot :
[< `Touch_down | `Touch_up | `Touch_motion | `Touch_cancel ] t ->
intval get_x : [< `Touch_down | `Touch_motion ] t -> floatval get_y : [< `Touch_down | `Touch_motion ] t -> floatval get_x_transformed :
[< `Touch_down | `Touch_motion ] t ->
width:int ->
floatval get_y_transformed :
[< `Touch_down | `Touch_motion ] t ->
height:int ->
float